bluuebunny/crossref_metadata_2025 huggingface dataset:
Realizations of fully differential voltage second generation current conveyor with an application
Authors: Sobhy Ehab A. , Soliman Ahmed M.
Published: November 2008

Three novel CMOS realizations for the fully differential voltage second‐generation inverting current conveyor (FDVCCII‐) are proposed in this paper. The first realization has a limited input range, and the other two realizations have a rail to rail input range and show excellent features in linearity and bandwidth. As an application to the FDVCCII‐, a floating gyrator is proposed. A floating inductor is realized using the floating gyrator and it is used in realizing a second‐order low‐pass filter, which is simulated and compared with the ideal result. All circuits are simulated with SPICE using CMOS 0.35µm technology and supply voltages ±1.5V to verify the theoretical results. Copyright © 2008 John Wiley & Sons, Ltd.
Fine‐needle aspiration of cystic pancreatic mucinous tumor: Oncotic cell as an aiding diagnostic feature in paucicellular specimens
Authors: Xiao Guang‐Qian
Published: November 2008

In juxtaposition with imaging studies, endoscopic ultrasound‐guided fine‐needle aspiration has gained popularity in the initial evaluation of pancreatic masses, especially cystic lesions of pancreas. Cystic pancreatic mucinous tumors include mucinous cystic neoplasm and intraductal papillary mucinous tumor, both of which have been known to have a low malignant potential and a high rate of association with invasive adenocarcinoma. As such, preoperative diagnosis is of great significance in guiding patient management. Although fine‐needle aspiration cytological diagnosis of pancreatic tumor in cellular specimens has been well described, as with other cystic lesions, the yield of diagnostic cells from needle aspiration of cystic pancreatic mucinous tumors is typically low. Cytological diagnosis from these paucicellular specimens remains challenging. An additional compounding problem is the high frequency of gastrointestinal mucin and epithelial contamination. The diagnostic morphology and criteria in these paucicellular specimens have not been well addressed in the literature. The cytopathologists' ongoing efforts tend to improve the diagnostic accuracy. In this current study, oncotic cells, characterized by cytoplasmic swelling and karyolysis, were analyzed from 17 cases of cystic pancreatic mucinous tumor, of which the diagnosis was either confirmed by surgical resection or supported by cell block and/or increased CEA. Oncotic cells were found in variable amounts in almost all the cystic pancreatic mucinous tumors in this series. None of the five fine‐needle aspirations intended for aspirations of hypoechoic nonlesional pancreas, which yielded either gastrointestinal tract material only or admixture of gastrointestinal and normal pancreatic components, was found to contain oncotic cells, evidencing the utility of oncotic cell as a surrogate morphologic marker in aiding the diagnosis of cystic pancreatic mucinous tumor as well as its differentiation from gastrointestinal contaminant, particularly in paucicellular specimens. Diagn. Cytopathol. 2009. © 2008 Wiley‐Liss, Inc.
Ductopapillary apocrine carcinoma of the eyelid metastatic to the parotid gland: Report of a case diagnosed by fine‐needle aspiration biopsy
Authors: Akhtar Israh , Ispas Cristina Luminita , Flowers Rhyne , Siddiqi Anwer , Young LaFarra , Donnellan Kimberly A. , Heard Ken , Baliga Mithra
Published: November 2008

Ductopapillary apocrine carcinoma (DPAC) of the eyelid is a rare malignant neoplasm in the periocular region. The relative rarity of this tumor is a diagnostic challenge to the cytopathologist, especially when present as a metastatic lesion to an intraparotid lymph node, where the differential diagnosis includes primary parotid neoplasms, as well as various other metastatic malignancies. There are only a few reported cases of recurrent and metastatic DPAC of the eyelid, and to our knowledge, metastatic DPAC diagnosed by fine‐needle aspiration biopsy (FNAB) has not been described. We report a case of a 65‐year‐old African‐American male with a history of ductopapillary apocrine adenocarcinoma of the eyelid, diagnosed 6 weeks ago now presenting with a recurrence in the same area. Magnetic resonance imaging of the head and neck revealed an intraparotid mass also. FNAB of the parotid mass showed a well‐differentiated papillary adenocarcinoma with a cystic component, similar to a previously excised ductopapillary apocrine adenocarcinoma of the eyelid. Diagn. Cytopathol. 2009. © 2008 Wiley‐Liss, Inc.
Utility of the thromboplastin‐plasma cell‐block technique for fine‐needle aspiration and serous effusions
Authors: Kulkarni Manisha B. , Desai Sangeeta B. , Ajit Dulhan , Chinoy R. F.
Published: November 2008

(I) To assess the feasibility of thromboplastin‐plasma (TP) method for cell block, (II) to concentrate the minimal cellular material from effusions and needle‐rinses by block preparation and improve visual details, (III) to compare conventional cytological smears with cell blocks for final assessment, and (IV) to assess utility of immunocytochemistry (ICC) for diagnostic accuracy.

Seventy cell blocks were prepared by TP technique using surplus fluid from 38 serous effusions, and for 32 ultrasonography‐guided fine‐needle aspiration cytology (FNAC) material, rinses of syringes and needles were collected in normal saline after conventional cytological smears. Then, cell blocks were compared with conventional smears for adequacy, morphologic preservation, and ICC.

