bluuebunny/crossref_metadata_2025 huggingface dataset:
Conserving a subpopulation of the northern Atlantic cod metapopulation with a marine protected area
Authors: Hu Liuming , Wroblewski Joseph S.
Published: September 2008

Marine reserves can play an important role in the conservation of subpopulations of marine fish metapopulations. The population spatial structure of northern Atlantic cod of Newfoundland and Labrador has characteristics of a metapopulation. Subpopulations of northern Atlantic cod on the continental shelf were decimated by decades of overfishing, and have not recovered. The remaining northern cod are concentrated in coastal areas.

A Marine Protected Area (MPA) was established in Gilbert Bay, Labrador by the Government of Canada in 2005 to protect the bay's resident subpopulation of northern Atlantic cod. Conservation of Gilbert Bay cod will help protect the genetic diversity of the northern cod metapopulation.

Unlike some other MPAs, Gilbert Bay is not a harvest refugium or ‘no‐take’ reserve. Aboriginal subsistence fisheries for salmonids with a bycatch of cod are allowed in designated areas of the MPA. A recreational fishery for Atlantic cod by angling open to all people is under consideration. Management of the MPA must ensure that fishing activities do not endanger the local cod population.

The population dynamics of Gilbert Bay cod were simulated using an age‐structured Leslie matrix model to estimate the total mortality under various recreational fishing scenarios. The level of sustainable harvest by a recreational fishery depends on the natural mortality of the Gilbert Bay cod population, which is unknown. Therefore, there is risk in permitting a recreational fishery in the MPA.

There may be benefits to the northern cod metapopulation, if the Gilbert Bay subpopulation is allowed to rebuild to the carrying capacity of the bay. If the abundance of Gilbert Bay cod exceeds the level which the local marine ecosystem can support, some cod may emigrate from the bay and recolonize adjacent coastal areas. The potential for Gilbert Bay cod to recolonize continental shelf areas is less certain.

Copyright © 2008 John Wiley & Sons, Ltd.
Separation of flavins and nicotinamide cofactors in Chinese hamster ovary cells by capillary electrophoresis
Authors: Li Ye , Silva Piyanka G. de , Xi Lu , Winkle Alissa van , Lin Jim Jung‐Ching , Ahmed Semeena , Geng Maxwell Lei
Published: September 2008

Simultaneous extraction, separation and quantitation of reduced nicotinamide adenine dinucleotide (NADH), reduced nicotinamide adenine dinucleotide phosphate (NADPH), flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) in Chinese Hamster Ovary (CHO) cells were investigated. The separation of flavins and nicotinamide cofactors was performed by capillary electrophoresis with laser‐induced fluorescence detection at the excitation wavelength of 325 nm. The separation protocol was established by investigating the excitation wavelength, high voltage and effects of buffer nature, pH and concentration. All endogenous fluorophores riboflavin, FAD, FMN, NADH and NADPH show wide linear range of quantitation. The limits of detection for the five compounds ranged from 4.5 to 23 nm. Extraction conditions were optimized for high‐efficiency recovery of all endogenous fluorophores from CHO cells. To account for the complex matrix of cell extracts, a standard addition method was used to quantify FAD, FMN, NADH and NADPH in CHO cells. The quantitative results should be useful to reveal the metabolic status of cells. The protocols for extraction, separation and quantitation are readily adaptable to normal and cancer cell lines for the analysis of endogenous fluorophores. Copyright © 2008 John Wiley & Sons, Ltd.
Development and validation of a sensitive LC‐MS/MS method with electrospray ionization for quantitation of pramipexole in human plasma: application to a clinical pharmacokinetic study
Authors: Bharathi D. Vijaya , Hotha Kishore Kumar , Sagar P. V. Vidya , Kumar S. Sirish , Naidu A. , Mullangi Ramesh
Published: September 2008

A highly sensitive and specific LC‐MS/MS method has been developed and validated for the estimation of pramipexole (PPX) with 500 µL human plasma using memantine as an internal standard (IS). The API‐4000 was operated under multiple‐reaction monitoring mode (MRM) using the electrospray ionization technique. Solid‐phase extraction was used to extract PPX and IS from human plasma. The resolution of peaks was achieved with 0.01 m ammonium acetate buffer (pH 4.4):acetonitrile (30:70, v/v) on a Discovery CN column. The total chromatographic run time was 3.0 min and the elution of PPX and IS occurred at approximately 2.32 and 2.52, respectively. The MS/MS ion transitions monitored were 212.10 → 153.10 for PPX and 180.20 → 107.30 for IS. The method was proved to be accurate and precise at linearity range of 20–3540 pg/mL with a correlation coefficient (r) of ≥0.999. The intra‐ and inter‐day precision and accuracy values found to be within the assay variability limits as per the FDA guidelines. The developed assay method was applied to a pharmacokinetic study in human volunteers following oral administration of 0.25 mg PPX tablet. Copyright © 2008 John Wiley & Sons, Ltd.
Correlated waves of actin filaments and PIP3 in Dictyostelium cells
Authors: Asano Yukako , Nagasaki Akira , Uyeda Taro Q.P.
Published: September 2008

