bluuebunny/crossref_metadata_2025 huggingface dataset:
Interaction of profilin‐1 and F‐actin via a β‐arrestin‐1/JNK signaling pathway involved in prostaglandin E2‐induced human mesenchymal stem cells migration and proliferation
Authors: Yun Seung Pil , Ryu Jung Min , Jang Min Woo , Han Ho Jae
Published: August 2010

Although many previous reports have examined the function of prostaglandin E2 (PGE2) in the migration and proliferation of various cell types, the role of the actin cytoskeleton in human mesenchymal stem cells (hMSCs) migration and proliferation has not been reported. The present study examined the involvement of profilin‐1 (Pfn‐1) and filamentous‐actin (F‐actin) in PGE2‐induced hMSC migration and proliferation and its related signal pathways. PGE2 (10−6 M) increased both cell migration and proliferation, and also increased E‐type prostaglandin receptor 2 (EP2) mRNA expression, β‐arrestin‐1 phosphorylation, and c‐Jun N‐terminal kinase (JNK) phosphorylation. Small interfering RNA (siRNA)‐mediated knockdown of β‐arrestin‐1 and JNK (‐1, ‐2, ‐3) inhibited PGE2‐induced growth of hMSCs. PGE2 also activated Pfn‐1, which was blocked by JNK siRNA, and induced F‐actin level and organization. Downregulation of Pfn‐1 by siRNA decreased the level and organization of F‐actin. In addition, specific siRNA for TRIO and F‐actin‐binding protein (TRIOBP) reduced the PGE2‐induced increase in hMSC migration and proliferation. Together, these experimental data demonstrate that PGE2 partially stimulates hMSCs migration and proliferation by interaction of Pfn‐1 and F‐actin via EP2 receptor‐dependent β‐arrestin‐1/JNK signaling pathways. J. Cell. Physiol. 226: 559–571, 2011. © 2010 Wiley‐Liss, Inc.
Asymmetrical cell division and differentiation are not dependent upon stratification in a corneal epithelial cell line
Authors: Gómez‐Flores Eber , Sánchez‐Guzmán Erika , Castro‐Muñozledo Federico
Published: August 2010

To determine whether asymmetrical cell division takes place during growth and differentiation of corneal epithelial cells, we analyzed the expression of some proteins required for the correct execution of the asymmetric division in cultured RCE1‐(5T5) cells, which mimic the differentiation of corneal epithelial cells. RT‐PCR and immunostaining showed that Par‐3, LGN (GPSM2), NuMA, and the mammalian homolog of inscuteable (Insc) are expressed by the cultured cells. Semi‐quantitative RT‐PCR demonstrated that Insc mRNA levels were stable throughout the experiment. Conversely, LGN and NuMA mRNAs increased slightly and steadily in proliferative cells, reaching a peak of about 20% above basal levels when cells were confluent. At later times, LGN and NuMA mRNAs decreased to become barely detectable when cells organized into a four‐layered epithelium and expressed terminal phenotype as indicated by the highest expression of LDH‐H mRNA. Cultivation under low Ca2+ conditions (0.09 mM) reduced about 50% Insc mRNA expression both in proliferating and confluent cultures, but did not affect the levels of LGN and NuMA mRNAs. Hence, asymmetric cell division seems to take place with a lower frequency in cells grown with low Ca2+ concentrations, in spite of the absence of stratification. Immunostaining experiments raise the possibility of an interaction between k3/K12 keratin cytoskeleton and Par‐3. The results show for the first time the coordination between the expression of corneal epithelial cell differentiation and the expression of cell polarity machinery. They also suggest that asymmetric division does not depend on stratification; instead, it seems to be part of the differentiation program. J. Cell. Physiol. 226: 700–709, 2011. © 2010 Wiley‐Liss, Inc.
The Forkhead factor FoxQ1 influences epithelial differentiation
Authors: Feuerborn A. , Srivastava P.K. , Küffer S. , Grandy W.A. , Sijmonsma T.P. , Gretz N. , Brors B. , Gröne H.‐J.
Published: August 2010

The Forkhead family of transcription factors comprises numerous members and is implicated in various cellular functions, including cell growth, apoptosis, migration, and differentiation. In this study, we identified the Forkhead factor FoxQ1 as increased in expression during TGF‐β1 induced changes in epithelial differentiation, suggesting functional roles of FoxQ1 for epithelial plasticity. The repression of FoxQ1 in mammary epithelial cells led to a change in cell morphology characterized by an increase in cell size, pronounced cell–cell contacts, and an increased expression of several junction proteins (e.g., E‐cadherin). In addition, FoxQ1 knock‐down cells revealed rearrangements in the actin‐cytoskeleton and slowed down cell cycle G1‐phase progression. Furthermore, repression of FoxQ1 enhanced the migratory capacity of coherent mammary epithelial cells. Gene expression profiling of NM18 cells indicated that FoxQ1 is a relevant downstream mediator of TGF‐β1‐induced gene expression changes. This included the differential expression of transcription factors involved in epithelial plasticity, for example, Ets‐1, Zeb1, and Zeb2. In summary, this study has elucidated the functional impact of FoxQ1 on epithelial differentiation. J. Cell. Physiol. 226: 710–719, 2011. © 2010 Wiley‐Liss, Inc.
Hyperosmolarity‐mediated mitochondrial dysfunction requires Transglutaminase‐2 in human Corneal epithelial cells
Authors: Png Evelyn , Samivelu G.K. , Yeo S.H. , Chew J. , Chaurasia Shyam S. , Tong Louis
Published: August 2010

