bluuebunny/crossref_metadata_2025_split huggingface dataset:
Three validation metrics for automated probabilistic image segmentation of brain tumours
Authors: Zou Kelly H. , Wells William M. , Kikinis Ron , Warfield Simon K. 
Published: April 2004

AbstractThe validity of brain tumour segmentation is an important issue in image processing because it has a direct impact on surgical planning. We examined the segmentation accuracy based on three two‐sample validation metrics against the estimated composite latent gold standard, which was derived from several experts' manual segmentations by an EM algorithm. The distribution functions of the tumour and control pixel data were parametrically assumed to be a mixture of two beta distributions with different shape parameters. We estimated the corresponding receiver operating characteristic curve, Dice similarity coefficient, and mutual information, over all possible decision thresholds. Based on each validation metric, an optimal threshold was then computed via maximization. We illustrated these methods on MR imaging data from nine brain tumour cases of three different tumour types, each consisting of a large number of pixels. The automated segmentation yielded satisfactory accuracy with varied optimal thresholds. The performances of these validation metrics were also investigated via Monte Carlo simulation. Extensions of incorporating spatial correlation structures using a Markov random field model were considered. Copyright © 2004 John Wiley & Sons, Ltd.
Subject allocation and study curtailment for fixed event comparative poisson trials
Authors: Hoover Donald R. 
Published: April 2004

AbstractComparative Poisson trials of prophylactic interventions, such as vaccines, can be lengthy and costly. We evaluate two easily implemented approaches to reduce numbers of disease cases and person years of follow up (Nu+t) for comparative Poisson trials with fixed numbers of cases (T); (i) altering k the portion of Nu+t allocated to treatment and (ii) curtailed stopping before T cases if numbers of cases in the treatment or control group indicate that H0 has already been rejected or will not be rejected at T cases. Normal and arcsine approximations as well as discrete exact tests are evaluated. For studies not stopped early, allocating about ${1/(1+\sqrt r_a)}$ of person years to treatment roughly minimizes T needed for given size and power (where ra is the alternative hypothesized relative disease incidence in treated subjects used to power the study). This reduces T moderately vs equal allocation (k=0.5) by 2–3 cases in our examples with exact tests. However, the common practice of allocating k=0.5 of the person years to treatment may be the overall best strategy to minimize Nu+t for studies that are not stopped early. For studies analysed by exact test and planned with a one‐sided α ranging from 0.005 to 0.025, β from 0.1 to 0.2 and ra from 0.2 to 0.5, curtailed stopping reduces both the number of disease cases and Nu+t by 6–40 per cent depending on true treatment benefit. With curtailed stopping, allocating k=0.5 person years to treatment approximately minimizes the numbers of cases and person years under most conditions, although k as large as 0.6 often performs comparably well. If a specific localized k is selected to minimize disease cases for a study analysed by exact test, the study may be underpowered should the final allocation deviate even slightly from that k when it is conducted. Copyright © 2004 John Wiley & Sons, Ltd.
Eight interval estimators of a common rate ratio under stratified poisson sampling
Authors: Lui Kung‐Jong 
Published: April 2004

AbstractUnder the assumption that the rate ratio (RR) is constant across strata, we consider eight interval estimators of RR under stratified Poisson sampling: the weighted least‐squares (WLS) interval estimator with the logarithmic transformation, the interval estimator using the principle analogous to that of Fieller's Theorem, the interval estimators using Wald's statistic with and without the logarithmic transformation, the interval estimators using the Mantel–Haenszel statistic with and without the logarithmic transformation, the score test‐based interval estimator, and the asymptotic likelihood ratio test‐based interval estimator. We apply Monte Carlo simulation to evaluate and compare the performance of these estimators with respect to the coverage probability and the average length in a variety of situations. We find that the coverage probability of the commonly used WLS interval estimator tends to be smaller than the desired confidence level, especially when we have a large number of strata with a small expected total number of cases (ETNC) per stratum and the underlying RR is far away from 1 (i.e. RR18 or RR8). We further find that the two estimators with the logarithmic transformation, as well as the two test‐based estimators can consistently perform well in a variety of situations. When RR1 with a given reasonable size of ETNC per stratum, we note that the interval estimators without the logarithmic transformation can be preferable to the corresponding ones with the logarithmic transformation in the situations considered here. However, when evaluating the non‐coverage probability in the two tails, we find that the former tends to shift the left, while the latter is generally not subject to this concern. We also note that interval estimator using the Mantel–Haenszel (MH) statistic with the logarithmic transformation is likely less efficient than the two test‐based interval estimators using the score and the likelihood ratio tests. Finally, we use the data taken from a study of the postmenopausal hormone use on the risk of breast cancer in women as an example to illustrate the use of these interval estimators considered here. Copyright © 2004 John Wiley & Sons, Ltd.
Spatiotemporal pattern of calmodulin and [Ca2+]iis related to resumption of meiosis in mouse oocytes
Authors: Bi Chun‐Ming , Dai Gu , Chen Yan , Wu Yao‐Chun , Zhang Xi‐Ran , Li Chao‐Jun 
Published: April 2004

AbstractDuring meiotic maturation, mammalian oocytes undergo a series of morphological and physiological changes that prepare them for fertilization. Calcium‐initiated signaling is thought to trigger these processes. In this study, we examine the spatio—temporal pattern of calcium and calmodulin (CaM), its downstream receptor, in order to investigate their association with meiotic maturation. Intracellular free calcium and activated CaM levels were measured using the fluorescent probes Calcium Green™‐1 and TA‐CaM, respectively. The distribution patterns were examined using confocal microscopy. Both calcium and activated CaM showed a dynamic spatiotemporal distribution during meiotic maturation. After release from IBMX buffer, calcium was found to periodically translocate from the perinuclear region to the germinal vesicle (GV) in 90 s intervals. After 90 min, calcium stopped oscillating and became concentrated within the GV. After a further 60 min, the GV broke down and calcium dispersed into the ooplasm, but calcium levels were slightly lower here than in the original nuclear region. Activated CaM also showed a dynamic patterning process similar to calcium. Taking the data from calcium chelation and CaM inhibition together, our results suggest that the dynamic distribution patterns of calcium and activated CaM are crucial for oocyte maturation.
Randomized double‐blind comparison of serotonergic (Citalopram) versus noradrenergic (Reboxetine) reuptake inhibitors in outpatients with somatoform, DSM‐IV‐TR pain disorder
Authors: Aragona Massimiliano , Bancheri Lara , Perinelli Donatella , Tarsitani Lorenzo , Pizzimenti Alessia , Conte Antonella , Inghilleri Maurizio 
Published: April 2004

AbstractObjectives: Whether the effect of tricyclic antidepressants on Pain Disorder arises from their noradrenergic or serotonergic actions or both remains unclear. We compared the selective serotonin reuptake inhibitor (SSRI) citalopram and the noradrenergic reuptake inhibitor (NARI) reboxetine in outpatients with Pain Disorder. We also distinguished the drugs' analgesic and antidepressant effects.Methods: In this 8‐week, randomized double‐blind study, 35 patients with a DSM‐IV‐TR diagnosis of Pain Disorder were randomly assigned to receive either citalopram 40 mg/day (N=17 patients) or reboxetine 8 mg/day (N=18). The Present Pain Intensity (PPI) scale and the Total Pain Rating Index (tPRI) of the McGill Pain Questionnaire were used to measure the effect on pain symptoms. Changes in the Zung Self‐Rating Depression Scale (Zung‐D) scores were evaluated to monitor a possible antidepressant effect. For all patients who had at least one assessment, an intent‐to‐treat analysis was performed.Results: No significant differences were found in the demographic variables or clinical characteristics of the two treatment groups. In the citalopram group, PPI and tPRI scores measured at baseline decreased after treatment (tPRI: 41.9 vs. 30.0, p=.004; PPI: 3.5 vs. 2.8, p=.045) whereas in the reboxetine group differences were not statistically significant (tPRI: 35.2 vs. 31.5; PPI: 3.7 vs. 3.1). The Zung‐D showed no significant changes between baseline and endpoint assessment in either group.Conclusions: Our study suggests that the SSRI citalopram may have a moderate analgesic effect in patients with Pain Disorder, and that this analgesic activity appears to be not correlated to changes in depressive scores. If confirmed in a larger sample, this evidence suggests that patients who are intolerant or resistant to tricyclic antidepressants, may be treated with SSRIs.
Enhanced Ras activity in pyramidal neurons induces cellular hypertrophy and changes in afferent and intrinsic connectivity in synRas mice
Authors: Gärtner Ulrich , Alpár Alán , Seeger Gudrun , Heumann Rolf , Arendt Thomas 
Published: April 2004

AbstractNeurotrophic actions are critically controlled and transmitted to cellular responses by the small G protein Ras which is therefore essential for normal functioning and plasticity of the nervous system. The present study summarises findings of recent studies on morphological changes in the neocortex of synRas mice expressing Val12‐Ha‐Ras in vivo under the control of the rat synapsin I promoter. In the here reported model (introduced by Heumann et al. [J. Cell Biol. 151 (2000) 1537]), transgenic Val12‐Ha‐Ras expression is confined to the pyramidal cell population and starts postnatally at a time, when neurons are postmitotic and their developmental maturation has been basically completed. Expression of Val12‐Ha‐Ras results in a significant enlargement of pyramidal neurons. Size, complexity and spine density of dendritic trees are increased, which leads, finally, to cortical expansion. However, the main morphological design principles of ‘transgenic’ pyramidal cells remain preserved. In addition to somato‐dendritic changes, expression of Val12‐Ha‐Ras in pyramidal cells induces augmented axon calibres and upregulates the establishment of efferent boutons. Despite the enlargement of cortical size, the overall density of terminals representing intra‐ or interhemispheric, specific and non‐specific afferents is unchanged or even higher in transgenic mice suggesting a significant increase in the total afferent input to the neocortex. Although interneurons do not express the transgene and are therefore excluded from direct, intrinsic Val12‐Ha‐Ras effects, they respond with morphological adaptations to structural changes. Thus, dendritic arbours of interneurons are extended to follow the cortical expansion and basket cells establish a denser inhibitory innervation of ‘transgenic’ pyramidal cells perikarya.It is concluded that expression of Val12‐Ha‐Ras in pyramidal neurons results in remodelling of neocortical structuring which strongly implicates a crucial involvement of Ras in cortical plasticity.
Risk factors for the development versus maintenance of posttraumatic stress disorder
Authors: Schnurr Paula P. , Lunney Carole A. , Sengupta Anjana 
Published: April 2004

AbstractThis study examined risk factors for posttraumatic stress disorder (PTSD) in Vietnam veterans: 68 women and 414 men of whom 88 were White, 63 Black, 80 Hispanic, 90 Native Hawaiian, and 93 Japanese American. Continuation ratio logistic regression was used to compare the predictive power of risk factors for (he development versus maintenance of full or partial PTSD. The development of PTSD was related to premilitary, military, and postmilitary factors. The maintenance of PTSD was related primarily to military and postmilitary factors. Multivariate analyses identified different models for development and maintenance. We conclude that development of PTSD is related to factors that occur before, during, and after a traumatic event, whereas failure to recover is related primarily to factors that occur during and after the event.
International publication trends in the traumatic stress literature
Authors: Bedard Michele , Greif Jennifer L. , Buckley Todd C. 
Published: April 2004

AbstractThis analysis looked at international publication trends in the field of trauma by examining first author affiliations of over 13,000 trauma publications from 1987 to 2001. Searches were conducted using the Published International Literature on Traumatic Stress (PILOTS) database to determine frequency of international contributions. A similar search of the Journal of Traumatic Stress (JTS) was also conducted. Although the majority of trauma research comes from investigators in North America, examining publication trends over time revealed that trauma research is becoming, increasingly international in its representation. Results suggest that of the overall trauma literature, 36% of contributions come from authors outside North America. Likewise, among JTS publications over the first 14 years of circulation, 27% came from authors outside North America. More recent publication years reflect higher levels of international contributions for both sources. The majority of trauma research published over the 15‐year span was in English. Implications for the field of traumatic stress research are discussed.
Social attitudes toward traumatized men and women: A vignette study
Authors: Mendelsohn Michaela , Sewell Kenneth W. 
Published: April 2004

AbstractThis study investigated social beliefs about gender‐appropriate reactions to trauma. Ninety‐three men and 179 women completed vignette measures of attitudes toward victims, the Bern Sex Role Inventory, and the Trauma History Questionnaire. Participants evaluated male victims less favorably than female victims. Women responded more positively toward all victims than men. Participants regarded female crime victims more positively than their male counterparts, but did not distinguish between male and female natural disaster victims. Feminine‐sex‐typed women rated victims more favorably than masculine‐sex‐typed individuals. There was a positive relation between personal trauma exposure and attitudes toward male victims among male participants. These findings contribute to an understanding of factors influencing the social reactions experienced by traumatized men and women, and have implications for clinical practice and psychoeducation.
Trauma exposure and retention in adolescent substance abuse treatment
Authors: Jaycox Lisa H. , Ebener Patricia , Damesek Leslie , Becker Kirsten 
Published: April 2004

AbstractTrauma exposure and related symptoms interfere with adult adherence to drug treatment. Whether these findings hold true for adolescents is unknown. We examined trauma exposure. PTSD symptoms, and psychosocial functioning among 212 adolescents upon admission to long‐term residential drug treatment and examined retention in treatment at 6 months. Seventy‐one percent reported lifetime trauma exposure, and 29% of the trauma‐exposed met criteria for current PTSD. Trauma‐exposed adolescents reported more behavioral problems, with gender differences apparent. We divided the sample into three groups: no trauma exposure (21%), trauma‐exposed without PTSD (59%), and trauma‐exposed with PTSD (20%). Survival analysis showed that trauma‐exposed adolescents without PTSD left treatment sooner than the nonexposed. Need for attention to trauma in substance abuse treatment programs is discussed.
Bringing order out of chaos: A culturally competent approach to managing the problems of refugees and victims of organized violence
Authors: Eisenbruch Maurice , de Jong Joop T. V. M. , van de Put Willem 
Published: April 2004

AbstractThe collaborative program of the Transcultural Psychosocial Organization (TPO) provides a community‐oriented and culturally sensitive public health response to the psychosocial problems of refugees and victims of organized violence. This paper describes the 9‐step model that TPO has developed as a blueprint for each new intervention. Beneficiaries participate in determining priorities and there is an orientation toward culturally competent training, capacity‐building, and sustainability. Two cases, one related to Sudanese refugees in Uganda and the other to internally displaced persons and returnees in postwar Cambodia, show how the TPO intervention protocol is adapted to local settings. The paper provides preliminary evaluative comments on the model's performance.
Prevalence of posttraumatic stress disorder and comorbid depression in earthquake survivors in Turkey: An epidemiological study
Authors: Başoǧlu Metin , Kiliç Cengiz , Şalcioǧlu Ebru , Livanou Maria 
Published: April 2004

AbstractThis study examined the prevalence of posttraumatic stress disorder (PTSD) and depression 14 months after the earthquake in Turkey in 2 randomly selected samples from the epicenter (n = 530) and a suburb of Istanbul 100 km from the epicenter (n = 420). The rates of PTSD and depression comorbid with PTSD were, respectively, 23 and 16% at the epicenter and 14 and 8% in Istanbul. The strongest predictor of traumatic stress symptoms was fear during the earthquake, whereas predictions with female gender, past psychiatric illness, damage to home, participation in rescue work, past trauma, and loss of close ones were significant but weak. Our findings suggest that devastating earthquakes have long‐term psychological effects. Psychological interventions reducing fear may improve PTSD in survivors.
Treatment of posttraumatic stress disorder in postwar Kosovo high school students using mind–body skills groups: A pilot study
Authors: Gordon James S. , Staples Julie K. , Blyta Afrim , Bytyqi Murat 
Published: April 2004

AbstractThis preliminary study examined whether the practice of mind–body techniques decreases symptoms of posttraumatic stress in adolescents. Posttraumatic Stress Reaction Index questionnaires were collected from 139 high school students in Kosovo who participated in a 6‐week program that included meditation, biofeedback, drawings, autogenic training, guided imagery, genograms, movement, and breathing techniques. Three separate programs were held approximately 2 months apart. There was no control group. Posttraumatic stress scores significantly decreased after participation in the programs. These scores remained decreased in the 2 groups that participated in the follow‐up study when compared to pretest measures. These data indicate that mind–body skills groups were effective in reducing posttraumatic stress symptoms in war‐traumatized high school students.
Perceived social support and secondary traumatic stress symptoms in emergency responders
Authors: Hyman Ofra 
Published: April 2004

AbstractThis study investigated prevalence rates of secondary traumatic stress symptoms in Israeli Police forensic technicians, and the relationship between these symptoms and perceived social support as well as perceived severity of prior trauma (combat, work, personal). Ninety technicians from the Israeli Police Forensic Investigation Unit participated in the study. Intrusion and avoidance measured within the medium range of severity, whereas distress symptoms were below clinical threshold. Intrusion was significantly related to avoidance, distress, and the perceived severity of prior personal and work‐related exposure. No significant relationship was found between perceived social support and secondary traumatic stress symptoms. The data suggest that this cohort utilized avoidance effectively as a defense against intrusion.
Twenty‐four‐hour ambulatory assessment of heart rate and blood pressure in chronic PTSD and non‐PTSD veterans
Authors: Buckley Todd C. , Holohan Dana , Greif Jennifer L. , Bedard Michele , Suvak Michael 
Published: April 2004

AbstractThis study examined 24‐hr levels of ambulatory heart rate (HR) and blood pressure (BP) in 2 groups of male veterans: 19 with chronic posttraumatic stress disorder (PTSD) and 17 who never met criteria for PTSD. The relationships between diagnostic status, basal cardiovascular activity, and cardiovascular reactivity to stress were examined. Hierarchical linear modeling analyses revealed that the PTSD group had higher resting HR than the non‐PTSD group. Moreover, the PTSD group showed greater BP reactivity during times of affective distress than the non‐PTSD group. The health care implications of these findings are discussed, as are directions for future research.
Revictimization and interpersonal resource loss predicts PTSD among women in substance‐use treatment
Authors: Schumm Jeremiah A. , Hobfoll Stevan E. , Keogh Nancy Jones 
Published: April 2004

AbstractChild physical abuse (CPA) and child sexual abuse (CSA) were hypothesized to be associated with revictimization and interpersonal resource loss in adulthood. These adulthood experiences were, in turn, hypothesized to increase risk for current posttraumatic stress disorder (PTSD). High‐risk women were recruited from an innercity drug and alcohol treatment center (N = 105). Interpersonal resource losses, partner‐produced physical assault, adulthood rape, CPA, and CSA had direct effects on PTSD. CPA and CSA also had indirect effects on PTSD through rape, which, in turn, predicted PTSD. Results suggest that the traumatic origins of current PTSD among substance‐using women are multifaceted and support the importance of considering interpersonal coping resources in evaluating and treating female substance users.
Failure of inactivated influenza A vaccine to protect healthy children aged 6−24 months
Authors: Maeda Taro , Shintani Yukihiro , Nakano Kanako , Terashima Kazuhiro , Yamada Yoshiyasu 
Published: April 2004

Abstract
Background
: The efficacy of inactivated influenza vaccine in healthy infants and children younger than 24 months has not been confirmed. The aim of the present study was to determine the prophylactic effect of inactivated influenza vaccine against influenza A in healthy children aged 6−24 months.
Methods
: Healthy infants and young children (6−24 months old) were immunized by subcutaneous injection of inactivated influenza vaccine before influenza seasons. Age matched children were randomly assigned as the control. These children were followed up from January to April in each year (2000, 2001 and 2002). The attack rates of influenza A infection was compared and statistically assessed.
Results
: The attack rate of influenza A virus infection in the vaccine group and the control group were 14.8% (n = 27) vs 12.5% (n = 32) in 2000 (P = 0.526); 2.8% (n = 72) vs 7.2% (n = 69) in 2001 (P = 0.203); and 3.4% (n = 52) vs 8.9% (n = 56) in 2002 (P = 0.205). The attack rates of influenza A between the two groups were not significantly different.
Conclusion
: Inactivated influenza vaccine did not reduce the attack rate of influenza A infection in 6−24 month old children.