Chemotaxis‐deficient amiB‐null mutant Dictyostelium cells show two distinct movements: (1) they extend protrusions randomly without net displacements; (2) they migrate persistently and unidirectionally in a keratocyte‐like manner. Here, we monitored the intracellular distribution of phosphatidylinositol (3,4,5)‐trisphosphate (PIP3) to gain insight into roles PIP3 plays in those spontaneous motilities. In keratocyte‐like cells, PIP3 showed convex distribution over the basal membrane, with no anterior enrichment. In stalled cells, as well as in wild type cells, PIP3 repeated wave‐like changes, including emergence, expansion and disappearance, on the basal membrane. The waves induced lamellipodia when they approached the cell edge, and the advancing speed of the waves was comparable to the migration speed of the keratocyte‐like cells. LY294002, an inhibitor of PI3 kinase, abolished PIP3 waves in stalled cells and stopped keratocyte‐like cells. These results together suggested that keratocyte‐like cells are “surfing” on the PIP3 waves by coupling steady lamellipodial protrusions to the PIP3 waves. Simultaneous live observation of actin filaments and PIP3 in wild type or stalled amiB− cells indicated that the PIP3 waves were correlated with wave‐like distributions of actin filaments. Most notably, PIP3 waves often followed actin waves, suggesting that PIP3 induces local depolymerization of actin filaments. Consistent with this idea, cortical accumulation of PIP3 was often correlated with local retraction of the periphery. We propose that the waves of PIP3 and actin filaments are loosely coupled with each other and play important roles in generating spontaneous cell polarity. Cell Motil. Cytoskeleton 2008. © 2008 Wiley‐Liss, Inc.
Patterns of p57Kip2 expression in embryonic rat brain suggest roles in progenitor cell cycle exit and neuronal differentiation
Authors: Ye Weizhen , Mairet‐Coello Georges , Pasoreck Elise , DiCicco‐Bloom Emanuel
Published: September 2008

In developing central nervous system, a variety of mechanisms couple cell cycle exit to differentiation during neurogenesis. The cyclin‐dependent kinase (CDK) inhibitor p57Kip2 controls the transition from proliferation to differentiation in many tissues, but roles in developing brain remain uncertain. To characterize possible functions, we defined p57Kip2 protein expression in embryonic (E) day 12.5 to 20.5 rat brains using immunohistochemistry combined with markers of proliferation and differentiation. The p57Kip2 was localized primarily in cell nuclei and positive cells formed two distinct patterns including wide dispersion and laminar aggregation that were brain region‐specific. From E12.5 to E16.5, p57Kip2 expression was detected mainly in ventricular zone (VZ) and/or mantle zone of hippocampus, septum, basal ganglia, thalamus, hypothalamus, midbrain, and spinal cord. After E18.5, p57Kip2 was detected in select regions undergoing differentiation. The p57Kip2 expression was also compared with regional transcription factors, including Ngn2, Nkx2.1, and Pax6. Time course studies performed in diencephalon showed that p57Kip2 immunoreactivity colocalized with BrdU at 8 hr in nuclei exhibiting the wide dispersion pattern, whereas colocalization in the laminar pattern occurred only later. Moreover, p57Kip2 frequently colocalized with neuronal marker, β‐III tubulin. Finally, we characterized relationships of p57Kip2 to CDK inhibitor p27Kip1: in proliferative regions, p57Kip2 expression preceded p27Kip1 as cells underwent differentiation, though the proteins colocalized in substantial numbers of cells, suggesting potentially related yet distinct functions of Cip/Kip family members during neurogenesis. Our observations that p57Kip2 exhibits nuclear expression as precursors exit the cell cycle and begin expressing neuronal characteristics suggests that the CDK inhibitor contributes to regulating the transition from proliferation to differentiation during brain development. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2009
Matrix metalloproteinase‐2 is involved in myelination of dorsal root ganglia neurons
Authors: Lehmann Helmar C. , Köhne Angelika , Bernal Fabian , Jangouk Parastoo , Meyer Zu Hörste Gerd , Dehmel Thomas , Hartung Hans‐Peter , Previtali Stefano C. , Kieseier Bernd C.
Published: September 2008

Matrix metalloproteinases (MMPs) comprise a large family of endopeptidases that are capable of degrading all extracellular matrix components. There is increasing evidence that MMPs are not only involved in tissue destruction but may also exert beneficial effects during axonal regeneration and nerve remyelination. Here, we provide evidence that MMP‐2 (gelatinase A) is associated with the physiological process of myelination in the peripheral nervous system (PNS). In a myelinating co‐culture model of Schwann cells and dorsal root ganglia neurons, MMP‐2 expression correlated with the degree of myelination as determined by immunocytochemistry, zymography, and immunosorbent assay. Modulation of MMP‐2 activity by chemical inhibitors led to incomplete and aberrant myelin formation. In vivo MMP‐2 expression was detected in the cerebrospinal fluid (CSF) of patients with Guillain‐Barré syndrome as well as in CSF and sural nerve biopsies of patients with chronic inflammatory demyelinating polyneuropathy. Our findings suggest an important, previously unrecognized role for MMP‐2 during myelination in the PNS. Endogenous or exogenous modulation of MMP‐2 activity may be a relevant target to enhance regeneration in demyelinating diseases of the PNS. © 2008 Wiley‐Liss, Inc.
Human fetal radial glia cells generate oligodendrocytes in vitro
Authors: Mo Zhicheng , Zecevic Nada
Published: September 2008

