bluuebunny/crossref_metadata_2025 huggingface dataset:
GLD-3 and Control of the Mitosis/Meiosis Decision in the Germline of Caenorhabditis elegans
Authors: Eckmann Christian R , Crittenden Sarah L , Suh Nayoung , Kimble Judith
Published: September 2004

Germ cells can divide mitotically to replenish germline tissue or meiotically to produce gametes. In this article, we report that GLD-3, a Caenorhabditis elegans Bicaudal-C homolog, promotes the transition from mitosis to meiosis together with the GLD-2 poly(A) polymerase. GLD-3 binds GLD-2 via a small N-terminal region present in both GLD-3S and GLD-3L isoforms, and GLD-2 and GLD-3 can be co-immunoprecipitated from worm extracts. The FBF repressor binds specifically to elements in the gld-3S 3′-UTR, and FBF regulates gld-3 expression. Furthermore, FBF acts largely upstream of gld-3 in the mitosis/meiosis decision. By contrast, GLD-3 acts upstream of FBF in the sperm/oocyte decision, and GLD-3 protein can antagonize FBF binding to RNA regulatory elements. To address the relative importance of these two regulatory mechanisms in the mitosis/meiosis and sperm/oocyte decisions, we isolated a deletion mutant, gld-3(q741), that removes the FBF-binding site from GLD-3L, but leaves the GLD-2-binding site intact. Animals homozygous for gld-3(q741) enter meiosis, but are feminized. Therefore, GLD-3 promotes meiosis primarily via its interaction with GLD-2, and it promotes spermatogenesis primarily via its interaction with FBF.
SNR1 (INI1/SNF5) Mediates Important Cell Growth Functions of the Drosophila Brahma (SWI/SNF) Chromatin Remodeling Complex
Authors: Zraly Claudia B , Marenda Daniel R , Dingwall Andrew K
Published: September 2004

SNR1 is an essential subunit of the Drosophila Brahma (Brm) ATP-dependent chromatin remodeling complex, with counterparts in yeast (SNF5) and mammals (INI1). Increased cell growth and wing patterning defects are associated with a conditional snr1 mutant, while loss of INI1 function is directly linked with aggressive cancers, suggesting important roles in development and growth control. The Brm complex is known to function during G1 phase, where it appears to assist in restricting entry into S phase. In Drosophila, the activity of DmcycE/CDK2 is rate limiting for entry into S phase and we previously found that the Brm complex can suppress a reduced growth phenotype associated with a hypomorphic DmcycE mutant. Our results reveal that SNR1 helps mediate associations between the Brm complex and DmcycE/CDK2 both in vitro and in vivo. Further, disrupting snr1 function suppressed DmcycEJP phenotypes, and increased cell growth defects associated with the conditional snr1E1 mutant were suppressed by reducing DmcycE levels. While the snr1E1-dependent increased cell growth did not appear to be directly associated with altered expression of G1 or G2 cyclins, transcription of the G2-M regulator string/cdc25 was reduced. Thus, in addition to important functions of the Brm complex in G1-S control, the complex also appears to be important for transcription of genes required for cell cycle progression.
Ethical issues in identifying and recruiting participants for familial genetic research
Authors: Beskow Laura M. , Botkin Jeffrey R. , Daly Mary , Juengst Eric T. , Lehmann Lisa Soleymani , Merz Jon F. , Pentz Rebecca , Press Nancy A. , Ross Lainie Friedman , Sugarman Jeremy , Susswein Lisa R. , Terry Sharon F. , Austin Melissa A. , Burke Wylie
Published: September 2004

Family‐based research is essential to understanding the genetic and environmental etiology of human disease. The success of family‐based research often depends on investigators' ability to identify, recruit, and achieve a high participation rate among eligible family members. However, recruitment of family members raises ethical concerns due to the tension between protecting participants' privacy and promoting research quality, and guidelines for these activities are not well established. The Cancer Genetics Network Bioethics Committee assembled a multidisciplinary group to explore the scientific and ethical issues that arise in the process of family‐based recruitment. The group used a literature review as well as expert opinion to develop recommendations about appropriate approaches to identifying, contacting, and recruiting family members. We conclude that there is no single correct approach, but recommend a balanced approach that takes into account the nature of the particular study as well as its recruitment goals. Recruitment of family members should be viewed as part of the research protocol and should require appropriate informed consent of the already‐enrolled participant. Investigators should inform prospective participants why they are being contacted, how information about them was obtained, and what will happen to that information if they decide not to participate. The recruitment process should also be sensitive to the fact that some individuals from families at increased genetic risk will have no prior knowledge of their risk status. These recommendations are put forward to promote further discussion about the advantages and disadvantages of various approaches to family‐based recruitment. They suggest a framework for considering alternative recruitment strategies and their implications, as well as highlight areas in need of further empirical research. © 2004 Wiley‐Liss, Inc.
Axially dissymmetric N‐thioacylated (S)‐(–)‐1,1′‐binaphthyl‐2,2′‐diamine ligands for copper‐catalyzed asymmetric Michael addition of diethylzinc to α,β‐unsaturated ketone
Authors: Shi Min , Duan Wei‐Liang , Rong Guo‐Bin
Published: September 2004