Hyperosmolar‐induced ocular surface cell death is a key mitochondria‐mediated event in inflammatory eye diseases. Transglutaminase (TGM)‐2, a cross‐linking enzyme, is purported to mediate cell death, but its link to mitochondria is unclear. In the cornea, the integrity of the epithelial cells is important for maintaining transparency of the cornea and therefore functional vision. We evaluated the role of TGM‐2 and its involvement in hyperosmolarity‐stimulated mitochondrial cell death in human corneal epithelial (HCE‐T) cells. HCE‐T cell lines stably expressing either shRNA targeting TGM‐2 (shTG) or scrambled shRNA (shRNA) were constructed. Hyperosmolar conditions reduced viability and increased mitochondrial depolarization in shRNA cells. However, hyperosmolarity failed to induce mitochondrial depolarization to the same extent in shTG cells. Transient overexpression of TGM‐2 resulted in very high levels of TGM‐2 expression in shTG and shRNA cells. In the case of shTG cells after overexpression of TGM‐2, hyperosmolarity induced the same extent of mitochondrial depolarization as similarly treated shRNA cells. Overexpression of TGM‐2 also elevated transamidase activity and reduced viability. It also induced mitochondrial depolarization, increased caspase‐3/7 and ‐9 activity, and these increases were partially suppressed by pan‐caspase inhibitor Z‐VAD‐FMK. Corneal epithelial apoptosis via mitochondrial dysfunction after hyperosmolar stimulation is partially dependent on TGM‐2. This TGM‐2‐dependent mechanism occurs in part via caspase‐3/7 and ‐9. Protection against mitochondrial stress in the ocular surface targeting TGM‐2 may have important implications in the survival of cells in hyperosmolar stress. J. Cell. Physiol. 226: 693–699, 2011. © 2010 Wiley‐Liss, Inc.
Wnt‐3a and Wnt‐3 differently stimulate proliferation and neurogenesis of spinal neural precursors and promote neurite outgrowth by canonical signaling
Authors: David Monica D. , Cantí Carles , Herreros Judit
Published: August 2010

Wnt factors regulate neural stem cell development and neuronal connectivity. Here we investigated whether Wnt‐3a and Wnt‐3, expressed in the developing spinal cord, regulate proliferation and the neuronal differentiation of spinal cord neural precursors (SCNP). Wnt‐3a promoted a sustained increase of SCNP proliferation and decreased the expression of cyclin‐dependent kinase inhibitors. In contrast, Wnt‐3 transiently enhanced SCNP proliferation and increased neurogenesis through β‐catenin signaling. Furthermore, both Wnt‐3a and Wnt‐3 stimulated neurite outgrowth in SCNP‐derived neurons through β‐catenin‐ and TCF4‐dependent transcription. Glycogen synthase kinase‐3β inhibitors mimicked Wnt signaling and promoted neurite outgrowth in established cultures. We conclude that Wnt‐3a and Wnt‐3 factors signal through the canonical Wnt/β‐catenin pathway to regulate different aspects of SCNP development. These findings may be of therapeutic interest for the treatment of neurodegenerative diseases and nerve injury. © 2010 Wiley‐Liss, Inc.
Incidental gallbladder cancer: Analysis of surgical findings and survival
Authors: Butte Jean M. , Waugh Enrique , Meneses Manuel , Parada Hugo , De La Fuente Hernán A.
Published: August 2010

Background and Objectives

Incidental gallbladder cancer (IGBCA) has risen worldwide and its prognosis depends on complete radical cholecystectomy (CRC). This study evaluated surgical findings during re‐operation and survival of patients with IGBCA.

Methods

Demographics, surgical treatment, staging, and survival data for all IGBCA patients who underwent surgery at Instituto Oncológico Fundación Arturo López Pérez (FALP) between 2000 and 2008 were analyzed. Differences between groups were analyzed by Student's t‐test, Mann–Whitney, chi‐square, or Fisher log‐rank tests.

Results

Forty‐nine patients were studied (38 women/11 men, median age = 58 years). Pathology reports from cholecystectomy showed that 32 patients had a T2 tumor and 12 had positive resection margin. Thirty‐six patients underwent surgical re‐exploration and 20 underwent CRC; 10 with (+) residual disease and 10 with (−). For patients with at least T1b tumor, median survival was 28 months and 5‐year disease‐specific survival (DSS) was 29%. The 3‐year DSS was 64% for CRC (−), 30% for CRC (+), and 8% for non‐resected cases (P < 0.007). The 3‐year DSS was better for patients with stage Ib than those with stages II and IV (P < 0.007).

Conclusions

Patients with IGBCA have a high chance of intra‐abdominal metastases or local residual disease. In CRC patients, intra‐abdominal metastases were associated with a worse prognosis. J. Surg. Oncol. 2010;102:620–625. © 2010 Wiley‐Liss, Inc.
Safety and potential benefit of hyperthermic intraperitoneal chemotherapy (HIPEC) in peritoneal carcinomatosis from primary or recurrent ovarian cancer
Authors: Roviello Franco , Pinto Enrico , Corso Giovanni , Pedrazzani Corrado , Caruso Stefano , Filippeschi Marco , Petrioli Roberto , Marsili Stefania , Mazzei Maria Antonietta , Marrelli Daniele
Published: August 2010

Objectives

To analyze the outcomes of cytoreductive surgery and HIPEC in patients with peritoneal carcinomatosis from ovarian cancer.

Methods

Fifty‐three patients with peritoneal carcinomatosis from primary (45 cases) and recurrent (8 cases) ovarian cancer were previously treated by systemic chemotherapy with platinum and taxanes and then submitted to surgical cytoreduction and HIPEC (cisplatin and mitomycin‐C) with a closed abdomen technique. The median follow‐up period was 27 months (range: 3–107).