Absolute concordance seen in 66 cases (94%) between the smears and cell blocks. Advantages with the blocks were cellular concentration in a limited field and better cellular preservation with architectural pattern. Quality of ICC was comparable to that of standard controls. Diagnostic discrepancy was seen in two cases where cell blocks were positive but smears were negative. Two cell blocks were nonrepresentative.

Cell block serves as a useful adjunct to traditional cytological smears. TP method is simple, cost effective, and reproducible. It is easy when compared with agar‐embedding technique. Ancillary techniques like ICC can be performed successfully. Diagn. Cytopathol. 2009. © 2008 Wiley‐Liss, Inc.
Impact of ASC‐H terminology on the detection of HSILs in medically underserved California women
Authors: Howell Lydia Pleotis , Gurusinghe Sunitha , Tabnak Farzaneh
Published: November 2008

In this study we evaluated CDP: EWC, a large public health screening program for low‐income women to determine whether the ASC‐H term, introduced in the 2001 revision to the Bethesda System, has facilitated the detection of the most serious precancerous cervical lesions such as CIN‐II–III/CIS, including accuracy of detection and minimizing diagnostic delays. Pap test and biopsy data from the period 2003–2006 were compared with those from 1995–1999, and included analysis of a subset of rarely and never‐screened for each study period. More ASC‐H Pap tests were followed by CIN‐II+ biopsies (20%) than ASCUS Pap tests (5%). Thirteen percent of ASC‐H showed CIN‐III/CIS on follow‐up biopsy. Following the introduction of ASC‐H, negative and LSIL Pap tests followed by CIN‐III/CIS biopsies decreased from 5.6% to 0.37% and 9.2% to 4.4%, respectively. Fewer CIN‐III/CIS cases were preceded by Pap tests with negative and ASCUS results in 2003–2005 as compared with 1995–1999. The number of days from screening to diagnosis for women aged 25–39 years with ASC‐H Pap test results (58 days) was less than for ASCUS results (78 days) for the current study period. In this high‐risk multi‐ethnic population, ASC‐H more effectively communicates equivocal findings likely to represent HSIL leading to more rapid follow‐up. The incidence of CIN‐II or CIN‐III/CIS following ASC‐H Pap tests is lower than generally appreciated for this population, including for rarely or never‐screened high‐risk women. Fewer CIN‐III/CIS lesions were detected following negative and ASCUS Pap results. Compliance with follow‐up is less than ideal for this population. Diagn. Cytopathol. 2009. © 2008 Wiley‐Liss, Inc.
Paediatric cutaneous blastomycosis: A rare case diagnosed on FNAC
Authors: Shukla Shailaja , Singh Smita , Jain Manjula , Kumar Singh Sanjeet , Chander Ram , Kawatra Neha
Published: November 2008

Blastomycosis, usually presenting as pneumonia, is more common in adults than in children. Moreover, cutaneous blastomycosis is quite uncommon in children. We describe a case of cutaneous blastomycosis in an 8‐year‐old boy who presented with multiple hyperkeratotic verrucous plaques where diagnosis was made on fine‐needle aspiration cytology, and the infection responded well to oral itraconazole therapy with reduction in number of spores and size of lesions. Diagn. Cytopathol. 2009. © 2008 Wiley‐Liss, Inc.
Fine‐needle aspiration of brown tumor of bone: Cytologic features with radiologic and histologic correlation
Authors: Pavlovic Sasha , Valyi‐Nagy Tibor , Profirovic Jasmina , David Odile
Published: November 2008

We report the case of a 40‐year‐old man with tertiary hyperparathyroidism due to end stage renal disease who initially presented with acute‐onset paraplegia, elevated serum parathyroid hormone, and multiple bone abnormalities, including a large extradural intraspinal mass seen by magnetic resonance imaging. In contrast with imaging features, fine‐needle aspiration cytology showed numerous benign‐appearing multinucleated osteoclast‐type giant cells that are the characteristics of either brown tumor or benign giant cell tumor of bone. Sheets of mononuclear spindled stromal cells were also noted. A core‐needle biopsy confirmed the diagnostic features of brown tumor of hyperparathyroidism. Diagn. Cytopathol. 2009. © 2008 Wiley‐Liss, Inc.
Current utilization of breast FNA in a cytology practice
Authors: Simsir Aylin , Rapkiewicz Amy , Cangiarella Joan
Published: November 2008

Over the past decade, core biopsy rapidly replaced fine needle aspiration (FNA) in evaluation of diseases of the female breast in many centers in the USA. The inability to diagnose invasive cancer by FNA, and the general feeling of unease in interpretation of cytologic specimens among pathologists who are not trained in cytopathology are among factors leading to decline in the use of FNA. At our institution, we continue to rely heavily on FNA for evaluation of breast masses. In this article, we discuss our multidisciplinary team approach which is essential in sustaining a successful breast cancer screening program. We also review the general utility of breast FNA and core biopsy in a comparative fashion. In the second part of this article which will appear in an upcoming issue, we will review the use of FNA and core biopsy in challenging breast lesions focusing on the pitfalls and limitations of both modalities in selected specific lesions. Diagn. Cytopathol. 2009. © 2008 Wiley‐Liss, Inc.
Decentralized ℋ︁∞ controller design for large‐scale civil structures
Authors: Wang Yang , Lynch Jerome P. , Law Kincho H.
Published: November 2008

Complexities inherent to large‐scale modern civil structures pose many challenges in the design of feedback structural control systems for dynamic response mitigation. With the emergence of low‐cost sensors and control devices creating technologies from which large‐scale structural control systems can deploy, a future control system may contain hundreds, or even thousands, of such devices. Key issues in such large‐scale structural control systems include reduced system reliability, increasing communication requirements, and longer latencies in the feedback loop. To effectively address these issues, decentralized control strategies provide promising solutions that allow control systems to operate at high nodal counts.