Axially chiral thioamide ligands L5, L6, L8, L11, and bis(thioamide) ligand L13 were prepared from the reaction of (S)‐(–)‐1,1′‐binaphthyl‐2,2′‐diamine with acyl chlorides and phosphorus pentasulfide (P2S5). The catalytic asymmetric 1,4‐addition of diethylzinc to α,β‐unsaturated ketones was examined using this novel chiral ligand system with 28–73% ee in moderate to good yields. Chirality 16:642–651, 2004. © 2004 Wiley‐Liss, Inc.
Iodine‐131 metaiodobenzylguanidine treatment for metastatic carcinoid
Authors: Safford Shawn D. , Coleman R. Edward , Gockerman Jon P. , Moore Joseph , Feldman Jerome , Onaitis Mark W. , Tyler Douglas S. , Olson John A.
Published: September 2004

BACKGROUND

Iodine‐131 metaiodobenzylguanidine (131I‐MIBG) is useful for imaging carcinoid tumors and recently has been applied to the palliative treatment of metastatic carcinoid in small studies. The authors now report their results on the therapeutic utility of high‐dose 131I‐MIBG treatment in a large group of patients with metastatic carcinoid tumors.

METHODS

The authors performed a retrospective review of 98 patients with metastatic carcinoid who were treated at their institution with 131I‐MIBG over a 15‐year period. Endpoints examined included the World Health Organization criteria for treatment response: symptoms, hormone (5‐hydroxyindoleacetic acid [5‐HIAA]) production, and clinical tumor response.

RESULTS

Patients received a median dose of 401 ± 202 millicuries (mCi) 131I‐MIBG. The median survival after treatment was 2.3 years. Patients who experienced a symptomatic response had improved survival (5.76 years vs. 2.09 years; P < 0.01). For the 56 patients who had 5‐HIAA levels monitored, the mean urine 5‐HIAA levels decreased significantly after 131I‐MIBG treatment (126 ± 122 ng/mL vs. 91 ± 125 ng/mL; P < 0.01); however, the patients with reduced 5‐HIAA levels did not experience improved survival (4.11 years vs. 3.42 years; P = 0.2). Patients who received an initial 131I‐MIBG dose > 400 mCi lived longer than patients who received < 400 mCi (4.69 years vs. 1.86 years; P = 0.05). Radiographic tumor response did not predict survival. Toxicity included pancytopenia, thrombocytopenia, nausea, and emesis.

CONCLUSIONS

The current data support 131I‐MIBG treatment in select patients with metastatic carcinoid who progress despite optimal medical management. Improved survival was predicted best by symptomatic response to 131I‐MIBG treatment, but not by hormone or radiographic response. Cancer 2004. © 2004 American Cancer Society.
Total Synthesis of Sequential Retro‐Peptide Oligomers
Authors: Ceretti Simone , Luppi Gianluigi , De Pol Silvia , Formaggio Fernando , Crisma Marco , Toniolo Claudio , Tomasini Claudia
Published: September 2004

The total synthesis of sequential oligomers of retro‐peptides of the general formula Boc(‐gGly‐mAib)n‐OBn, starting from dimethylmalonic acid, has been carried out in good overall yield. The key step is the formation of the gGly unit >N−CH2−N<, which is easily obtained in a one‐pot/three‐step reaction from BnO‐mAib‐Gly‐OH and diphenylphosphoryl azide. The synthesis of the sequential oligomers of RCO(‐gAla‐mAib)n‐OR′ was also attempted, but the oligomerization step failed because the gAla moiety readily decomposes or racemizes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Acetylenes in Catalysis: Enantioselective Additions to Carbonyl Groups and Imines and Applications Beyond
Authors: Cozzi Pier Giorgio , Hilgraf Robert , Zimmermann Nicole
Published: September 2004

Acetylenes represent a class of versatile building blocks, which are widely used in organic synthesis. Over the past years, a considerable number of publications have appeared that focus on the enantioselective addition of acetylenes to carbonyls and imines. In addition, novel applications for acetylenes have emerged in the literature. We herein present an overview of recent results in these areas. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Preparation of Intermediates for the Synthesis of Polycyclic Alkaloids: A New Access to the Azabicyclic Core of the Stemona Alkaloids
Authors: Cid Pau , Closa Montserrat , de March Pedro , Figueredo Marta , Font Josep , Sanfeliu Elena , Soria Angeles
Published: September 2004

Several isoxazolidines, derived from the 1,3‐dipolar cycloaddition of α,β‐hexenolides to cyclic nitrones, were converted into the corresponding piperidine‐ and pyrrolidine‐oxepinones by reduction of the nitrogen−oxygen bond. The potential of the resulting amino alcohols as synthetic precursors of polycyclic alkaloids was explored. These intermediates provide a new access to the 1‐azabicyclo[5.3.0]decane core of the Stemona alkaloids. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Interface HostGuest Interaction Between Calix[4]pyrrole and Neutral Derivatives of Phenol as the Base for Their Potentiometric Discrimination
Authors: Radecki Jerzy , Radecka Hanna , Piotrowski Tomasz , Depraetere Stefaan , Dehaen Wim , Plavec Janez
Published: September 2004

