bluuebunny/crossref_metadata_2025 huggingface dataset:
Common Genetic Variation in TP53 Is Associated with Lung Cancer Risk and Prognosis in African Americans and Somatic Mutations in Lung Tumors
Authors: Mechanic Leah E. , Bowman Elise D. , Welsh Judith A. , Khan Mohammed A. , Hagiwara Nobutoshi , Enewold Lindsey , Shields Peter G. , Burdette Laurie , Chanock Stephen , Harris Curtis C.
Published: February 2007

Lung cancer is primarily caused by tobacco smoking, but susceptibility is likely modified by common genetic variation. In response to many forms of cellular stress, including DNA damage, the p53 protein functions to induce cell cycle arrest, DNA repair, senescence, or apoptosis. We hypothesized that common TP53 haplotypes modulate pathways of lung carcinogenesis and lung cancer susceptibility or prognosis. To investigate our hypothesis, 14 polymorphisms in TP53, including haplotype tagging and coding single nucleotide polymorphisms, were genotyped in two studies from the greater Baltimore, Maryland area. One study is a case-control study and the second is a case-only study for which TP53 mutational spectra data are available. African Americans with Pro-T-A-G-G haplotypes of the combined TP53 polymorphisms TP53_01 (rs1042522), TP53_65 (rs9895829), TP53_66 (rs2909430), TP53_16 (rs1625895), and TP53_11 (rs12951053) had both an increased risk for lung cancer (odds ratio, 2.32; 95% confidence interval, 1.18-4.57) and a worsened lung cancer prognosis (hazards ratio, 2.38; 95% confidence interval, 1.38-4.10) compared with those with Arg-T-A-G-T haplotypes. No associations of TP53 polymorphisms with lung cancer were observed in Caucasians. In the case-only study, several polymorphisms in TP53 and TP53 haplotypes, overlapping regions of TP53 associated with risk and prognosis in African Americans, were associated with increased odds of somatic TP53 mutation in lung tumors in Caucasians. In conclusion, common genetic variation in TP53 could modulate lung cancer pathways, as suggested by the association with lung cancer in African Americans and somatic TP53 mutation frequency in lung tumors. (Cancer Epidemiol Biomarkers Prev 2007;16(2):214–22)
Relationship between P-Wave Dispersion and Effective Hemodialysis in Chronic Hemodialysis Patients
Authors: Ozmen Namik , Cebeci Beker Sitki , Kardesoglu Ejder , Atasoyu Enes Murat , Unver Suat , Celik Turgay , Aparci Mustafa , Dincturk Mehmet
Published: February 2007

Objective: To investigate whether or not P-wave dispersion (PWD) can be used as a good indicator of effective hemodialysis. Subjects andMethods: The study included 35 patients (20 males, 15 females, mean age 61 ± 10 years) who regularly received hemodialysis treatment for chronic renal failure. Following hemodialysis, the patients whose hemodynamic parameters were preserved and who reached dry body weight were included. Twelve-lead resting electrocardiogram (ECG) at a speed of 25–50 mm/s, the value of total body fluid (TBF) and bioelectric impedance using bipedal bioelectric impedance equipment were obtained before and immediately after hemodialysis. Blood samples were also taken for the assessment of blood electrolytes, urea and creatinine. PWD was defined as the difference between the maximum and minimum P-wave duration calculated on a standard 12-lead ECG before and after dialysis. Results: The following parameters were obtained before and after hemodialysis: blood pressure 132 ± 21 vs. 130 ± 10 mm Hg (p > 0.05), TBF 33.9 ± 6 vs. 32 ± 5.6 liters (p = 0.001), impedance 499 ± 110 vs. 596 ± 136 Ω (p = 0.001), P-max 103.1 ± 8.9 vs. 106.3 ± 12.7 ms (p > 0.05), P-min 70.2 ± 11 vs. 72.5 ± 7.9 ms (p > 0.05), PWD 32.2 ± 11.9 vs. 33.8 ± 13.4 ms (p > 0.05). Although statistically significant decreases were observed in urea and creatinine levels after hemodialysis, no such changes were observed in blood electrolytes. Conclusion: The P-max and PWD did not change significantly after hemodialysis, hence these two parameters can be used as an indicator of effective hemodialysis.
Development and Validation of an Internationally Reliable Short-Form of the Positive and Negative Affect Schedule (PANAS)
Authors: Thompson Edmund R.
Published: February 2007

This article reports the development and validation of a 10-item international Positive and Negative Affect Schedule (PANAS) Short Form (I-PANAS-SF) in English. A qualitative study ( N = 18) and then an exploratory quantitative study ( N = 407), each using informants from a range of cultural backgrounds, were used to identify systematically which 10 of the original 20 PANAS items to retain or remove. A same-sample retest study ( N = 163) was used in an initial examination of the new 10-item international PANAS's psychometric properties and to assess its correlation with the full, 20-item, original PANAS. In a series of further validation studies ( N = 1,789), the cross-sample stability, internal reliability, temporal stability, cross-cultural factorial invariance, and convergent and criterion-related validities of the I-PANAS-SF were examined and found to be psychometrically acceptable.
The Role of Culture in Engaging Latino Parents’ Involvement in School
Authors: De Gaetano Yvonne
Published: February 2007