Results

At the end of operation a complete cytoreduction (CCR‐0) was obtained in 37 patients (70%). Major morbidity occurred in 12 patients (23%); reoperation was necessary in 2 patients (4%), and no postoperative mortality was observed. Overall 5‐year survival probability was 55%; it was 71% in CCR‐0, 44% in CCR‐1, and none in patients with CCR‐2 or CCR‐3 residual tumor (log‐rank test: P = 0.017). The cumulative risk of recurrence in 37 CCR‐0 cases was 54% at 5 years from operation.

Conclusions

The results of our study indicate the feasibility and the potential benefit of a protocol including systemic chemotherapy, surgical cytoreduction and HIPEC in patients with peritoneal carcinomatosis from ovarian cancer. A phase III trial to compare this approach with conventional treatment is needed. J. Surg. Oncol. 2010;102:663–670. © 2010 Wiley‐Liss, Inc.
Subtotal stomach‐preserving pancreaticoduodenectomy (SSPPD) prevents postoperative delayed gastric emptying
Authors: Kurahara Hiroshi , Takao Sonshin , Shinchi Hiroyuki , Mataki Yuko , Maemura Kousei , Sakoda Masahiko , Ueno Shinichi , Natsugoe Shoji
Published: August 2010

Background and Objectives

Delayed gastric emptying (DGE) is one of main complications after pylorus‐preserving pancreaticoduodenectomy (PPPD) with regional lymph node dissection (RLND). The aim of this study was to retrospectively investigate whether subtotal stomach‐preserving PD (SSPPD) decreased incidence of DGE.

Methods

This study included 112 consecutive patients underwent PPPD (n = 48) or SSPPD (n = 64) with/without RLND. DGE was classified into three categories (grades A, B, and C) according to the guideline proposed by the International Study Group of Pancreatic Surgery.

Results

The incidence of DGE grade B/C in SSPPD with RLND (13.0%) was lower compared with that (34.8%) in PPPD with RLND (P = 0.0326). Consequently, the mean length of postoperative hospital stay of SSPPD with RLND group was significantly shorter than that of PPPD with RLND (P = 0.0476).

Conclusions

SSPPD could be substituted for PPPD due to decreased postoperative DGE when RLND is involved. A randomized control trial of SSPPD versus PPPD should be considered. J. Surg. Oncol. 2010;102:615–619. © 2010 Wiley‐Liss, Inc.
Relation of MT1‐MMP gene expression to outcomes in colorectal cancer
Authors: Kanazawa Amane , Oshima Takashi , Yoshihara Kazue , Tamura Shuzo , Yamada Takanobu , Inagaki Daisuke , Sato Tsutomu , Yamamoto Naoto , Shiozawa Manabu , Morinaga Soichiro , Akaike Makoto , Kunisaki Chikara , Tanaka Katsuaki , Masuda Munetaka , Imada Toshio
Published: August 2010

Background

Matrix metalloproteinases are members of a large family of endopeptidases that participate in the extracellular‐matrix degradation that accompanies cancer cell invasion, metastasis and angiogenesis. The membrane‐type 1 matrix metalloproteinase (MT1‐MMP) gene has been reported in various cancers and is associated with tumor invasion and metastasis. This study examined the relation of the relative expression of MT1‐MMP gene to clinicopathological factors and outcomes in patients with colorectal cancer (CRC).

Methods

We studied surgical specimens of cancer tissue and adjacent normal mucosa obtained from 202 patients with untreated CRC. The relative expression levels of MT1‐MMP mRNA in cancer and in normal adjacent mucosa were measured by quantitative real‐time reverse‐transcriptase polymerase chain reaction.

Results

MT1‐MMP gene expression was higher in cancer tissue than in adjacent normal mucosa. The level of MT1‐MMP gene expression was not related to any clinicopathological factor. Overall survival at 5 years differed significantly between patients with high MT1‐MMP gene expression and those with low expression.

Conclusions

Overexpression of the MT1‐MMP gene is considered a useful independent predictor of outcomes in patients with CRC. J. Surg. Oncol. 2010;102:571–575. © 2010 Wiley‐Liss, Inc.
New techniques to detect unknown primaries in cervical lymph node metastasis
Authors: Sakai Akihiro , Okami Kenji , Ebisumoto Koji , Sugimoto Ryosuke , Maki Daisuke , Iida Masahiro
Published: August 2010

Objective:

Various methods have been reported for the detection of unknown primaries in cervical lymph node metastasis. Recently, we applied new optical devices and modifications of endoscopic techniques for the detection of primary lesions, and obtained excellent results. The detection rate of the new method was compared with that of previous methods.

Study Design:

Retrospective.

Methods:

A total of 51 patients with cervical lymph node metastasis from an unknown primary site (CUP) were referred to our hospital between January 2000 and May 2009, and were retrospectively analyzed. Between 2000 and 2005, the observation by normal video‐endoscope in straight head position was performed to detect the primary lesions in the outpatient setting. Since 2006, a new method for detection of primary lesions has been employed. The method includes the use of new optical devices (hooded video‐endoscope and narrow‐band imaging endoscope) and different head positions (head torsion technique, Valsalva maneuver, and the Killian position).

Results:

The detection rate of primary lesions using the new method was 71% (15 of 21), which was better than the 30% (10 of 30) obtained with the conventional method. All primary lesions identified using the new method were located in the hypopharynx.

Conclusions:

The new method was able to detect primary lesions in 71% of cases with CUP. The higher rate achieved with the new method was probably due to the clear visualization of the hypopharynx. Thus, the new method was shown to be useful for the detection of primary lesions in cases of CUP. Laryngoscope, 2010
Evaluation of guinea pig model for ocular and cervical vestibular‐evoked myogenic potentials for vestibular function test
Authors: Yang Ting‐Hua , Liu Shing‐Hwa , Young Yi‐Ho
Published: August 2010

Objectives/Hypothesis:

This study used air‐conducted sound (ACS) and bone‐conducted vibration (BCV) stimuli in eliciting ocular vestibular‐evoked myogenic potential (oVEMP) and cervical VEMP (cVEMP) in guinea pigs.