Limited knowledge about human oligodendrogenesis prompted us to explore the lineage relationship between cortical radial glia (RG) cells and oligodendrocytes (OLs) in the human fetal forebrain. RG cells were isolated from cortical ventricular/subventricular zone and their progeny was followed in vitro. One portion of RG cells differentiated into cells of OL lineage identified by cell‐type specific antibodies, including platelet‐derived growth factor receptor‐alpha (PDGFRα), NG2, O4, myelin basic protein, and myelin oligodendrocyte glycoprotein. Moreover, using Cre Lox fate mapping (brain lipid binding protein‐Cre/Floxed‐yellow fluorescent protein) we established a direct link between RG cells and OL progenitors. In vitro generation of RG‐derived O4+ OL progenitors was enhanced by addition of sonic hedgehog (SHH) and reduced by the SHH inhibitor, cyclopamine, suggesting the role of SHH signaling in this process. In summary, our in vitro experiments revealed that a portion of cortical RG cells isolated from human forebrain at the second trimester of gestation generates OL progenitors and this suggests a role of SHH in this process. © 2008 Wiley‐Liss, Inc.
Persistent apathy in Alzheimer's disease as an independent factor of rapid functional decline: the REAL longitudinal cohort study
Authors: Lechowski L. , Benoit M. , Chassagne P. , Vedel I. , Tortrat D. , Teillet L. , Vellas B.
Published: September 2008

Objective

To determine the role of persistent apathy in rapid loss of autonomy in Instrumental Activities of Daily Living (IADL) in women with Alzheimer´s disease (AD), taking into account the grade of cognitive decline.

Methods

The study was conducted on 272 women from the French REAL cohort. At inclusion patients had a Mini‐Mental State Examination (MMSE) score between 10–26. A rapid functional decline was defined as a yearly drop of 4 points or more on the 14‐point IADL Lawton scale. Persistent apathy was defined as a frequency score equal to 3 or 4 on the Neuro‐Psychiatric Inventory at the three consecutive 6‐monthly assessments.

Results

27.6% of women had rapid functional decline in 1 year and 22.1% of them had persistent apathy. A logistic regression analysis showed that, in addition to cognitive decline, persistent apathy plays a role in rapid functional decline in 1 year. For example, for a 3‐point decline in MMSE in 1 year, the probability of a rapid loss in IADL is 0.45 for women with persistent apathy compared with 0.28 for those without persistent apathy.

Conlusions

In this study, a rapid loss in IADL score was partly explained by persistent apathy. Copyright © 2008 John Wiley & Sons, Ltd.
Smell test predicts performance on delayed recall memory test in elderly with depression
Authors: Scalco Monica Z. , Streiner David L. , Rewilak Dmytro , Castel Saulo , Van Reekum Robert
Published: September 2008

Introduction

Elderly with depression are at increased risk for cognitive dysfunction and dementia. Smell tests are correlated with performance on cognitive tests in the elderly and therefore might serve as a screening test for cognitive impairment in depressed elderly.

Purpose

To assess the validity of the CC‐SIT (Cross‐Cultural Smell Identification Test) as a screening test for cognitive impairment in elderly with depression.

Methods

Forty‐one patients, aged 60 and over, were assessed with the CC‐SIT and CVLT (California Verbal Learning Test) after 3 months treatment of a Major Depressive Episode (DSM‐IV) at the Day Hospital for Depression, Baycrest. Patients already diagnosed with dementia, or other psychiatric and neurological disorders, were excluded. Receiver Operating Characteristics (ROC) analysis was applied to assess the CC‐SIT's accuracy in identifying individuals with impairment (2 SD below the mean for age and education or less) on CVLT delayed recall trials.

Results

Forty‐one patients (33 women and eight men) were assessed. Mean age was 76.8 (SD: 6.5), mean HRSD scores before treatment was 22.0 (SD: 5.1). Nine patients had impairment on CVLT delayed recall measures. The area under the ROC curve was 0.776 (95% CI = 0.617–0.936).

Conclusions

Our results support the use of the CC‐SIT as a screening tool for cognitive impairment among elderly with depression as an indicator for the need of a comprehensive neuropsychological evaluation. Replication with larger samples is necessary. Copyright © 2008 John Wiley & Sons, Ltd.
Oncogenic NRAS has multiple effects on the malignant phenotype of human melanoma cells cultured in vitro
Authors: Eskandarpour Malihe , Huang Fei , Reeves Karen A. , Clark Edwin , Hansson Johan
Published: September 2008

Activating mutations in the NRAS gene, which occur predominantly in codon 61 (Q61R, Q61K) are among the most common genetic events in malignant melanoma. NRAS protein with oncogenic codon 61 mutations may therefore be good therapeutic targets. In the present study, we used gene expression profiling as a method for global characterization of gene expression alterations that resulted from treatment of melanoma cells with siRNA specifically targeting NRASQ61R. Sixteen probe sets representing 15 unique genes were identified whose expression was significantly altered by siRNA against NRASQ61R in 2 melanoma cell lines. The genes with altered expression are involved in several functions, including modulation of cell growth, invasion and migration. The results suggest that downregulation of cyclin E2 and cyclin D1 and also upregulation of the negative cell‐cycle regulator HBP1 in NRASQ61R knockdown cells contribute to the inhibition of cell proliferation. Furthermore, suppression of oncogenic NRAS results in reduced migration and invasion, which is accompanied by downregulation of EphA2 (a receptor tyrosine kinase), uPAR (urokinase receptor) and cytoskeleton proteins such as leupaxin, paxillin and vinculin. These studies support the concept that suppression of oncogenic NRAS by siRNA can induce growth arrest and inhibit invasion of human melanoma cells by modulating the levels of these gene products. © 2008 Wiley‐Liss, Inc.
Phosphoglycerate kinase 1‐overexpressing lung cancer cells reduce cyclooxygenase 2 expression and promote anti‐tumor immunity in vivo
Authors: Tang Shye‐Jye , Ho Ming‐Yi , Cho Huan‐Chieh , Lin Ying‐Chun , Sun Guang‐Huan , Chi Kwan‐Hwa , Wang Yu‐Shan , Jhou Ren‐Shiang , Yang Winnie , Sun Kuang‐Hui
Published: September 2008

