bluuebunny/crossref_metadata_2025_split huggingface dataset:
The use of client surveys to gauge the threat of contamination in welfare reform experiments
Authors: Camasso Michael J. , Jagannathan Radha , Harvey Carol , Killingsworth Mark 
Published: March 2003

AbstractThis paper examines the type of evidence policy analysts have used to identify the presence and magnitude of contamination in welfare reform experiments. Peter Rossi's critique of the New Jersey Family Development Program evaluation motivates the following discussion. In this critique Rossi and others contend that client misperception about experimental control‐group assignment resulted in contamination that negates reported treatment effectiveness. By applying the framework of the Rubin Causal Model (RCM) to isolate “pure” and “impure” experimental and control cases, the actual group assignment and not self‐reported membership is shown to be a more accurate gauge of treatment level and effect. The analysis reveals that the form of contamination Rossi detected leads to underestimates of treatment effects, not their evaporation. While contamination is a legitimate threat in any research design its identification must be based on empirical measures. © 2003 by the Association for Public Policy Analysis and Management.
Managing contract performance: A transaction costs approach
Authors: Brown Trevor L. , Potoski Matthew 
Published: March 2003

AbstractManaging contracts is a complex process, often exacerbated by high transaction costs inherent in negotiating, implementing, and monitoring contract relationships with vendors. Through analyses of data from a 1997 International City/County Management Association survey of municipal and county governments, the way in which municipal and county governments respond to transaction cost factors inherent in contract service delivery is examined. The results of the analyses demonstrate that when governments contract for services in contexts that risk contract failure, they engage in a variety of monitoring techniques to improve their ability to monitor and correct vendor performance. © 2003 by the Association for Public Policy Analysis and Management.
Guanidine hydrochloride extraction and detection of prion proteins in mouse and hamster prion diseases by ELISA
Authors: Kang Shin‐Chung , Li Ruliang , Wang Chuanping , Pan Tao , Liu Tong , Rubenstein Richard , Barnard Geoff , Wong Boon‐Seng , Sy Man‐Sun 
Published: March 2003

AbstractCurrent detection of transmissible spongiform encephalopathy (TSE) relies on the proteolytic generation of a protease‐resistant core from the scrapie isoform of prion protein (PrPSc) followed by immunoblotting. This process is non‐quantitative, time‐consuming, and technically demanding. Recently, an alternative in vitro test for TSE based on the differential extraction of brain homogenates using guanidine hydrochloride followed by DELFIA (Dissociation Enhanced Lanthanide FluoroImmunoAssay) has been developed. In the present study, this approach was adopted using a panel of anti‐PrP monoclonal antibodies (MAbs) in conventional sandwich enzyme‐linked immunosorbent assay (ELISA) to investigate hamster and two distinct strains of mouse prion diseases. Although PrP species were present in both soluble and insoluble fractions from normal as well as TSE samples, only the PrP species in the insoluble fractions from the latter samples were protease‐resistant. In addition, certain anti‐PrP MAb pairs could distinguish the PrP species in infected brains from those in the normal samples. The ability to differentiate disease‐associated PrP isoforms without proteinase K digestion could serve as a panacea for developing a reliable and rapid diagnostic test for prion diseases. Copyright © 2003 John Wiley & Sons, Ltd.
Abnormalities of E‐ and P‐cadherin and catenin (β‐, γ‐catenin, and p120ctn) expression in endometrial cancer and endometrial atypical hyperplasia
Authors: Moreno‐Bueno Gema , Hardisson David , Sarrió David , Sánchez Carolina , Cassia Raúl , Prat Jaime , Herman James G , Esteller Manel , Matías‐Guiu Xavier , Palacios José 
Published: March 2003

