bluuebunny/crossref_metadata_2025_split huggingface dataset:
OCT4: biological functions and clinical applications as a marker of germ cell neoplasia
Authors: Cheng L , Sung M‐T , Cossu‐Rocca P , Jones TD , MacLennan GT , De Jong J , Lopez‐Beltran A , Montironi R , Looijenga LHJ 
Published: November 2006

AbstractGerm cell tumours (GCTs) are a heterogeneous group of neoplasms, which develop in the gonads as well as in extragonadal sites, that share morphological patterns and an overall good prognosis, owing to their responsiveness to current surgical, chemotherapeutic, and radiotherapeutic measures. GCTs demonstrate extremely interesting biological features because of their close relationships with normal embryonal development as demonstrated by the pluripotentiality of some undifferentiated GCT variants. The similarities between GCTs and normal germ cell development have made it possible to identify possible pathogenetic pathways in neoplastic transformation and progression of GCTs. Genotypic and immunophenotypic profiles of these tumours are also useful in establishing and narrowing the differential diagnosis in cases of suspected GCTs. Recently, OCT4 (also known as OCT3 or POU5F1), a transcription factor that has been recognized as fundamental in the maintenance of pluripotency in embryonic stem cells and primordial germ cells, has been proposed as a useful marker for GCTs that exhibit features of pluripotentiality, specifically seminoma/dysgerminoma/germinoma and embryonal carcinoma. The development of commercially available OCT4‐specific antibodies suitable for immunohistochemistry on paraffin‐embedded specimens has generated increasing numbers of reports of OCT4 expression in a wide variety of gonadal and extragonadal GCTs. OCT4 immunostaining has been shown to be a sensitive and specific marker for seminomatous/(dys)germinomatous tumours and in embryonal carcinoma variants of non‐seminomatous GCTs, whether in primary gonadal or extragonadal sites or in metastatic lesions. Therefore, OCT4 immunohistochemistry is an additional helpful marker both in the differential diagnosis of specific histological subtypes of GCTs and in establishing a germ cell origin for some metastatic tumours of uncertain primary. OCT4 expression has also been reported in pre‐invasive conditions such as intratubular germ cell neoplasia, unclassified (IGCNU) and the germ cell component of gonadoblastoma. Additionally, OCT4 immunostaining shows promise as a useful tool in managing patients known to be at high risk for the development of invasive GCTs. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Psychological distress and concerns of elderly patients treated with palliative radiotherapy for lung cancer
Authors: Turner N. J. , Muers M. F. , Haward R. A. , Mulley G. P. 
Published: November 2006

AbstractWe conducted a prospective observational cohort study of 83 elderly patients (aged 75 and above) being treated with palliative radiotherapy for lung cancer, with a comparison group of 49 younger patients (aged 65 and under). Psychological distress and concerns were measured before and after treatment using the Hospital Anxiety and Depression Scale (HADS) and a Concerns Checklist.Psychosocial morbidity was common, however, prevalence was similar in both age groups. There was a trend towards worsening of both anxiety and depression scores after treatment, but this did not reach statistical significance. Younger patients reported more concerns than the older group (median 12 vs 10) but this too was not statistically significant. Concerns about the illness and symptoms were more likely to have been addressed by the care team than were concerns about psychosocial issues such as the family and the future.People of all ages have similar concerns and levels of anxiety and depression whilst receiving palliative radiotherapy for lung cancer. Further research is needed to explore the use of screening tools, like those used in this study, to identify patients' difficulties and target interventions to improve their quality of life. Copyright © 2006 John Wiley & Sons, Ltd.
Nitrite‐assisted peptide iodination and conjugation
Authors: Deng Haiteng 
Published: November 2006

AbstractIn this study, a simple method for selective iodination of peptides and proteins is established. Using angiotensin II as the model system, we demonstrate that nitrite catalyzed the selective iodination of the peptide at the N‐terminus in an acidic solution. The N‐terminal‐iodinated peptides alkylated thiol‐containing molecules such as N‐acetylcysteine and glutathione to form peptide conjugates in a basic solution. Reactive species formed by increasing the pH of the reaction mixture of sodium nitrite and sodium iodide from 4 to 8 selectively iodinated peptides and proteins at tyrosine and histidine residues. These results show that nitrite is a useful catalyst for peptide and protein ligation. Copyright © 2006 European Peptide Society and John Wiley & Sons, Ltd.
Soft Coulomb hole method applied to molecules
Authors: Ortega‐Castro J. , Alfonso‐Méndez L. , Otto P. , Hernández‐Laguna A. 
Published: November 2006