In addition to the known function in the glycolytic pathway, phosphoglycerate kinase 1 (PGK‐1) promotes reduction of plasmin disulfide bonds leading to angiostatin formation and inhibition of tumor angiogenesis. In this study, the effects of PGK‐1 on anti‐ tumor immunity against lung cancer were evaluated using the Tet‐Off control of PGK‐1 expression in the Lewis lung carcinoma (LLC‐1). There was no significant difference in cell proliferation between parental LLC‐1 and LLC‐1 transduced with PGK‐1 (PGK‐LLC‐1). However, expression of PGK‐1 was found to limit tumor growth in mice subcutaneously injected with the cell lines and tumor growth was restored after doxycycline treatment. In addition, the cell invasion ability of PGK‐LLC‐1 became weaker than that of LLC‐1. Expressions of COX‐2, TGF‐β1 and PGE2 were all found to be down‐regulated in PGK‐LLC‐1. PGK‐LLC‐1 cells treated with doxycycline recovered their COX‐2 protein expression. In the presence of conditioned medium from PGK‐LLC‐1, the endothelial cell migration was reduced. Moreover, PGK‐LLC‐1 also stimulated T lymphocytes to express higher levels of Th1 cytokine (IFN‐γ) and lower levels of IL‐10 in comparison with parental LLC‐1. PGK‐LLC‐1 cells restored the growth rate in immunodeficient mice when compared with the growth rate in normal mice. In the tissue sections, reduced COX‐2 expressions and marked infiltrated CD3 T lymphocytes were observed in the PGK‐LLC‐1 injected group. These findings indicate that overexpression of PGK‐1 in LLC‐1 reduces the COX‐2 expression, and, in turn, affect PGE2, cell invasion, angiogenesis, and the immune functions, and finally inhibit the tumor progression. © 2008 Wiley‐Liss, Inc.
A prospective analysis of the association between dietary fiber intake and prostate cancer risk in EPIC
Authors: Suzuki Reiko , Allen Naomi E. , Key Timothy J. , Appleby Paul N. , Tjønneland Anne , Johnsen Nina Føns , Jensen Majken K. , Overvad Kim , Boeing Heiner , Pischon Tobias , Kaaks Rudolf , Rohrmann Sabine , Trichopoulou Antonia , Misirli Gesthimani , Trichopoulos Dimitrios , Bueno‐de‐Mesquita H. Bas , van Duijnhoven Fränzel , Sacerdote Carlotta , Pala Valeria , Palli Domenico , Tumino Rosario , Ardanaz Eva , Quirós José Ramón , Larrañaga Nerea , Sánchez Maria‐José , Tormo María‐José , Jakszyn Paula , Johansson Ingegerd , Stattin Pär , Berglund Göran , Manjer Jonas , Bingham Sheila , Khaw Kay‐Tee , Egevad Lars , Ferrari Pietro , Jenab Mazda , Riboli Elio
Published: September 2008

Few studies have examined the association between dietary fiber intake and prostate cancer risk. We evaluated the association between dietary fiber intake and the risk of prostate cancer among 142,590 men in the European Prospective Investigation into Cancer and Nutrition (EPIC). Consumption of dietary fiber (total, cereal, fruit and vegetable fiber) was estimated by validated dietary questionnaires and calibrated using 24‐hr dietary recalls. Incidence rate ratios were estimated using Cox regression and adjusted for potential confounding factors. During an average of 8.7 years follow‐up, prostate cancer was diagnosed in 2,747 men. Overall, there was no association between dietary fiber intake (total, cereal, fruit or vegetable fiber) and prostate cancer risk, although calibrated intakes of total fiber and fruit fiber were associated with nonstatistically significant reductions in risk. There was no association between fiber derived from cereals or vegetables and risk and no evidence for heterogeneity in any of the risk estimates by stage or grade of disease. Our results suggest that dietary fiber intake is not associated with prostate cancer risk. © 2008 Wiley‐Liss, Inc.
Promoting neurite outgrowth from spiral ganglion neuron explants using polypyrrole/BDNF‐coated electrodes
Authors: Evans Alison J. , Thompson Brianna C. , Wallace Gordon G. , Millard Rodney , O'Leary Stephen J. , Clark Graeme M. , Shepherd Robert K. , Richardson Rachael T.
Published: September 2008

Release of neurotrophin‐3 (NT3) and brain‐derived neurotrophic factor (BDNF) from hair cells in the cochlea is essential for the survival of spiral ganglion neurons (SGNs). Loss of hair cells associated with a sensorineural hearing loss therefore results in degeneration of SGNs, potentially reducing the performance of a cochlear implant. Exogenous replacement of either or both neurotrophins protects SGNs from degeneration after deafness. We previously incorporated NT3 into the conducting polymer polypyrrole (Ppy) synthesized with para‐toluene sulfonate (pTS) to investigate whether Ppy/pTS/NT3‐coated cochlear implant electrodes could provide both neurotrophic support and electrical stimulation for SGNs. Enhanced and controlled release of NT3 was achieved when Ppy/pTS/NT3‐coated electrodes were subjected to electrical stimulation. Here we describe the release dynamics and biological properties of Ppy/pTS with incorporated BDNF. Release studies demonstrated slow passive diffusion of BDNF from Ppy/pTS/BDNF, with electrical stimulation significantly enhancing BDNF release over 7 days. A 3‐day SGN explant assay found that neurite outgrowth from explants was 12.3‐fold greater when polymers contained BDNF (p < 0.001), although electrical stimulation did not increase neurite outgrowth further. The versatility of Ppy to store and release neurotrophins, conduct electrical charge, and act as a substrate for nerve‐electrode interactions is discussed for specialized applications such as cochlear implants. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Seafloor glacial features reveal the extent and decay of the last British Ice Sheet, east of Scotland
Authors: Graham Alastair G. C. , Lonergan Lidia , Stoker Martyn S.
Published: September 2008