One of the critical issues for schools is how to actively involve Latino parents in the schooling process. Although Latino parents are often marginalized in schools due to race, class, and cultural differences, many school personnel suspect Latino parents of not caring about their children’s education. This article highlights how a small group of educators working together in a project actively enlisted the participation of Latino parents in schools through a positive and consistent focus on their own cultures. The author suggests that teacher preparation programs explore the power of a culturally relevant approach to working with parents.
Lack of endothelial cell survivin causes embryonic defects in angiogenesis, cardiogenesis, and neural tube closure
Authors: Zwerts Femke , Lupu Florea , De Vriese Astrid , Pollefeyt Saskia , Moons Lieve , Altura Rachel A. , Jiang Yuying , Maxwell Patrick H. , Hill Peter , Oh Hideyasu , Rieker Claus , Collen Désiré , Conway Simon J. , Conway Edward M.
Published: February 2007

We explored the physiologic role of endothelial cell apoptosis during development by generating mouse embryos lacking the inhibitor of apoptosis protein (IAP) survivin in endothelium. This was accomplished by intercrossing survivinlox/lox mice with mice expressing cre recombinase under the control of the endothelial cell specific tie1 promoter (tie1-cre mice). Lack of endothelial cell survivin resulted in embryonic lethality. Mutant embryos had prominent and diffuse hemorrhages from embryonic day 9.5 (E9.5) and died before E13.5. Heart development was strikingly abnormal. Survivin-null endocardial lineage cells could not support normal epithelial-mesenchymal transformation (EMT), resulting in hypoplastic endocardial cushions and in utero heart failure. In addition, 30% of mutant embryos had neural tube closure defects (NTDs) that were not caused by bleeding or growth retardation, but were likely due to alterations in the release of soluble factors from endothelial cells that otherwise support neural stem cell proliferation and neurulation. Thus, regulation of endothelial cell survival, and maintenance of vascular integrity by survivin are crucial for normal embryonic angiogenesis, cardiogenesis, and neurogenesis.
Inclusion of the glucocorticoid receptor in a hypothalamic pituitary adrenal axis model reveals bistability
Authors: Gupta Shakti , Aslakson Eric , Gurbaxani Brian M , Vernon Suzanne D
Published: February 2007

Background

The body's primary stress management system is the hypothalamic pituitary adrenal (HPA) axis. The HPA axis responds to physical and mental challenge to maintain homeostasis in part by controlling the body's cortisol level. Dysregulation of the HPA axis is implicated in numerous stress-related diseases.

Results

We developed a structured model of the HPA axis that includes the glucocorticoid receptor (GR). This model incorporates nonlinear kinetics of pituitary GR synthesis. The nonlinear effect arises from the fact that GR homodimerizes after cortisol activation and induces its own synthesis in the pituitary. This homodimerization makes possible two stable steady states (low and high) and one unstable state of cortisol production resulting in bistability of the HPA axis. In this model, low GR concentration represents the normal steady state, and high GR concentration represents a dysregulated steady state. A short stress in the normal steady state produces a small perturbation in the GR concentration that quickly returns to normal levels. Long, repeated stress produces persistent and high GR concentration that does not return to baseline forcing the HPA axis to an alternate steady state. One consequence of increased steady state GR is reduced steady state cortisol, which has been observed in some stress related disorders such as Chronic Fatigue Syndrome (CFS).

Conclusion

Inclusion of pituitary GR expression resulted in a biologically plausible model of HPA axis bistability and hypocortisolism. High GR concentration enhanced cortisol negative feedback on the hypothalamus and forced the HPA axis into an alternative, low cortisol state. This model can be used to explore mechanisms underlying disorders of the HPA axis.
Common genetic variation in IGF1, IGFBP-1, and IGFBP-3 in relation to mammographic density: a cross-sectional study
Authors: Tamimi Rulla M , Cox David G , Kraft Peter , Pollak Michael N , Haiman Christopher A , Cheng Iona , Freedman Matthew L , Hankinson Susan E , Hunter David J , Colditz Graham A
Published: February 2007

Introduction

Mammographic density is one of the strongest risk factors for breast cancer and is believed to represent epithelial and stromal proliferation. Because of the high heritability of breast density, and the role of the insulin-like growth factor (IGF) pathway in cellular proliferation and breast development, we examined the association between common genetic variation in this pathway and mammographic density.

Methods

We conducted a cross-sectional analysis among controls (n = 1,121) who were between the ages of 42 and 78 years at mammography, from a breast cancer case-control study nested within the Nurses' Health Study cohort. At the time of mammography, 204 women were premenopausal and 917 were postmenopausal. We genotyped 29 haplotype-tagging SNPs demonstrated to capture common genetic variation in IGF1, IGF binding protein (IGFBP)-1, and IGFBP-3.

Results

Common haplotype patterns in three of the four haplotype blocks spanning the gene encoding IGF1 were associated with mammographic density. Haplotype patterns in block 1 (p = 0.03), block 3 (p = 0.009), and block 4 (p = 0.007) were associated with mammographic density, whereas those in block 2 were not. None of the common haplotypes in the three haplotype blocks spanning the genes encoding IGFBP-1/IGFBP-3 were significantly associated with mammographic density. Two haplotype-tagging SNPs in IGF1, rs1520220 and rs2946834, showed a strong association with mammographic density. Those with the homozygous variant genotype for rs1520220 had a mean percentage mammographic density of 19.6% compared with those with the homozygous wild-type genotype, who had a mean percentage mammographic density of 27.9% (p for trend < 0.0001). Those that were homozygous variant for rs2946834 had a mean percentage mammographic density of 23.2% compared with those who were homozygous wild-type with a mean percentage mammographic density of 28.2% (p for trend = 0.0004). Permutation testing demonstrated that results as strong as these are unlikely to occur by chance (p = 0.0005).