Study Design:

Prospective study.

Methods:

Ten guinea pigs were treated with gentamicin (4 mg) on the left ear, whereas the right ear served as a control. One week after treatment, each animal underwent oVEMP and cVEMP tests using ACS and BCV modes in a randomized order, and was sacrificed for morphological study.

Results:

Using ACS mode, oVEMPs were absent in all 10 (100%) animals despite the stimulus intensity increased up to 120 dB pe SPL. Conversely, using BCV mode, oVEMPs were present on the left (lesion) eye, and absent on the right (control) eye in all (100%) animals. For the cVEMPs via ACS mode, all right (control) necks had clear cVEMPs, and all (100%) left (lesion) necks revealed absent cVEMPs. However, via BCV mode, all right (control) necks and six (60%) left (lesion) necks showed clear cVEMPs. Morphological study demonstrated substantial loss of hair cells in the utricular and saccular macula.

Conclusions:

The cVEMP test via ACS mode is specific for investigating the saccular disorder, whereas the oVEMP test via BCV mode is preferable for investigating the utricular disorders in humans. The guinea pig model is consistent with the findings of humans. Restated, appropriate animal models for cVEMP and oVEMP in guinea pigs are via ACS and BCV modes, respectively. Laryngoscope, 2010
Amplification of CyclinL1 in uterine cervical carcinoma has prognostic implications
Authors: Mitra Sraboni , Mazumder (Indra) Dipanjana , Basu Partha S. , Mondal Ranajit K. , Roy Anup , Roychoudhury Susanta , Panda Chinmay K.
Published: August 2010

The chromosomal 3q25.31 region was consistently amplified in primary cancer of cervix (CACX). CyclinL1 is a candidate gene of this region and already have been implicated as an oncogene in head and neck cancers. In this study, we aimed to investigate the involvement of CyclinL1 in cervical carcinogenesis and for this purpose its copy number variation (CNV) was studied in 23 cervical intraepithelial neoplasia (CIN) and 110 CACX samples. In CIN lesions CyclinL1 was not amplified; however, the amplification frequency was 16% (9/56) in stage I/II tumors which remained comparable during subsequent stages of tumorigenesis. This implied association of CyclinL1 amplification with development of early invasiveness. Quantitation of mRNA expression revealed 2.6 ± 1.53‐fold overexpression of this gene in primary CACX. The amplification/copy number gain of CyclinL1 and its mRNA profile were concordant, in tumors. Immunohistochemical (IHC) analysis in primary CACX, cell lines: SiHa and HeLa revealed intense nuclear expression of cyclinL1, which was further confirmed by Western blot in the cell lines. However 47% (7/15) CACX samples expressed high/intermediate level of cyclin L1. Kaplan–Meier survival analysis indicated CyclinL1 amplification as a determinant of poor patient outcome. Tumor radio‐resistance developed as a consequence of CyclinL1 amplification. Cox multivariate analysis revealed that multiparous (≥5) CACX patients with amplified CyclinL1 locus along with advanced tumor stage (III/IV) had worst prognosis. Our data suggest importance of CyclinL1 in cervical carcinogenesis with its associated pathways viz: pre‐mRNA splicing, cell‐cycle regulation (G0/G1 and G2/M) being potential targets of therapeutic interventions in CACX. © 2010 Wiley‐Liss, Inc.
Association of a common AGO1 variant with lung cancer risk: A two‐stage case–control study
Authors: Kim Jong‐Sik , Choi Yi Young , Jin Guang , Kang Hyo‐Gyoung , Choi Jin‐Eun , Jeon Hyo‐Sung , Lee Won‐Kee , Kim Dong‐Sun , Kim Chang Ho , Kim Young Jin , Son Ji‐Woong , Jung Tae Hoon , Park Jae Yong
Published: August 2010

Based on the important role of microRNA (miRNA) biosynthesis genes in carcinogenesis, we hypothesized that polymorphisms in the miRNA biosynthesis genes may modulate susceptibility to lung cancer. To test this hypothesis, we conducted a two‐stage study to evaluate the associations between single nucleotide polymorphisms (SNPs) in the miRNA biosynthesis genes and the risk of lung cancer. In stage 1 of the study, 24 SNPs in the 11 miRNA biosynthesis genes (DROSHA, DGCR8, RAN, XPO5, DICER, AGO1, AGO2, HIWI, GEMIN3, GEMIN4, and TRBP) were genotyped in 100 lung cancer patients and 100 healthy controls using a sequenome mass spectrometry‐based genotyping assay. One promising SNP (AGO1 rs636832A > G) was selected for stage 2 of the study, and genotyped by a melting‐curve analysis using fluorescence‐labeled hybridization probes in an independent set of 552 cases and 552 controls. The AGO1 rs636832A > G exhibited highly consistent results between the two stages of the study. In combined analysis, the 636832A > G was associated with a significantly decreased risk of lung cancer in a dose‐dependent manner (Ptrend = 6.0 × 10−4). Individuals with at least one rs636832G allele were at a significantly decreased risk of lung cancer compared with those with the AA genotype (adjusted odds ratio = 0.67, 95% confidence interval = 0.53–0.84, P = 4.0 × 10−4). This finding suggests that the AGO1 rs636832A > G might be a useful marker for determining the susceptibility to lung cancer and that the AGO1 gene might be involved in the development of lung cancer. © 2010 Wiley‐Liss, Inc.
Impaired sense of smell and color discrimination in monogenic and idiopathic Parkinson's disease
Authors: Kertelge Lena , Brüggemann Norbert , Schmidt Alexander , Tadic Vera , Wisse Claudia , Dankert Sylwia , Drude Laura , van der Vegt Joyce , Siebner Hartwig , Pawlack Heike , Pramstaller Peter P. , Behrens Maria Isabel , Ramirez Alfredo , Reichel Dirk , Buhmann Carsten , Hagenah Johann , Klein Christine , Lohmann Katja , Kasten Meike
Published: August 2010

