bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sox9b/sox9a2‐EGFP transgenic medaka reveals the morphological reorganization of the gonads and a common precursor of both the female and male supporting cells
Authors: Nakamura Shuhei , Aoki Yumiko , Saito Daisuke , Kuroki Yoko , Fujiyama Asao , Naruse Kiyoshi , Tanaka Minoru 
Published: May 2007

AbstractWe have established an enhanced green fluorescent protein (EGFP) transgenic medaka line that mimics the expression of sox9b/sox9a2 to analyze the morphological reorganization of the gonads and characterize the sox9b‐expressing cells during gonadal formation in this fish. After the germ cells have migrated into the gonadal areas, a cluster of EGFP‐expressing cells in the single gonadal primordium was found to be separated by the somatic cells along the rostrocaudal axis and form the bilateral lobes. We observed in these transgenic fish that EGFP expression persists only in the somatic cells directly surrounding the germ cells. As sex differentiation proceeds, dmrt1 and foxl2 begin to be expressed in the EGFP‐expressing cells in the XY and the XX gonads, respectively. This indicates that the sox9b‐expressing cells reorganize into two lobes of the gonad and then differentiate into Sertoli or granulosa cells, as common precursors of the supporting cells. Hence, our sox9b‐EGFP medaka system will be useful in future studies of gonadal development. Mol. Reprod. Dev. 75: 472–476, 2008. © 2007 Wiley‐Liss, Inc.
Development of Langerhans cell histiocytosis associated with chronic active Epstein–Barr virus infection
Authors: Sakata Naoki , Toguchi Naomi , Kimura Masatomo , Nakayama Masahiro , Kawa Keisei , Takemura Tsukasa 
Published: May 2007

AbstractChronic active Epstein–Barr virus (CAEBV) infection is characterized by a status of lymphoproliferative disease of EBV‐infected cells, resulting in chronic or recurrent infectious mononucleosis‐like symptoms. CAEBV is always accompanied by life‐threatening complications. We report the case of a 2‐year‐old female patient with CAEBV who subsequently developed Langerhans cell histiocytosis (LCH) presenting with bilateral exophthalmos, bone, and skin involvement. In situ hybridization for EBER revealed EBV‐infected B‐cells present in lesional tissue implying that interactions between EBV‐infected B‐cells and lesional Langerhans cells may be associated with the development of LCH. Pediatr Blood Cancer 2008;50:924–927. © 2007 Wiley‐Liss, Inc.
The prostate‐associated lymphoid tissue (PALT) is linked to the expression of homing chemokines CXCL13 and CCL21
Authors: Carlo Emma Di , Magnasco Salvatore , D'Antuono Tommaso , Tenaglia Raffaele , Sorrentino Carlo 
Published: May 2007

AbstractBACKGROUNDThe genitourinary tract is regarded as part of the mucosal immune system. However, the structural and functional aspects of the human prostate‐associated lymphoid tissue (PALT) have never been extensively explored.METHODSThis article describes our investigation of this issue by means of immunohistological, confocal, and ultrastructural examination of the normal human prostate.RESULTSPALT consists of two main components: (1) intraepithelial leukocytes, namely CD3+T cells with prevalent CD8+ and CD45RA−CD45RO+ phenotype, sometimes CD69+, followed by CD94+NK, CD11c+DCs, some expressing CD86, DC‐SIGN+DCs and a few B lymphocytes; (2) lymphoid aggregates, frequently below the epithelia, arranged in B cell follicles, endowed with a central ICAM‐1+VCAM‐1+CD21+FDCs network expressing BLC/CXCL13, and parafollicular T cell areas crossed by PNAd+HEV‐like vessels showing SLC/CCL21 expression. Parafollicular areas were formed of prevalent CD4+T lymphocytes, both CD45RA− and CD45RO+, and intermingled with CD11c+DCs. Germinal‐center‐containing follicles are few and their parafollicular areas are scantily infiltrated by Foxp3+CD69− highly suppressive regulatory T cells. Most lymphoid follicles lack a distinct germinal center and their parafollicular area harbor numerous Foxp3+CD69− cells.CONCLUSIONSComparison with the tonsils shows that PALT displays immunomorphological features required for the onset of cellular and humoral immune responses, while its T regulatory cells appear to function as suppressor‐regulators of T and B cell responses. Prostate 67: 1070–1080, 2007. © 2007 Wiley‐Liss, Inc.
Modeling of epoxy oligomers with nonlinear optical chromophores in the main chain: molecular dynamics and quantum chemical study
Authors: Balakina Marina Yu. , Fominykh Olga D. , Rua Federico , Branchadell Vicenç 
Published: May 2007