Conclusion

Common genetic variation in IGF1 is strongly associated with percentage mammographic density.
A Disruptive Mutation in Exon 3 of the GNAS Gene with Albright Hereditary Osteodystrophy, Normocalcemic Pseudohypoparathyroidism, and Selective Long Transcript Variant Gsα-L Deficiency
Authors: Thiele Susanne , Werner Ralf , Ahrens Wiebke , Hoppe Ute , Marschke Christine , Staedt Pia , Hiort Olaf
Published: February 2007

Objective: The GNAS gene encodes the α-subunit of stimulatory G proteins, which play a crucial role in intracellular signal transduction of peptide and neurotransmitter receptors. In addition to transcript variants that differ in their first exon due to different promoters, there are two long (Gsα-L) and two short (Gsα-S) splice variants, created by alternative splicing. Heterozygous inactivating maternally inherited mutations of GNAS lead to a phenotype in which Albright hereditary osteodystrophy is associated with pseudohypoparathyroidism type Ia.

Methods and Results: The GNAS gene of a 10-yr-old girl with brachymetacarpia, mental retardation, normocalcemic pseudohypoparathyroidism, and hypothyroidism was investigated. We found a heterozygous insertion of an adenosine in exon 3 altering codon 85 and leading to a frame shift inducing a stop codon in exon 4. Molecular studies of cDNA from blood RNA demonstrated normal, biallelic expression of Gsα-S transcripts, whereas expression of Gsα-L transcripts from the maternal allele was reduced. Immunoblot analysis revealed a reduced Gsα-L protein level to about 50%, whereas the protein level of Gsα-S was unaltered. Furthermore, the Gsα protein activity in erythrocyte membranes was diminished to about 75% of normal. Both the reduced activity and the mutation were also found in the mother and the affected younger brother.

Conclusion: This report demonstrates the first evidence for a pathogenic mutation in exon 3 of the GNAS gene. The mutation is associated with a phenotype of Albright hereditary osteodystrophy and pseudohypoparathyroidism type Ia due to selective deficiency of Gsα-L and a partial reduction of Gsα activity.
Stimulation of ES-cell-derived cardiomyogenesis and neonatal cardiac cell proliferation by reactive oxygen species and NADPH oxidase
Authors: Buggisch Martina , Ateghang Bernadette , Ruhe Carola , Strobel Catrin , Lange Sabine , Wartenberg Maria , Sauer Heinrich
Published: February 2007

After birth the proliferation of cardiac cells declines, and further growth of the heart occurs by hypertrophic cell growth. In the present study the cell proliferation capacity of mouse embryonic stem (ES) cells versus neonatal cardiomyocytes and the effects of reactive oxygen species (ROS) on cardiomyogenesis and cardiac cell proliferation of ES cells was investigated. Low levels of hydrogen peroxide stimulated cardiomyogenesis of ES cells and induced proliferation of cardiomyocytes derived from ES cells and neonatal mice, as investigated by nuclear translocation of cyclin D1, downregulation of p27Kip1, phosphorylation of retinoblastoma (Rb), increase of Ki-67 expression and incorporation of BrdU. The observed effects were blunted by the free radical scavengers vitamin E and 2-mercaptoglycin (NMPG). In ES cells ROS induced expression of the cardiac-specific genes encoding α-actin, β-MHC, MLC2a, MLC2v and ANP as well as the transcription factors GATA-4, Nkx-2.5, MEF2C, DTEF-1 and the growth factor BMP-10. During differentiation ES cells expressed the NADPH oxidase isoforms Nox-1, Nox-2 and Nox-4. Treatment of cardiac cells with ROS increased Nox-1, Nox-4, p22-phox, p47-phox and p67-phox proteins as well as Nox-1 and Nox-4 mRNA, indicating feed-forward regulation of ROS generation. Inhibition of NADPH oxidase with diphenylen iodonium chloride (DPI) and apocynin abolished ROS-induced cardiomyogenesis of ES cells. Our data suggest that proliferation of neonatal and ES-cell-derived cardiac cells involves ROS-mediated signalling cascades and point towards an involvement of NADPH oxidase in cardiovascular differentiation of ES cells.
Canadian Circumstances: The Evolution of Canada's Climate Change Policy
Authors: Samson Paul R.
Published: February 2007

A tracing and analysis of Canadian climate change policies and international negotiation positions over the past two decades reveals more than the complexity involved in the subject itself. Indeed, analysis suggests that “national circumstances” have consistently been the primary driver of Canada's climate change policy. These circumstances include a decentralized national policy system that necessitates broad governmental and stakeholder participation; a strong economic reliance on natural and energy-intensive resources and exports; a national sense of belonging to the land; and a tradition of leadership and brokering in international affairs. Canada's policies have been, and will continue to be, primarily driven by these national circumstances as negotiations and implementation issues around the Kyoto Protocol further evolve.
In vitro trans-translation of Thermus thermophilus: Ribosomal protein S1 is not required for the early stage of trans-translation
Authors: Takada Kazuma , Takemoto Chie , Kawazoe Masahito , Konno Takayuki , Hanawa-Suetsugu Kyoko , Lee SungGa , Shirouzu Mikako , Yokoyama Shigeyuki , Muto Akira , Himeno Hyouta
Published: February 2007