Olfaction is typically impaired in idiopathic Parkinson's disease (IPD), but its role is uncertain in monogenic PD. Diminished color discrimination has been suggested as another early sign of dopaminergic dysfunction but not been systematically studied. Furthermore, it is unknown whether both deficits are linked. We examined 100 patients with IPD, 27 manifesting mutation carriers (MC), 20 nonmanifesting mutation carriers (NMC), and 110 controls. Participants underwent a standardized neurological examination, the University of Pennsylvania Smell Identification Test (UPSIT), the Farnsworth‐Munsell (FM) color discrimination test, and mutation testing in known PD genes. The monogenic group consisted of 15 Parkin (6MC/9NMC), 17 PINK1 (10MC/7NMC), 8 LRRK2 (4MC/4NMC), 3 SNCA (MC), and 4 ATP13A2 (MC) carriers. Olfaction was most impaired in IPD (UPSIT percentiles 10.1 ± 13.5) compared with all other groups (MC 13.8 ± 11.9, NMC 19.6 ± 13.0, controls 33.8 ± 22.4). Within MC, carriers of two mutations in Parkin and PINK1 showed higher UPSIT percentiles than LRRK2 and SNCA carriers. Color discrimination was reduced in IPD (FM total error score 134.8 ± 92.7). In MC (122.4 ± 142.4), the reduction was most pronounced in LRRK2, NMC (80.0 ± 38.8) were comparable with controls (97.2 ± 61.1). UPSIT and FM scores were correlated in the control (r = −0.305; P = 0.002) and the IPD group (r = −0.303; P = 0.006) but not among mutation carriers. First, we confirmed olfaction and color discrimination to be impaired in IPD and suggest olfaction to be a premotor sign. Second, olfaction differed between carriers with one and two mutations in Parkin/PINK1‐associated PD. Third, olfaction and color discrimination impairment do not necessarily evolve in parallel. © 2010 Movement Disorder Society
Comprehensive sequencing of the LRRK2 gene in patients with familial Parkinson's disease from North Africa
Authors: Jasinska‐Myga Barbara , Kachergus Jennifer , Vilariño‐Güell Carles , Wider Christian , Soto‐Ortolaza Alexandra I. , Kefi Mounir , Middleton Lefkos T. , Ishihara‐Paul Lianna , Gibson Rachel A. , Amouri Rim , Yahmed Samia Ben , Sassi Samia Ben , Zouari Mourad , Euch Ghada El , Ross Owen A. , Hentati Faycal , Farrer Matthew J.
Published: August 2010

The LRRK2 gene is a key player in Parkinson's disease (PD), however prevalence and pathogenicity of LRRK2 variants remain to be investigated in ethnically diverse populations. Herein, we performed comprehensive sequencing of the LRRK2 gene in 92 Tunisian probands with familial PD. We then performed an association study using all identified variants in a series of 167 Lrrk2 p.G2019S‐negative patients with sporadic PD and 365 Lrrk2 p.G2019S‐negative healthy control subjects, all from the same Arab‐Berber ethnicity. We identified one novel coding substitution (p.M2408I) and 24 known coding changes. Only the Lrrk2 p.G2019S mutation segregated with disease within families and was found in 39% of familial probands. None of the variants displayed significant association with risk for sporadic PD, however a trend was observed for Lrrk2 p.Y2189C. The present study underscores the importance of the LRRK2 gene in the Tunisian PD population. © 2010 Movement Disorder Society
Novel planar triple band monopole antenna for WiMAX/WLAN applications
Authors: Liu Hsien‐Wen , Ku Chia‐Hao
Published: August 2010

A coplanar waveguide (CPW)‐fed planar monopole antenna with triple band operation for worldwide interoperability for microwave access (WiMAX) and wireless local area network (WLAN) applications is presented. The antenna, which occupies a small size of 25 (L) × 25 (W) × 0.8 (H) mm3, is simply composed of a pentagonal radiating patch with two bent slots. By carefully selecting the positions and lengths of these slots, good dual stopband rejection characteristic of the antenna can be obtained, so that three operating bands covering 2.14–2.85, 3.29–4.08, and 5.02–6.09 GHz can be achieved. The measured results also demonstrate that the proposed antenna has good omnidirectional radiation patterns with appreciable gain across the operating bands, and is thus suitable to be integrated within the portable devices for WiMAX/WLAN applications. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2405–2408, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25497
Wideband U‐shaped dielectric resonator antenna fed by triangle patch
Authors: Zhang Li‐Na , Zhong Shun‐Shi , Liang Xian‐Ling
Published: August 2010

A U‐shaped dielectric resonator antenna fed by a conformal triangle patch is proposed for ultrawideband communication applications.The multiband resonances of two parts, the U‐shaped dielectric resonator and the triangle patch, are combined to expand the antenna bandwidth. To validate the design, an optimized antenna prototype was fabricated and measured. A good agreement between the simulated and measured results is achieved, and a measured bandwidth of 84.1% around the center frequency 5.375 GHz is obtained with the broadside radiation. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2435–2438, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25513
Frequency‐multiplier design using negative‐image device models
Authors: Kim Nam‐Tae
Published: August 2010