This paper examines the feasibility of designing a decentralized controller that minimizes the ℋ︁∞ norm of the closed‐loop system. ℋ︁∞ control is a natural choice for decentralization because imposition of decentralized architectures is easy to achieve when posing the controller design using linear matrix inequalities. Decentralized control solutions are investigated for both continuous‐time and discrete‐time ℋ︁∞ formulations. Numerical simulation results using a 3‐story and a 20‐story structure illustrate the feasibility of the different decentralized control strategies. The results also demonstrate that when realistic semi‐active control devices are used in combination with the decentralized ℋ︁∞ control solution, better performance can be gained over the passive control cases. It is shown that decentralized control strategies may provide equivalent or better control performance, given that their centralized counterparts could suffer from longer sampling periods due to communication and computation constraints. Copyright © 2008 John Wiley & Sons, Ltd.
Use of medications with anticholinergic properties and cognitive function in a young‐old community sample
Authors: Low Lee‐Fay , Anstey Kaarin J. , Sachdev Perminder
Published: November 2008

Objectives

To examine whether anticholinergic medications have effects on the level of cognitive function or cognitive decline in persons in their early to mid 60s.

Methods

A randomly selected community‐based sample of 2058 persons aged 60–64 at baseline was interviewed twice over four years. Anticholinergic medication use was determined from self‐report medication data using the Anticholinergic Drug Scale. Cognition was assessed with the California Verbal Learning Test I (one trial), Digits Backwards, the Symbol Digit Modalities Test, the Mini‐Mental State Exam and simple and choice reaction time. Persons meeting criteria for Mild Cognitive Impairment were identified in a clinical substudy. Mixed models adjusting for age, sex, self‐rated depression and physical health, and total number of medications were used to analyse the data.

Results

There was a significant main effect of anticholinergic group averaged across time for the Symbol Digits Modalities Test with poorer performance among anticholinergic medication users. Main effects for the other cognitive tests and mild cognitive impairment were non‐significant. No time by anticholinergic group interactions were significant.

Conclusions

This study suggests that exposure to anticholinergic medication is associated with lower level of complex attention in the young‐old, but not with greater cognitive decline over time. Although the clinical significance of this is not clear, caution should be taken when prescribing medications with anticholinergic effects to older persons. Copyright © 2008 John Wiley & Sons, Ltd.
Early serum HBsAg drop: A strong predictor of sustained virological response to pegylated interferon alfa-2a in HBeAg-negative patients #
Authors: Moucari Rami , Mackiewicz Vincent , Lada Olivier , Ripault Marie-Pierre , Castelnau Corinne , Martinot-Peignoux Michelle , Dauvergne Agnes , Asselah Tarik , Boyer Nathalie , Bedossa Pierre , Valla Dominique , Vidaud Michel , Nicolas-Chanoine Marie-Hélène , Marcellin Patrick
Published: November 2008

Pegylated interferon alfa-2a (PEG-IFN) may induce sustained virological response (SVR) in 20% of hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB) patients. In addition, loss of hepatitis B surface antigen (HBsAg) is achieved with a 10% yearly rate after treatment cessation in sustained responders. The aim of this study was to assess on-treatment serum HBsAg kinetics to predict SVR in HBeAg-negative patients treated with PEG-IFN. Forty-eight consecutive patients were treated with PEG-IFN (180 μg/week) for 48 weeks. Serum hepatitis B virus (HBV) DNA (COBAS TaqMan) and HBsAg (Abbott Architect HBsAg QT assay) were assessed at baseline, during treatment (weeks 12, 24, and 48), and during follow-up (weeks 72 and 96). SVR was defined as undetectable serum HBV DNA (<70 copies/mL) 24 weeks after treatment cessation. Twenty-five percent of patients achieved SVR. They were not different from those who failed treatment regarding age, sex, ethnicity, HBV genotype, baseline serum HBV DNA and HBsAg levels, or liver histology. During treatment, serum HBsAg levels decreased only in patients who developed SVR, with mean decreases of 0.8 ± 0.5, 1.5 ± 0.6, and 2.1 ± 1.2 log10 IU/mL at weeks 12, 24, and 48, respectively. A decrease of 0.5 and 1 log10 IU/mL in serum HBsAg levels at weeks 12 and 24 of therapy, respectively, had high predictive values of SVR (negative predictive value [NPV] 90%, positive predictive value [PPV] 89% for week 12; NPV 97%, PPV 92% for week 24). HBsAg loss was observed in three patients, all with SVR. Conclusion: Early serum HBsAg drop has high predictive values of SVR to PEG-IFN in HBeAg-negative CHB patients. Serum quantitative HBsAg may be a useful tool to optimize the management of PEG-IFN therapy in these patients. (Hepatology 2009.)
Radiologic–pathologic correlation of hepatocellular carcinoma treated with internal radiation using yttrium-90 microspheres #
Authors: Riaz Ahsun , Kulik Laura , Lewandowski Robert J. , Ryu Robert K. , Giakoumis Spear Georgia , Mulcahy Mary F. , Abecassis Michael , Baker Talia , Gates Vanessa , Nayar Ritu , Miller Frank H. , Sato Kent T. , Omary Reed A. , Salem Riad
Published: November 2008

