bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluating current policy for detecting mosaicism in amniotic fluid cultures: implications for current cell counting practices
Authors: Caudill Samuel P. , Van Dyke Daniel L. , Chen Andrew T. L. , Reidy John A. , Ing Paul S. , Schwartz Stuart , Vance Gail H. 
Published: January 2005

AbstractChromosomal mosaicism is one of the most vexing problems for clinical cytogenetic laboratories and personnel time used for analysis at the microscope is one of the principle costs in cytogenetic laboratories. We use data collected from 26 cytogenetic laboratories to evaluate whether the American College of Medical Genetics guidelines for minimum number of cells to count to exclude mosaicism in amniotic fluid specimens is appropriate. An accurate estimate of the number of mosaics that are missed by current cell counting practices is an important step in this process. Thus, we present a new method for estimating the number of mosaics that are missed and we use computer simulation to evaluate this new method. Our results indicate that if the clinical significance of mosaicism is suspected to be minimal for certain cytogenetic anomalies when the percentage of abnormal cells is 15 per cent or less, then it may be sufficient to use a 15‐cell counting‐rule‐for‐detection along with a minimum total cell count of 30 regardless of whether abnormal cells or normal cells are in the minority. Published in 2005 by John Wiley & Sons, Ltd.
A mixed‐effects quintile‐stratified propensity adjustment for effectiveness analyses of ordered categorical doses
Authors: Leon Andrew C. , Hedeker Donald 
Published: January 2005

AbstractObservational studies can be used to evaluate treatment effectiveness among patients with a broader range of illness severity than typically seen in randomized controlled clinical trials. However, there are several difficulties with observational evaluations including non‐equivalent comparison groups, treatment doses and durations that vary widely, and, in longitudinal studies, multiple courses of treatment per subject. A mixed‐effects approach to the propensity adjustment for non‐equivalent comparison groups is described that can account for each of these perturbations. The strategy involves two stages. First, characteristics that distinguish among subjects who receive various levels of treatment are examined in a model of propensity for treatment intensity using mixed‐effects ordinal logistic regression. Second, the propensity‐stratified effectiveness of ordered categorical doses is compared in a mixed‐effects grouped time survival model of time until recovery. The model is applied in a longitudinal, observational study of antidepressant effectiveness. Then a Monte Carlo simulation study indicates that the strategy has acceptable type I error rates and minimal bias in the estimates of treatment effectiveness. Statistical power exceeds 0.90 for an odds ratio of 1.5 withN= 250 and 500, and is acceptable for an odds ratio of 2.0 withN= 100. Nevertheless, withN= 100, the models that had high intraclass correlation coefficients had greater tendency towards non‐convergence. This approach is a useful strategy for observational studies of treatment effectiveness. It is capable of adjusting for selection bias, incorporating multiple observations per subject, and comparing effectiveness of ordinal doses. Copyright © 2005 John Wiley & Sons, Ltd.
Statistical collaboration to impact policy decisions
Authors: Morton Sally C. 
Published: January 2005

AbstractThe objective of this paper is to support the following thesis: In health services research, a statistician can, and often should, contribute beyond what is generally defined as the ‘classical’ statistician project role. I use projects from RAND Health, the health services research division of the RAND Corporation, to demonstrate the issues that arise for the statistician in this expanded collaborative role. These projects are the ‘HIV Cost and Services Utilization Study’ (HCSUS) and the ‘Ephedra: Clinical Efficacy and Side Effects Project’. HCSUS collected information on a nationally representative sample of people in care for HIV infection in order to determine what services were being delivered and their cost in order to guide policy decisions on the allocation of limited health care resources. The ephedra project was a systematic review conducted by the Southern California Evidence‐Based Practice Centre to provide information on the existing science so that the National Institutes of Health could guide an expanded research effort to better understand the safety of ephedrine alkaloids. In order to collaborate on more than just the data analysis of a typical project, the statistician must proactively contribute to all project phases. These phases include problem formulation, study design, data collection, analysis, and the communication of results. The statistician needs to effectively and efficiently balance methodological, substantive, practical, and sometimes even ethical demands. As a result of contributing beyond standard statistical tasks, the statistician may directly impact health policy decisions. Copyright © 2005 John Wiley & Sons, Ltd.
Recrystallization of Bacterial S‐Layers on Flat Polyelectrolyte Surfaces and Hollow Polyelectrolyte Capsules
Authors: Toca‐Herrera José Luis , Krastev Rumen , Bosio Vera , Küpcü Seta , Pum Dietmar , Fery Andreas , Sára Margit , Sleytr Uwe B. 
Published: January 2005

AbstractPolyelectrolyte multilayer (PE) deposition and S‐layer technology have been combined to make novel robust biomimetic surfaces and membranes. Isolated subunits of the bacterial cell surface layer from Bacillus sphaericus CCM2177 SbpA was self‐assembled on PE multilayer supports, with the composition of the multilayer playing a crucial role in determining the structure of the resulting supported protein layers. Flat substrates were studied using atomic force microscopy and neutron reflectometry; protein on suitable PE combinations showed a crystalline structure with lattice constants equal to those found in vivo on bacterial surfaces. The mechanical stability of the S‐layer is higher when recrystallized on PEs than directly on silicon supports. The recrystallization process was subsequently used to coat colloidal particles, permitting the determination of zeta potentials before and after coating. Hollow capsules could also be coated in the same way, as proven by various techniques. Our results suggest that electrostatic interactions via divalent cations are important for the assembly process. The results also demonstrate that the versatility of the PE multilayer membranes can be successfully combined with the well‐defined surface chemistry and structure of 2D protein crystals.
A General in situ Hydrothermal Rolling‐Up Formation of One‐Dimensional, Single‐Crystalline Lead Telluride Nanostructures
Authors: Zhang Lizhi , Yu Jimmy C. , Mo Maosong , Wu Ling , Kwong Kwan Wai , Li Quan 
Published: January 2005