AbstractAbnormal expression of cadherins and catenins plays a critical role in the initiation and progression of multiple human tumours. This study aimed to evaluate the immunoreactivity of E‐ and P‐cadherin, β‐ and γ‐catenin, and p120ctn in premalignant and malignant endometrial lesions and to correlate their membranous expression with clinicopathological features. In addition, we examined whether or not LOH and promoter hypermethylation of the CDH1 gene were associated with E‐cadherin expression and clinicopathological variables. Finally, we studied the frequency of β‐catenin mutations in premalignant endometrial lesions. Immunohistochemical staining was performed in 21 atypical endometrial hyperplasias (AEHs), 95 endometrioid carcinomas (EECs), and 33 non‐endometrioid carcinomas (NEECs). Reduced E‐cadherin expression was observed in 57.8% of the cases, being more frequent in NEECs (87.1%, p = 0.001) and carcinomas of more advanced stage (85.7% of stage III–IV carcinomas, p = 0.01). LOH of CDH1 gene was found in 57.1% of NEECs but only in 22.5% of EECs (p = 0.011) and showed a trend towards association with reduced E‐cadherin expression (p = 0.089). CDH1 promoter hypermethylation was found in 21.2% of endometrial carcinomas but was not associated with clinicopathological or immunohistochemical variables. Reduced expression of β‐ and γ‐catenin and p120ctn was found in 76.1%, 94.3%, and 63.6% of the cases, respectively, being more frequent in lesions with reduced E‐cadherin expression. In addition, β‐catenin, but not γ‐catenin or p120ctn expression, was associated with the histology of the lesion, since it was reduced in 35% of AEHs, 80.3% of EECs, and 96.9% of NEECs (p = 0.000). Mutations in exon 3 of the β‐catenin gene, associated with β‐catenin nuclear expression, were detected in 3 (14.0%) AEH, a frequency similar to that previously reported in this series of ECs. Finally, upregulation of P‐cadherin was observed in 28.6% of cases. This alteration was associated with the histology of the lesion, since it was found in 9.5% of AEHs, 27.7% of EECs, and 46.2% of NEECs (p = 0.021). Copyright © 2003 John Wiley & Sons, Ltd.
Elevated telomerase activity, c‐MYC‐, and hTERT mRNA expression: association with tumour progression in malignant lipomatous tumours
Authors: Schneider‐Stock Regine , Boltze Carsten , Jäger Viola , Epplen Jörg , Landt Olfert , Peters Brigitte , Rys Janusz , Roessner Albert 
Published: March 2003

AbstractThe role of telomerase activity in tumour progression of liposarcomas is not well understood. Therefore, we investigated 72 liposarcomas of different histological subtypes for an association between telomeric lengths and telomerase activity, and assessed the association between the catalytic subunit human telomerase reverse transcriptase (hTERT) and its activator c‐MYC. Telomeric repeat fragment lengths were determined using radioactive DNA–fingerprint analysis with the telomere‐specific probe (TTAGGG)3, whereas telomerase activity was ascertained using the non‐radioactive TRAP‐assay. To evaluate the expression of hTERT and c‐MYC, we applied real‐time RT‐PCR using a LightCycler. Eight tumours were investigated by microdissection. The MIB1‐proliferation index and hTERT and c‐MYC protein expression were determined immunohistochemically. Genetic alterations showed a high degree of tumour specificity. Highly malignant myxoid/round cell liposarcomas showed the longest telomeres, the strongest telomerase activity, and the highest hTERT and c‐MYC expression levels compared with the pure myxoid variants (p < 0.001), which are of low malignancy. Pleomorphic liposarcoma was characterized by zero or low hTERT and c‐MYC expression and telomerase activity, but long telomeres, underlining their different pathogenetic pathway. Elevated gene expression was accompanied by protein immunopositivity. MIB1‐proliferation index did not correlate with other molecular markers. We conclude that hTERT and c‐MYC expression are associated with telomerase activity in liposarcomas. Elevated hTERT and c‐MYC expression as well as high telomerase activity play a role in the tumour progression of this sarcoma type. Nevertheless, each histological subtype of liposarcomas is defined by a specific molecular pattern. Telomerase activation is the most common pathway in liposarcomas maintaining telomeric length. Copyright © 2003 John Wiley & Sons, Ltd.
Expression of cyclins E, A, and B, and prognosis in lymph node‐negative breast cancer
Authors: Kühling Heidi , Alm Per , Olsson Håkan , Fernö Mårten , Baldetorp Bo , Parwaresch Reza , Rudolph Pierre 
Published: March 2003

AbstractUnexpected outcomes in breast cancer demand a refinement of prognostic criteria. This study therefore investigated the prognostic relevance of cyclin expression in a cohort of 332 T1–T2 N0 infiltrating ductal carcinomas with long‐term follow‐up (median 99 months). By univariate analysis, tumour size, histopathological grade, hormone receptor content, cyclin E, cyclin B, and the Ki‐S5 (Ki‐67) index significantly predicted disease‐specific and metastasis‐free survival. Cyclin A did not achieve statistical significance. In a multivariate analysis, both cyclin E [relative risk (RR) 2.01, p = 0.021] and cyclin B (RR 1.85, p = 0.033) were selected as independent prognosticators of metastasis‐free survival when the Ki‐67 index was omitted, but only cyclin E expression was associated with disease‐specific survival (RR 2.56, p = 0.006). When Ki‐67 was included as a covariate, cyclin E lost its significance with respect to disease‐specific survival but remained significant for metastasis‐free survival. In an analogous analysis including Ki‐67, the number of concurrently overexpressed cyclins did not attain statistical significance regarding disease‐specific survival but was selected as the leading predictor of metastatic disease. It is concluded that combined overexpression of cyclins may imply genetic instability enhancing metastatic potential, but that survival ultimately depends on the proliferative activity of tumour cells. Copyright © 2003 John Wiley & Sons, Ltd.
Was macht Krebs aggressiv?
Authors: Gießen Hannelore 
Published: March 2003