AbstractThe Molecular Dynamics simulations in chloroform at room temperature of the monomer and dimer of the molecular system based on bisphenol‐A diglycidyl ether with a p‐nitroaniline (PNA) chromophore attached to the bearing chain is performed. The starting conformations for the simulation were obtained by the conformational search in the framework of Monte Carlo method with MMFF94 force field. The monomer was shown to represent an adequate model for the corresponding oligomer unit. The analysis of the torsion angles values along the bearing chain of dimer demonstrates the availability of flexible fragments, thus giving promise for efficient orientation of chromophore groups in a chosen polymer matrix when the electric field is switched on. The polarizability and first hyperpolarizability of the studied systems are calculated by TDHF/AM1. The values of β∥ increase by nearly 50% when passing from the monomer to the dimer. The nonempirical calculation of β, performed for the monomer, examines the obtained trends and exhibits significant enhancement of the first hyperpolarizability in chloroform approximately by a factor of 3 with respect to the gas phase value. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Density functional theory studies of nitrous oxide adsorption and decomposition on Ga‐ZSM‐5
Authors: Solkan V. N. , Zhidomirov G. M. , Kazansky V. B. 
Published: May 2007

AbstractIn this study, density functional theory (DFT/B3LYP) was used to assess a possible reaction pathway for the catalytic dissociation of N2O. The active centers were taken to be mononuclear [Ga]+ and [GaO]+, and the surrounding portion of the zeolite was represented by a 3T cluster, namely (AlSi2O4H8). The first step of N2O decomposition involves the formation of [GaO]+ and the release of N2. The metal‐oxo species produced in this step then react with N2O again, to release N2 and form GaO2. The calculated activation energies for N2O dissociation in Ga‐ZSM‐5 and GaO‐ZSM‐5 at B3LYP/6‐31+G* level are 22.2 and 24.9 kcal/mol, respectively. The calculated energy of the molecular oxygen elimination from 3T‐(GaO2) cluster is ΔH (298 K) = +46.5 kcal/mol and ΔG (298 K) = 35.9 kcal/mol. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Direct standardization of incidence rates in the presence of incomplete data
Authors: Emerson Scott S. , Emerson Julia C. 
Published: April 2007

AbstractWhen comparing the disease incidence rates for several subpopulations, epidemiologists often use direct standardization to adjust for potential confounding variables. In population‐based studies, however, the data are often incompletely classified with respect to membership in the subpopulations of interest. In such a situation, one often assumes that the cases with missing data have the same distribution as the complete cases, that is the data are missing completely at random. In this setting, we derive variance estimates for the directly standardized rates which account for the use of incomplete data. We illustrate the use of these methods with data from a study of the incidence of gastrointestinal cancer by immigrant status where birthplace data are often incomplete.
A new sequential procedure for surveillance of Down's syndrome
Authors: Lie Rolv Terje , Heuch Ivar , Irgens Lorentz M. 
Published: April 2007

AbstractA new method is proposed for the surveillance of Down's syndrome among newborn. Despite the strong dependence of overall risk of Down's syndrome on maternal age, it has been suggested that an environmentally induced increase in risk may be additive over all maternal ages. The surveillance method introduced here is specifically designed to detect such changes. The method is based on registry data for successive periods for a given population. It is assumed that the number of Down's syndrome cases as well as the total number of births are known in all maternal age groups. Tables of average run lengths until an alarm (ARLs) are calculated for a total sample size of 14,500 in each period, the approximate number of births in a three‐month period in Norway. Comparison with the Poisson cusum shows that the new surveillance method can detect moderate additive increases significantly faster. Applied retrospectively to quarterly data from the Medical Birth Registry of Norway for 1978–89, the proposed method was close to an alarm in 1985 and actually signalled a strong alarm in 1986, reflecting a previously reported increase in risk in this period. The cusum method was not so sensitive to the aberration in Down's syndrome risks in 1985 and 1986.
A refinement to the analysis of serial data using summary measures
Authors: Matthews J. N. S. 
Published: April 2007