We present the correlation between radiologic and pathologic findings in HCC patients who underwent radioembolization with yttrium-90 (90Y) microspheres prior to resection or transplantation. Thirty-five patients with a total of 38 lesions who underwent liver explantation after 90Y radioembolization were studied. Imaging surrogates following treatment were evaluated; the explants were examined for assessment of necrosis by pathology. The correlation betwen radiologic and histologic findings of the treated lesions was analyzed. Twenty-three of 38 (61%) target lesions showed complete pathologic necrosis. All target lesions demonstrated some degree of histologic necrosis at explant. Complete histologic necrosis was seen in 89% of lesions with pretreatment size <3 cm. Complete pathologic necrosis was seen in 100%, 78%, and 93% of the lesions that were shown to have complete response by European Association for the Study of the Liver (EASL) necrosis criteria, partial response by World Health Organizaton (WHO) criteria, or thin rim enhancement on posttreatment imaging, respectively. In contrast, complete pathologic necrosis was seen in only 52% and 38% of the lesions that showed partial response by EASL criteria and peripheral nodular enhancement, respectively. Conclusion: Post-radioembolization imaging findings of response by EASL and WHO criteria are predictive of the degree of pathologic necrosis. Rim enhancement was an imaging characteristic that correlated well with histologic necrosis. (Hepatology 2009.)
Differential microRNA expression between hepatitis B and hepatitis C leading disease progression to hepatocellular carcinoma #
Authors: Ura Shunsuke , Honda Masao , Yamashita Taro , Ueda Teruyuki , Takatori Hajime , Nishino Ryuhei , Sunakozaka Hajime , Sakai Yoshio , Horimoto Katsuhisa , Kaneko Shuichi
Published: November 2008

MicroRNA (miRNA) plays an important role in the pathology of various diseases, including infection and cancer. Using real-time polymerase chain reaction, we measured the expression of 188 miRNAs in liver tissues obtained from 12 patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) and 14 patients with hepatitis C virus (HCV)-related HCC, including background liver tissues and normal liver tissues obtained from nine patients. Global gene expression in the same tissues was analyzed via complementary DNA microarray to examine whether the differentially expressed miRNAs could regulate their target genes. Detailed analysis of the differentially expressed miRNA revealed two types of miRNA, one associated with HBV and HCV infections (n = 19), the other with the stage of liver disease (n = 31). Pathway analysis of targeted genes using infection-associated miRNAs revealed that the pathways related to cell death, DNA damage, recombination, and signal transduction were activated in HBV-infected liver, and those related to immune response, antigen presentation, cell cycle, proteasome, and lipid metabolism were activated in HCV-infected liver. The differences in the expression of infection-associated miRNAs in the liver correlated significantly with those observed in Huh7.5 cells in which infectious HBV or HCV clones replicated. Out of the 31 miRNAs associated with disease state, 17 were down-regulated in HCC, which up-regulated cancer-associated pathways such as cell cycle, adhesion, proteolysis, transcription, and translation; 6 miRNAs were up-regulated in HCC, which down-regulated anti-tumor immune response. Conclusion: miRNAs are important mediators of HBV and HCV infection as well as liver disease progression, and therefore could be potential therapeutic target molecules. (Hepatology 2009.)
Thyroid hormone receptor ligands induce regression of rat preneoplastic liver lesions causing their reversion to a differentiated phenotype #
Authors: Perra Andrea , Kowalik Marta Anna , Pibiri Monica , Ledda-Columbano Giovanna M. , Columbano Amedeo
Published: November 2008

Triiodothyronine (T3), through interaction with its intracellular thyroid hormone receptors (TRs), influences various physiological functions, including metabolism, development, and growth. We investigated the effect of T3 and the selective TR-β agonist GC-1 in two models of hepatocarcinogenesis. Preneoplastic lesions were induced in F-344 rats via a single dose of diethylnitrosamine, followed by a choline-deficient (CD) diet for 10 weeks. Rat subgroups were then fed the CD diet or a CD diet containing either 4 mg/kg T3 or 5 mg/kg GC-1 for another week. Rats fed a CD diet alone showed a large number (65/cm2) of preneoplastic lesions positive for the placental form of glutathione S-transferase (GSTP). Coadministration of T3 for the last week caused an almost complete disappearance of the foci (3/cm2). A reduction of GSTP-positive foci was also observed in rats fed a CD + GC-1 diet (28/cm2 versus 75/cm2 of rats fed a CD diet alone) in the absence of significant differences in labeling or apoptotic index of preneoplastic hepatocytes between the two groups. An antitumoral effect of GC-1 was also observed with the resistant hepatocyte model of hepatocarcinogenesis. Nodule regression was associated with a return to a fully differentiated phenotype, indicated by the loss of the fetal markers GSTP and gamma glutamyl transpeptidase, and reacquisition of the activity of glucose 6-phosphatase and adenosine triphosphatase, two enzymes expressed in normal hepatocytes. Conclusion: Our results indicate that activated TRs negatively influence the carcinogenic process through induction of a differentiation program of preneoplastic hepatocytes. The results also suggest that TRs could be a meaningful target in liver cancer therapy. (Hepatology 2009.)
A metric for space
Authors: Moser Edvard I. , Moser May‐Britt
Published: November 2008