This article presents a novel design methodology for wireless frequency multipliers using negative‐image device models applicable to nonlinear devices. Negative‐image device models of nonlinear devices are generated by incorporating optimization techniques into a hypothetical negative‐image multiplier model. The negative‐image device‐modeling methodology provides the following advantages over previously developed techniques: (1) It can predict achievable multiplier performance in the device‐modeling stage and (2) it provides an accurate starting point for the synthesis of impedance‐matching networks. The negative‐image device‐modeling method is described, and its application to the design of a field‐effect transistor (FET) frequency multiplier is presented. Results of an experimental implementation of the multiplier demonstrate the effectiveness of the proposed methodology. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2544–2548, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25521
Quantum cryptography via a wavelength router for internet security
Authors: Threepak T. , Mitatha S. , Luangvilay X. , Yupapin P. P.
Published: August 2010

We propose a new system of quantum cryptography for internet security using Gaussian pulses propagating within a nonlinear ring resonator system, quantum processor, and a wavelength router. To increase the channel capacity and security, the multiplexer is operated incorporating a quantum processing unit via an optical multiplexer. The transmission part can be used to generate the high capacity quantum codes within the series of microring resonators and an add/drop filter. The receiver part can be communicated by using the quantum key (quantum bit, qubit) via a wavelength router and quantum processors. The reference states can be recognized by using the cloning unit, which is operated by the add/drop filter, where the communication between Alice and Bob can be performed. Results obtained have shown that the correlated photons can be generated and formed the entangled photon pair, which is allowed to form the secret key between Alice and Bob. In application, the embedded system within the computer processing unit is available for quantum computer. Furthermore, such a concept is also available for internet application via hybrid communications, for instance, wire/wireless, satellite, which can be used to form the internet security. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2505–2509, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25523
Accelerometer based on all‐fiber Fabry–Pérot interferometer formed by hollow‐core photonic crystal fiber
Authors: Ke Tao , Zhu Tao , Rao Yunjiang , Deng Ming
Published: August 2010

An all‐fiber Fabry–Pérot accelerometer based on cantilever structure is constructed in this article.The Fabry–Pérot interferometer is formed by splicing the ends of two SMF‐28e fibers to the cleaved end of a hollow‐core photonic crystal fiber (HCPCF). We analyzed the relationship between the length of HCPCF cavity, light intensity, voltage of photoelectronic detector, and the deflection of the cantilever free end. Thus, the simple theoretical formula is achieved to calculate acceleration. Experimental results show that the resolution of the measuring system is about 8.42 × 10−7g and the sensitivity is 0.3386 v/g. In addition, Such kind of Fabry–Perot sensing structure is low sensitive to temperature and bending. It is anticipated that the Fabry–Pérot interferometer accelerometers have wide application prospects in the field of inertial navigation and vibration measurements. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2531–2535, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25529
Noise‐parameter measurements with a reflection type phase shifter
Authors: Gu Dazhen , Walter David K. , Randa James
Published: August 2010

We report a miniaturized phase shifter operating in the frequency range from 5 to 7 GHz for noise‐parameter extraction. Such a tunable solid‐state unit represents a significant reduction in the size and mass as a source‐pull component, compared to its mechanical counterparts. It provides adequate impedance coverage, ultra‐fast response, as well as high repeatability, across the designed region. A packaged low‐noise amplifier was measured at integer frequencies by use of the phase shifter on the NIST NFRad system. The measured results exhibited good accuracy. The combined uncertainties (Type‐A and Type‐B) are below 6% for both the minimum noise temperature and the magnitude of the optimum input reflection coefficient. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2600–2603, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25532
Parallel efficient method of moments exploiting graphics processing units
Authors: De Donno D. , Esposito A. , Monti G. , Tarricone L.
Published: August 2010

In this article we adopt the graphical processing units as a low‐cost and efficient solution of challenging electromagnetic numerical problems. Based on the compute unified device architecture, an optimized method of moments algorithm has been implemented which adopts direct solvers based on LU decomposition. Numerical results obtained on the practical case of a patch antenna analysis demonstrate the high performance of the approach. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2568–2572, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25534
Wideband surface‐mount chip antenna for eight‐band LTE/WWAN slim mobile phone application
Authors: Wong Kin‐Lu , Lee Cheng‐Tse
Published: August 2010

Surface‐mount chip antenna with a thin thickness of 3 mm and a small volume of 3 × 4 × 50 mm3 (0.6 cm3) for eight‐band long term evolution/wireless wide area network (LTE/WWAN) operation in the slim mobile phone is presented.The antenna is a simple two‐strip shorted monopole, yet it can provide two wide operating bands of at least 698–960/1710–2690 MHz to cover the three LTE bands (LTE700/2300/2500) and five WWAN bands (GSM850/900/1800/1900/UMTS). The antenna is suitable to be mounted on the no‐ground board space of the system circuit board of the mobile phone. Wideband operation is achieved by incorporating an on‐board feeding structure formed by a short shorting strip and a chip capacitor–loaded feeding strip, both are of 8 mm in length and disposed on the no‐ground board space, to the proposed chip antenna. Details of the antenna including the on‐board feeding structure are presented. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2554–2560, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25543
A W‐band monolithic down‐converter for MMW module based on metamorphic HEMTs
Authors: Baek Yong‐Hyun , Lee Sang‐Jin , Baek Tae‐Jong , Mun Sung‐Woon , Ko Dong‐Sik , Jeon Byoung‐Chul , Kim Wan‐Joo , Choi Jae‐Hyun , Lee Nam‐Jae , Rhee Jin‐Koo
Published: August 2010