AbstractA widely used method for the analysis of data collected serially over time is to reduce the data on each subject to a single summary that reflects some salient aspect of the response. The summaries from all subjects are then analysed using appropriate univariate methods. In some cases it may be unreasonable to suppose that summaries in a group share a common distribution. A weighted analysis may be preferable, with data from each subject used to determine the weights. This approach is explored in the context of an analysis of data on foetal distress during labour.
Establishing a national in vitro fertilization registry: Methodological problems and analysis of success rates
Authors: de Mouzon Jacques , Bachelot Annie , Spira Alfred 
Published: April 2007

AbstractA national registry for in vitro fertilization (IVF) was established in France in January 1986 and has been in operation since that date. During 1987, data on 14,763 attempts were collected from 72 teams, representing 80 per cent of all French IVF activity. In this registry, a form is completed for every oocyte recovery attempt, containing information about the infertility diagnosis, the attempt itself and its result. This paper presents results for the years 1986 and 1987 and studies the relationship between pregnancy occurrence and some couple or cycle characteristics. Methodological aspects are discussed, concerning the possible sources of bias, and the analysis of results. Results obtained in this registry are compared with those from other similar registries.
The succession procedure for interim analysis: Extensions for early acceptance of h0 and for flexible times of analysis
Authors: Falissard Bruno , Lellouch Joseph 
Published: April 2007

AbstractThe succession procedure is a new method for group sequential analysis based on a succession of significant tests. In this paper, the procedure is extended by the addition of a lower boundary, which allows the early acceptance of the null hypothesis H0 according to the stochastic curtailing approach. The succession procedure is also adapted to the type I error spending rate function α*(t), leading to the method of semisequential analysis for which the times of analysis need not be specified in advance.
Analysis of crossover designs with multivariate response
Authors: Grender Julie Myers , Johnson William D. 
Published: April 2007

AbstractCrossover designs involve observing the same response variate under different experimental conditions for each subject. Univariate methods are commonly used for analysis of data arising in these designs, but multivariate procedures offer a more general approach. The general multivariate linear model provides a natural framework for the simplest data structure as well as more complex settings with two or more response variates and measurements repeated over time. Multivariate models for crossover designs provide a unified approach that clarifies specification of hypotheses, assumptions required, and testing procedures in a wide class of applications that include longitudinal data as a special case. We focus on the 2 × 2 crossover design, but also describe models for analysing more complex crossover designs.
Letters to the editor methods of adjustment for estimating the attributable risk in case—control studies: A review
Authors: Gefeller Olaf , Eide Geir Egil , Benichou Jacques 
Published: April 2007

AbstractIn a recent issue Benichou provided an excellent comprehensive review on adjustment methods for estimating attributable risk (AR) in the framework of case‐control studies. Its didactic nature illustrating all theoretical considerations using data from the Ille‐et‐Vilaine study ensures that Benichou's paper will soon be one of the leading references on AR estimation. It closes the gap between Walter's classic methodologic review paper1 on AR and more modern developments during the 1980's in this evolving area. Additional comments in this letter may help to clarify further some issues discussed in the paper.
Design and analysis of studies to reduce the incidence of colon polyps
Authors: Emerson Scott S. , McGee Daniel L. , Fennerty Brian , Hixson Lee , Garewal Harinder , Alberts David 
Published: April 2007

AbstractDecisions regarding the design and analysis of a phase III study to reduce the incidence of colorectal polyps must take into account two complicating factors: the possibility that polyps are missed during screening exams, and variable lengths of follow‐up. In this paper we investigate the effects due to misclassification on the power of statistical tests to detect a change in polyp recurrence rates. We also use Monte Carlo studies to examine the relative efficiency of different methods of adjusting for variable times of follow‐up.
Evaluating the effects of tubal sterilization on menstrual function: Selected issues in data analysis
Authors: Martinez‐Schnell Beverly , Wilcox Lynne S. , Peterson Herbert B. , Jamison Patricia M. , Hughes Joyce M. 
Published: April 2007