Three‐dimensional (3D) seismic datasets, 2D seismic reflection profiles and shallow cores provide insights into the geometry and composition of glacial features on the continental shelf, offshore eastern Scotland (58° N, 1–2° W). The relic features are related to the activity of the last British Ice Sheet (BIS) in the Outer Moray Firth. A landsystem assemblage consisting of four types of subglacial and ice marginal morphology is mapped at the seafloor. The assemblage comprises: (i) large seabed banks (interpreted as end moraines), coeval with the Bosies Bank moraine; (ii) morainic ridges (hummocky, push and end moraine) formed beneath, and at the margins of the ice sheet; (iii) an incised valley (a subglacial meltwater channel), recording meltwater drainage beneath former ice sheets; and (iv) elongate ridges and grooves (subglacial bedforms) overprinted by transverse ridges (grounding line moraines). The bedforms suggest that fast‐flowing grounded ice advanced eastward of the previously proposed terminus of the offshore Late Weichselian BIS, increasing the size and extent of the ice sheet beyond traditional limits. Complex moraine formation at the margins of less active ice characterised subsequent retreat, with periodic stillstands and readvances. Observations are consistent with interpretations of a dynamic and oscillating ice margin during BIS deglaciation, and with an extensive ice sheet in the North Sea basin at the Last Glacial Maximum. Final ice margin retreat was rapid, manifested in stagnant ice topography, which aided preservation of the landsystem record. Copyright © 2008 John Wiley & Sons, Ltd.
The definition, source, manifestation and assessment of unintended effects in genetically modified plants
Authors: Deng Ping‐Jian , Zhou Xiang‐Yang , Yang Dong‐Yan , Hou Hong‐Li , Yang Xiao‐Ke , Li Yong‐Hong , Yang Yong‐Cun , Wang Xue‐Lin , Fang Shi‐Song , Wu Shui‐Qing , Liu Jin
Published: September 2008

At present, there is consensus among many relevant international agencies that unintended effects should be paid particular attention in the process of edible safety assessment of genetically modified plants (GMPs) and their products, especially in regard to some long‐term and potential food safety issues. However, with respect to the current risk assessment of GMPs, serious dissension on the apprehension of unintended effects exists. The present paper interprets and systematically analyses this dissension in order to review development on the definition, source and manifestation of unintended effects in GMPs. First, differences in the various concepts of unintended effect are discussed and compared. Then the mechanisms whereby unintended effects may arise during GMP breeding are analysed and the main unexpected variation manifestations in GMPs are presented. With regard to the safety assessment of unintended effects in GMPs, the current evaluation strategy, detection methods and several assessment cases are expounded. In addition, the unique assessment standard for unintended effects in GMPs in China is outlined. Copyright © 2008 Society of Chemical Industry
Relationship between pattern of tumor enhancement and clinicopathologic characteristics in intrahepatic cholangiocarcinoma
Authors: Nanashima Atsushi , Sumida Yorihisa , Abo Takafumi , Oikawa Masayuki , Murakami Goshi , Takeshita Hiroaki , Fukuoka Hidetoshi , Hidaka Shigekazu , Nagayasu Takeshi , Sakamoto Ichiro , Sawai Terumitsu
Published: September 2008

Aim

Common enhancement pattern of intrahepatic cholangiocarcinoma (ICC) on computed tomography (CT) is that of hypovascular enhancement; however, in some cases, tumor shows identical enhancement in the arterial phase to that in hepatocellular carcinoma. To identify the specific characteristics of different enhancement patterns, we examined the relationship between CT enhancement pattern and clinicopathological features or postoperative prognosis.

Method

Subjects were 43 consecutive ICC patients who had undergone hepatectomy. Enhancement patterns were divided into two types: hypovascular or delayed enhancement (Type A), and early enhancement in the arterial phase (Type B).

Results

Type A enhancement was observed in 23 patients and Type B in 20. Accompanying chronic viral hepatitis was significantly more frequent in Type B than Type A. Well‐differentiated adenocarcinoma was significantly more frequent in Type B than Type A. Multiple tumors were significantly more frequent in Type A than Type B. Japanese TNM stage I and II was more frequent in patients with Type B than those with Type A. Disease‐free or overall survival was significantly better in patients with Type B than those with Type A.

