bluuebunny/crossref_metadata_2025_split huggingface dataset:
c‐KIT is frequently mutated in bilateral germ cell tumours and down‐regulated during progression from intratubular germ cell neoplasia to seminoma
Authors: Biermann K , Göke F , Nettersheim D , Eckert D , Zhou H , Kahl P , Gashaw I , Schorle H , Büttner R 
Published: September 2007

AbstractTesticular germ cell tumours (TGCTs) are the most frequent cancer type in young men; 5% of these patients develop a second TGCT in the contralateral testis. The pathogenesis of TGCT is closely linked to primordial germ cells (PGCs) or gonocytes. The receptor tyrosine kinase (c‐KIT) is necessary for migration and survival of PGCs and is expressed in intratubular neoplastic germ cells (IGCNUs) and seminomas. We studied the frequency of c‐KIT exon 11 and 17 mutations in 155 unilateral (108 seminomas and 47 non‐seminomas) and 22 bilateral (18 seminomas, two embryonal carcinomas, two IGCNU) cases. While no mutations were detected in exon 11, the mutation frequency in exon 17 was significantly higher in bilateral (14/22, 63.6%) compared to unilateral TGCT (10/155, 6.4%) (p < 0.001). Different activating mutations (Y823D, D816V, D816H and N822K) were detected in bilateral TGCT. Y823D mutation was identical in both testes in three cases and quantitative pyrosequencing showed that up to 76% of the cells analysed in tumour samples carried this mutation. One bilateral synchronous seminoma revealed a S821F mutation in one testis and a Y823D mutation contralaterally. To study the role of c‐KIT in TGCT progression, we compared its expression in 41 seminomas and adjacent IGCNUs. Immunohistochemical analysis revealed that c‐KIT expression was significantly reduced in seminomas compared to IGCNUs (p < 0.006) and that there were no significant changes in c‐KIT mRNA copy numbers in progressed compared to low‐stage seminomas. In summary, our study shows that patients with c‐KIT mutations are more prone to develop a bilateral TGCT and suggests that in a portion of bilateral TGCTs, c‐KIT mutations occur early during embryonal development, prior to the arrival of PGCs at the genital ridge. Furthermore, our findings show that c‐KIT down‐regulation occurs during the progression of IGCNU to seminoma. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Effect of Plasma Treatment on the Gas Permeability of Poly(4‐methyl‐2‐pentyne) Membranes
Authors: Shao Lei , Samseth Jon , Hägg May‐Britt 
Published: September 2007

AbstractThe surface of a poly(4‐methyl‐2‐pentyne) membrane was modified by plasma treatment using CCl4; the permeabilities of O2, N2, H2, CH4 and CO2 were measured before and after the plasma treatment, and the selectivities of O2/N2, H2/N2, CO2/N2, CO2/CH4 and H2/CH4 were calculated. The selectivities were found to be remarkably improved after plasma treatment while gas permeabilities decreased. The effect of the plasma conditions such as the treatment time and discharge power on the permeabilities of the membranes was investigated in detail. The surface of modified membranes was analyzed by XPS, and the contact angles of water on the membranes were measured by a contact‐angle goniometer.magnified image
Adhesion Improvement of Plasma‐Polymerized Maleic Anhydride Films on Gold Using HMDSO/O2 Adhesion Layers
Authors: Chifen Anye N. , Jenkins A. Toby A. , Knoll Wolfgang , Förch Renate 
Published: September 2007

AbstractThe use of SiO2‐like layers as adhesion‐promoting inter‐layers between a reactive plasma polymer film and a gold substrate is compared to a self‐assembled monolayer of dodecanethiol and to bare gold. The chemical structure of the silicon oxide film is optimized by varying feed gas ratios and process input power. A 5 s oxygen plasma modification of the SiO2‐like film deposited from hexamethyldisiloxane has been found to be vital to prepare the surface for covalent bonding of the subsequently deposited reactive polymer layer. Film chemical structures and reactivity have been studied using IR reflection‐absorption spectroscopy, XPS, contact angle goniometry and SPR spectroscopy.magnified image
Catalytic Effects of Metals on the Conversion of Methane in Gliding Discharges
Authors: Schmidt‐Szałowski Krzysztof , Krawczyk Krzysztof , Młotek Michał 
Published: September 2007