Not all areas of neuronal systems investigation have matured to the stage where computation can be understood at the microcircuit level. In mammals, insights into cortical circuit functions have been obtained for the early stages of sensory systems, where signals can be followed through networks of increasing complexity from the receptors to the primary sensory cortices. These studies have suggested how neurons and neuronal networks extract features from the external world, but how the brain generates its own codes, in the higher‐order nonsensory parts of the cortex, has remained deeply mysterious. In this terra incognita, a path was opened by the discovery of grid cells, place‐modulated entorhinal neurons whose firing locations define a periodic triangular or hexagonal array covering the entirety of the animal's available environment. This array of firing is maintained in spite of ongoing changes in the animal's speed and direction, suggesting that grid cells are part of the brain's metric for representation of space. Because the crystal‐like structure of the firing fields is created within the nervous system itself, grid cells may provide scientists with direct access to some of the most basic operational principles of cortical circuits. © 2008 Wiley‐Liss, Inc.
Grid cells and theta as oscillatory interference: Electrophysiological data from freely moving rats
Authors: Jeewajee A. , Barry C. , O'Keefe J. , Burgess N.
Published: November 2008

The oscillatory interference model (Burgess et al. (2007) Hippocampus 17:801–812) explains the generation of spatially stable, regular firing patterns by medial entorhinal cortical (mEC) grid cells in terms of the interference between velocity‐controlled oscillators (VCOs) with different preferred directions. This model predicts specific relationships between the intrinsic firing frequency and spatial scale of grid cell firing, the EEG theta frequency, and running speed (Burgess,2008). Here, we use spectral analyses of EEG and of spike autocorrelograms to estimate the intrinsic firing frequency of grid cells, and the concurrent theta frequency, in mEC Layer II in freely moving rats. The intrinsic firing frequency of grid cells increased with running speed and decreased with grid scale, according to the quantitative prediction of the model. Similarly, theta frequency increased with running speed, which was also predicted by the model. An alternative Moiré interference model (Blair et al.,2007) predicts a direction‐dependent variation in intrinsic firing frequency, which was not found. Our results suggest that interference between VCOs generates the spatial firing patterns of entorhinal grid cells according to the oscillatory interference model. They also provide specific constraints on this model of grid cell firing and have more general implications for viewing neuronal processing in terms of interfering oscillatory processes. © 2008 Wiley‐Liss, Inc.
Grid cell mechanisms and function: Contributions of entorhinal persistent spiking and phase resetting
Authors: Hasselmo Michael E.
Published: November 2008

This article presents a model of grid cell firing based on the intrinsic persistent firing shown experimentally in neurons of entorhinal cortex. In this model, the mechanism of persistent firing allows individual neurons to hold a stable baseline firing frequency. Depolarizing input from speed‐modulated head direction cells transiently shifts the frequency of firing from baseline, resulting in a shift in spiking phase in proportion to the integral of velocity. The convergence of input from different persistent firing neurons causes spiking in a grid cell only when the persistent firing neurons are within similar phase ranges. This model effectively simulates the two‐dimensional firing of grid cells in open field environments, as well as the properties of theta phase precession. This model provides an alternate implementation of oscillatory interference models. The persistent firing could also interact on a circuit level with rhythmic inhibition and neurons showing membrane potential oscillations to code position with spiking phase. These mechanisms could operate in parallel with computation of position from visual angle and distance of stimuli. In addition to simulating two‐dimensional grid patterns, models of phase interference can account for context‐dependent firing in other tasks. In network simulations of entorhinal cortex, hippocampus, and postsubiculum, the reset of phase effectively replicates context‐dependent firing by entorhinal and hippocampal neurons during performance of a continuous spatial alternation task, a delayed spatial alternation task with running in a wheel during the delay period (Pastalkova et al., Science, 2008), and a hairpin maze task. © 2008 Wiley‐Liss, Inc.
How heterogeneous place cell responding arises from homogeneous grids—A contextual gating hypothesis
Authors: M. Hayman Robin , Jeffery Kathryn J.
Published: November 2008

How entorhinal grids generate hippocampal place fields remains unknown. The simplest hypothesis—that grids of different scales are added together—cannot explain a number of place field phenomena, such as (1) Summed grids form a repeating, dispersed activation pattern whereas place fields are focal and nonrepeating; (2) Grid cells are active in all environments but place cells only in some, and (3) Partial environmental changes cause either heterogeneous (“partial”) remapping in place cells whereas they result in all‐or‐nothing “realignment” remapping in grid cells. We propose that this dissociation between grid cell and place cell behavior arises in the entorhinal‐dentate projection. By our view, the grid‐cell/place‐cell projection is modulated by context, both organizationally and activationally. Organizationally, we propose that when the animal first enters a new environment, the relatively homogeneous input from the grid cells becomes spatially clustered by Hebbian processes in the dendritic tree so that inputs active in the same context and having overlapping fields come to terminate on the same sub‐branches of the tree. Activationally, when the animal re‐enters the now‐familiar environment, active contextual inputs select (by virtue of their clustered terminations) which parts of the dendritic tree, and therefore which grid cells, drive the granule cell. Assuming this pattern of projections, our model successfully produces focal hippocampal place fields that remap appropriately to contextual changes. © 2008 Wiley‐Liss, Inc.
Effect of moisture sorption of underwear material on clothing microclimate in a hot environment
Authors: Satsumoto Yayoi , Murayama Chikako , Takeuchi Masaaki
Published: November 2008