In this article, we fabricated a 94 GHz monolithic down‐converter that consists of a two‐stage amplifier and a single‐balanced mixer using the 0.1‐μm metamorphic high electron mobility transistor (MHEMT) technology. The down‐converter of a 3.3 × 2.5 mm2 chip size shows a low conversion loss of ∼2.8 dB at 94 GHz and excellent LO‐to‐RF isolation above 35 dB in a frequency of 90–98 GHz. Also, we fabricated the millimeter‐wave (MMW) module that exhibits a conversion loss of 7–8.5 dB from 93.66 to 94.365 GHz. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2618–2621, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25546
Structure and morphology of a commercial high‐impact polypropylene in‐reactor alloy synthesized using a spherical Ziegler–Natta catalyst
Authors: Mahdavi Hossein , Nook Mojtaba Enayati
Published: August 2010

A commercial high‐impact polypropylene (hiPP) was fractionated by temperature‐gradient elution fractionation into nine fractions. All fractions were studied using Fourier transform infrared spectroscopy and differential scanning calorimetry. The amount of ethylene in the fractions was also determined. The results demonstrate that the ethylene–propylene statistical copolymer (or ethylene–propylene rubber, EPR) content in this hiPP is rather low and the amounts of ethylene–propylene segmented copolymer and ethylene–propylene block copolymer (that act as adhesive and compatibilizer between elastomeric phase and matrix, respectively) are negligible. Furthermore, the morphology of the resin was studied using scanning electron microscopy observations of microtome‐cut original and etched samples, which reveals that EPR particles are too large and their distribution inside the matrix is not uniform. Copyright © 2010 Society of Chemical Industry
A mutant form of PTEN linked to autism
Authors: Redfern Roberta E. , Daou Marie‐Claire , Li Li , Munson Mary , Gericke Arne , Ross Alonzo H.
Published: August 2010

The tumor suppressor, phosphatase, and tensin homologue deleted on chromosome 10 (PTEN), is a phosphoinositide (PI) phosphatase specific for the 3‐position of the inositol ring. PTEN has been implicated in autism for a subset of patients with macrocephaly. Various studies identified patients in this subclass with one normal and one mutated PTEN gene. We characterize the binding, structural properties, activity, and subcellular localization of one of these autism‐related mutants, H93R PTEN. Even though this mutation is located at the phosphatase active site, we find that it affects the functions of neighboring domains. H93R PTEN binding to phosphatidylserine‐bearing model membranes is 5.6‐fold enhanced in comparison to wild‐type PTEN. In contrast, we find that binding to phosphatidylinositol‐4,5‐bisphosphate (PI(4,5)P2) model membranes is 2.5‐fold decreased for the mutant PTEN in comparison to wild‐type PTEN. The structural change previously found for wild‐type PTEN upon interaction with PI(4,5)P2, is absent for H93R PTEN. Consistent with the increased binding to phosphatidylserine, we find enhanced plasma membrane association of PTEN‐GFP in U87MG cells. However, this enhanced plasma membrane association does not translate into increased PI(3,4,5)P3 turnover, since in vivo studies show a reduced activity of the H93R PTEN‐GFP mutant. Because the interaction of PI(4,5)P2 with PTEN's N‐terminal domain is diminished by this mutation, we hypothesize that the interaction of PTEN's N‐terminal domain with the phosphatase domain is impacted by the H93R mutation, preventing PI(4,5)P2 from inducing the conformational change that activates phosphatase activity.
Determining macromolecular assembly structures by molecular docking and fitting into an electron density map
Authors: Lasker Keren , Sali Andrej , Wolfson Haim J.
Published: August 2010

Structural models of macromolecular assemblies are instrumental for gaining a mechanistic understanding of cellular processes. Determining these structures is a major challenge for experimental techniques, such as X‐ray crystallography, NMR spectroscopy and electron microscopy (EM). Thus, computational modeling techniques, including molecular docking, are required. The development of most molecular docking methods has so far been focused on modeling of binary complexes. We have recently introduced the MultiFit method for modeling the structure of a multisubunit complex by simultaneously optimizing the fit of the model into an EM density map of the entire complex and the shape complementarity between interacting subunits. Here, we report algorithmic advances of the MultiFit method that result in an efficient and accurate assembly of the input subunits into their density map. The successful predictions and the increasing number of complexes being characterized by EM suggests that the CAPRI challenge could be extended to include docking‐based modeling of macromolecular assemblies guided by EM. Proteins 2010. © 2010 Wiley‐Liss, Inc.
Nanocrystalline boron‐doped diamond films, a mixture of BCS‐like and non‐BCS‐like superconducting grains
Authors: Dahlem F. , Achatz P. , Williams O. A. , Araujo D. , Courtois H. , Bustarret E.
Published: August 2010

Scanning tunneling topography and spectroscopy are performed below 100 mK on granular nanocrystalline boron‐doped diamond (BDD) films. We found the superconductivity behavior to follow mainly the granular features of the BDD films. The temperature dependence of the local differential conductance spectra shows our nanocrystalline BDD films as made of grains with a supercondutivity either BCS‐like or non‐BCS‐like. Such a distribution is not discernible in transport measurements, which present a sharp macroscopic superconducting transition at a temperature of a few Kelvins. Our local scanning tunneling microscopies also confirm the good coupling between these grains: only a few opaque interfaces are detected. Such a transparency of intergrain interfaces is responsible for a proximity effect in weakly superconductive grains and an inverse proximity effect in strongly superconducting grains.
Local electrostatic charging differences of sub‐100 nm nanocrystalline diamond films
Authors: Verveniotis E. , Čermák J. , Kromka A. , Ledinský M. , Remeš Z. , Rezek B.
Published: August 2010