AbstractWe examined selected issues in data analysis in the Collaborative Review of Sterilization (CREST). CREST is a multicentre, prospective, observational study of women undergoing tubal sterilization. We analysed menstrual function after sterilization in over 5000 women who were enrolled in the period 1978–1983 and followed for 5 years with yearly follow‐up interviews. To take into account the dependency among repeated responses from the same individuals, we used the generalized estimating equations (GEE) approach to longitudinal data analysis. Marginal modelling resulted in a statistically significant increase in the odds of menstrual dysfunction at 5 years after tubal sterilization. Transitional modelling produced rates of menstrual dysfunction given a woman's menstrual function at baseline, after adjusting for other baseline characteristics such as method of contraception before sterilization. To examine the direction of the bias that could result from non‐random missing data, we refitted our models using imputed values. The models with imputed values showed the same trends as the original models.
Refusal assertion versus conversational skill role‐play competence: Relevance to prevention of tobacco use
Authors: Sussman Steve , Stacy Alan W. , Dent Clyde W. , Burciaga Catherine , Burton Dee , Flay Brian R. 
Published: April 2007

AbstractConversational and refusal assertion skills of 768 seventh grade youth were assessed through ratings of global (for example, effectiveness) and non‐verbal (for example, eye contact) behaviour performed in two role‐play scenarios. The ratings were completed after each scenario by the subjects themselves, as well as by classmate and trained adult observers. Use of the Hays and Hayashi multitrait scaling method to interpret these data revealed two results. First, the items used to measure role‐play behaviour did not achieve sufficient internal consistency to create global and non‐verbal composites. Second, inter‐rater agreement and discriminant validity were obtained only for ratings of the global effectiveness of each of the two social skills. Next, a series of multiple regression analyses indicated that an index of the global effectiveness of refusal assertion skill, but not of conversational skill, was predictive of intention to use tobacco. Those who were relatively unskilful at refusing offers were more likely to intend to use tobacco. Analyses exploring relations of trained observer ratings of the effectiveness of both role‐play types, trained observer ratings of the other global and non‐verbal items, and subjects' intention to use tobacco indicated that only a hesitant voice pattern was both negatively predictive of effective refusal assertion and positively predictive of intention to use tobacco in the future. In other words, those who are hesitant when they refuse a tobacco offer are the ones most likely to report an intention to use tobacco in the future. The consistency of this last finding in the tobacco use prevention literature is discussed.
Birth‐weight‐adjusted infant mortality in evaluations of perinatal care: Towards a useful summary measure
Authors: Kiely John L. , Kleinman Joel C. 
Published: April 2007

AbstractSince birth‐weight‐specific infant mortality rates are widely considered to be measures of the effects of perinatal medical care, birth‐weight‐adjusted and birth‐weight‐specific infant mortality rates have often been used in comparisons across hospitals and geographic areas. Wilcox and Russell1have provided a model which leads to the conclusion that birth weight adjustment is biased against populations with heavier birth weights and that birth‐weight‐specific infant mortality rates can yield misleading results. Nevertheless, evaluators and health planners still need a summary measure of the infant mortality rate in which some sort of birth weight adjustment is used to generate an (appropriately) weighted mean of birth‐weight‐specific relative risks. We used the 1983–85 national linked files of live births and infant deaths to investigate two new methods that extend the Wilcox—Russell approach, ‘mean adjustment’ and ‘Z‐adjustment’, to compare birth‐weight‐specific infant mortality rates among the white populations of the states. Colorado was used as the reference population in logistic regression analyses. Statistical interactions between state and birth weight on the conventional kilogram scale, the mean‐adjusted scale, and the Z scale were examined. There were substantial interactions with birth weight on all three scales. In addition, when Colorado was used as the reference population, mean adjustment shifted the odds ratios downward to implausibly low values, especially at lower weights. The Z‐adjustment method incorporating the Wilcox—Russell approach appears to be a useful alternative to birth weight adjustment. However, because birth‐weight‐specific mortality rates do not differ uniformly across all birth weight groups, multiple summary measures are needed.
Methods for analysing county‐level mortality rates
Authors: Stevenson John M. , Olson David R. 
Published: April 2007