In this study, to investigate the thermal comfort of underwear, it was experimentally evaluated how the moisture sorption of underwear material affected the transient condition on the clothing microclimate under the summer heat environment by using a perspiration thermal manikin. Three kinds of underwear with different mixed spinning rates of moisture absorbing synthetic fiber (MAS) were compared. It was shown that the higher the mixed spinning rate of MAS, the larger the decline of the humidity in the clothing was in insensible perspiration. In comparison, for PET70 with 100% cotton (COT100), though each of the official moisture regions was almost the same, the microclimate humidity declined more rapidly in COT100 and returned to the original humidity in a shorter time. The integration value of the humidity decline which returned to the original value was the same between the two materials. To show the effect of the initial condition of the material, the underwear in a moderate humid condition, which was 30°C, 65% RH, was compared with one in a dry condition. The fall in the clothing microclimate of the humid condition was about one third that of the dry one. In sensible perspiration, though the humidity decline was seen, it returned to the original humidity faster than in the insensible condition. A temperature rise in the clothing and a temperature drop occurred as frequently as in the standard underwear during drying on the skin surface. This suggested that the endothermic reaction occurred as moisture desorbed. © 2008 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20220
Transfer of carbon dioxide and methane through the soil‐water‐atmosphere system at Mer Bleue peatland, Canada
Authors: Dinsmore Kerry J. , Billett Mike F. , Moore Tim R.
Published: November 2008

Surface waters associated with peatlands, supersaturated with CO2 and CH4 with respect to the atmosphere, act as important pathways linking a large and potentially unstable global repository of C to the atmosphere. Understanding the drivers and mechanisms which control C release from peatland systems to the atmosphere will contribute to better management and modelling of terrestrial C pools. We used non‐dispersive infra‐red (NDIR) CO2 sensors to continuously measure gas concentrations in a beaver pond at Mer Bleue peatland (Canada); measurements were made between July and August 2007. Concentrations of CO2 in the surface water (10 cm) reached 13 mg C l−1 (epCO2 72), and 26 mg C l−1 (epCO2 133) at depth (60 cm). The study also showed large diurnal fluctuations in dissolved CO2 which ranged in amplitude from ∼1·6 mg C l−1 at 10 cm to ∼0·2 mg C l−1 at 60 cm depth. CH4 concentration and supersaturation (epCH4) measured using headspace analysis averaged 1·47 mg C l−1 and 3252, respectively; diurnal cycling was also evident in CH4 concentrations. Mean estimated evasion rates of CO2 and CH4 over the summer period were 44·92 ± 7·86 and 0·44 ± 0·25 µg C m−2s−1, respectively. Open water at Mer Bleue is a significant summer hotspot for greenhouse gas emissions within the catchment. Our results suggest that CO2 concentrations during the summer in beaver ponds at Mer Bleue are strongly influenced by biological processes within the water column involving aquatic plants and algae (in situ photosynthesis and respiration). In terms of carbon cycling, soil‐stream connectivity at this time of year is therefore relatively weak. Copyright © 2008 John Wiley & Sons, Ltd.
Temporal variability of selected dissolved elements in the lower Orinoco River, Venezuela
Authors: Mora Abrahan , Alfonso Juan A. , Sánchez Luzmila , Calzadilla Malvis , Silva Soraya , LaBrecque John J. , Azócar José A.
Published: November 2008

Monthly analyses of pH, conductance, alkalinity, total suspended solids, dissolved major cations (Na, K, Ca and Mg), and selected dissolved trace elements (Fe, Al, Mn, Cu, Zn and Cr) were conducted on waters of the lower Orinoco River from February 2004 to May 2006. The data show strong seasonal variability. Major cations had maximum concentrations at low water, and were correlated with pH, conductance and alkalinity because of the tributaries coming from the Andean zones, where the weathering of evaporites and carbonate shales controls water chemistry. K concentrations did not show any relation with evaporite weathering, probably because large amounts of K come from the Guayana Shield rivers as a consequence of feldspar weathering. The concentrations of dissolved Fe, Mn and Cu were highest during the high water stage. Concentrations of the elements K, Cr, Zn and Cu are correlated with each other but not with dissolved Fe and Al, which probably are complexed with humic and fulvic substances. Mn concentrations did not show relationships with other variables. Inter‐annual variability of dissolved elements is explained by temporal changes in precipitation. Copyright © 2008 John Wiley & Sons, Ltd.
Improving hydrological information acquisition from DEM processing in floodplains
Authors: Getirana Augusto C. V. , Bonnet Marie‐Paule , Rotunno Filho Otto C. , Mansur Webe J.
Published: November 2008