Nanocrystalline diamond (NCD) thin films are deposited on p‐type Si substrates at different deposition temperatures (600–820 °C) in thicknesses below 100 nm. The films are then terminated by oxygen using r.f. oxygen plasma. Atomic force microscopy (AFM) is used to induce electrostatically charged micrometer‐sized patterns on the diamond films by applying a bias voltage on the AFM tip during a contact mode scan. Trapped charge is detected by Kelvin force microscopy, showing potential shifts different in geometry and amplitude on each film for the same absolute bias voltages. The films have similar structure and grain size, measured by AFM and scanning electron microscope (SEM). Fourier transform infrared spectroscopy (FTIR) in reflection regime shows the solidity of the films. Material differences are resolved via micro‐Raman spectroscopy. Different charging properties are thus attributed to the differences in relative amount of diamond and sp2 phase.
Comparative study of TL created in undoped CVD diamond by β rays, UV and visible light
Authors: Chernov V. , Piters T. , May P. W. , Meléndrez R. , Pedroza‐Montero M. , Barboza‐Flores M.
Published: August 2010

The thermoluminescence (TL) properties of CVD diamond film irradiated with β rays and illuminated with UV and visible light (200–450 nm) have been studied. The film (23 µm) was grown for 47 h on monocrystalline silicon. The TL glow curves are similar for β irradiation and short wavelength UV light. The β dose response curves and UV light time response curves exhibit linear–supralinear–sublinear behaviour. The structure of the glow curve was determined by a simultaneous deconvolution of a set of curves recorded after preliminary heating to various temperatures. One set of the TL peak parameters was found for all the curves during the deconvolution. The TL glow curves were found to consist of five strongly overlapped peaks. The peaks at about 350 and 400 K obey first‐order kinetics. The next three peaks at about 480, 540 and 580 K are described well by general‐order kinetics. The TL curves created with light of wavelength between 250 and 450 nm are different from those created by β radiation and short wavelength UV light. The former have low sensitivity and consist of several strongly overlapped peaks, two of them are observed at about 330 and 600 K.
Doping of single crystalline diamond with nickel
Authors: Wolfer M. , Obloh H. , Williams O. A. , Leancu C.‐C. , Kirste L. , Gheeraert E. , Nebel C. E.
Published: August 2010

Nickel doped single crystal diamond layers were grown by microwave‐plasma enhanced chemical vapour deposition. Optical emission spectroscopy (OES) utilised during growth proved that the organometallic compound nickelocene is an applicable nickel source. It was possible to produce stable and adjustable nickel OES signals during growth by altering the flux of the nickelocene carrier gas. The successful incorporation of nickel into the diamond layers was verified by secondary ion mass spectrometry. Cathodoluminescence (CL) was applied to reveal optically active defects related to nickel. The signature of substitutionally incorporated nickel, namely the nickel related 1.4 eV centre, as well as the 2.369 and 1.563 eV centres were observed in CL. The latter is supposed to be a single‐photon emitter on the basis of a nickel–nitrogen defect centre.
The magnetic moments and their long‐range ordering for Fe atoms in a wide variety of metallic environments
Authors: Ayuela A. , March N. H.
Published: August 2010

The magnitudes of Fe magnetic moments, together with their long‐range ordering when appropriate, are compared and contrasted in a variety of metallic environments. Thus, Fe, in its stable body‐centered‐cubic (bcc) phase under ambient conditions, is considered under pressures p, which can yield different crystal structures at high p, including fcc. The modification of the ferromagnetism in bcc Fe is surveyed as one passes through a bc‐tetragonal lattice to the fcc form. In the latter, evidence is presented, both from theory and experiment, that the ordering is antiferromagnetic in character. Then, binary metallic alloys with Fe atoms as the majority component are considered, Fe–Co and Fe–Ga being focal points in both ordered and disordered materials. Finally, some discussion is given, involving again both experiment and theory, of the possible spin polarization of neighboring Cs atoms when Fe impurity atoms are inserted into the low conduction electron density characterizing this heavy alkali metal under ambient conditions. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Scanning electron microscope (SEM) disclosure of the effects of snake venom on living tissue integrity and cell surfaces
Authors: Gennaro Joseph F. , Elek E. Deborah
Published: August 2010

The tissue destruction produced by the bite of the viper is well known and the venom enzyme[s] that produce it have been thoroughly studied. Not so well examined is the view of the damage available to the electron microscope, especially the scanning electron microscope. Here we have used the SEM to view the effects of viper venom on living tissue in situ. SCANNING 32: 155–158, 2010. © 2010 Wiley Periodicals, Inc.
Consistency of captive giraffe behavior under two different management regimes
Authors: Bashaw Meredith J.
Published: August 2010

Long‐term animal behavior studies are sometimes conducted at a single site, leading to questions about whether effects are limited to animals in the same environment. Our ability to make general conclusions about behavior is improved when we can identify behaviors that are consistent across a range of environments. To extend Veasey and colleagues' ([1996b] Anim Welf 5:139–153) study, I compared not only activity budgets but also social behavior of an all‐female group of giraffe at The Maryland Zoo in Baltimore (MZiB) to those previously observed in breeding groups at The San Diego Zoo's Wild Animal Park (SDZWAP; Bashaw et al. [2007] J Comp Psychol 121:46–53). Morning activity budgets and the maintenance of social relationships were consistent across groups. MZiB female giraffe interacted more frequently and the identity of animals that formed the strongest relationships was less predictable than at SDZWAP. Results support earlier findings that captive giraffe maintain social relationships and suggest that studies of giraffe social relationships and activity are generalizable across a range of captive conditions. Zoo Biol 30:371–378, 2011. © 2010 Wiley‐Liss, Inc.