Conclusion

Early enhancement in the arterial phase might be a useful indicator of lower malignant potential and better survival in ICC patients. J. Surg. Oncol. 2008;98:535–539. © 2008 Wiley‐Liss, Inc.
What you should know about simulation and derivatives
Authors: Fu Michael C.
Published: September 2008

Derivatives (or gradients) are important for both sensitivity analysis and optimization, and in simulation models, these can often be estimated efficiently using various methods other than brute‐force finite differences. This article briefly summarizes the main approaches and discusses areas in which the approaches can most fruitfully be applied: queueing, inventory, and finance. In finance, the focus is on derivatives of another sort. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008
Stem cells in liver regeneration, fibrosis and cancer: the good, the bad and the ugly
Authors: Alison MR , Islam S , Lim S
Published: September 2008

The worldwide shortage of donor livers to transplant end stage liver disease patients has prompted the search for alternative cell therapies for intractable liver diseases, such as acute liver failure, cirrhosis and hepatocellular carcinoma (HCC). Under normal circumstances the liver undergoes a low rate of hepatocyte ‘wear and tear’ renewal, but can mount a brisk regenerative response to the acute loss of two‐thirds or more of the parenchymal mass. A body of evidence favours placement of a stem cell niche in the periportal regions, although the identity of such stem cells in rodents and man is far from clear. In animal models of liver disease, adopting strategies to provide a selective advantage for transplanted hepatocytes has proved highly effective in repopulating recipient livers, but the poor success of today's hepatocyte transplants can be attributed to the lack of a clinically applicable procedure to force a similar repopulation of the human liver. The activation of bipotential hepatic progenitor cells (HPCs) is clearly vital for survival in many cases of acute liver failure, and the signals that promote such reactions are being elucidated. Bone marrow cells (BMCs) make, at best, a trivial contribution to hepatocyte replacement after damage, but other BMCs contribute to the hepatic collagen‐producing cell population, resulting in fibrotic disease; paradoxically, BMC transplantation may help alleviate established fibrotic disease. HCC may have its origins in either hepatocytes or HPCs, and HCCs, like other solid tumours appear to be sustained by a minority population of cancer stem cells. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
SmgGDS is up‐regulated in prostate carcinoma and promotes tumour phenotypes in prostate cancer cells
Authors: Zhi H , Yang XJ , Kuhnmuench J , Berg T , Thill R , Yang H , See WA , Becker CG , Williams CL , Li R
Published: September 2008

SmgGDS is a guanine nucleotide exchange factor with the unique ability to activate multiple small GTPases, implicating it in cancer development and progression. Here, we investigated the role of SmgGDS in prostate cancer by studying the expression of SmgGDS in benign and malignant prostatic tissues. We also probed SmgGDS function in three prostate carcinoma cell lines using small interfering RNA (siRNA). Immunohistochemical analysis revealed that SmgGDS levels were elevated in prostatic intraepithelial neoplasia (PIN), prostate carcinoma, and metastatic prostate carcinoma. In addition, expression of SmgGDS positively correlated with that of cyclooxygenase‐2 (COX‐2), a protein believed to promote the development of prostate carcinoma. Reduction of SmgGDS expression in prostate carcinoma cells inhibited proliferation and migration, irrespective of androgen receptor status. These effects were accompanied by a reduction in COX‐2 expression and in activity of NF‐κB, a known regulator of COX‐2. Taken together, these findings suggest that SmgGDS promotes the development and progression of prostate cancer, possibly associated with NF‐κB‐dependent up‐regulation of COX‐2. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Vibrational force field effect on the melting process of a polymer solid against a sliding wall
Authors: Guangsheng Zeng , Jinping Qu
Published: September 2008

The melting of polymers caused by friction before a solid plug is an important phenomenon in the vibration‐induced plastic extrusion process. In order to better analyze the melting process of polymers in a vibration screw type extruder, a melting model is proposed as well as a corresponding experimental apparatus to test the model. Due to the introduction of vibration force field, the viscidity of a polymer melt behaves in a strong non‐linear and time‐dependent fashion. Therefore, the effect of heat generated by viscous dissipation is very important. Through sophisticated deduction, an analytical expression of the relationship between the velocity of polymer solid element and the parameters of vibration is derived. The model is then proved by comparing a calculated sample with experimental results, which indicate that, the introduction of vibration force field can improve the melting process to a great extent. This model can serve as the theoretical basis for a polymer melting process. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Chemical modification of rubber wood with styrene and glycidyl methacrylate
Authors: Devi Rashmi R. , Maji Tarun K.
Published: September 2008

Rubber wood was impregnated with styrene and glycidyl methacrylate (GMA) as the crosslinking monomer. Polymerization was accomplished by catalyst heat treatment. Compressive strength both in parallel and perpendicular to fiber directions was measured and improvement was observed for wood polymer composites. Bending strength in terms of Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) was measured and found improved on treatment over the untreated wood samples. Hardness for treated wood was also improved. Dynamic Mechanical Analysis (DMA) indicated an increase in interaction between wood, styrene, and GMA. Biodegradation of the treated and untreated wood samples was also determined and found to be improved on treatment. Scanning electron microscopy (SEM) study showed the wood polymer interaction. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
The morphing properties of a smart fiber metal laminate
Authors: Cortes P. , Cantwell W.J. , Kuang K.S.C. , Quek S.T.
Published: September 2008

This article investigates the activation characteristics of a novel fiber‐metal laminate (FML) based on a nickel–titanium (Ni–Ti) shape memory alloy. Initial attention focuses on manufacturing this smart FML in which a woven glass fiber reinforced epoxy material is sandwiched between two shape memory alloy (SMA) outer skins. Activation tests on cantilever beams using a hot air gun have shown that the FMLs exhibits a distinct actuation capability in which beam rotations of up to 11° were recorded. An examination of the edges of polished samples indicated that no damage was incurred by the FML during the activation process. The functionality of the FMLs was enhanced through the introduction of embedded electrical resistance wires located between the composite and metal plies. Here, the embedded electrical wires were heated by passing an electric current through them, thereby activating the SMA plies in a more effective and controllable manner. As before, significant beam tip rotations were recorded in the FMLs in a relatively short time period. Finally, polymer‐based optical fiber (POF) and fiber‐bragg grating (FBG) sensors were introduced into the FMLs in order to monitor their deflection during the activation process. The results of these tests showed that such sensing elements can be successfully employed to monitor the actuation response of these layered laminates. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Polypropylene–waste ground rubber tire powder microcellular composites: Effect of processing variables on morphology and physico‐mechanical properties
Authors: Zhang Zhen Xiu , Sridhar V. , Kim Jin Kuk
Published: September 2008