Extraction of hydrological information from digital elevation models (DEMs) is a required step when conducting any spatially distributed hydrological modelling. In particular, automated methods are proposed to extract the drainage structure from the DEM. However, a realistic river network is not always derived from conventional DEM processing methods. Indeed, inaccuracy occurs in flat areas corresponding to floodplains. In these areas, additional sources of information are required to extract the correct drainage direction from the DEM. In this study, it is demonstrated that traditional approaches of DEM‐preprocessing such as the commonly known ‘stream burning’ fail to provide correct maps of drainage directions and catchment areas when the extension of flat areas is large. A new method is proposed to take advantage of available imagery data. This method is based on a ‘double DEM burning’ process: DEM is first burned in the main rivers using the channel network, and then in the floodplain using the spatial distribution of floodplains provided by classified satellite images. In this sense, the method has been referred to as the floodplain burning approach (or simply FB approach). Spatial distribution of floodplains is derived from a multitemporal SAR image classification. A system of equations is used to vary the elevation offset required to be ‘burnt’ in each cell representing the floodplain, according to the minimal distance from the channel network, which is calculated by a distance transformation. The FB approach was applied to a sub‐basin located within the larger Amazon River basin. The region is characterized by large floodplain extensions. Basin delineation maps derived from the new method were compared with those obtained from the traditional stream burning method and highlighted more realistic results. Copyright © 2008 John Wiley & Sons, Ltd.
Proteomic profiling in pancreatic cancer with and without lymph node metastasis
Authors: Cui Yazhou , Wu Jianmei , Zong Meijuan , Song Guanhua , Jia Qing , Jiang Jinbo , Han Jinxiang
Published: November 2008

The aim of the study was to observe different protein profiles in pancreatic cancer with and without lymph node metastasis (LNM), and search for novel LNM‐associated proteins, which would help to understand the metastatic mechanisms and provide targets for therapeutic interventions. Cancer nests were manually miscrodissected from 8 LNM and 7 non‐LNM pancreatic cancer tissues, and the protein extracts were then separated by difference gel electrophoresis (DIGE) and identified by MALDI‐TOF‐TOF. Four differently regulated proteins, ezrin, radixin, moesin, and c14orf166, were selected for further validation by Western blot and immunohistochemistry. In DIGE analysis, we identified 18 up‐regulated proteins and 15 down‐regulated proteins in LNM pancreatic cancer nests compared with non‐LNM ones. Western blot and immunohistochemical analyses confirmed that radixin, moesin and c14orf166, but not ezrin, had significantly higher expression levels in LNM pancreatic cancers than in non‐LNM controls. In conclusion, the specific protein profiles found in this study might provide new insights into the mechanism of lymph node metastasis. For the first time, c14orf166 was identified asa novel metastasis‐associated protein, and the roles of radixin, moesin and c14orf166 in cancer metastasis deserve further investigations. © 2008 Wiley‐Liss, Inc.
Identification of a rhabdomyosarcoma targeting peptide by phage display with sequence similarities to the tumour lymphatic‐homing peptide LyP‐1
Authors: Witt Hendrik , Hajdin Katarina , Iljin Kristina , Greiner Oliver , Niggli Felix K. , Schäfer Beat W. , Bernasconi Michele
Published: November 2008

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. To improve existing therapies and broaden the spectrum of cytotoxic agents that can be used in RMS treatment, we performed a phage‐display‐based screening for peptides that bind specifically to RMS cells. Two peptides binding to RMS and to other tumour cell lines, but not to normal skeletal muscle cells and fibroblasts, were isolated from phage‐displayed random peptide libraries. One peptide, named RMS‐I (CQQSNRGDRKRC) contained the integrin‐binding motif RGD and its binding was blocked by an antibody against αvβ3integrin, which is expressed on the RMS cell line RD. The isolation of RMS‐I confirmed the validity of our screening procedure. The second peptide, named RMS‐II (CMGNKRSAKRPC), shows sequence similarity to a previously identified peptide with tumour lymphatic specificity, LyP‐1. However, RMS‐II binds in vivo to RMS xenografts better than LyP‐1 and homes to the tumour blood and not to lymphatic vessels. Therefore, RMS‐II represents a promising peptide for the development of RMS‐specific targeting approaches. © 2008 Wiley‐Liss, Inc.
In vitro estrogenicity of ambient particulate matter: contribution of hydroxylated polycyclic aromatic hydrocarbons
Authors: Wenger Daniela , Gerecke Andreas C. , Heeb Norbert V. , Schmid Peter , Hueglin Christoph , Naegeli Hanspeter , Zenobi Renato
Published: November 2008