AbstractOb sich ein Tumor bildet, hängt auf genetischer Ebene von Onkogenen, Tumor‐Suppressor‐Genen und DNA‐Reparaturgenen ab. Wie vehement eine Krebserkrankung jedoch verläuft, wird auch von der Rezeptorvariante für einen Wachstumsfaktor beeinflusst, die Wissenschaftler am Max‐Planck‐Institut für Biochemie in Martinsried entdeckt haben.
Arrays überall
Authors: Holzgrabe Ulrike 
Published: March 2003

AbstractVon Chips für die Analyse von DNA und Proteinen wird im Augenblick überall berichtet. So wundert es nicht, dass man auch versucht, G‐Protein‐gekoppelte Rezeptoren (GPCR) auf einen Chip zu bannen, um möglichst schnell die Affinität und Selektivität neu synthetisierter potenzieller Wirkstoffe zu evaluieren.
Neues zum alten Histamin II. Ionenkanäle in Drosophila
Authors: Stark Holger 
Published: March 2003

AbstractEs ist seit längerem bekannt, dass wichtige Neurotransmitterfunktionen bei Insekten über Histamin gesteuert werden. Die Entdeckung histamingesteuerter Chloridionen‐Kanäle verspricht Ansätze zu neuen Insektiziden.
Replicate real‐time PCR testing of DNA in maternal plasma increases the sensitivity of non‐invasive fetal sex determination
Authors: Hromadnikova Ilona , Houbova Bela , Hridelova Dana , Voslarova Sona , Kofer Josef , Komrska Vladimir , Habart David 
Published: March 2003

AbstractBackgroundWe determined fetal sex in pregnancies referred for invasive prenatal diagnosis procedures by analysis of DNA in maternal plasma.MethodsTwelve pregnancies at risk of X‐linked haemophilia and 32 pregnancies at risk of chromosomal aneuploidies at a gestational age ranging from 10 to 18 weeks recruited before chorionic villus sampling or amniocentesis were involved in the study. Male fetal DNA in maternal plasma was detected by using real‐time polymerase chain reaction with the SRY gene as a marker.ResultsThe specificity of the system reached 100% (no Y signal was detected in 17 women pregnant with a female fetus) and the sensitivity reached 100% (SRY amplification in 27 examined samples).ConclusionsAmplification of free fetal DNA in maternal plasma is a valid and rapid technique for predicting fetal sex in first‐ and second‐trimester pregnancies and could allow the restriction of invasive sampling procedures to male fetuses at risk of X‐linked disorders. Copyright © 2003 John Wiley & Sons, Ltd.
Idiopathic fetal intrauterine growth restriction: a possible inheritance pattern
Authors: Ghezzi Fabio , Tibiletti Maria Grazia , Raio Luigi , Di Naro Edoardo , Lischetti Barbara , Taborelli Monica , Franchi Massimo 
Published: March 2003

AbstractObjectiveThis study was conducted to assess if the delivery of a previous growth‐retarded (IUGR) fetus increases the risk of having an IUGR fetus in subsequent pregnancies and to explore if a familial pattern of transmission is involved.MethodsSeventy consecutive multiparous women whose fetus was IUGR (group 1) and 70 controls (group 2) were enrolled in this study.ResultsThe proportion of women who developed preeclampsia (9 versus 2, p = 0.05) and who had delivered an IUGR fetus in a previous pregnancy (20 versus 4, p < 0.05) were higher in group 1 than in group 2. There was no difference in the incidence of chronic hypertension, diabetes, smoking, substance or alcohol abuse, and HIV infection between the groups. After adjustment for preeclampsia, the delivery of a previous IUGR fetus remained a risk factor for having a subsequent IUGR fetus [Odds ratio = 6.7 (CI 2.15–21.22), p < 0.01]. Pedigree analysis conducted in 15 families revealed a familial cluster of IUGR infants in all families that were investigated. In 9 out of 15 families, a dominant pattern of inheritance of IUGR was observed while the remaining families were more heterogeneous. In one family, a balanced carrier of chromosome 7 inversion generated a malformed fetus and two IUGR infants.ConclusionsThis study clarifies that IUGR may be an inherited genetic condition and emphasizes that a knowledge of the family history and of the parental karyotype may be helpful in the prevention of both fetal malformations and adverse neonatal morbidity in subsequent low birth weight infants. Copyright © 2003 John Wiley & Sons, Ltd.
Maternal serum–integrated screening for trisomy 18 using both first‐ and second‐trimester markers
Authors: Palomaki Glenn E. , Neveux Louis M. , Knight George J. , Haddow James E. 
Published: March 2003