AbstractPlasma‐catalytic methane conversion was studied under gliding‐discharge conditions using a mobile (spouted) catalytic bed of fine particles. A new model of the GD reactor was tested for the non‐oxidative methane coupling using alumina‐supported catalysts containing Cu, Ni, Ag or Pt resistant against the plasma action. C2 hydrocarbons, besides hydrogen, were the main products, with some amounts of non‐volatile substances (mainly soot). With Cu/Al2O3, Ni/Al2O3, Ag/Al2O3, and alumina beds, acetylene was mainly produced from the CH4 + H2 mixture with none or a minor share of other C2 hydrocarbons. Using Pt/Al2O3, an increased ethylene and ethane content was found with lower acetylene content.
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Treatment of Carbon Tetrafluoride with Gas Discharges
Authors: Pietsch Gerhard J. , Saveliev Anatoli B. 
Published: September 2007

AbstractWaste gases from semiconductor industry contain perfluorocarbons, which cause global warming and therefore should be removed. There are several possibilities to do this, for example the treatment of the gas by thermal and non‐thermal plasmas, as well as by heating. In model gases containing up to 10 000 ppm CF4, destruction removal efficiencies of nearly 100% have been reached at atmospheric pressure using dielectric barrier and arc discharges. In order to reach high values, the dissociation products of CF4 must be bonded by reaction partners such as SiO2, CaO or H2O.
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Atmospheric Pressure PE‐CVD of Fluorocarbon Thin Films by Means of Glow Dielectric Barrier Discharges
Authors: Fanelli Fiorenza , d'Agostino Riccardo , Fracassi Francesco 
Published: September 2007

AbstractGlow dielectric barrier discharges (GDBDs) fed with He‐C3F6 and He‐C3F8‐H2 gas mixtures were used to deposit fluorocarbon thin films. The deposition process was studied inside the GDBD existence domain as evaluated by electrical measurements. The composition and structure of the deposited coatings were investigated through Fourier Transform Infrared Spectroscopy, X‐ray Photoelectron Spectroscopy, Water Contact Angle measurements, and Scanning Electron Microscopy. He‐C3F6 gas mixtures generate fluorocarbon films with F/C ratio of 1.5 at deposition rates up to 34 nm · min−1, while with He‐C3F8‐H2 fed GDBDs it is possible to tune the F/C ratio of the coating from 1.5 to 0.6 and to change its cross‐linking degree by varying the hydrogen concentration in the gas feed. H2 addition promotes the increase of the deposition rate which is maximum for fluorocarbon‐to‐hydrogen ratio close to 1. Results of optical emission spectroscopy investigation of the plasma phase are also presented.magnified image
Arc‐Free Atmospheric Pressure Cold Plasma Jets: A Review
Authors: Laroussi Mounir , Akan Tamer 
Published: September 2007

AbstractNon‐thermal atmospheric pressure plasma jets/plumes are playing an increasingly important role in various plasma processing applications. This is because of their practical capability to provide plasmas that are not spatially bound or confined by electrodes. This capability is very desirable in many situations such as in biomedical applications. Various types of ‘cold’ plasma jets have, therefore, been developed to better suit specific uses. In this paper a review of the different cold plasma jets developed to date is presented. The jets are classified according to their power sources, which cover a wide frequency spectrum from DC to microwaves. Each jet is characterized by providing its operational parameters such as its electrodes system, plasma temperature, jet/plume geometrical size (length, radius), power consumption, and gas mixtures used. Applications of each jet are also briefly covered.magnified image
Selective conversion of plasma glucose into CO2 by Saccharomyces cerevisiae for the measurement of 13C abundance by isotope ratio mass spectrometry: proof of principle
Authors: Rembacz Krzysztof P. , Faber Klaas Nico , Stellaard Frans 
Published: September 2007