Calix[4]pyrrole liquid membrane electrodes display a potentiometric response towards the neutral form of phenol derivatives. They do not respond towards the corresponding anionic forms. The mechanism of the generation of the potentiometric signal relies on: (1) The creation of supramolecular complex calix[4]pyrrolenitrophenol at the organic/aqueous interface; (2) The increasing of the acidity of OH group from nitrophenol molecules due to formation of hydrogen bond between calix[4]pyrrolenitrophenol at the interface; (3) The dissociation of the OH group from calix[4]pyrrolenitrophenol complex and the ejection of H+ to the aqueous layer adjusted to the membrane organic phase boundary. The sensitivity and selectivity of the calix[4]pyrrole liquid membrane electrodes are governed by the lipophilicity and acidity of the phenolic guests. Also, the affinity to create a hydrogen bond between the host and the target molecule is a parameter which has a strong influence on the phenomena studied.
Electrocatalytic Determination of Vitamin C Using Calixarene Modified Carbon Paste Electrodes
Authors: Ijeri Vijaykumar S. , Algarra Manuel , Martins Ana
Published: September 2004

Effect of in situ complexation of some ions with variable valencies, like Co(II), Ni(II), Mn(II), Cu(II) and Pb(II) on the the electrooxidation of Vitamin C (L‐ascorbic acid) was studied by cyclic voltammetry using carbon paste electrodes modified with p‐tert‐butylcalix[4]arene and p‐tert‐butylcalix[6]arene in perchloric acid, acetic acid and ammonium acetate media. Pb(II) was found to bind strongly with p‐tert‐butylcalix[4]arene in acetate medium, resulting in its being retained at the electrode surface and catalyzing the oxidation of ascorbic acid. The overpotential was reduced by about 200 mV with an increase in the peak currents. Linearity was observed over the range of 0.07–400 ppm with a detection limit of 30 ppb by differential pulse voltammetry. Interferences of some common substances like sugars and amino acids were studied and the modified electrode was used for the determination of vitamin C in commercial samples.
Asymmetry analysis of cingulum based on scale‐invariant parameterization by diffusion tensor imaging
Authors: Gong Gaolang , Jiang Tianzi , Zhu Chaozhe , Zang Yufeng , Wang Fei , Xie Sheng , Xiao Jiangxi , Guo Xuemei
Published: September 2004

Current analysis of diffusion tensor imaging (DTI) is based mostly on a region of interest (ROI) in an image dataset, which is specified by users. This method is not always reliable, however, because of the uncertainty of manual specification. We introduce an improved fiber‐based scheme rather than an ROI‐based analysis to study in DTI datasets of 31 normal subjects the asymmetry of the cingulum, which is one of the most prominent white matter fiber tracts of the limbic system. The present method can automatically extract the quantitative anisotropy properties along the cingulum bundles from tractography. Moreover, statistical analysis was carried out after anatomic correspondence specific to the cingulum across subjects was established, rather than the traditional whole‐brain registration. The main merit of our method compared to existing counterparts is that to find such anatomic correspondence in cingulum, a scale‐invariant parameterization method by arc‐angle was proposed. It can give a continuous and exact description on any segment of cingulum. More interestingly, a significant left‐greater‐than‐right asymmetry pattern was obtained in most segments of cingulum bundle (−50–25 degrees), except in the most posterior portion of cingulum (25–50 degrees). Hum Brain Mapp 24:92–98, 2005. © 2004 Wiley‐Liss, Inc.
Distinguishing between heterogeneity and inefficiency: stochastic frontier analysis of the World Health Organization's panel data on national health care systems
Authors: Greene William
Published: September 2004

The most commonly used approaches to parametric (stochastic frontier) analysis of efficiency in panel data, notably the fixed and random effects models, fail to distinguish between cross individual heterogeneity and inefficiency. This blending of effects is particularly problematic in the World Health Organization's (WHO) panel data set on health care delivery, which is a 191 country, 5‐year panel. The wide variation in cultural and economic characteristics of the worldwide sample produces a large amount of unmeasured heterogeneity in the data. This study examines several alternative approaches to stochastic frontier analysis with panel data, and applies some of them to the WHO data. A more general, flexible model and several measured indicators of cross country heterogeneity are added to the analysis done by previous researchers. Results suggest that there is considerable heterogeneity that has masqueraded as inefficiency in other studies using the same data. Copyright © 2004 John Wiley & Sons, Ltd.
Isoform‐specific expression of 14‐3‐3 proteins in human lung cancer tissues
Authors: Qi Wenqing , Liu Xiaobing , Qiao Dianhua , Martinez Jesse D.
Published: September 2004

14‐3‐3 Proteins play important roles in a wide range of vital regulatory processes, including signal transduction, apoptosis, cell cycle progression and DNA replication. In mammalian cells, 7 14‐3‐3 isoforms (β, γ, ϵ, η, σ, θ and ζ) have been identified and each of these seems to have distinct tissue localizations and isoform‐specific functions. Previous studies have shown that 14‐3‐3 protein levels are higher in human lung cancers as compared to normal tissues. It is unclear, however, which of the 14‐3‐3 isoform(s) are overexpressed in these cancers. In our study, the levels of all seven 14‐3‐3 isoforms were examined by RT‐PCR and Western blotting. We show that the message for only two isoforms, 14‐3‐3ϵ and ζ, could be detected in normal tissues. In lung cancer biopsies, however, four isoforms, 14‐3‐3β, γ, σ, and θ, in addition to 14‐3‐3ϵ and ζ, were present in abundance. The expression frequency of 14‐3‐3β, γ, σ and θ isoforms was 11, 10, 13 and 8 of the 14 biopsies examined, respectively. The data from immunohistochemical staining and Western blotting were consistent with the RT‐PCR results. Given the prevalence of elevated 14‐3‐3 expression in human lung cancers we propose that these proteins may be involved in lung cancer tumorigenesis and that specific 14‐3‐3 proteins may be useful as markers for lung cancer diagnosis and targets for therapy.
Epstein‐Barr virus‐encoded latent membrane protein 1 promotes stress‐induced apoptosis upstream of caspase‐2‐dependent mitochondrial perturbation
Authors: Zhang Xiangning , Uthaisang Wanlaya , Hu LiFu , Ernberg Ingemar T. , Fadeel Bengt
Published: September 2004