Transfer-messenger RNA (tmRNA) plays a dual role as a tRNA and an mRNA in trans-translation, during which the ribosome replaces mRNA with tmRNA encoding the tag-peptide. These processes have been suggested to involve several tmRNA-binding proteins, including SmpB and ribosomal protein S1. To investigate the molecular mechanism of trans-translation, we developed in vitro systems using purified ribosome, elongation factors, tmRNA and SmpB from Thermus thermophilus. A stalled ribosome in complex with polyphenylalanyl-tRNAPhe was prepared as a target of tmRNA. A peptidyl transfer reaction from polyphenylalanyl-tRNAPhe to alanyl-tmRNA was observed in an SmpB-dependent manner. The next peptidyl transfer to aminoacyl-tRNA occurred specifically to the putative resume codon for the tag-peptide, which was confirmed by introducing a mutation in the codon. Thus, the in vitro systems developed in this study are useful to investigate the early steps of trans-translation. Using these in vitro systems, we investigated the function of ribosomal protein S1, which has been believed to play a role in trans-translation. Although T. thermophilus S1 tightly bound to tmRNA, as in the case of Escherichia coli S1, it had little or no effect on the early steps of trans-translation.
Local RNA structural changes induced by crystallization are revealed by SHAPE
Authors: Vicens Quentin , Gooding Anne R. , Laederach Alain , Cech Thomas R.
Published: February 2007

We present a simple approach to locate sites that undergo conformational changes upon crystallization by comparative structural mapping of the same RNA in three different environments. As a proof of principle, we probed the readily crystallized P4–P6ΔC209 domain from the Tetrahymena thermophila group I intron in a native solution, in a solution mimicking the crystallization drop, and in crystals. We chose the selective 2′-hydroxyl acylation analyzed by primer extension (SHAPE) chemistry, which monitors the flexibility and the conformation of each nucleotide. First, SHAPE successfully revealed the structural changes that occur during the crystallization process. Specifically, 64% of the nucleotides implicated in packing contacts and present in the portion of the molecule analyzed were identified. Second, reactivity differences for some of these nucleotides were already observed in the crystallization solution, suggesting that the crystallization buffer locked down a particular structure that was favorable to crystal formation. Third, the probing of a known structure extends our understanding of the structural basis for the SHAPE reaction by suggesting that reactivity is enhanced by a C2′-endo sugar pucker. Furthermore, by identifying local conformational changes of the RNA that take place during crystallization, SHAPE could be combined with the in vitro selection of stable mutants to rationalize the design of RNA candidates for crystallization.
Use of Hematopoietic Growth Factors as Adjuvant Therapy for Anemia and Neutropenia in the Treatment of Hepatitis C
Authors: Santos Anne E Dar , Partovi Nilufar , Ford Jo-Ann E , Yoshida Eric M
Published: February 2007

Objective:

To review the hematologic adverse effects of hepatitis C virus (HCV) therapy and adjuvant treatment with epoetin alfa and granulocyte colony-stimulating factor (ie, filgrastim).

Data Sources:

Medical literature indexed in MEDLINE (1966–January 2007) and EMBASE (1980–January 2007) was searched, and published conference abstracts were reviewed.

Study Selection and Data Extraction:

Peer-reviewed articles and relevant conference abstracts regarding the use of epoetin alfa and granulocyte colony-stimulating factor were reviewed.

Data Synthesis:

Ribavirin induces a dose-dependent hemolytic anemia. Studies using epoetin alfa 40 000 units subcutaneously once weekly have demonstrated efficacy in maintaining hemoglobin, ribavirin dose, and quality of life scores, but clear benefit shown with sustained virologic response (SVR) is lacking. The hemoglobin threshold for initiation of epoetin alfa used in studies may not adequately reflect values used in clinical practice. Treatment-related neutropenia is caused primarily by interferon or peg interferon. Few studies have investigated the impact of granulocyte or granulocyte-macrophage colony-stimulating factor derivatives on neutropenia. Results of dose maintenance evaluation vary, and studies reporting data on SVR showed no effect from growth factor therapy. The frequency of bacterial infections was not reported.

Conclusions:

The role and benefit of hematopoietic growth factors in HCV therapy have not been conclusively determined to date. However, the possibility of a benefit to individual patients seen on an outpatient basis remains, and an individualized treatment approach is recommended.
Opioid Conversions in Acute Care
Authors: Patanwala Asad E , Duby Jeremiah , Waters Dustin , Erstad Brian L
Published: February 2007

Objective:

To discuss the historical basis and limitations of opioid conversion tables, review the relevant literature, and establish an evidence-based equianalgesic dose ratio (EDR) table for performing conversions in the acute care setting.

Data Sources:

Articles were identified through searches of MEDLINE (1966–January 2007) using the key words opioid, tolerance, conversion, dose, equianalgesic, equipotent, acute care, morphine, hydromorphone, fentanyl, methadone, and oxycodone. Additional references were located through a review of the bibliographies of articles cited and references cited in conversion tables.

Study Selection and Data Extraction:

All data sources identified were evaluated, and all information deemed relevant was included, with the exception of case series and case reports when higher level evidence was available.

Data Synthesis:

Opioid conversion tables are published in major textbooks, medical references, national guidelines, and review articles. Some conversion tables do not accurately reflect the dose ratios for which evidence is available. There is marginal evidence-based clinical data to support the dose ratios cited in these tables, particularly in the acute care setting where the clinical status of patients often changes rapidly. The barriers when performing route and opioid-to-opioid conversions in the acute care setting are formidable, but EDRs are provided, based on the best available evidence.

Conclusions:

In the acute care setting, calculation of dose ratios for opioids, based solely on opioid conversion tables, is an oversimplification of pain management, with a potential for adverse consequences. The calculation of EDRs is one step in an interdisciplinary process that must take into account patient- and institution-specific factors.
The impact of mood induction on the accessibility of positive and negative future events in a group of dysphoric adolescent in‐patients
Authors: de Jong‐Meyer Renate , Kuczmera Arkadius , Tripp Jürgen
Published: February 2007

Objective. This study aimed at experimentally affecting the fluency with which positive and negative future events are generated by depressive adolescents.