Microcellular composites made from polypropylene and waste ground rubber tire powder using azodicarbonamide as chemical blowing agent have been investigated. A small quantity of SEBS‐g‐MA has been added as compatibilizer. The effect of variation in processing variables such as pressure, heating time, and operating variables such as blowing agent and crosslinker concentrations have been investigated to establish a relationship between the structure and morphology of the microcellular composite and ultimate performance characteristics such as tensile strength, tear strength, and elongation at break. The results indicate that both processing and operating variables have tremendous effect on the morphological features such as average, minimum, and maximum cell size as observed from scanning electron microscopy. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Conductive copper‐PMMA nanocomposites: Microstructure, electrical behavior, and percolation threshold as a function of metal filler concentration
Authors: Poblete V.H. , Álvarez M.P. , Fuenzalida V.M.
Published: September 2008

The copper‐PMMA conductive composites were manufactured using different copper concentrations dispersed into the polymeric matrix by hot compression molding in inert atmosphere. The PMMA matrix was analyzed using dilute solution viscosimetry analysis and it did not evidence degradation in its molecular weight. The microstructure was examined by means of SEM and the electric conductivity was measured as a function of the concentration of copper particles in the polymer matrix. The 10 vol% copper composite presented conductivity between 11 and 13 orders of magnitude higher than that of pure PMMA. The experimental results are in agreement with the theoretical model considering the percolation path theory for a segregated structure. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Tensile properties and morphological evolution of polypropylene and poly(ethylene‐co‐1‐octene) blends
Authors: Song Na , Zhu Lin , Wang Fengjuan , Xu Xinhua
Published: September 2008

Extruded sheet of isotactic polypropylene and poly(ethylene‐co‐1‐octene) blends extruded from a counterrotating twin‐screw extruder were studied by scanning electron microscopy, tensile test, and small‐angle X‐ray scattering. The average characteristic length (Λm) determined by the statistical computing from the SEM images increases linearly with increasing of dispersed phase concentration. When POE content is 50 wt% (double continuous phase), Λm is two or three times as big as that of other blends ratio. The analyses of SAXS data confirm this result. Comparison has been made between experimental data of tensile test and those predicted from several meso‐mechanical models such as parallel model, series model, Halpin's model, Mori‐Tanaka's model, and modified mixture model. The modified mixture model is an effective method for predicting Young's modulus in comparison with other models. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
The influence of plasma treatment on the tribological properties of hybrid PTFE/cotton fabric/phenolic composites
Authors: Zhang Hui‐Juan , Zhang Zhao‐Zhu , Guo Fang , Liu Wei‐Min
Published: September 2008

In this study, the effects of air‐plasma and N2‐plasma treatment on the hybrid polytetrafluoroethylene (PTFE)/cotton fabric and a phenolic resin were investigated in detail. The tribological properties of the untreated and plasma‐treated hybrid PTFE/cotton fabric/phenolic composites were investigated. The results indicated that air‐plasma‐treated hybrid PTFE/cotton fabric/phenolic composites exhibited better antiwear and friction reduction properties. The combination of scanning electron microscopy and Fourier transform infrared spectroscopy analysis illustrated that hybrid PTFE/cotton fabric/phenolic composites treated with air‐plasma possessed more integrated structure and more functional groups, which plausibly contributed to the better tribological properties of the hybrid PTFE/cotton fabric/phenolic composites treated with air‐plasma. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Effect of clay with different cation exchange capacity on the morphology and properties of poly(methyl methacrylate)/clay nanocomposites
Authors: Tsai Tsung‐Yen , Wen Chih‐Kuo , Chuang Hsin‐Jou , Lin Mej‐Ju , Ray Umasankar
Published: September 2008

PMMA/clay nanocomposites were successfully prepared by in situ free‐radical polymerization with the organic modified MMT‐clay using methyl methacrylate monomer and benzoyl peroxide initiator. Two clays with different cation exchange capacity have been used to prepare and compare the several properties. The clays have been modified using Amphoterge K2 by ion exchange reaction to increase the compatibility between the clay and polymer matrices. The modified clays have been characterized by wide‐angle X‐ray diffraction pattern, Fourier transform infrared spectroscopy, and thermogravimetric analysis (TGA). The powdered X‐ray diffraction and transmission electron microscopy techniques were employed to study the morphology of the PMMA/clay nanocomposites which indicate that the modified clays are dispersed in PMMA matrix to form both exfoliated and intercalated PMMA/modified clay nanocomposites. The thermomechanical properties were examined by TGA, differential scanning calorimetry, and dynamic mechanical analysis. Gas permeability analyzer shows the excellent gas barrier property of the nanocomposites, which is in good agreement with the morphology. The optical property was measured by UV–vis spectroscopy which shows that these materials have good optical clarity and UV resistance. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Poly(methyl methacrylate)/montmorillonite nanocomposites prepared by bulk polymerization and melt compounding
Authors: Krajnc Matjaž , Šebenik Urška
Published: September 2008