Previous studies have shown that Epstein‐Barr virus (EBV)‐encoded latent membrane protein 1 (LMP1) enhances etoposide‐induced apoptosis in epithelial cells. Our study was undertaken to further dissect the modulation of tumor cell apoptosis by this viral protein. Using an inducible system of LMP1 expression in HeLa cells, we show herein that etoposide‐triggered apoptosis, as evidenced by nuclear condensation and caspase‐3 activation, is enhanced by LMP1. LMP1 also potentiates etoposide‐induced processing and activation of caspase‐2 in this model and enhances the dissipation of mitochondrial transmembrane potential and the release of cytochrome c in response to etoposide. Moreover, cisplatin‐triggered activation of caspases 2 and 3 is potentiated upon expression of LMP1. A similar LMP1‐mediated enhancement of cisplatin‐induced caspase activation was seen upon stable transfection of wild‐type LMP1 into the nasopharyngeal carcinoma cell line, TW03. Finally, using deletion mutants of LMP1 to determine the region of LMP1 required for apoptosis potentiation, we found that amino acids 350–386 (located within the CTAR2 domain) were responsible for sensitizing cells to cisplatin. We conclude that LMP1‐dependent potentiation of stress‐induced apoptosis occurs at an early step in the apoptosis cascade, upstream of the activation of caspase‐2, and involves the C‐terminal signaling domain of LMP1. These findings could have important ramifications for the treatment of EBV‐associated malignancies of epithelial origin, including nasopharyngeal carcinoma.
Maternal human polyomavirus infection and risk of neuroblastoma in the child
Authors: Stolt Annika , Kjellin Mimmi , Sasnauskas Kestutis , Luostarinen Tapio , Koskela Pentti , Lehtinen Matti , Dillner Joakim
Published: September 2004

To investigate if polyomavirus infection during pregnancy is linked to development of neuroblastoma in the child, serum samples of 115 index mothers from the pregnancy where the child eventually developed neuroblastoma were identified and matched with serum samples from 8 control mothers per index mother. The samples were tested for specific IgG and IgM antibodies to BK and JC virus using enzyme immunoassays based on purified yeast‐expressed virus‐like particles (VLPs). The serum samples as well as 10 neuroblastoma cell lines were also analyzed using Real Time (TaqMan) PCR for detection and quantification of BK virus DNA. The BK virus IgG seroprevalence was similar among index mothers (80%) and control mothers (83%) [OR 0.8; 95% confidence interval (95% CI): 0.5–1.3]. BK virus IgM was also not associated with neuroblastoma risk (OR was OR = 0.6; 95% with CI, 0.2–1.9). Also JC virus had no association, neither for IgG (OR = 0.9; 95% CI, 0.6–1.4) nor for IgM (OR = 0.9; 95% CI, 0.4–1.9). All serum samples and all neuroblastoma cell lines were negative for BKV DNA. In summary, a comprehensive cohort using both serology and polyomavirus DNA detection found no evidence for association between BKV or JCV polyomaviruses and neuroblastoma.
Serum testosterone levels and breast cancer recurrence
Authors: Berrino Franco , Pasanisi Patrizia , Bellati Cristina , Venturelli Elisabetta , Krogh Vittorio , Mastroianni Antonio , Berselli Edoardo , Muti Paola , Secreto Giorgio
Published: September 2004

Prospective studies show that high serum levels of androgens and estrogens are associated with increased incidence of postmenopausal breast cancer. The aim of the present analysis was to study the prognostic value of serum testosterone, estradiol and related factors in postmenopausal breast cancer patients. One hundred and ten patients without clinical recurrence were included in the study. After 5.5 years of follow‐up, 31 patients developed distant metastasis (16), local relapse (4), or contralateral breast cancer (11). The risk of adverse events in relation to hormone level was examined by Cox' proportional hazard modeling, adjusting for hormone receptor status and stage at diagnosis. Body mass index and serum levels of testosterone, estradiol and glucose were significantly higher in patients who recurred than those who did not. The hazard ratios were 1.8 (95% CI = 0.5–6.3) for the middle and 7.2 (95% CI = 2.4–21.4) for the upper tertiles of baseline testosterone distribution. Other hormones had only minor influence on prognosis. High testosterone predicts breast cancer recurrence. Further studies are required to determine whether dietary or other medical intervention to reduce testosterone can reduce the recurrence of breast cancer.
Mononucleotide repeats BAT‐26 and BAT‐25 accurately detect MSI‐H tumors and predict tumor content: Implications for population screening
Authors: Brennetot Caroline , Buhard Olivier , Jourdan Florence , Flejou Jean‐François , Duval Alex , Hamelin Richard
Published: September 2004