AbstractThe identification of counties burdened by exceptionally high rates of mortality is a fundamental step in the development of state‐based intervention and prevention strategies. However, the estimation of rates from small geographic areas presents special problems, especially for rare events. This paper compares the use of crude and age‐standardized rates to the use of Poisson regression models and empirical Bayes models for analysing county‐level mortality rates. The results demonstrate both practical and heuristic advantages of the empirical Bayes models. Age‐standardized rates adjust for differences in age structure among counties but are vulnerable to extreme variability in county age‐specific rates. In our example — an analysis of diabetes mortality rates — Poisson regression did not improve the variability of estimated county‐level rates. Adjusted empirical Bayes estimates dramatically shrink the observed rates while preserving some separation of the counties with extreme rates. Also, empirical Bayes estimates of rates for counties with no observed deaths are shrunk close to the prior mean.
Longitudinal height velocity standards for U.S. adolescents
Authors: Berkey Catherine S. , Dockery Douglas W. , Wang Xiaobin , Wypij David , Ferris Benjamin 
Published: April 2007

AbstractLongitudinally based height velocity centiles for U.S. children, appropriate for paediatric clinical use, were derived for growth from ages 7 to 18 years. A series of gender‐ and race‐specific figures present the median velocity curves for children by year of maturation. Smooth 3rd to 97th centile curves, for blacks and whites together, are provided for children who are early, average, and late maturers. The data were taken from 6532 black and white children participating in the Six Cities Study from 1974 to 1989.
Behind closed doors: The data monitoring board in randomized clinical trials
Authors: Wittes Janet 
Published: April 2007

AbstractMany randomized clinical trials include a data and safety monitoring board (DSMB) that is responsible for reviewing accruing data, monitoring performance of the trial, assuring safety of the participants in the trial, and assessing the efficacy of treatment. The DSMB often makes recommendations about continuation of the trial or alteration of the protocol. Although such boards are very influential in both the conduct and interpretation of randomized clinical trials, there is no standard mode in which DSMBs operate nor do they routinely report publicly about their deliberations. This paper describes the composition of DSMBs as well as their functions. It concludes with a series of questions that needs to be addressed to ensure that the DSMBs operate effectively.
A survey of monitoring practices in cancer clinical trials
Authors: George Stephen L. 
Published: April 2007

AbstractThis paper reports the results of a survey of data monitoring practices of the 12 clinical co‐operative groups in cancer sponsored by the National Cancer Institute in the United States. Most of these co‐operative groups conduct a large number of active clinical trials in a wide variety of cancers. The number of active phase III trials in 1991 was 244 with nearly 24,000 patients entered on these trials. The survey instrument used in this paper was modified from one originally developed by Geller and Stylianou,1 supplemented by questions on the responsibilities of data monitoring committees based on Hawkins.2 Topics covered included general policies and procedures on the monitoring of clinical trials in these groups as well as specific questions on the responsibilities and operational procedures of formal data monitoring committees. Although formal statistical stopping rules are almost always employed in cancer trials in these co‐operative groups, use of a formal data monitoring committee is a relatively new, but increasing practice. For a variety of economic and practical reasons, the members of data monitoring committees for cancer trials are rarely independent of the study participants.
Data monitoring committees for southwest oncology group clinical trials
Authors: Green Stephanie , Crowley John 
Published: April 2007

AbstractA monitoring committee policy was established by the Southwest Oncology Group in 1985 to address documented problems in study conduct. Committees consisting of the study co‐ordinators, disease committee chair, study statistician, Group chair, Group statistician, an uninvolved Southwest Oncology Group clinician, an NCI representative, and a representative from each involved group for intergroup studies have been appointed for each phase III study. Business is conducted largely through the mail and through conference calls. Since then, problems identified in older studies have been largely resolved. Appropriate and timely decisions are being made at modest additional expense to the Group.