AbstractThe soft Coulomb hole method introduces a perturbation operator, defined by −e/r12to take into account electron correlation effects, where ω represents the width of the Coulomb hole. A new parametrization for the soft Coulomb hole operator is presented with the purpose of obtaining better molecular geometries than those resulting from Hartree–Fock calculations, as well as correlation energies. The 12 parameters included in ω were determined for a reference set of 12 molecules and applied to a large set of molecules (38 homo‐ and heteronuclear diatomic molecules, and 37 small and medium‐size molecules). For these systems, the optimized geometries were compared with experimental values; correlation energies were compared with results of the MP2, B3LYP, and Gaussian 3 approach. On average, molecular geometries are better than the Hartree–Fock values, and correlation energies yield results halfway between MP2 and B3LYP. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Density functional theory study of the interaction between formamide and uracil
Authors: Duan Chunsheng , Wu Qunyan , Ma Hongkun , Zhou Xinming , Zhou Zhengyu 
Published: November 2006

AbstractThe hydrogen bonding of complexes formed between the formamide and uracil molecule has been fully investigated in the present study using the density functional theory (DFT) method at varied basis set levels from 6‐31G to 6‐311++G(d,p). Eight stable cyclic structures with two hydrogen bonds involved in the interaction are found on the potential energy surface (PES). The four structures are seven‐membered rings; the others are eight‐membered rings. The eight‐membered ring is preferred over the seven‐membered one by analyzing the hydrogen bond lengths and the interaction energies. The infrared (IR) spectrum frequencies, IR intensities, and the vibrational frequency shifts are reported. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Robust and efficient quantization and coding for control of multidimensional linear systems under data rate constraints
Authors: Li K. , Baillieul J. 
Published: November 2006

AbstractRecently, we reported results on coding strategies for scalar feedback systems with data‐rate‐limited feedback channels in which the data‐rate constraints are time varying. Such rate‐varying channels are typically encountered in communication networks in which links between nodes are subject to noise, congestion, and intermittent disruption.The present paper describes results of extending this research into the multidimensional domain. An important consideration is that for systems of dimension greater than one, many classical feedback designs cannot be realized for operation near the theoretical minimum possible data rate. A novel control coding scheme will be presented, and in terms of this, it will be shown that the advantages of coarse signal quantization that had been reported earlier for scalar systems remain in the multidimensional case. The key is to allocate the communication bandwidth efficiently among faster and slower modes. We discuss various strategies that allocate bandwidth by scheduling the time slots assigned to each mode. In particular, we propose a ‘robust attention varying’ technique, whose merit will be discussed in terms of its robustness with respect to time‐varying communication channel capacity and also in terms of how well it operates when the feedback channel capacity is near the theoretical minimum data rate. Copyright © 2006 John Wiley & Sons, Ltd.
Adaptive sensorless robust control of AC drives based on sliding mode control theory
Authors: Barambones O. , Garrido A. J. 
Published: November 2006

AbstractThis paper focuses in the design of a new adaptive sensorless robust control to improve the trajectory tracking performance of induction motors. The proposed design employs the so‐called vector (or field oriented) control theory for the induction motor drives, being the designed control law based on an integral sliding‐mode algorithm that overcomes the system uncertainties. This sliding‐mode control law incorporates an adaptive switching gain in order to avoid the need of calculating an upper limit for the system uncertainties. The proposed design also includes a new method in order to estimate the rotor speed. In this method, the rotor speed estimation error is presented as a first‐order simple function based on the difference between the real stator currents and the estimated stator currents.The stability analysis of the proposed controller under parameter uncertainties and load disturbances is provided using the Lyapunov stability theory. The simulated results show, on the one hand that the proposed controller with the proposed rotor speed estimator provides high‐performance dynamic characteristics, and on the other hand that this scheme is robust with respect to plant parameter variations and external load disturbances. Finally, experimental results show the performance of the proposed control scheme. Copyright © 2006 John Wiley & Sons, Ltd.
Estimation of attributable number of deaths and standard errors from simple and complex sampled cohorts
Authors: Graubard Barry I. , Flegal Katherine M. , Williamson David F. , Gail Mitchell H. 
Published: November 2006

AbstractEstimates of the attributable number of deaths (AD) from all causes can be obtained by first estimating population attributable risk (AR) adjusted for confounding covariates, and then multiplying the AR by the number of deaths determined from vital mortality statistics that occurred in the population for a specific time period. Proportional hazard regression estimates of adjusted relative hazards obtained from mortality follow‐up data from a cohort is combined with a joint distribution of risk factor and confounders to compute an adjusted AR. Two estimators of adjusted AR are examined. These estimators differ according to which reference population is used to obtain the joint distribution of risk factor and confounders. Two types of reference populations were considered: (i) the population represented by the baseline cohort and (ii) a population that is external to the cohort. Methods used in survey sampling are applied to obtain estimates of the variance of the AD estimator. These variances can be applied to data that range from simple random samples to multistage stratified cluster samples, which are used in national household surveys. The variance estimation of AD is illustrated in an analysis of excess deaths due to having a non‐ideal body mass index using the second National Health and Examination Survey (NHANES) Mortality Study and the 1999–2002 NHANES. These methods can also be used to estimate the attributable number of cause‐specific deaths and their standard errors when the time period for the accrual of deaths is short. Published in 2006 by John Wiley & Sons, Ltd.
Confidence intervals for the standardized effect arising in the comparison of two normal populations
Authors: Kulinskaya Elena , Staudte Robert G. 
Published: November 2006

AbstractConfidence intervals for a standardized effect are derived after stabilizing the variance of the Welch t‐statistic. Simulation studies demonstrate the viability of the resulting intervals for a wide range of parameter values and sample sizes as small as five. The methodology is extended to the combination of results from several studies, so as to obtain a confidence interval for a representative standardized effect for all the studies. The methods are illustrated on a recent meta‐analytic study of systolic blood pressure reduction during a weight reducing regime, as well as the classical Mumford data on psychological intervention and hospital length of stay. Copyright © 2006 John Wiley & Sons, Ltd.
Role of cyclic GMP signaling in the melanocyte response to hypergravity
Authors: Ivanova Krassimira , Block Ingrid , Das Pranab K. , Gerzer Rupert 
Published: November 2006

AbstractThe human skin acts as a first barrier of defense to protect the internal organs from various chemical and physical environmental stress factors like solar ultraviolet radiation (UV) and mechanical stimuli. Human melanocytes (located strategically in the basal layer of the skin epidermis) represent a crucial protective barrier against UV irradiation and oxidative stress by generating the radical‐scavenging pigment melanin. However, melanin is also known to act as a photosensitizer that generates active oxygen species upon UV irradiation, which may initiate pigmentary disorders like vitiligo due to loss of melanocytes as well as oncogenic melanocyte transformation. Melanocytes may further act as a protective immune barrier at the dermo‐epidermal junction and thus participate in immune surveillance. For melanocytes it is known that the second messenger cyclic guanosine‐3′,5′‐monophosphate (cGMP) plays a key role in UVB‐induced melanogenesis involving nitric oxide (NO) signaling. Moreover, cGMP is involved in NO‐induced perturbation of melanocyte‐extracellular matrix interactions that may lead to loss of melanocytes and support melanoma metastasis. In the frame of the current space exploration, investigations on the influence of altered gravity on melanocyte physiology are of special interest. As cGMP appears to play an important signaling role in melanocyte physiology, a brief overview is presented on the role of the guanylyl cyclase‐cGMP signaling, with a focus on the melanocyte response to hypergravity. An estimation of the gravity impact on melanocyte function may be of importance to asses the risk of astronauts to develop pigmentary disorders, particularly melanoma and other relevant skin cancers, during long‐term spaceflights.
Signal transduction in gravisensing of flagellates
Authors: Häder Donat‐P. , Richter Peter , Lebert Michael 
Published: November 2006