Tumors with a defective DNA mismatch repair system (MSI‐H tumors) have distinct molecular and clinicopathologic profiles compared with mismatch repair‐proficient tumors and are associated with a relatively favorable prognosis. There is evidence to suggest that colorectal cancer patients with MSI‐H tumors respond differently to adjuvant chemotherapy. Determination of MSI status also has clinical application for assisting in the diagnosis of suspected hereditary nonpolyposis colorectal cancer cases. For these reasons, it is becoming increasingly apparent that testing for MSI should be conducted routinely in human cancer types that frequently present with such a phenotype. BAT‐26 and BAT‐25 are mononucleotide repeats that are widely used to establish the MSI status of human tumors. We show here that their allelic size profiles provide an estimate of the percentage of contaminating normal cells in MSI‐H tumors. These markers are sensitive enough to detect instability when the tumor cell content of a sample is as low as 5–10%. MSI‐H tumors contain mutations in coding repeats within genes known to be targets for instability. In cases with low tumor cell content, no mutations in any of 9 coding repeats were detected. However, when these samples were enriched for tumor cells, mutations were detected in the same target genes. Thus, BAT‐26 and BAT‐25 markers accurately identify MSI‐H tumors without prior need for enrichment for tumor cells and indicate which samples require further purification before screening for mutations in target genes for instability. Our results have implications for large‐scale screening of cancer patients to determine MSI‐H status and prognosis.
Do nonattenders in mammography screening programmes seek mammography elsewhere?
Authors: Jensen Allan , Olsen Anne Helene , von Euler‐Chelpin My , Helle Njor Sisse , Vejborg Ilse , Lynge Elsebeth
Published: September 2004

The objectives of our study were to analyse the use of diagnostic mammography among nonattenders and attenders in organised mammography screening in Denmark in 2000, to assess the contamination from organised screening of noninvited age groups and to measure the impact of local policy on opportunistic screening. Data on all diagnostic mammographies performed in Denmark in 2000 and data on women targeted by the 2 organised mammography screening programmes in Copenhagen and the county of Fyn were collected. All data were linked by the Danish personal identification number. Information on the official policy in 2000 with regard to opportunistic screening was collected from all counties. The proportion of women using diagnostic mammography was only 1–3% for both attenders and nonattenders in organised mammography screening, but it was significantly higher in Copenhagen than in Fyn, due to availability of mammography in private clinics. The proportion of women using diagnostic mammography varied from 1–4% across counties. The official policy on access to diagnostic mammography and contamination from organised mammography screening of adjacent age groups had no impact on the use. Instead, urbanisation was positively correlated with use of diagnostic mammography. In conclusion, our results clearly showed that nonattenders in organised mammography screening programmes do not seek mammography outside the programme. Since a positive policy toward opportunistic screening did not have any effect, our results add further evidence to existing knowledge that the only reasonable way to achieve high mammography coverage is through a well‐organised screening programme.
Breast cancer risk associated with genotype polymorphism of the catechol estrogen‐metabolizing genes: A multigenic study on cancer susceptibility
Authors: Cheng Ting‐Chih , Chen Shou‐Tung , Huang Chiun‐Sheng , Fu Yi‐Ping , Yu Jyh‐Cherng , Cheng Chun‐Wen , Wu Pei‐Ei , Shen Chen‐Yang
Published: September 2004

Estrogen has been suggested to trigger breast cancer development via an initiating mechanism involving its metabolite, catechol estrogen (CE). To examine this hypothesis, we carried out a multigenic case‐control study of 469 incident breast cancer patients and 740 healthy controls to define the role of important genes involved in the different metabolic steps that protect against the potentially harmful effects of CE metabolism. We studied the 3 genes involved in CE detoxification by conjugation reactions involving methylation (catechol‐O‐methyltransferase, COMT), sulfation (sulfotransferase 1A1, SULT1A1), or glucuronidation (UDP‐glucuronosyltransferase 1A1, UGT1A1), one (manganese superoxide dismutase, MnSOD) involved in protection against reactive oxidative species‐mediated oxidation during the conversion of CE‐semiquinone (CE‐SQ) to CE‐quinone (CE‐Q), and 2 of the glutathione S‐transferase superfamily, GSTM1 and GSTT1, involved in CE‐Q metabolism. Support for this hypothesis came from the observations that (i) there was a trend toward an increased risk of breast cancer in women harboring a greater number of putative high‐risk genotypes of these genes (p < 0.05); (ii) this association was stronger and more significant in those women who were more susceptible to estrogen [no history of pregnancy or older (≥26 years) at first full‐term pregnancy (FFTP)]; and (iii) the risks associated with having one or more high‐risk genotypes were not the same in women having experienced different menarche‐to‐FFTP intervals, being more significant in women having been exposed to estrogen for a longer period (≥12 years) before FFTP. Furthermore, because CE‐Q can attack DNA, leading to the formation of double‐strand breaks (DSB), we examined whether the relationship between cancer risk and the genotypic polymorphism of CE‐metabolizing genes was modified by the genotypes of DSB repair genes, and found that a joint effect of CE‐metabolizing genes and one of the two DSB repair pathways, the homologous recombination pathway, was significantly associated with breast cancer development. Based on comprehensive CE metabolizing gene profiles, our study provides support to the hypotheses that breast cancer can be initiated by estrogen exposure and that increased estrogen exposure confers a higher risk of breast cancer by causing DSB to DNA.
The role of environmental factors in growth accounting
Authors: Jeon Byung M. , Sickles Robin C.
Published: September 2004

This paper explores a relatively new methodology, the directional distance function method, to analyse productivity growth. The method allows us to explicitly evaluate the role that undesirable outputs of the economy, such as carbon dioxide and other greenhouse gases, have on the frontier production process which we specify as a piecewise linear and convex boundary function. We decompose productivity growth into efficiency change (catching up) and technology change (innovation). We test the statistical significance of the estimates using recently developed bootstrap methods. We also explore implications for growth of total factor productivity in the OECD and Asian economies. Copyright © 2004 John Wiley & Sons, Ltd.
Modelling low income transitions
Authors: Cappellari Lorenzo , Jenkins Stephen P.
Published: September 2004

We examine the determinants of low income transitions using first‐order Markov models that control for initial conditions effects (those found to be poor in the base year may be a non‐random sample) and for attrition (panel retention may also be non‐random). The model estimates, derived from British panel data for the 1990s, indicate that there is substantial state dependence in poverty, separate from persistence induced by heterogeneity. We also provide estimates of low income transition rates and lengths of poverty and non‐poverty spells for persons of different types. Copyright © 2004 John Wiley & Sons, Ltd.
Convergence in European GDP series: a multivariate common converging trend–cycle decomposition
Authors: Luginbuhl Rob , Koopman Siem Jan
Published: September 2004

Convergence in the gross domestic product series of five European countries is empirically identified using multivariate time series models that are based on unobserved components with dynamic converging properties. We define convergence in terms of a decrease in dispersion over time and model this decrease via mechanisms that allow for gradual reductions in the ranks of covariance matrices associated with the disturbance vectors driving the unobserved components of the model. The inclusion of such convergence mechanisms within the formulation of unobserved components makes the identification of various types of convergence possible. The common converging component model is estimated for the per capita gross domestic product of five European countries: Germany, France, Italy, Spain and the Netherlands. It is found that convergence features in trends and cycles are present and are associated with some key events in the history of European integration. Copyright © 2004 John Wiley & Sons, Ltd.
Conditional heteroscedasticity of exchange rates: further results based on the fractionally integrated approach
Authors: Tsui Albert K. , Ho Kin‐Yip
Published: September 2004

A recent article (Tse, 1998) published in this journal analysed the conditional heteroscedasticity of the yen–dollar exchange rate based on the fractionally integrated asymmetric power ARCH model. In this paper, we present replication results using Tse's (1998) yen–dollar series. We also examine the robustness of Tse's (1998) findings across different currencies, sample periods and non‐nested GARCH‐type models. Unlike Tse (1998), we find some evidence of asymmetric conditional volatility for daily returns of currencies measured against the dollar or the yen. Copyright © 2004 John Wiley & Sons, Ltd.
Resin penetration through submicrometer hiatus structures: A SEM and CLSM study
Authors: Pioch Thomas , Sorg Tina , Stadler Robin , Hagge Mark , Dörfer Christof E.
Published: September 2004

The purpose of this study was to confirm the existence of submicrometer hiatus structures and to examine the degree of resin penetration through these formations. Dentin disks 2.0 mm in thickness were sectioned from 48 human molars with the use of a microtome saw. Three different fifth‐generation (total‐etch, combined primer/resin) dentin adhesive systems were used to bond a light‐cured, resin‐based composite to the dentin disks (n = 16 each group). Bonded disks from the three groups were then sectioned. Half of each group was examined with the use of a scanning electron microscope (SEM) (n = 8), and the other half with the use of a confocal laser scanning microscope (CLSM) (n = 8). The frequency of submicrometer hiatus formation was recorded and documented with associated imaging techniques. Resin penetration within submicrometer hiati were observed in 41.7% (10/24) of SEM specimens and 83.3% (20/24) of CLSM specimens. The location and size of these structures were found to be quite uniform. Submicrometer hiati approximated 200 μm in each of the three dentin bonding systems examined. Resin penetration through submicrometer hiati does not appear to be an artifact of desiccation. These structures were clearly identified within the hybrid layer of each dentin adhesive system used in this study. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 71B: 238–243, 2004
Effects of different sterilization methods on the morphology, mechanical properties, and cytotoxicity of chitosan membranes used as wound dressings
Authors: Marreco Paula Rulf , Moreira Patrícia da Luz , Genari Selma Candelária , Moraes Ângela Maria
Published: September 2004

The aim of this work was to compare the effects induced by two different sterilization methods (exposure to gamma radiation or ethylene oxide) and an antiseptic technique (immersion in 70% ethanol aqueous solution) on the morphology, tensile strength, percentage of strain at break, and in vitro cytotoxicity to Vero cells on chitosan membranes designed for wound healing. Four distinct membrane compositions were evaluated, with chitosan, glycerol, and chitin used as components. Gamma radiation, in spite of being one of the most commonly employed sterilizing agents, negatively affected the morphology of membranes composed solely by chitosan as well as the percentage of strain at break of the chitosan‐membranes containing glycerol on their composition. Moreover, its use affected the color of the chitosan membranes. The use of 70% ethanol aqueous solution did not change the chitosan‐membrane characteristics significantly, but its use has limitations concerning the process scale up. With ethylene oxide (EtO), chitosan‐membrane morphology, percentage of strain at break, and in vitro cytotoxicity to Vero cells were not significantly affected. The tensile strength of the membranes containing chitin were reduced after the treatment with ethylene oxide; however, the obtained values were comprised in the range verified for normal human skin. Therefore, because the final characteristics of the membranes treated with ethylene oxide are appropriate when considering their use as wound healing devices, and because this sterilization process is easily adjusted to use on an industrial scale, EtO can be considered the most adequate sterilizing agent for chitosan membranes. However, it should be considered that this chemical is associated with toxicity, flammability, and environmental risks, as well as with possible material contamination with ethylene oxide residues. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 71B: 268–277, 2004
Acute phase lipocalin Ex‐FABP is involved in heart development and cell survival
Authors: Gentili C. , Tutolo G. , Zerega B. , Di Marco E. , Cancedda R. , Cancedda F. Descalzi
Published: September 2004