AbstractObjectivesTo estimate the prenatal screening performance of an integrated serum test for detecting trisomy 18, which combines measurements of first‐ and second‐trimester markers with maternal age to assign patient‐specific risks.MethodsPublished and new observations of maternal serum marker levels in trisomy 18 and unaffected pregnancies are used to derive population parameters. These parameters are then combined in a multivariate Gaussian model to assign patient‐specific risks for trisomy 18.ResultsThe best combination of serum markers includes pregnancy‐associated plasma protein‐A in the first trimester and alpha‐fetoprotein, unconjugated estriol and human chorionic gonadotropin in the second trimester. At a second‐trimester risk cutoff of 1 : 100, these 4 markers, in combination with maternal age, detect 90% of trisomy 18 pregnancies at a false‐positive rate of 0.1%. The odds of a trisomy 18 pregnancy among screen‐positive women are 1 : 4. Without the first‐trimester marker, detection is reduced to 67% at about the same false‐positive rate.ConclusionThe algorithm described here is highly efficient for detecting trisomy 18 and should be considered by programs that offer serum‐integrated screening for Down syndrome. Copyright © 2003 John Wiley & Sons, Ltd.
Modelling a monolithically integrated vertical junction cell in low and high injection
Authors: Catchpole K. R. , Blakers A. W. , Weber K. J. 
Published: March 2003

AbstractA monolithic vertical junction cell design suitable for high‐quality lifted‐off silicon films is modelled and the factors influencing the efficiency are investigated. The structure has a high efficiency potential and could potentially be manufactured with a simple process. An interesting effect is described which leads to a higher short‐circuit current in high injection than in low injection in certain circumstances, and the reason for the increase is explained. Copyright © 2002 John Wiley & Sons, Ltd.
Suprafluidität — Von den Schwierigkeiten einer Messung
Authors: Sichau Christian 
Published: March 2003

AbstractDer Vater der Tieftemperaturphysik, Heike Kammerlingh Onnes, benötigte zu Beginn des 20. Jahrhunderts für die Verflüssigung von wenigen Litern Heliums noch mehrere Jahre, eine riesige Apparatur und viel Geld. Heute gelingt dies routinemäßig. Die Untersuchung der Materie bei tiefen Temperaturen, insbesondere zur Suprafluidität, bietet viele Überraschungen.
A new method to improve sensitivity and resolution in matrix‐assisted laser desorption/ionization time of flight mass spectrometry
Authors: Xiong Shaoxiang , Ding Qinxue , Zhao Zhengwen , Chen Wenzhang , Wang Guanghui , Liu Shaojun 
Published: March 2003

AbstractHigh detection sensitivity and resolution are two critical parameters for recording good peptide mass fingerprints (PMF) of low abundance proteins. This paper reports a mass spectrometry (MS) sample preparation technique that could improve sensitivity and resolution. By coating the MS steel target with a thin layer of pentadecafluorooctamido propyltrimethoxysilane, which was both polar and nonpolar solvent repellent, the transferred sample droplets on its surface were significantly smaller. As a result, the analyte of the peptide mixture became more concentrated and homogeneous, which helped to improve the sensitivity. The advantages of a modified MS target were documented by mass spectra improvement of attomole level standard peptides and silver‐stained proteins from polyacrylamide gels. The mass signal of angiotensin II at 100 attomole was difficult to record on the conventional support, whereas it was easily detected on the modified one. The PMF of cytochrome C was also better recorded on the modified support, in terms of both signal‐to‐noise ratio and the number of detected peptides. When silver‐stained proteins from two‐dimensional electrophoresis gels were analyzed, in most cases more satisfactory peptide mass spectra were obtained from the modified support. Searching protein databases with more mass data from the improved PMFs, several unknown proteins were successfully identified.
Wheat proteomics: Relationship between fine chromosome deletion and protein expression
Authors: Islam Nazrul , Tsujimoto Hisashi , Hirano Hisashi 
Published: March 2003