AbstractTo study carbohydrate digestion and glucose absorption, time‐dependent 13C enrichment in plasma glucose is measured after oral administration of naturally occurring 13C‐enriched carbohydrates. The isotope enrichment of the administered carbohydrate is low (APE <0.1%) and plasma 13C glucose measurements are routinely determined with gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) or liquid chromatography/combustion/isotope ratio mass spectrometry (LC/C/IRMS). In this study, plasma glucose was converted into CO2 by an in‐tube reaction with yeast permitting direct measurement of 13CO2 in the headspace. Saccharomyces cerevisiae incubated under anaerobic conditions was able to convert sufficient glucose into CO2 to produce a consistent CO2 peak in IRMS with little variation in peak area and precise δ13CPDB values for corn glucose: −11.40 ± 0.16‰, potato glucose: −25.17 ± 0.13‰, and plasma glucose: −26.29 ± 0.05‰. The measurement showed high linearity (R2 = 0.999) and selectivity and was not affected by the glucose concentration in the tested range of 5–15 mM. Comparison with GC/C/IRMS showed a good correlation of enrichment data: R2 > 0.98 for both sources of glucose and plasma samples. Commercially available, instant dried baker's yeast was qualitatively and quantitatively comparable with freshly prepared yeast: R2 > 0.96, slope 1.03 and 1.08 for glucose solutions and plasma, respectively. Thus, yeast conversion of plasma glucose into CO2 and 13C measurement applying a breath 13CO2 analyzer is an inexpensive, simple and equally accurate alternative to the more expensive and laborious GC/C/IRMS and LC/C/IRMS measurements. Copyright © 2007 John Wiley & Sons, Ltd.
A new approach to overcome natural cholesterol interference during simultaneous determination of two stable isotope‐enriched cholesterol tracers in human plasma
Authors: Wolff E. , Vergnes M. F. , Kaloustian J. , Abou L. , Mikail C. , Lairon D. , Portugal H. , Nicolay A. 
Published: September 2007

AbstractWe have developed a validated gas chromatography/mass spectrometry (GC/MS) method with two labelled cholesterol tracers, i.e. 2H4 ([2H4]‐Chol) and 2H7 ([2H7]‐Chol) enriched moieties, with a new way of calculating the abundance of labelled cholesterol in plasma without natural cholesterol interference. The isotopomers of the analytes could interfere during analysis. Elimination of these interferences can be performed by the blank or mathematical subtraction method. Validation was performed with the two interference elimination methods. For both methods, linearity was obtained in the range 5 × 10−4 to 10−2 mM for both labelled cholesterol moieties. In the same range, repeatability and reproducibility were less than 6.5% and 7.5% for [2H4]‐Chol and [2H7]‐Chol, respectively. Accuracy was about 100% and recoveries always included 100% for the two labelled cholesterols. We demonstrate that measurement of blank plasma is not necessary when using the validated abundance isotope calculation method. This saves time, reagent and samples. This calculation strategy can be extrapolated to comparable tracer approaches. Copyright © 2007 John Wiley & Sons, Ltd.
Quantitative comparison of a flared and a standard heated metal capillary inlet with a voltage‐assisted air amplifier on an electrospray ionization linear ion trap mass spectrometer
Authors: Dixon R. Brent , Muddiman David C. 
Published: September 2007

AbstractThe performance characteristics (i.e., ion abundance and electrospray ion current) of a flared and blunt‐ended heated metal capillary were evaluated with a voltage‐assisted air amplifier on a linear ion trap mass spectrometer (LTQ‐MS). The results demonstrated that a standard capillary afforded higher ion abundance than a flared capillary, thus further work is necessary to investigate conditions for which significant benefits with the flared capillary will be observed. The compatibility of a voltage‐assisted air amplifier is explored for both types of capillaries and in all cases resulted in improved ion abundance and spray current. Copyright © 2007 John Wiley & Sons, Ltd.
RNA interference and HIV‐1 infection
Authors: Kanzaki Luis Isamu Barros , Ornelas Socrates Souza , Argañaraz Enrique R. 
Published: September 2007

AbstractLife‐prolonging antiretroviral therapy remarkably reduces viral load, but it does not eradicate the virus. An important obstacle preventing virus clearance is the presence of latent virion reservoirs in the host. However, new promising antiviral approaches are emerging, and a number of host cell factors involved in the disease progression and control of HIV‐1 replication have been recently discovered. For instance, the RNA interference (RNAi) mechanism, besides many functions conserved throughout evolution, works as a defence mechanism against noxious transcripts which may provide a new tool to block viral replication. The recent definition of basic RNAi mechanisms, as well as the discovery of micro RNAs (microRNAs) encoded by the host cell genome and by HIV‐1, also suggest that RNAi may be involved in the control of HIV replication. Copyright © 2007 John Wiley & Sons, Ltd.
Sensitivity analysis of progression‐free survival with dependent withdrawal
Authors: Ruan Ping K. , Gray Robert J. 
Published: September 2007