AbstractMany photosynthetic or heterotrophic flagellates, from various taxa, show positive, negative and, in some cases, transversal gravitaxis. Most flagellates are unicellular; however, they can form aggregates or colonies. Two species have been studied in more detail, Chlamydomonas and Euglena, which can serve as model systems. Earlier theories suggested that gravitaxis is caused by a buoy effect: The cell is tail‐heavy, and the propelling flagellum (flagella), inserting at the anterior end, pulls the organism upwards. Recent investigations, however, falsify these hypotheses and indicate the presence of an active, physiological graviperception mechanism, in some cases supported by a passive mechanism. In the photosynthetic Euglena, the cell body is heavier (1.04 g/mL) than the surrounding medium (water) and is assumed to exert pressure onto the lower membrane. The resulting force is believed to trigger mechano‐sensitive calcium‐specific ion channels. The molecular sensory transduction chain starts with the Ca influx which causes a depolarization of the membrane potential. The calcium is believed to bind to calmodulin which in turn activates an adenylyl cyclase. The produced cAMP is a secondary messenger and finally activates the flagellum reorientation. In Chlamydomonas, a mutant with defective mechano‐sensitive channels was found which is agravitactic, indicating that also in this flagellate gravitaxis is mediated by an active physiological receptor.
Topographical organization of GABAergic neurons within the ventral tegmental area of the rat
Authors: Olson Valerie G. , Nestler Eric J. 
Published: November 2006

AbstractThe ventral tegmental area (VTA), the origin of dopaminergic cell bodies that comprise the mesocorticolimibic DA system, is widely implicated in drug and natural reward, cognition, and several psychiatric disorders. In addition to dopaminergic neurons, this region is populated by GABAergic neurons, which both regulate the firing of their dopaminergic counterparts and send projections throughout the brain. Although the dopaminergic neurons of the VTA have been extensively characterized neuroanatomically, much less is known about the GABAergic neurons in this region. Recent data suggest that the rostro‐caudal topographic organization of these GABAergic neurons may correspond to their ability to regulate drug reward. In the present study, we used immunohistochemical techniques to examine the frequency and topography of GABAergic neurons throughout the rostro‐caudal axis of the VTA and the extent to which they coexpress other proteins, including tyrosine hydroxylase (a marker of DA neurons), cholecystokinin, parvalbumin, calretinin, and calbindin d 28k. Synapse 61:87–95, 2007. © 2006 Wiley‐Liss, Inc.
In vivo and in vitro measurement of brain phosphodiesterase 4 in rats after antidepressant administration
Authors: Fujita Masahiro , Imaizumi Masao , D'Sa Carrol , Zoghbi Sami S. , Crescenzo Matthew S. , Hong Jinsoo , Musachio John L. , Gee Antony D. , Seidel Jurgen , Green Michael V. , Pike Victor W. , Duman Ronald S. , Innis Robert B. 
Published: November 2006

AbstractBased largely on in vitro measurements, the mechanism of several antidepressant treatments is thought to involve upregulation of 3′‐5′‐cyclic adenosine monophosphate (cAMP) signal transduction cascade and a corresponding increase in phosphodiesterase (PDE) 4, the enzyme that metabolizes cAMP. To assess the in vivo status of PDE4, rats were chronically treated with imipramine and then studied with: (1) in vivo positron emission tomography (PET) measurement of (R)‐[11C]rolipram binding, (2) in vitro measurement of [3H]rolipram binding in brain homogenates, and (3) Western blotting for protein levels of PDE4 isoforms. Imipramine administration caused no significant change in Bmax/Kd, for both in vivo measurements with (R)‐[11C]rolipram and in vitro measurements with [3H]rolipram in frontal cortex, hippocampus, and diencephalon. None of 10 isoforms of PDE4A, B, and D measured with immunoblots of frontal cortex and hippocampus showed a significant change. In summary, using relatively large brain regions for both in vivo imaging and in vitro measures of radiolabeled ligand binding and protein levels, chronic imipramine treatment via continuous mini‐pump administration caused no significant change in PDE4 levels. Most, but not all, prior in vitro studies have found increased PDE4 levels after antidepressant administration. The current results raise questions about the in vivo effects of antidepressant treatment on PDE4 and on other potentially important experimental factors (e.g., continuous infusion vs. intermittent injection of antidepressant) in large brain areas. However, the results do not deny possibility of changes in discrete areas, which were not studied in the current study applying PET. Synapse 61:78–86, 2007. Published 2006 Wiley‐Liss, Inc.
Effect of a P‐glycoprotein inhibitor, cyclosporin A, on the disposition in rodent brain and blood of the 5‐HT1A receptor radioligand, [11C](R)‐(––)‐RWAY
Authors: Liow Jeih‐San , Lu Shuiyu , McCarron Julie A. , Hong Jinsoo , Musachio John L. , Pike Victor W. , Innis Robert B. , Zoghbi Sami S. 
Published: November 2006

AbstractLimited brain uptake of radioligands with otherwise optimal properties for imaging brain receptors can be improved by blocking the effect of P‐glycoprotein (P‐gp), an efflux pump at the blood‐brain barrier. Using small animal positron emission tomography (PET), we investigated how P‐gp and its blockade with Cyclosporin A (CsA) affect rodent brain uptake of [11C](R)‐(−)‐RWAY, a radioligand for brain 5‐HT1A receptors. Brain uptake of radioactivity was compared in control and CsA‐treated rats as well as P‐gp knockout and wild type mice. Parent radioligand and radiometabolite in plasma and brain samples were determined at 30 min after injection of radioligand. PET binding potential (BP) was calculated with a reference tissue model. P‐gp knockout mice had 2.5‐ and 2.8‐fold greater brain uptake of [11C](R)‐(−)‐RWAY than wild type ones, measured by in vivo PET and ex vivo tissue sampling, respectively. Similarly, CsA increased rat brain uptake 4.9‐ and 5.3‐fold, in vivo and ex vivo. In addition, CsA increased the plasma free fraction of [11C](R)‐(−)‐RWAY in rats by 2.7‐fold. Although CsA increased brain uptake in wild type mice by 2.5‐fold, it had no effect on plasma free fraction in knockout animals. Three radiometabolites of [11C](R)‐(−)‐RWAY were uniformly distributed in rat brain, suggesting they were inactive. CsA treatment increased brain uptake of [11C](R)‐(−)‐RWAY and only one of its radiometabolites. Regional rat brain BP increased 27–70% in the CsA‐treated rats and the P‐gp knockout mice. [11C](R)‐(−)‐RWAY is a P‐gp substrate in rat and mouse. The effects of CsA in rats are mediated by both P‐gp blockade and displacement of the radiotracer from plasma proteins. Studies with wild type and knockout mice showed that CsA affected only P‐gp in this species. Synapse 61:96–105, 2007. © 2006 Wiley‐Liss, Inc.
Sugar fatty acid ester surfactants: Structure and ultimate aerobic biodegradability
Authors: Baker Irene J. A. , Matthews Barry , Suares Hector , Krodkiewska Irena , Furlong D. Neil , Grieser Franz , Drummond Calum I. 
Published: November 2006

AbstractUltimate aerobic biodegradabilities of an array of sugar ester surfactants were determined by International Standards Organisation method 7827, “Water Quality—Evaluation in an Aqueous Medium of the Aerobic Biodegradability of Organic Compounds, Method by Dissolved Organic Carbon” (1984). The surfactants were nonionic sugar esters with different‐sized sugar head groups (formed from glucose, sucrose, or raffinose) and different lengths and numbers of alkyl chains [formed from lauric (C12) or palmitic (C16) acid]. Analogous anionic sugar ester surfactants, formed by attaching an α‐sulfonyl group adjacent to the ester bond, and sugar esters with α‐alkyl substituents were also studied. It was found that variations in sugar head group size or in alkyl chain length and number do not significantly affect biodegradability. In contrast, the biodegradation rate of sugar esters with α‐sulfonyl or α‐alkyl groups, although sufficient for them to be classified as readily biodegradable, was dramatically reduced compared to that of the unsubstituted sugar esters. An understanding of the relationship between structure and biodegradability provided by the results of this study will aid the targeted design of readily biodegradable sugar ester surfactants for use in consumer products.