Ex‐FABP is an extracellular fatty acid binding protein, expressed during chicken embryo development in cartilage, muscle fibers, and blood granulocytes. Transfection of chondrocytes and myoblasts with anti‐sense Ex‐FABP cDNA results in inhibition of cell proliferation and apoptosis induction. Ex‐FABP expression is dramatically enhanced by inflammatory stimuli and in pathological conditions. In this paper, by in situ whole mount and immunohistochemistry analysis we show that, at early developmental stage, Ex‐FABP is diffuse in all tissues of chick embryos. Particularly high level of transcript and protein are expressed in the heart. During acute phase response (APR) induced by endotoxin LPS injection, a marked increase of Ex‐FABP mRNA was observed in embryos, highest Ex‐FABP expression being in heart and liver. To investigate in vivo the biological role of Ex‐FABP, we have directly microinjected chicken embryos with antibody against Ex‐FABP. Almost 70% of chicken embryos died and the target tissue was the heart. We detected in heart of the treated embryos a significant increase of apoptotic cells and high level of fatty acids. We propose that the accumulation of fatty acid, specific ligand of Ex‐FABP, in the cell microenvironment is responsible of heart cell death, and we suggest that Ex‐FABP may act as a survival protein by playing a role as scavenger for fatty acids. © 2004 Wiley‐Liss, Inc.
The impact of relative tenure on newcomer socialization dynamics
Authors: Rollag Keith
Published: September 2004

Although many researchers have examined the impact of organizational tenure on newcomer socialization dynamics, few have explored whether relative tenure influences perceptions and behaviors inside organizations. This study introduces the concept of relative tenure and shows through a sociometric survey of 200 employees across four organizations that an individual's relative position in his or her firm's tenure distribution explains a significantly greater percentage of variance in newcomer status, social network position, and information‐providing behavior than does absolute measures of tenure. The results suggest that organizational growth and turnover may have a bigger impact on newcomer socialization dynamics than has been discussed in the literature. The implications of the findings for socialization researchers and managers are discussed. Copyright © 2004 John Wiley & Sons, Ltd.
The effect of other orientation on self–supervisor rating agreement
Authors: Korsgaard M. Audrey , Meglino Bruce M. , Lester Scott W.
Published: September 2004

Employees generally rate their performance more favorably than do their supervisors, which can lead to conflict and poor job performance. However, comparative international research indicates that persons from other‐oriented collectivist cultures are less self‐enhancing, suggesting that other‐oriented employees will exhibit greater agreement with ratings provided by their supervisors. We examined the effect of subordinates' other orientation on self‐supervisor performance rating agreement. Consistent with cultural expectations, self‐ratings of other‐oriented subordinates showed greater agreement with ratings provided by their supervisors and less leniency relative to their supervisors' evaluations. These findings have implications for understanding how employees in different professions, organizations, and cultures utilize feedback from their supervisors. Copyright © 2004 John Wiley & Sons, Ltd.
Climatic conditions and crop‐residue quality differentially affect N, P, and S mineralization in soils with contrasting P status
Authors: Kabba Bachitter S. , Aulakh Milkha S.
Published: September 2004

The substitution of the widely practiced crop‐residue burning by residue incorporation in the subtropical zone requires a better understanding of factors determining nutrient mineralization. We examined the effect of three temperature (15°C, 30°C, and 45°C) and two moisture regimes (60% and 90% water‐filled pore space (WFPS)) on the mineralization‐immobilization of N, P, and S from groundnut (Arachis hypogae) and rapeseed (Brassica napus) residues (4 t ha–1) in two soils with contrasting P fertility. Crop‐residue mineralization was differentially affected by incubation temperature, soil aeration status, and residue quality. Only the application of groundnut residues (low C : nutrient ratios) resulted in a positive net N and P mineralization within 30 days of incubation, while net N and P immobilization was observed with rapeseed residues. Highest N and P mineralization and lowest N and P immobilization occurred at 45°C under nearly saturated soil conditions. Especially net P mineralization was significantly higher in nearly saturated than in aerobic soils. In contrast, S mineralization was more from rapeseed than from groundnut residues and higher in aerobic than in nearly saturated soil. The initial soil P content influenced the mineralization of N and P, which was significantly higher in the soil with a high initial P fertility (18 mg P (kg soil)–1) than in the soil with low P status (8 mg P (kg soil)–1). Residue‐S mineralization was not affected by soil P fertility. The findings suggest that climatic conditions (temperature and rainfall‐induced changes in soil aeration status) and residue quality determine N‐ and S‐mineralization rates, while the initial soil P content affects the mineralization of added residue N and P. While the application of high‐quality groundnut residues is likely to improve the N supply to a subsequent summer crop (high temperature) under aerobic and the P supply under anaerobic soil condition, low‐quality residues (rapeseed) may show short‐term benefits only for the S nutrition of a following crop grown in aerobic soil.
Bound amino acids in humic acids from arable cropping systems
Authors: Szajdak Lech , Życzyńska‐Bałoniak Irena , Meysner Teresa , Blecharczyk Andrzej
Published: September 2004