AbstractTo explore the relationship between fine chromosome deletion and protein expression in common wheat, the changes in protein composition of wheat seed proteome were investigated by using chromosome 1B. A momosomic alien chromosome addition line of common wheat was used to produce the fine deletion lines. Endosperm and embryo proteins were separated by two‐dimensional gel electrophoresis (2‐DE) and visualized by staining with Commassie Brilliant Blue, and gel images were analyzed with a computer assisted image analyzer. For the first time, fine gene locations of a few endosperm and embryo proteins were identified on the chromosome 1B. These proteins with their specific gene location on the chromosome can be used as protein markers in breeding programs for quality of wheat proteins. To identify wheat seed proteins and to understand their expression in relation to chromosome deletion, the feasibility of a new analytical approach based on isotope coded affinity tag labeling (ICAT) of peptides in tryptic digests followed by electrospray ionization mass spectrometry has been described. Simplification of the complex tryptic digest prior to mass spectral analysis was performed by treating the samples with light and heavy ICAT labeling reagents. A clear separation of peptide fragment containing the light and heavy reagents was achieved in mass spectral analysis. Out of the 14 peptides detected by mass fragment analysis of the euploid, four were down‐regulated, nine up‐regulated and one did not show any change due to the terminal deletion of chromosome 1B. Selected peptide fragments were subjected to tandem mass spectrometry analysis for sequence information and the resulting sequence information was submitted to databases for protein identification. Of the five proteins submitted, four were identified as alpha‐amylase inhibitor, alpha‐amylase/subtilisin inhibitor precursor, proteasome subunit alpha‐type 7 and 1,4 alpha‐glucan‐D‐maltohydrolase. With this approach it is possible to identify wheat seed proteins and to understand their expression, which have been reported to be difficult by 2‐DE due to cosynthesis of proteins by genes from three genomes, A, B and D.
Proteomic analysis of Lactococcus lactis, a lactic acid bacterium
Authors: Guillot Alain , Gitton Christophe , Anglade Patricia , Mistou Michel‐Yves 
Published: March 2003

AbstractLactococcus lactis is a Gram‐positive bacteria, which belongs to the group of lactic acid bacteria among which several genera play an essential role in the manufacture of food products. Cytosolic proteins of L. lactis IL1403 cultivated in M17 broth have been resolved by two‐dimensional gel electrophoresis using two pH gradients (pH 4–7, 4.5–5.5). More than 230 spots were identified by peptide mass fingerprints, corresponding to 25% of the predicted acid proteome. The present study made it possible to describe at the proteome level a significant number of cellular pathways (glycolysis, fermentation, nucleotide metabolism, proteolysis, fatty acid and peptidoglycan synthesis) related to important physiological processes and technological properties. It also indicated that the fermentative metabolism, which characterizes L. lactis is associated with a high expression of glycolytic enzymes. Thirty‐four proteins were matched to open reading frames for which there is no assigned function. The comparison at the proteome level of two strains of L. lactis showed an important protein polymorphism. The comparison of the proteomes of glucose‐ and lactose‐grown cells revealed an unexpected link between the nature of the carbon source and the metabolism of pyrimidine nucleotides.
Bulk hydrosilylation reaction of poly(dimethylsiloxane) chains catalyzed by a platinum salt: Effect of the initial concentration of reactive groups on the final extent of reaction
Authors: Roth Leandro E. , Vallés Enrique M. , Villar Marcelo A. 
Published: March 2003

AbstractModel silicone networks obtained by curing linear poly(dimethylsiloxane) (PDMS) chains with end‐vinyl groups, (B2), with a polyfunctional silane‐terminated crosslinker of functionality f, (Af), through a hydrosilylation reaction have been widely used. In these networks, the principal characteristics of their ultimate molecular structure are strongly affected by the final extent of reaction reached during the crosslinking reaction. This work analyzes the effect of the initial concentration of the reactive end groups on the maximum attainable extent of reaction under normal bulk crosslinking conditions. This was accomplished by examining the reaction between linear B2 PDMS chains with difunctional and trifunctional silanes. The experimental results were fitted by an exponential equation to have an empirical equation able to predict the maximum extent of reaction to be obtained as a function of the initial concentration of reactive groups. Molecular parameters relevant to this study, such as the degree of polymerization, the weight‐average molecular weight for the A2 + B2 system, or the weight fraction of solubles for the A3 + B2 system, were calculated with a mean field theory (recursive approach). © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1099–1106, 2003