AbstractWe develop a sensitivity analysis method for comparing treatment‐specific distributions where the endpoint is progression‐free survival (PFS). The censoring process may be informative due to selective patient withdrawal, which occurs whenever disease evaluation has been discontinued without progression being documented. The sensitivity analysis explores the effects of the dependence between patient withdrawal and progression time using a conditional probability model which incorporates a set of sensitivity parameters. We propose an EM algorithm for estimation of PFS under the model for dependence and construct log‐rank‐type score statistics from the estimated distributions. Bootstrap procedures are used to estimate the variance of the score statistic. We also extend the methodology to incorporate additional survival information, which may be available on the cases who were withdrawn. An Eastern Cooperative Oncology Group (ECOG) advanced lung cancer clinical trial (E1594) is used to illustrate the methodology. Copyright © 2007 John Wiley & Sons, Ltd.
Fixed vs random effects meta‐analysis in rare event studies: The Rosiglitazone link with myocardial infarction and cardiac death
Authors: Shuster Jonathan J. , Jones Lynn S. , Salmon Daniel A. 
Published: September 2007

AbstractMeta‐analyses can be powerful tools to combine the results of randomized clinical trials and observational studies to make consensus inferences about a medical issue. It will be demonstrated that a common practice of testing for homogeneity of effect size, and acting upon the inference to decide between fixed vs random effects, can lead to potentially misleading results. A by‐product of this paper is a new ratio estimator approach to random effects meta‐analysis of a large set of studies with low event rates. As a case study, we shall use the recent Rosiglitazone example, where diagnostic testing failed to reject homogeneity, leading the investigators to use fixed effects. The results for the fixed and random effects analyses are discordant. In the fixed (random) effects analysis, the p‐values for myocardial infarction were 0.03 (0.11) while those for cardiac death were 0.06 (0.0017). Had the fixed effects analysis controlled the study error for multiple testing via a Bonferonni correction, the joint 95+ per cent confidence rectangle for the two outcomes would have included odds ratios of (1.0, 1.0). For the Rosiglitazone example, random effects analysis, where all studies receive the same weight, is the superior choice over fixed effects, where two large studies dominate. Copyright © 2007 John Wiley & Sons, Ltd.
Changes in left heart hemodynamics after technically successful in‐utero aortic valvuloplasty
Authors: Selamet Tierney E. S. , Wald R. M. , McElhinney D. B. , Marshall A. C. , Benson C. B. , Colan S. D. , Marcus E. N. , Marx G. R. , Levine J. C. , Wilkins‐Haug L. , Lock J. E. , Tworetzky W. 
Published: September 2007

AbstractObjectiveSevere aortic stenosis in the mid‐gestation fetus can progress to hypoplastic left heart syndrome (HLHS). @ In‐utero aortic valvuloplasty is an innovative therapy to promote left ventricular growth and function and potentially to prevent HLHS. This study evaluated the effects of mid‐gestation fetal balloon aortic valvuloplasty on subsequent fetal left ventricular function and left heart Doppler characteristics.MethodsWe reviewed fetuses with aortic stenosis that underwent attempted in‐utero aortic valvuloplasty between 2000 and 2006. Pre‐intervention and the latest post‐intervention fetal echocardiograms were analyzed to characterize changes in left heart function and Doppler characteristics in utero.ResultsForty‐two fetuses underwent attempted aortic valvuloplasty during the study period, 12 of which were excluded from analysis secondary to inadequate follow‐up data, termination or fetal demise. Study fetuses (n = 30) underwent pre‐intervention echocardiography at a median gestational age of 23 weeks, and were followed for a median of 66 ± 23 days post‐intervention. In 26 fetuses, aortic valvuloplasty was technically successful. Among these 26, left heart physiology was abnormal pre‐intervention and improved or normalized after intervention in most cases: biphasic mitral inflow was present in 5/25 (20%) cases pre‐intervention and in 21/23 (91%) post‐intervention (P < 0.001); moderate or severe mitral regurgitation was present in 14/26 (54%) cases pre‐intervention and in 5/23 (22%) post‐intervention (P = 0.02); bidirectional flow across the patent foramen ovale was present in 0/26 cases pre‐intervention and in 6/25 (24%) post‐intervention (P = 0.01); antegrade flow in the transverse arch was present in 0/25 cases pre‐intervention and in 17/26 (65%) post‐intervention (P < 0.001). The left ventricular ejection fraction increased from 19 ± 10% pre‐intervention to 39 ± 14% post‐intervention (P < 0.001). These changes were not observed in control fetuses (n = 18).ConclusionFetal aortic valvuloplasty, when technically successful, improves left ventricular systolic function and left heart Doppler characteristics. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Selection of internal standards for determining quantitative recovery of isoprenoid acids after urea complexing
Authors: Ackman R. G. , Sipos J. C. , Hooper S. N. , Dube G. 
Published: September 2007

AbstractVarious types of esters are considered as internal standards for the quantitative gas liquid Chro‐matographic determination of isoprenoid fatty acids after urea complex treatment of esters of total or saturated fatty acids. It is shown that aromatic esters are potentially unsuitable because of on‐column losses with polyester columns. Two classes of ali‐phatic esters, either of 2‐ethyl‐l‐hexanol, or of 3‐cyclohexylpropionic acid, have been evaluated as satisfactory and certain gas liquid Chromatographic retention data is given to show which ester might be selected for a particular application.
Aminimides: III antimicrobial effect of various hexadecyl and quaternary derivatives
Authors: Kabara Jon J. 
Published: September 2007

AbstractAminimides, a new class of surfactants, have been screened for in vitro antimicrobial activity. Greatest activity against gram (+) and yeast organisms is achieved when a chain length of C16 is reached. This generalization is true whether or not the chain length is joined to the imide or amine group. The type of functional group associated with the surfactant is less important than chain length. Gram (‐) organisms do not fit this generalization, since shorter (<C16) rather than longer chain derivatives are more active. The importance of surfactant chain length to biodegrad‐ability is discussed.
Quantitative analysis of furanoid fatty acids in crude and refined cod liver oil
Authors: Scrimgeour Charles M. 
Published: September 2007

AbstractA method is described for determining the furan‐oid fatty acids F1‐F6 in cod liver oil using squalane as an internal standard added prior to isolation of the F esters by silver ion chromatography (Ag+ TLC) and urea crystallization. The F acids amount to about 1% of the oil and can be determined with an accuracy of ± 15%. There is no significant change in the amount of F acids after refining.
Marfanoid features in a child with combined methylmalonic aciduria and homocystinuria (CblC type)
Authors: Heil Sandra G. , Hogeveen Marije , Kluijtmans Leo A. J. , van Dijken P. J. , van de Berg Gerard B. , Blom Henk J. , Morava Eva 
Published: September 2007

SummaryCobalamin is an essential cofactor for two mammalian enzymes: methionine synthase and methylmalonyl‐CoA mutase. Patients with the cobalamin C (CblC) defect have combined methylmalonic aciduria and homocystinuria. Recently, the gene responsible for the CblC type, MMACHC, was identified, which enables molecular diagnostics. In this study, we describe two siblings, a 16‐year‐old girl and her 11‐year‐old brother, of a consanguineous family who presented with a very distinct clinical manifestation. The girl presented at the age of 13 years with macrocytic anaemia, cognitive regression and Marfanoid features such as increased arm‐span, arachnodactyly, joint hyperlaxity and scoliosis. Her brother presented at the age of 10 months with developmental delay and behavioural abnormalities. Biochemical analysis showed severely increased homocysteine and methylmalonic acid levels in plasma of both siblings. In addition, plasma cysteine levels were decreased in the girl but not in her brother. The diagnosis of CblC defect was confirmed by genomic sequencing of the coding exons of the MMACHC gene. Two heterozygous mutations were identified in both siblings; the common c.271dupA p.Arg91LysfsX14 and a novel mutation, c.1A>G p.Met1?. Therapy consisting of folic acid, vitamin B6, l‐carnitine and intramuscular vitamin B12 resulted in a clear improvement of biochemical parameters and, importantly, resulted in amelioration of the Marfanoid features in the girl. These data might suggest that low cysteine levels account for the Marfanoid features observed in the girl and indicate that the CblC type of combined methylmalonic aciduria and homocystinuria should be considered in the differential diagnosis of patients with Marfanoid features.