We investigated the varying concentrations of bound amino acids in humic acids (HA) extracted from soils under both crop rotation and continuous cropping of rye. The experiment was created in 1957. Since then, winter rye had been grown continuously and also the sequence of the 7 yr rotation had been started: potato, spring barley, alfalfa, alfalfa, oil seed rape, winter rye, and winter rye. Soils were fertilized with NPK and manure. Continuous cropping of rye increased total acidity of soils and the contents of carboxylic and phenolic groups in HA. The total amounts of the bound amino acids in HA from soils under crop rotation were higher than from continuous cropping of rye. Fertilization with NPK increased the contents of bound amino acids more than manure. Neutral amino acids dominated in all samples of HA, and basic amino acids had the lowest concentrations. In both types of cultivation, glutamic acids, glycine, alanine, valine, and lysine dominated. The proline contents in HA from continuous rye cropping were higher than in HA from soils under crop rotation. The concentrations of β‐alanine and lysine were higher in HA from crop rotation indicating a higher microbial biomass since these compounds are typical constituents of bacteria cell walls.
Short‐term N2O, CO2, NH3 fluxes, and N/C transfers in a Danish grass‐clover pasture after simulated urine deposition in autumn
Authors: Bol Roland , Petersen Søren O. , Christofides Calliopi , Dittert Klaus , Hansen Martin N.
Published: September 2004

Urine patches are significant hot‐spots of C and N transformations. To investigate the effects of urine composition on C and N turnover and gaseous emissions from a Danish pasture soil, a field plot study was carried out in September 2001. Cattle urine was amended with two levels of 13C‐ and 15N‐labeled urea, corresponding to 5.58 and 9.54 g urea‐N l–1, to reflect two levels of protein intake. Urine was then added to a sandy‐loam pasture soil equivalent to a rate of 23.3 or 39.8 g urea‐N m–2. Pools and isotopic labeling of nitrous oxide (N2O) and CO2 emissions, extractable urea, ammonium (NH4+), and nitrate (NO3–), and plant uptake were monitored during a 14 d period, while ammonia (NH3) losses were estimated in separate plots amended with unlabeled urine. Ammonia volatilization was estimated to account for 14% and 12% of the urea‐N applied in the low (UL) and high (UH) urea treatment, respectively. The recovery of urea‐derived N as NH4+ increased during the first several days, but isotopic dilution was significant, possibly as a result of stress‐induced microbial metabolism. After a 2 d lag phase, nitrification proceeded at similar rates in UL and UH despite a significant difference in NH4+ availability. Nitrous oxide fluxes were low, but generally increased during the 14 d period, as did the proportion derived from urea‐N. On day 14, the contribution from urea was 23% (UL) and 13% (UH treatment), respectively. Cumulative total losses of N2O during the 14 d period corresponded to 0.021% (UL) and 0.015% (UH) of applied urea‐N. Nitrification was probably the source of N2O. Emission of urea‐derived C as CO2 was only detectable within the first 24 h. Urea‐derived C and N in above‐ground plant material was only significant at the first sampling, indicating that uptake of urine‐C and N via the leaves was small. Urine composition did not influence the potential for N2O emissions from urine patches under the experimental conditions, but the importance of site conditions and season should be investigated further.
Seed priming enhances germination and seedling growth of barley under conditions of P and Zn deficiency
Authors: Ajouri Aziza , Asgedom Haben , Becker Mathias
Published: September 2004

Low‐input production of barley on the predominantly calcareous soils in most countries of West Asia and North Africa is affected by drought and a low availability of P and Zn. Especially during the early growth stages, P and Zn deficiencies retard seedling growth, rendering the young plantlets particularly sensitive to the frequently encountered dry spells. Seed priming (soaking in water and drying back to storage moisture until use) has been shown to improve crop establishment and, in some instances, to increase crop yields. While increased seedling vigor will improve barley establishment, possible benefits are likely to be limited when P and Zn are deficient. A promising variation of the priming concept is the seed treatment with solutions containing the limiting nutrient. A series of experiments was conducted in a phytotron in 2003 to develop a nutrient‐priming approach to foster the establishment of barley under marginal growing conditions. Seeds of the traditional barley cultivar Arabi aswad were soaked for 0–48 hours in water and for 12 hours in solutions containing 5–500 mM P, Zn, and P+Zn, and dried back to 12% moisture until further use. Seeds were incubated at 10°C, and germination was evaluated over a 6‐ to 8‐day period. Additionally, growth and nutrient uptake of 4‐week‐old seedlings, grown at 25% and 100% field capacity in a typical Xerosol from Syria were evaluated. Water priming for 12 hours with subsequent seed storage of up to 9 weeks increased germination rate from 65% to 95%, and advanced germination by up to 3 days compared to unprimed seeds. Addition of 10 mM Zn and 50 mM P to the priming solution increased the P and Zn content of the seeds without affecting germination. It furthermore significantly stimulated growth and P and Zn uptake by 4‐week‐old seedlings and improved the water use efficiency of drought‐stressed plants by 44% above that of unprimed seeds.