Atmospheric particulate matter (PM1) was collected at an urban and a rural site in Switzerland during a hibernal high air pollution episode and was investigated for estrogenicity using an estrogen‐sensitive reporter gene assay (ER‐CALUX). All samples that were tested induced estrogen receptor‐mediated gene expression in T47D human breast adenocarcinoma cells. Observed estrogenic activities corresponded to 17β‐estradiol (E2) CALUX equivalent concentrations ranging from 2 to 23 ng E2‐CEQ per gram of PM1 (particulate matter of ≤ 1 µm aerodynamic diameter) and from 0.07 to 1.25 pg E2‐CEQ per m3 of sampled air. There was a strong correlation between the PM1 estrogenicity of the urban and rural sites (r = 0.92). Five hydroxylated polycyclic aromatic hydrocarbons (hydroxy‐PAHs), which show structural similarities to E2, were assessed for their estrogenic activity. The following order of estrogenic potency was found: 2‐hydroxychrysene > 2‐hydroxyphenanthrene > 1‐hydroxypyrene > 2‐hydroxynaphthalene > 1‐hydroxynaphthalene. Three of these hydroxy‐PAHs, namely 2‐hydroxyphenanthrene, 2‐hydroxynaphthalene and 1‐hydroxynaphthalene, were detected in all PM1 extracts. However, they contributed only 0.01–0.2% to the overall estrogenic activity. Hence, mainly other estrogenic compounds not yet identified by chemical analysis must be responsible for the observed activity. The temporal trend of PM1 estrogenicity at the urban and rural site, respectively, was compared with the time course of several air pollutants (NO2, NO, SO2, O3, CO) and meteorological parameters (temperature, humidity, air pressure, solar irradiation, wind velocity). However, specific emission sources and formation processes of atmospheric xenoestrogens could not be elucidated. This study showed that ambient particulate matter contains compounds that are able to interact with estrogen receptors in vitro and potentially also interfere with estrogen‐regulated pathways in vivo. Copyright © 2008 John Wiley & Sons, Ltd.
In vitroandin vivoimaging of xenobiotic transport in human skin and in the rat liver
Authors: Roberts Michael S. , Roberts Matthew J. , Robertson Thomas A. , Sanchez Washington , Thörling Camilla , Zou Yuhong , Zhao Xin , Becker Wolfgang , Zvyagin Andrei V.
Published: November 2008

Multiphoton tomography was used to examine xenobiotic transportin vivo. We used the photochemical properties of zinc oxide and fluorescein and multiphoton tomography to study their transport in the skin and in the rat liverin vivo. Zinc oxide nanoparticles were visualised in human skin using the photoluminescence properties of zinc oxide and either a selective emission wavelength band pass filter or a filter with fluorescence lifetime imaging (FLIM). Zinc oxide nanoparticles (30 nm) did not penetrate into human skinin vitroandin vivoand this was validated by scanning electron microscopy with X‐ray photoelectron spectroscopy. Fluorescein was measured in the liver using FLIM. Fluorescein is rapidly extracted from the blood into the liver cells and then transported into the bile. It is suggested that multiphoton tomography may be of particular use in definingin vivo4D (in both space and time) pharmacokinetics. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Oncoprotein BMI‐1 induces the malignant transformation of HaCaT cells
Authors: Wang Qian , Li Wen‐Lin , You Pu , Su Juan , Zhu Ming‐Hua , Xie Dong‐Fu , Zhu Hai‐Yin , He Zhi‐Ying , Li Jian‐Xiu , Ding Xiao‐Yan , Wang Xin , Hu Yi‐Ping
Published: November 2008

BMI‐1 (B‐cell‐specific Moloney murine leukemia virus integration site 1), a novel oncogene, has attracted much attention in recent years for its involvement in the initiation of a variety of tumors. Recent evidence showed that BMI‐1 was highly expressed in neoplastic skin lesions. However, whether dysregulated BMI‐1 expression is causal for the transformation of skin cells remains unknown. In this study, we stably expressed BMI‐1 in a human keratinocyte cell line, HaCaT. The expression of wild‐type BMI‐1 induced the malignant transformation of HaCaT cells in vitro. More importantly, we found that expression of BMI‐1 promoted formation of squamous cell carcinomas in vivo. Furthermore, we showed that BMI‐1 expression led to the downregulation of tumore suppressors, such as p16INK4a and p14ARF, cell adhesion molecules, such as E‐Cadherin, and differentiation related factor, such as KRT6. Therefore, our findings demonstrated that dysregulated BMI‐1 could indeed lead to keratinocytes transformation and tumorigenesis, potentially through promoting cell cycle progression and increasing cell mobility. J. Cell. Biochem. 106: 16–24, 2009. © 2008 Wiley‐Liss, Inc.
The culture of neural stem cells
Authors: Ahmed Sohail
Published: November 2008

A stem cell has three important features. Firstly, the ability of self‐renewal: making identical copies of itself. Secondly, multipotency, generating all the major cell lineages of the host tissue (in the case of embryonic stem cells—pluripotency). Thirdly, the ability to generate/regenerate tissues. Thus, the study of stem cells will help unravel the complexity of tissue development and organisation, and will also have important clinical applications. Neural stem cells (NSCs) are present during embryonic development and in certain regions of the adult central nervous system (CNS). Mobilizing adult NSCs to promote repair of injured or diseased CNS is a promising approach. Since NSCs may give rise to brain tumor, they represent in vitro models for anti‐cancer drug screening. To facilitate the use of NSCs in clinical scenarios, we need to explore the biology of these cells in greater details. One clear goal is to be able to definitively identify and purify NSCs. The neurosphere‐forming assay is robust and reflects the behavior of NSCs. Clonal analysis where single cells give rise to neurospheres need to be used to follow the self‐renewal and multipotency characteristics of NSCs. Neurosphere formation in combination with other markers of NSC behavior such as active Notch signaling represents the state of the art to follow these cells. Many issues connected with NSC biology need to be explored to provide a platform for clinical applications. Important future directions that are highlighted in this review are; identification of markers for NSCs, the use of NSCs in high‐throughput screens and the modelling of the central nervous development. There is no doubt that the study of NSCs is crucial if we are to tackle the diseases of the CNS such as Parkinson's and Alzheimer's. J. Cell. Biochem. 106: 1–6, 2009. © 2008 Wiley‐Liss, Inc.