Method. Adolescent in‐patients with elevated depression were randomized into a positive or negative mood induction condition (N=24 in each group) and then presented with the Future Thinking Task asking participants to generate as many future events of a specified valence as possible.

Results. The inductions resulted in significant mood differences between groups. The assumed interaction between mood condition and reported positive and negative future events was confirmed. Particularly, the generation of negative future event representations differed between the mood induction groups.

Conclusions. Dysphoric adolescents given a negative mood induction differ from those given a positive mood induction in their ability to think of future positive and negative events that they might experience.
Neural Activity Is Modulated by Trial History: A Functional Magnetic Resonance Imaging Study of the Effects of a Previous Antisaccade
Authors: Manoach Dara S. , Thakkar Katherine N. , Cain Matthew S. , Polli Frida E. , Edelman Jay A. , Fischl Bruce , Barton Jason J. S.
Published: February 2007

Saccadic latencies are influenced by what occurred during the previous trial. When the previous trial is an antisaccade, the latencies of both prosaccades and antisaccades are prolonged. The aim of this study was to identify neural correlates of this intertrial effect of antisaccades. Specifically, based on both monkey electrophysiology and human neuroimaging findings, we expected trials preceded by antisaccades to be associated with reduced frontal eye field (FEF) activity relative to those preceded by prosaccades. Twenty-one healthy participants performed pseudorandom sequences of prosaccade and antisaccade trials during functional magnetic resonance imaging (fMRI) with concurrent monitoring of eye position. We compared activity in trials preceded by an antisaccade with activity in trials preceded by a prosaccade. The primary result was that a previous antisaccade prolonged saccadic latency and reduced fMRI activity in the FEF and other regions. No regions showed increased activity. We interpret the reduced FEF activity and slower saccadic responses to reflect inhibitory influences on the response system as a consequence of performing an antisaccade in the previous trial. This demonstrates that neural activity is modulated by trial history, consistent with a rapid, dynamic form of learning. More generally, these results highlight the importance of trial history as a source of variability in both behavioral and neuroimaging studies.
Zeitdiskrete approximative Zustandslinearisierung (Time-discrete Approximative State Linearization)
Authors: Bauer Robert , Dourdoumas Nicolaos
Published: February 2007

Die Vor- und Nachteile der so genannten exakten Eingangs-Ausgangslinearisierung sind wohlbekannt. Ein großer Nachteil besteht darin, dass es sich um ein zeitkontinuierliches Regelgesetz handelt, das bei einer zeitdiskreten Regeleinrichtung eventuell nur unbefriedigend angewendet werden kann. Die in diesem Beitrag vorgestellte Methode ist speziell für eine zeitdiskrete Anwendung ausgelegt und in der Wirkung mit der exakten Linearisierung vergleichbar. Die Funktionstüchtigkeit des Regelungskonzeptes wird anhand zweier Beispiele demonstriert.
Dynamische Priorisierung von Prüfschritten in der Werkstattdiagnose (Dynamic Priorisation of Inspection Steps in Workshop Diagnosis)
Authors: Renninger Harald , Konieczny Martin
Published: February 2007

Werkstattdiagnose ist ein wichtiges Element im Lebenszyklus eines Fahrzeugs. Der Fahrzeugkunde erwartet eine schnelle und kostengünstige Abhilfe im Falle eines Defekts. Der Servicetechniker in der Werkstatt muss bei modernen Fahrzeugen bei dieser Aufgabe unterstützt werden. Dabei ist es nur noch mit Computerunterstützung möglich, die grosse Menge an verfügbaren Informationen zu verarbeiten und den Prüfablauf effizient zu gestalten. Unser Ansatz arbeitet mit einem Entscheidungsverfahren basierend auf Entropie- und Kostenbewertungen von Prüfungen, mit dem Ziel dem Servicetechniker zu jedem Zeitpunkt der Diagnosesitzung optimale Prüfungen vorschlagen zu können. Die Prüfdomäne, die Relationen zwischen Prüfungen und geprüften Komponenten, kann durch Naive Bayes'sche Netze beschrieben werden. Der Schwerpunkt dieses Artikels liegt im automatischen Modellaufbau der Bayesnetze und in der Konstruktion einer Entscheidungsfunktion zur Prüfschrittbewertung.
Entwurf einer dezentralen Synchronisationsregelung für elektrische Landeklappenantriebe (Design of a decentralised Synchronisation-Controller for Single-Flap-Drive-Systems)
Authors: Geilsdorf Hendrik , Carl Udo
Published: February 2007

Der Beitrag beschreibt den Entwurf sowie die Analyse eines elektrischen Einzelklappenantriebs für Transportflugzeuge. Besonderes Augenmerk wird dabei auf die optimale Wahl der beeinflussbaren Systemparameter gelegt, um eine hinreichende Synchronität der verwendeten Antriebe und die Vermeidung grenzstabiler Schwingungen zu erreichen. Ergebnisse einer nichtlinearen Simulation runden die Betrachtung ab.
Death, Buddhism, and Existentialism in the Songs of Trinh Côông Sóón
Authors: Schafer John C.
Published: February 2007

Various explanations have been offered for the extraordinary popularity of the composer and singer Tr]nh Côông SKn: his poetic lyrics, his avoidance of the clichéés of prewar music, his antiwar themes, his ability to choose talented female singers, and the like. But little has been said about the Buddhist themes in his songs, perhaps because Vietnamese scholars take them for granted. This article points out these themes and argues that they help explain the Trinh Côông S Kn phenomenon. It also discusses European existentialism, which the author argues fascinated Trinh Côông S Kn but was ultimately not a major influence on his work.
Toxicity of cadmium to six species in two genera of crayfish and the effect of cadmium on molting success
Authors: Wigginton Andrew J. , Birge Wesley J.
Published: February 2007

Nine acute (96-h) toxicity tests were conducted on six species of crayfish (Cambaridae). Six tests focused on adults, and three tests examined juveniles. Lethal concentration to 50% of a population (LC50) and lethal concentration to 10% of a population (LC10) values, respectively, for the adults of individual test species were as follows: Orconectes juvenilis, 2.44 and 0.623 mg Cd/L; Orconectes placidus, 0.487 and 0.092 mg Cd/L; Orconectes virilis, 3.30 and 0.947 mg Cd/L; Procambarus acutus, 0.368 and 0.048 mg Cd/L; Procambarus alleni, 3.07 and 0.386 mg Cd/L; and Procambarus clarkii, 2.66 and 0.486 mg Cd/L. The Orconectes LC50 genus mean acute value (GMAV) was 1.57 mg Cd/L, whereas the LC50 GMAV for Procambarus was 1.44 mg Cd/L. The LC10 GMAVs were 0.379 and 0.208 mg Cd/L, respectively. Family mean acute values (FMAVs) also were calculated for the Cambaridae using all species data (LC50, 1.51 mg Cd/L; LC10, 0.281 mg Cd/L). For tests with juvenile crayfish, the LC50 and LC10 values, respectively, were as follows: O. juvenilis, 0.060 and 0.014 mg Cd/L; O. placidus, 0.037 and 0.002 mg Cd/L; and P. clarkii, 0.624 and 0.283 mg Cd/L. The GMAVs were calculated for juvenile Orconectes (LC50, 0.047 mg Cd/L; LC10, 0.005 mg Cd/L). Additionally, FMAVs were calculated for juvenile crayfish (LC50, 0.111 mg Cd/L; LC10, 0.020 mg Cd/L). Crayfish sensitivity to Cd varied by a factor of nine among species tested as adults and by a factor of 17 among species tested as juveniles. Molting was a sensitive life stage for crayfish. Most individuals that molted shortly before or during exposure to Cd died, whereas all controls that molted in the adult assays survived. Because molting is a sensitive, recurring life-cycle event, molting individuals should be included in toxicological analysis despite some contrary recommendations.
Variability of the protective effect of sodium on the acute toxicity of copper to freshwater cladocerans
Authors: De Schamphelaere Karel A.C. , Bossuyt Bart T.A. , Janssen Colin R.
Published: February 2007

The acute biotic ligand model (BLM) is proposed by the U.S. Environmental Protection Agency (U.S. EPA) to incorporate bioavailability in calculating aquatic life criteria for Cu in freshwater. This approach currently assumes that the effects of water chemistry on acute Cu toxicity can be described with one single set of identical BLM parameters for all organisms. An important water characteristic is the concentration of Na, which protects aquatic organisms against Cu toxicity. Based on physiological considerations related to the mechanism of Cu toxicity and the possible role of Na therein, we hypothesized that an interspecies variability of the protective effect of sodium on Cu toxicity might exist among freshwater organisms. To test this hypothesis, acute 48-h toxicity assays with Cu were conducted with 16 field-collected cladoceran populations and a laboratory-reared clone of Ceriodaphnia dubia at Na concentrations of between 0.077 and 10 mM. Increased Na protected all but one population. Contrary to what the BLM predicts, however, an upper limit to this protective effect was observed for some populations at Na concentrations of greater than 4 mM. This may suggest that processes other than just Cu-Na competition at a single unidentate biotic ligand site may be involved in Cu toxicity. Between populations, conditional stability constants for binding of Na to the biotic ligand (log K*NaBL which quantify the protective effect of Na, varied between 2.2 and 4.4. Higher log K values generally were associated with more sensitive populations. Although a full mechanistic explanation for our observations is lacking, our data may potentially be used to refine the U.S. EPA procedure to establish site-specific water-quality criteria for Cu.
Mutagenicity assessment of produced water during photoelectrocatalytic degradation
Authors: Li Guiying , An Taicheng , Nie Xiangping , Sheng Guoying , Zeng Xiangying , Fu Jiamo , Lin Zheng , Zeng Eddy Y.
Published: February 2007

Oilfield produced water was treated by photocatalysis, electro-oxidation, and photoelectrocatalysis, respectively. The chemical composition and toxicity of the raw effluent and treated products were assessed by chemical and mutagenicity analysis. The raw effluent exhibited mutagenic activity in both strains of Salmonella typhimurium. The lowest concentration of the dichloromethane extract capable of inducing a positive response in strains TA98 and TA100 were as low as 4 and 5 μg/plate, respectively. All three technologies could detoxify direct-acting mutagenic organic pollutants efficiently, although they could not completely eliminate mutagenicity in the water after 60 min of treatment. At equivalent doses, photoelectrocatalysis exhibited the greatest capability to reduce genotoxicity, whereas photocatalysis was the least effective and did not cause appreciable change in mutagenicity. The gas chromatography—mass spectrometry (GC-MS) analysis revealed that n-alkanes (259.4 ng/L) and phenolic compounds (2,501.4 ng/L) were the main organic constituents in the oilfield produced water. Thus, the results of both biological and chemical analysis indicate that photoelectocatalysis was the most effective technology for degradation of oilfield wastewater.
The theory underlying dose-response models influences predictions for intermittent exposures
Authors: Zhao Yuan , Newman Michael C.
Published: February 2007

Prediction of pulsed or intermittent exposure effects on populations is emerging as an important issue in ecotoxicology. However, the underlying theory of the dose-response models has not been tested rigorously enough to provide a true understanding for predicting the effects of pulsed exposures. Since its introduction, the individual effective dose (IED) theory has remained the dominant explanation in the literature. The present study tested whether the IED theory is the dominant explanation for the probit model (or similar models) for both copper sulfate (CuSO4) and sodium pentachlorophenol (NaPCP). Three groups of amphipods (Hyalella azteca) were first exposed to lethal, sublethal, and zero concentrations of each toxicant. After recovery, all survivors were exposed to lethal concentrations, and their mortalities during a second exposure were compared. Under the specific concentrations and durations used, stochastic processes were dominant for CuSO4. Both stochasticity and IED appeared to be relevant for NaPCP, but stochasticity dominated the dynamics. Current ecotoxicology tests should include assessment of the underlying dynamics as one of the first steps of studying pulsed or intermittent exposure effects.
Rheological properties and processability of chemically modified poly(ethylene terephthalate‐co‐ethylene isophthalate)
Authors: Yamaguchi Masayuki , Wakabayashi Takashi
Published: February 2007

Rheological properties and extrusion processability have been evaluated for poly(ethylene terephthalate‐co‐ethylene isophthalate) (P(ET‐EI)) modified by a styrene‐acrylate‐based copolymer with glycidyl functionality in an extruder. Adding a small amount of the modifier enhances melt elasticity to a great extent. Consequently, modified P(ET‐EI) exhibits excellent processability without sagging, that is, downward deformation of extrudates by gravitational force. Considering that molecular weight and its distribution hardly change, which is confirmed by GPC measurements, generation of long‐chain branches is responsible for the rheological properties and thus the processability. © 2007 Wiley Periodicals, Inc. Adv Polym Techn 25:236–241, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20078
Treatment of chronic knee synovitis with arthroscopic synovectomy after failure of intraarticular injection of radionuclide
Authors: Combe Bernard , Krause Eric , Sany Jacques
Published: February 2007

Although satisfactory results have been obtained with conventional synovectomy of the knee, there are frequent complications, and a long period of rehabilitation is necessary after this surgery. We performed arthroscopic synovectomy of the knees of 30 patients (33 knees), 22 of whom had rheumatoid arthritis. These patients underwent the procedure after failure to respond to an intraarticular injection of either osmic acid or yttrium 90. The operated knee was moved 3–5 hours after the arthroscopy, and the patients walked the next day. No rehabilitation was needed. The followup period ranged from 6 months to 36 months, with an average of 17.7 months. Except for 1 patient with severe arthritis, all patients experienced improvement. Results were rated as “good” or “very good” in 27 knees. Six months after synovectomy, the patients were asked to rate their improvement; the mean ± SEM degree of improvement was 79.1 ± 22.9%. All patients had significant improvement in the range of motion of the knee. One patient required manipulation of the knee (while under anesthesia) soon after the arthroscopy. There were no other complications. There was no detectable radiographic evidence of disease progression in 24 patients who were seen 1 year after the procedure or in 9 patients who were seen 2 years after the arthroscopy. Thus, arthroscopic synovectomy appears to be an effective and simple treatment for chronic knee synovitis, and has a low morbidity rate.
Relative role of genetic and environmental factors in disease expression: sib pair analysis in ankylosing spondylitis
Authors: Calin Andrei , Elswood Judith
Published: February 2007

Forty‐two sib pairs concordant for ankylosing spondylitis (mean disease duration 20.1 years) were assessed to define the relative role of genetic and environmental factors in determining age and calendar year of disease onset, systemic features, functional outcome and prognosis, and radiologic progression. Twenty‐seven pairs were of the same sex (male/male n = 21, female/female n = 6). The correlation coefficient was not significant for age at onset (rs = 0.235), but was much higher for calendar year of onset (rs = 0.702, P < 0.01). These data were confirmed by two‐way analysis of variance: between sibs, the F probability was 0.07 for age at onset (41 degrees of freedom, F ratio 1.6) and was < 0.001 for calendar year of onset (41 degrees of freedom, F ratio 5.45). Thus, it is suggested that environmental factors play the greater role in the timing of onset. Concordance for the presence or absence of uveitis was only 43%, again suggesting that genetic factors are less significant than the environment. Conversely, genetic factors are more important in influencing prognosis. A disability and pain index revealed that sibs had a closer score than expected by chance alone (P = 0.035); also, the correlation coefficient for blinded radiologic analysis (pelvic and lumbar views) was significant for pairs of sibs (rs = 0.859, P < 0.01), but was not significant for random pairs of subjects (rs = ‐0.144). In contrast, within–sib pair and random subject–pair analyses of hip radiographs revealed rs = ‐0.111 and ‐0.033, respectively, neither of which was significant. In summary, these results suggest that environmental factors are more important in determining date of onset, and therefore, coincidental age at onset, of ankylosing spondylitis. This in turn relates to the risk of hip involvement because younger age at onset is associated with greater risk of hip disease. Genetic factors have the greater influence on radiologic progression and disability. The phenotypic expression is a composite picture of both.
Class ii major histocompatibility complex gene sequences in rheumatoid arthritis. The third diversity regions of both DRβ1 genes in two DR1, DRw10–positive individuals specify the same inferred amino acid sequence as the DRβ1 and DRβ2 Genes of a DR4 (Dw14) haplotype
Authors: Merryman Parvin F. , Crapper Richard M. , Lee Sicy , Gregersen Peter K. , Winchester Robert J.
Published: February 2007

The DR1 and DRw10β1, chain genes were isolated from each of 2 individuals with rheumatoid arthritis who were heterozygous for these class II major histocompatibility complex specificities. The sequences of the DR1β1 chains from both patients were identical, differing from previously reported DRβ1 chains of individuals without RA by 2 amino acid substitutions, at positions 85 (Val‐Ala) and 86 (Gly‐Val), and by a silent mutation at the last nucleotide of codon 78 (C–T), resulting in the loss of a Pst I restriction endonuclease site. Identical DRw10β1, chain genes were found in both patients. These were shown to encode the epitope recognized by monoclonal antibody 109d6. This antibody also recognizes an epitope on the DRw53β2 chain of the DR4 haplotype. The third diversity regions of the DR1β (amino acids 67–74) and the DRw10β1 chains (amino acids 67–73) were identical, respectively, with those of the DR4 (Dw14) β1, and β2 chains, raising the possibility that in these patients, the third diversity regions of the two DRβ1, chain genes present in trans are conformationally equivalent to the cis‐encoded third diversity regions of the DR4 (Dw14), DRβ1, and β2 chains. The nucleotide sequences of the DQβ complementary DNA clones were identical to that of the DQw1β chain, and no DRβ2 complementary DNA clones were identified.
Changes in lymphocyte infiltration of the synovial membrane and the clinical course of rheumatoid arthritis
Authors: Rooney Madeleine , Whelan Alex , Feighery Conleth , Bresnihan Barry
Published: February 2007

Multiple samples of synovial membrane were obtained by needle biopsy from 24 patients with rheumatoid arthritis (RA) before, and 1 year after, standard antirheumatic drug therapy was given. Changes in the immunohistologic features of the synovial membrane (read blindly) were compared with the clinical course of RA in each patient. A composite clinical index of disease activity (IDA) and spontaneous in vitro synthesis of IgM rheumatoid factor (IgM‐RF) by blood mononuclear cells were also measured before and after treatment. In 16 patients (group A), the IDA indicated 26–69% improvement, and the values for spontaneous IgM‐RF decreased substantially. In 8 patients (group B), the IDA indicated deterioration or no improvement, and the values for spontaneous IgM‐RF were unchanged. In group A patients, the intensity of the T cell infiltrate decreased from a mean score of 1.3 to a mean score of 0.8 (P = 0.025). The ratio of T helper cells to T suppressor/cytotoxic cells was ⩽2:1 in 90% of group A patients before treatment, compared with 20% of these patients after treatment (P = 0.016), and the number of biopsy samples that contained identifiable B cells decreased from 36% before treatment to 7% after treatment. In group B patients, there were no changes in the intensity of T cell infiltration, the ratio of T helper cells to T suppressor/cytotoxic cells, or the number of biopsy samples with identifiable B cells.
The effects of methotrexate on the production and activity of interleukin‐1
Authors: Segal Rafael , Mozes Edna , Yaron Michael , Tartakovsky Boris
Published: February 2007

To explore the possibility that the mechanism of action of methotrexate (MTX) in rheumatoid arthritis (RA) is related to modulation of interleukin‐1 (IL‐1), the effects of MTX on IL‐1 production and activity were evaluated. Human peripheral blood mononuclear cells and murine peritoneal and splenic cells were stimulated by lipopolysaccharide to produce IL‐1. No inhibition of IL‐1 synthesis or secretion caused by MTX treatment could be demonstrated either in vitro or in vivo, in patients with RA or in mice treated with MTX. We did show, however, that MTX had an inhibitory effect on IL‐1 activity in 2 assays that demonstrate 2 different functions of IL‐1. In a 2‐step assay using LBRM‐33‐1A5 (1A5) and CTLD cells, MTX inhibited the secretion of IL‐2 by 1A5 lymphoma cells in response to phytohemag‐glutinin and IL‐1. In an assay using D10.G4.1 (D10) cells, MTX inhibited IL‐1–induced proliferation of the D10 T cell clone. No effect of the drug on IL‐2 activity was observed. The results demonstrate that MTX is capable of inhibiting some IL‐1 activities without affecting IL‐1 production or secretion. We propose that the inhibition of IL‐1 activity or IL‐1–dependent events may be one of the mechanisms of action of MTX in RA.
Antiproliferative effects of methotrexate on peripheral blood mononuclear cells
Authors: Olsen Nancy J. , Murray Lisa M.
Published: February 2007

Methotrexate was added to cultured mononuclear cells from the peripheral blood of normal individuals and patients with rheumatoid arthritis (RA) to study the drug's effects on mononuclear cell proliferation and antibody synthesis. In the presence of methotrexate, marked antiproliferative effects (to levels <15% of baseline) were seen with 3H‐deoxyuridine, but not with 3H‐thymidine, as the marker of cell division. This difference was not due to altered kinetics of proliferation or the presence of salvage nucleotides in the culture medium. The absence of suppression of antibody production preactivated by pokeweed mitogen in vitro and the low levels of suppression of spontaneous IgM rheumatoid factor production by blood mononuclear cells from RA patients suggested a relative resistance of activated cells to the effects of methotrexate. The effects of methotrexate on both cell proliferation and antibody synthesis were completely reversed by the addition of high concentrations of exogenous folinic acid. The results suggest that methotrexate has effects on immuno‐competent cells that may contribute to the efficacy of this drug in the treatment of RA and other autoimmune diseases.