This article focuses on structural, thermal, and mechanical properties of nanocomposites in dependence of preparation method and poly(methyl mathacrylate) (PMMA)/organically modified montmorillonite (OMMT) ratio. PMMA/OMMT nanocomposites were prepared by bulk polymerization and by melt compounding. Properties of nanocomposites of the same composition prepared by the two methods were compared. It was observed that nanocomposites prepared via melt compounding at 200°C had a highly oriented structure with lower interlayer spacing values than nanocomposites prepared via bulk polymerization. Two reasons for the observed smaller interlayer spacing obtained by melt compounding were identified. The first is enhanced PMMA penetration and/or formation between layers in the case of bulk polymerization, which was confirmed by determination of stronger interactions between OMMT and PMMA by Soxhlet extraction, infrared spectroscopy, and differential dynamic calorimery. The second reason for smaller interlayer spacing for nanocomposites prepared by melt compounding is organic modifier degradation during melt compounding process, which was confirmed by thermogravimetric analysis. Both reasons lead to the fracture of melt compounded nanocomposites on the OMMT‐polymer interface, which was observed by scanning electron microscopy. For nanocomposites with disoriented structure and larger interlayer spacing prepared via bulk polymerization the fracture occurred in the polymer matrix. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Experimental investigation of acid environment influences on load‐bearing performance of pin‐connected continuous glass‐fiber‐reinforced polyphenylenesulfide composites
Authors: Yilmaz T. , Sinmazcelik T.
Published: September 2008

In this study we aimed to investigate the load‐bearing performance of pinned connections in corrosive environment. Experimental results are presented for the effect of acid environment on load‐bearing performance of pin‐connected continuous glass‐fiber‐reinforced polyphenylenesulfide composites. Chemical corrosion was also observed as an important environmental factor which affected the load‐bearing performance remarkably. Specimens were exposed to hydrochloric acid in order to find the durability of glass‐fiber‐reinforced plastics in hostile environments. An attempt is made to explain this phenomenon. The failure formation of material was affected by exposure time to HCl. Consequently, after the material has been exposed to acidic environment for 16 weeks, there were ∼93 and 95% performance decrease in the final failure load and first failure load, respectively. POLYM. COMPOS., 2010. © 2008 Society of Plastics Engineers
Techniques for chorionic villus sampling and amniocentesis: a survey of practice in specialist UK centres
Authors: Carlin A. J. , Alfirevic Z.
Published: September 2008

Objectives

Guidelines exist for amniocentesis and chorionic villous sampling (CVS) practice, but there is no consensus regarding individual techniques. Our survey sought to review current practice within specialist centres in the United Kingdom.

Methods

RCOG sub‐specialist training centres were invited to complete a postal questionnaire, seeking their consultants' primary choices for amniocentesis and CVS techniques. Information sought included needle choice, local anaesthetic (LA), suction methods, quantity of samples obtained; and with regard to CVS, preferred approach [transcervical (TC) or transabdominal (TA)].

Results

Response rate was 96% providing information on 111 consultants (111 amniocentesis/90 CVS). During amniocentesis, 86% use 22G needles and 70% are helped by an assistant who aspirates a set liquor volume (69%). For CVS, 98% use a TA approach, 89% use LA, and 29% an 18G single needle with 38% preferring a 17/19G double needle but no clear consensus regarding the use of assistants.

Conclusions

There is some agreement among specialists in the United Kingdom regarding techniques for invasive prenatal diagnosis. For amniocentesis, most operators use 22G needles, with an assistant to aspirate a set volume of fluid regardless of gestation. For CVS, there is considerable variation in needle choice, although most operators use a TA approach with LA. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of processing parameters on the uniformity of adhesive meltblown web
Authors: Wang Xiaomei , Zhao Qiming
Published: September 2008

The influence of the main processing parameters, including the primary air pressure, the accessory air pressure, the melt throughput rate, and the die‐to‐collector distance, on the uniformity of adhesive meltblown web produced on the pilot‐scale melt‐blowing equipment with the added accessory device is investigated using weight measurement and thickness measurement. The effects of the process parameters on the web weight unevenness and the web thickness unevenness are similar, so both the weight unevenness and the thickness unevenness can be used to analyze the web unevenness. The results show that the web unevenness increases with the increasing melt throughput rate and the accessory air pressure; the web unevenness decreases firstly and increases later with the increasing primary air pressure and the die‐to‐collector distance. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Mathematical modeling for the ionic inclusion process inside conducting polymer‐based thin‐films
Authors: Majumdar Saptarshi , Kargupta Kajari , Ganguly Saibal
Published: September 2008

Ionic inclusion inside thin conducting polymer (CP) film is a major and common feature for actuator as well as membrane‐based drug release. In this study, an electro‐active polymeric thin‐film system has been conceptualized. PNP‐electro‐neutrality (Poisson–Nernst– Planck) based modeling framework with customized boundary conditions is used to depict the electrochemical phenomena. In dynamic model, kinetics of probable redox reactions is included along with electro‐migration and diffusion terms in the overall PNP framework. At steady state, interfacial voltage seems to hold the critically important role, while ionic migration and reaction kinetics play very crucial roles in determining the dynamics of such systems. The validated model predicts that lowering in the standard potential of the polymeric electrode accelerates the process of ionic ingress. Higher ionic flux is obtained using slower voltage scan. Variation of diffusivity shows the large spectrum of relatively unexplored dynamics for such electro‐active thin‐film‐based system. The significance is in designing actuator‐ or membrane‐based controlled molecular release systems. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers