bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of clinical data with breached blindness
Authors: Chow Shein‐Chung , Shao Jun 
Published: April 2004

AbstractIn clinical trials, blinding is usually employed to prevent bias that may be introduced due to the knowledge of the identity of the treatment codes. This bias could alter the conclusion of statistical inference on the treatment effect. The purpose of this article is to propose a method for analysing clinical data with breached blindness. The example regarding the study of the effectiveness of an appetite suppressant in weight loss in obese woman as described in Brownell and Stunkard (Am. J. Psychiatry 1982; 139:1487–1489) is used to illustrate the application of the proposed methods. Copyright © 2004 John Wiley & Sons, Ltd.
Allowing for imprecision of the intracluster correlation coefficient in the design of cluster randomized trials
Authors: Turner Rebecca M. , Toby Prevost A. , Thompson Simon G. 
Published: April 2004

AbstractThe sample size required for a cluster randomized trial depends on the magnitude of the intracluster correlation coefficient (ICC). The usual sample size calculation makes no allowance for the fact that the ICC is not known precisely in advance. We develop methods which allow for the uncertainty in a previously observed ICC, using a variety of distributional assumptions. Distributions for the power are derived, reflecting this uncertainty. Further, the observed ICC in a future study will not equal its true value, and we consider the impact of this on power. We implement calculations within a Bayesian simulation approach, and provide one simplification that can be performed using simple simulation within spreadsheet software. In our examples, recognizing the uncertainty in a previous ICC estimate decreases expected power, especially when the power calculated naively from the ICC estimate is high. To protect against the possibility of low power, sample sizes may need to be very substantially increased. Recognizing the variability in the future observed ICC has little effect if prior uncertainty has already been taken into account. We show how our method can be extended to the case in which multiple prior ICC estimates are available. The methods presented in this paper can be used by applied researchers to protect against loss of power, or to choose a design which reduces the impact of uncertainty in the ICC. Copyright © 2004 John Wiley & Sons, Ltd.
Bayesian inference for randomized clinical trials with treatment failures
Authors: Shaffer Michele L. , Chinchilli Vernon M. 
Published: April 2004

AbstractDuring the course of a clinical trial, subjects may experience treatment failure. For ethical reasons, it is necessary to administer emergency or rescue medications for such subjects. However, the rescue medications may bias the set of response measurements. This bias is of particular concern if a subject has been randomized to the control group, and the rescue medications improve the subject's condition. The standard approach to analysing data from a clinical trial is to perform an intent‐to‐treat (ITT) analysis, wherein the data are analysed according to treatment randomization. Supplementary analyses may be performed in addition to the ITT analysis to account for the effect of treatment failures and rescue medications. A Bayesian, counterfactual approach, which uses the data augmentation (DA) algorithm, is proposed for supplemental analysis. A simulation study is conducted to compare the operating characteristics of this procedure with a likelihood‐based, counterfactual approach based on the EM algorithm. An example from the Asthma Clinical Research Network (ACRN) is used to illustrate the Bayesian procedure. Copyright © 2004 John Wiley & Sons, Ltd.
Bayesian estimation of cost‐effectiveness from censored data
Authors: Heitjan Daniel F. , Kim Clara Yuri , Li Huiling 
Published: April 2004

AbstractWe describe a Bayesian methodology for estimating the cost‐effectiveness of a new treatment compared to a standard in a clinical trial, when censoring of survival, the effectiveness variable, induces censoring of total cost. The statistical model assumes that survival follows a Weibull distribution and that total health care cost follows a gamma distribution whose mean has a linear regression on survival time. We summarize the posterior distributions of key parameters by importance sampling. We illustrate the method with an analysis of data from a randomized clinical trial of a treatment for cardiovascular disease. Copyright © 2004 John Wiley & Sons, Ltd.
Parametric modelling of cost data in medical studies
Authors: Nixon R. M. , Thompson S. G. 
Published: April 2004

AbstractThe cost of medical resources used is often recorded for each patient in clinical studies in order to inform decision‐making. Although cost data are generally skewed to the right, interest is in making inferences about the population mean cost. Common methods for non‐normal data, such as data transformation, assuming asymptotic normality of the sample mean or non‐parametric bootstrapping, are not ideal. This paper describes possible parametric models for analysing cost data.Four example data sets are considered, which have different sample sizes and degrees of skewness. Normal, gamma, log‐normal, and log‐logistic distributions are fitted, together with three‐parameter versions of the latter three distributions. Maximum likelihood estimates of the population mean are found; confidence intervals are derived by a parametric BCabootstrap and checked by MCMC methods. Differences between model fits and inferences are explored.Skewed parametric distributions fit cost data better than the normal distribution, and should in principle be preferred for estimating the population mean cost. However for some data sets, we find that models that fit badly can give similar inferences to those that fit well. Conversely, particularly when sample sizes are not large, different parametric models that fit the data equally well can lead to substantially different inferences. We conclude that inferences are sensitive to choice of statistical model, which itself can remain uncertain unless there is enough data to model the tail of the distribution accurately. Investigating the sensitivity of conclusions to choice of model should thus be an essential component of analysing cost data in practice. Copyright © 2004 John Wiley & Sons, Ltd.
Post‐awakening changes in salivary cortisol in veterans with and without PTSD
Authors: Lauc Gordan , Zvonar Kristina , Vuks̆ić‐Mihaljević Z̆eljka , Flögel Mirna 
Published: April 2004

AbstractCortisol shows a well‐documented circadian rhythm with peak levels observed shortly after awakening and steadily decreasing values thereafter. This is a relatively robust diurnal pattern that is displayed by most non‐ill individuals, but recently it has been shown that in the general population some 10–15 per cent of individuals have ‘flat’ circadian cycles of cortisol. We have analyzed post‐awakening variations in levels of salivary cortisol in veterans without post‐traumatic stress disorder (PTSD), veterans with diagnosed PTSD that were not hospitalized, and hospitalized veterans with PTSD. ‘Flat’ circadian cycles of salivary cortisol were observed in 6 per cent of veterans without PTSD, 29 per cent of non‐hospitalized veterans with PTSD, and 42 per cent of veterans hospitalized for PTSD. Copyright © 2004 John Wiley & Sons, Ltd.
Covalent and noncovalent chemical modifications of arginine residues decrease dopamine transporter activity
Authors: Volz Trent J. , Kim M. , Schenk James O. 
Published: April 2004

AbstractRotating disk electrode voltammetry was used to measure dopamine (DA) transport in rat striatum and in human embryonic kidney cells expressing the rat dopamine transporter (DAT). The goals of this study were to determine 1) if arginine (Arg) selective agents could alter DA transport, and 2) if DA analogs and DAT inhibitors could attenuate the effects of these agents on the DAT. Phenylglyoxal (PG), Hill coefficient 2.5, and other Arg selective agents decreased DA transport velocities. DA, Hill coefficient 1.0, and its analogs 3‐hydroxyphenethylamine and 4‐hydroxyphenethylamine attenuated the effects of PG on the DAT while phenethylamine did not. The tropane‐based DAT inhibitors cocaine, WIN 35065‐2, and WIN 35428 also attenuated the effects of PG. Benztropine, GBR 12935, and GBR 12909 did not. Thus, Arg residues are important for DAT activity and the results suggest that DA and cocaine both interact with Arg residues. Structure–activity studies suggest that DA interacts with Arg through its catechol hydroxyl groups and cocaine through the ester linkage attached to carbon 2 of the tropane ring. The results that 1) DA and cocaine may interact with the same functionally important Arg residue at the DAT, and 2) some members of the tropane and 1,4‐dialkylpiperazine classes of DAT inhibitors may interact differently with DAT‐derived Arg residue(s) furthers the notion that DAT activity sparing antagonists of cocaine can be designed. Synapse 52:272–282, 2004. © 2004 Wiley‐Liss, Inc.
Novel peripheral benzodiazepine receptor ligand [11C]DAA1106 for PET: An imaging tool for glial cells in the brain
Authors: Maeda Jun , Suhara Tetsuya , Zhang Ming‐Rong , Okauchi Takashi , Yasuno Fumihiko , Ikoma Yoko , Inaji Motoki , Nagai Yuji , Takano Akihiro , Obayashi Shigeru , Suzuki Kazutoshi 
Published: April 2004

AbstractPeripheral benzodiazepine receptor (PBR) is expressed in most organs and its expression is reported to be increased in activated microglia in the brain. [11C]PK11195 has been widely used for the in vivo imaging of PBRs, but its signal in the brain was not high enough for stable quantitative analysis. We synthesized a novel positron emission tomography (PET) ligand, [11C]DAA1106, for PBR and investigated its in vivo properties in rat and monkey brain. High uptake of [11C]DAA1106 was observed in the olfactory bulb and choroid plexus area, followed by the pons/medulla and cerebellum by in vivo autoradiography of rat brain, correlating with the binding in vitro. [11C]DAA1106 binding was increased in the dorsal hippocampus with neural destruction, suggesting glial reaction. [11C]DAA1106 binding was both inhibited and displaced by 1.0 mg/kg of DAA1106 and 5 mg/kg of PK11195 by 80% and 70%, respectively. Specific binding was estimated as 80% of total binding. [11C]DAA1106 binding was four times higher compared to the binding of [11C]PK11195 in the monkey occipital cortex. These results indicated that [11C]DAA1106 might be a good ligand for in vivo imaging of PBR. Synapse 52:283–291, 2004. © 2004 Wiley‐Liss, Inc.
How to enter the pediatric airway for bronchoscopy
Authors: Niggemann Bodo , Haack Marion , Machotta Andreas 
Published: April 2004

Abstract
Background
: Bronchoscopies are performed in childhood for diagnostic reasons (e.g. evaluation of stridor, unexplained cough, possible malformations) and therapeutic reasons (e.g. foreign body removal, management of the difficult airway).
Methods
: Various procedures of entering the pediatric airways are presented, based on an overview of the literature and the experience of the authors.
Results
: The advantages and disadvantages of direct fibreoptic bronchoscopy, bronchoscopy via face mask, via laryngeal mask airway, via tracheal tube, and for combined flexible and rigid bronchoscopy are discussed. In addition, practical aspects of bronchoscopy are considered, including local anesthesia, oxygen supplementation, monitoring, antibiotic treatment.
Conclusions
: Although inspection of the pediatric airways has become a well‐accepted routine procedure with a high diagnostic yield, and bronchoscopies are well tolerated, it is important that the most appropriate means of access to the airways is chosen according to the indications and the age of the child.
Screening for developmental dysplasia of the hip: Results of a 7‐year follow‐up study
Authors: Şahİn Fİgen , Aktürk Aysİma , Beyazova Ufuk , ÇakIr Banu , BoyunaĞa Öznur , Tezcan Sabahat , BölükbaŞI Selçuk , KanatlI Ulunay 
Published: April 2004

Abstract
Background
: Screening for developmental dysplasia of the hip (DDH) is widely recommended for all infants to prevent disability from late diagnosis of dislocation of the hip. The present study evaluates the results of screening for developmental dislocation of hip in a clinic in Turkey over the course of 7 years.
Methods
: Hospital records of 5798 infants who were examined regularly until walking age at Gazi University well child clinics between January 1995 and December 2001 were reviewed. Infants with known risk factors for DDH such as breech presentation, family history of DDH or swaddling, and of infants with physical examination findings suggestive of DDH, were referred to orthopedic surgeons for diagnosis. Based on this final diagnosis, sensitivity, specificity, positive and negative predictive values of risk factors and physical examination findings were calculated.
Results
: Of the 5798 infants, risk factors were detected in the medical history of 111 infants, and in 14 infants a musculoskeletal deformity was detected. In 606 infants the physical examination findings were suggestive of DDH. Ten patients were subsequently diagnosed with DDH. The sensitivity, specificity, positive predictive value and negative predictive values of having a risk factor for DDH in history were 10.0%, 98.1%, 0.9%, 99.8%, and having abnormal hip examination findings were 100.0%, 88.9%, 1.6% and 100.0%, respectively.
Conclusion
: A careful history and physical examination is the cornerstone of DDH screening. Serial hip examinations performed during health examination visits provide an opportunity to identify DDH cases. The sensitivity of risk factors in history and physical examination findings together is high enough to be accepted as a screening tool.
Enteroviral hepatitis in children
Authors: Kawashima Hisashi , Ryou Shimizu , Nishimata Shigeo , Ioi Hiroaki , Kashiwagi Yasuyo , Iizumi Mamoru , Takami Takeshi , Sasamoto Masato , Takekuma Kouji , Hoshika Akinori , Mori Takayuki 
Published: April 2004

Abstract
Background
: The pathogen causing enteroviral hepatitis is often not found despite careful examination.
Methods
: This study investigates the enterovirus genome in serum and liver tissue obtained from patients who showed abnormal liver function without negative data of usual studies and cytomegalovirus (CMV) serologically positive cases.’
Results
: Nine out of 21 serum samples were positive by using reverse transcriptase‐polymerase chain reaction (RT‐PCR) for enterovirus. The 21 samples had CMV‐IgM antibodies in five cases. These CMV serologically positive cases were all negative for enterovirus using RT‐PCR. Therefore, nine out of 16 (60%) were of unknown etiology. Some cases showed liver dysfunction over a period of more than 6 months. The liver function revealed that all cases finally improved. The sequences coincided with those of Coxsackie B5 or B6 with the highest score by gene homology search. The liver pathology revealed that two of three subjected cases had mild fibrosis and small cell infiltration. RT‐PCR of liver tissue for enterovirus were positive in all three cases comparing the house keeping gene. The viral load was high in acute phase and low in convalescent phase.
Conclusion
: In more than half of children with illnesses of unknown etiology, the pathogen was found to be enteroviruses, and RT‐PCR and quantification of serum is an easy method to identify these diseases.
Spontaneous closure of ventricular septal defects followed up from <3 months of age
Authors: Miyake Toshiharu , Shinohara Tohru , Nakamura Yoshihide , Fukuda Tsuyoshi , Tasato Hiroshi , Toyohara Keiko , Tanihira Yuko 
Published: April 2004

Abstract
Background
: This study evaluates the incidence and timing of spontaneous closure (SC) of ventricular septal defect (VSD) using Doppler color flow mapping.
Methods
: A total of 225 infants (mean age 30 days) were diagnosed with uncomplicated VSD: 31 (14%) subpulmonary VSD, 159 (70%) perimembranous, and 35 (16%) muscular. The patients were divided into two groups according to the presence or absence of congestive heart failure (CHF). SC was confirmed with color Doppler.
Results
: Surgical closure was performed in 59 patients (26%). SC occurred in 107 patients (48%); three (10%) of 31 with subpulmonary VSD, 75 (47%) of 159 with perimembranous VSD, and 29 (83%) of 35 with a muscular VSD. Average age at SC was 19 months. In three SC patients with a subpulmonary VSD, there was no aortic valve prolapse and no aortic regurgitation. SC occurred in 96% of SC patients with a perimembranous VSD by the age of 6 years, and in 93% of those with a muscular VSD by the age of 3 years. In patients without CHF, the rate of SC was 72%; 23% in subpulmonary VSD, 74% in perimembranous, and 85% in muscular. SC occurred in only 23% of patients with a perimembranous VSD with CHF. Mean age at the final examination was 6.9 years in 59 patients with a VSD remaining open, and 63% of patients with a perimembranous VSD remaining open had an aneurysm of the ventricular membranous septum.
Conclusions
: The SC rate of VSD by mean age of 6.9 years was 48%, but it was 72% in patients without CHF. In patients with CHF, SC was seen only in patients with a perimembranous VSD. The rate of SC was 10% in subpulmonary VSD. The authors contend that SC probably occurred by growth of muscular septum surrounding VSD. Muscular VSD spontaneously closed earlier than perimembranous VSD.
Rare clinical presentation mode of intestinal malrotation after neonatal period: Malabsorption‐like symptoms due to chronic midgut volvulus
Authors: İmamoĞlu Mustafa , Çay Ali , Sarihan Haluk , Şen YaŞar 
Published: April 2004

Abstract
Background
: Many different and non‐specific clinic presentation modes of malrotation anomalies (MA) have been reported after neonatal period. The authors describe four children with MA presented with malabsorption‐like clinical features.
Methods
: Three children aged from 8 months to 7 years, with a history of long‐standing diarrhea and failure to thrive attributed to malabsorption, were referred to Department of Pediatric Surgery, for evaluation of suspected MA. Another patient, a 10‐year‐old boy who was treated for malabsorption for 6 years, presented with acute duodenal obstruction findings. The duration of symptoms averaged 35 months, ranging 8 months to 6 years. All patients had undergone extensive evaluation and empiric trials of different formulas with no improvement in their symptoms. One underwent jejunal biopsy.
Results
: Primary presentation complaints were chronic diarrhea and failure to thrive in three patients. Their histories revealed chronic (in one) and intermittent colicky (in two) abdominal pain, and intermittent nonbilious vomiting (in three). The remaining patient presented with acute illness, with chronic diarrhea, failure to thrive, and intermittent abdominal pain and vomiting on his history. They were below 30th percentile according to body weight and height. Laboratory studies revealed hypoproteinemia, hypoalbunemia, raised liver function tests, and anemia in all patients. The patient who presented acutely had double‐bubble sign on the plain abdominal film obtained at admission. In the other three, plain films obtained during an attack of abdominal pain and/or vomiting revealed findings of partial intestinal obstruction. The diagnosis was confirmed by upper gastrointestinal series. At their laparotomy, a classical type of malrotation with circumstantial evidence of chronic volvulus was noted. All patients had normal laboratory values between postoperative 3 and 5 weeks, and they were up to 30th percentile at the end of the 6 months.
Conclusion
: Malrotation anomalies should be included in the differential diagnosis in a child presented with malabsorption‐like clinical features.
Role of serum neutralizing antibody in reinfection of respiratory syncytial virus
Authors: Kawasaki Yukihiko , Hosoya Mitsuaki , Katayose Masahiko , Suzuki Hitoshi 
Published: April 2004

Abstract
Background
: To clarify the role of serum antibody in respiratory syncytial virus (RSV) reinfection, the authors conducted a follow‐up study of patients with primary RSV infection.
Methods
: From 1994 to 1995, 256 patients were a diagnosed with primary RSV infection based on the antigen detection in nasopharyngeal secretions using enzyme linked immunoassay method. One hundred and sixty‐five patients were followed‐up for 1 year, and 87 of the 165 patients showed respiratory symptoms in winter. When a patient had a symptom such as cough, wheezing, rhinorrhea or fever, the nasopharyngial secretion was examined for the presence of RSV. Forty‐one patients (group 1) were diagnosed with reinfection with RSV and the other 46 patients (group 2) were not diagnosed with reinfection. The authors compared clinical features between primary infection and reinfection of group 1 and serum neutralization test (NT) antibody titers to RSV between group 1 and 2.
Results
: The mean age was 6.0 ± 3.6 months at RSV primary infection and 14.6 ± 8.2 months at RSV reinfection. Hospitalization, oxygen supplementation, and use of respirator were required by 71%, 39%, 2%, respectively, in primary infection, and by 22%, 0%, 0%, respectively, in reinfection. All children in group 1 had titers of 1 : 16 or lower, while 39.1% of children in group 2 had titers of 1 : 16 or lower (P < 0.05). No patient with the titers of 1 : 32 or higher had symptomatic reinfection. Serum NT antibodies to RSV of outpatients were higher than those of inpatients at reinfection.
Conclusions
: The severity of illness in RSV reinfection is generally milder than that in primary infection. Our findings suggest that NT antibodies play an important role in reducing the severity of illness as well as in protection from RSV reinfection.
Molecular epidemiology of measles virus in Japan
Authors: Nakayama Tetsuo , Fujino Motoko , Yoshida Naoko 
Published: April 2004

Abstract
Background
: Measles virus has been classified into 22 genotypes. The present report examines the molecular epidemiology of measles virus in Japan from 1984 to 2002, and the epidemiological link between imported cases in several foreign countries and Japanese strains was elucidated from the literature.
Methods
: B95a or Vero cells was used to isolate the measles virus. The measles virus genome was amplified in the N and H genes by reverse transcriptase‐polymerase chain reaction and were partially sequenced. Phylogenetic analysis of a partial sequence of the N gene, from position 1230 to 1685, of the recent measles strains was performed in comparison with the World Health Organization reference strains.
Results
: There were large outbreaks of measles in Japan in 1984, 1987−1988, 1991−1993, and 2001−2002 and each outbreak was caused by a different genotype. Genotype C1 was an indigenous strain for a long period before 1985, while D3 was isolated in 1987−1988 and D5 in 1991−1993 outbreaks. In addition, the Chicago‐type D3 caused sporadic regional outbreaks from 1998 to 1999. After 2000, H1 became the dominant circulating strain. It should be noted that the Japanese strains were detected as imported cases by epidemiological linkage in several countries.
Conclusion
: Among the recent circulating strain of measles virus in Japan the genotype H1 was dominant after 2000 and the Japanese strains D3, D5, and H1 were exported to several countries. It is recommended that Japan should adopt a more extensive and active vaccination strategy for measles elimination in line with other countries in the world.