AbstractIn this study we demonstrate that one‐dimensional (1D) nanostructured lead telluride (PbTe) can be synthesized in a hydrothermal reaction between lead foil and tellurium powder. The resulting materials were characterized by X‐ray diffraction, scanning electron microscopy, and transmission electron microscopy. The formation of the 1D structure can be explained by an in situ hydrothermal rolling‐up mechanism whereby PbTe is formed hydrothermally and deposited on the lead substrate. The lead underneath the PbTe layer is then selectively etched by a cetyltrimethylammonium bromide solution, thus allowing the PbTe to roll up into 1D structures. This method can be extended to prepare other 1D tellurides, including CdTe, Cu2Te, and Ag2Te.
Outcomes for children with acute myocarditis
Authors: English Robert F. , Janosky Janine E. , Ettedgui Jose A. , Webber Steven A. 
Published: January 2005

The optimum treatment for myocarditis in children is unknown. We present outcomes for this disease as seen in a large series of children. Thus, we identified all children seen with myocarditis at Children’s Hospital of Pittsburgh since 1985, including only those with biopsy-proven myocarditis, or cardiac dysfunction and proof of concomitant cardiotropic viral infection. Outcomes were defined as complete recovery, incomplete recovery, and death or transplantation.We identified 41 patients, 37 proven by histology, and 4 patients who were too unstable for biopsy but had proof of viral infection. Of the group, 27 (66%) made a complete recovery, 4 (10%) had incomplete recovery, and 10 (24%) either died (5) or underwent transplantation (5). The median time to death or transplantation was 8.4 months, with a range from 1 day to 49 months. Steroids had been administered to 16 patients, of whom 10 made a complete recovery, 2 an incomplete recovery, 2 died, and 2 were transplanted. Intravenous immune globulin was given in isolation to one patient, who made a complete recovery, and to 18 in combination with steroids, of whom 12 made a complete recovery, 2 an incomplete recovery, 2 died, and 2 were transplanted. The remaining 6 patients received neither steroids nor intravenous immune globulin, and of these, 4 made a complete recovery, 1 was transplanted, and 1 died. Freedom from death or transplantation was 81% at 1 year, and 74% at 5 years, with no difference between the modes of treatments. The median time to recovery of function was also comparable between the groups. Thus, in our patients, treatment with intravenous immune globulin appeared to confer no advantage to steroid therapy alone. These data emphasise the need for randomised trials to assess the efficacy of current treatments, as well as that of new therapies.
Quantitative analysis of right atrial performance after surgical repair of tetralogy of Fallot
Authors: Hui Wei , Abd El Rahman Mohamed Y. , Dsebissowa Fatima , Rentzsch Axel , Gutberlet Matthias , Alexi-Meskishvili Vladimir , Hetzer Roland , Lange Peter E. , Abdul-Khaliq Hashim 
Published: January 2005

We aimed to assess the right atrial performance in patients after surgical correction of tetralogy of Fallot, and to clarify the relationship between the pump function of the right atrium and right ventricular systolic function.We included in the study 50 asymptomatic patients following corrective surgery of tetralogy of Fallot, comparing them to 30 normal subjects. Right atrial areas were measured by echocardiography, and the active fractional area of emptying was expressed, in percentages, as the area measured at the onset of atrial contraction, minus the minimal area, divided by the area at the onset of atrial contraction. We used this value to assess the atrial pump function. Right atrial peak strain rates were measured by tissue Doppler imaging. Compared to controls, patients with tetralogy of Fallot had a significantly reduced right atrial active fractional area of emptying (p = 0.005), along with a reduced peak late diastolic strain rate (p = 0.002). Among 20 patients who underwent magnetic resonance tomographic examination, a relatively higher right atrial peak late diastolic strain rate was shown in patients with a right ventricular ejection fraction of less than 50% (p = 0.021).Right atrial performance is reduced in patients after surgical correction of tetralogy of Fallot. When facing right ventricular systolic dysfunction, nonetheless, the right atrial pump function may be relatively enhanced. Tissue Doppler derived strain rate can provide quantitative analysis of regional right atrial performance.
A population-based study of extra-cardiac anomalies in children with congenital cardiac malformations
Authors: Eskedal Leif , Hagemo Petter , Eskild Anne , Aamodt Geir , Seiler Karry Stephen , Thaulow Erik 
Published: January 2005

We describe the prevalence of extra-cardiac anomalies in children with congenital cardiac malformations, and their impact on survival, compared to the outcome in children with the congenital cardiac lesions as the only recognised anomaly.Our population comprises the 3527 children born with congenital cardiac anomalies between 1990 and 1999, and registered at the largest tertiary centre for Paediatric Cardiology in Norway. Extra-cardiac anomalies were found in one-fifth of the population, with Down's syndrome accounting for nearly one-third. Survival improved for children born between 1995 and 1999 compared with those born in the period from 1990 to 1994 for all groups, except for children with additional extra-cardiac anomalies in the absence of Down's syndrome. The results were the same for children undergoing surgical treatment of their cardiac malformation. The survival in children with Down's syndrome improved in comparable fashion to those without extra-cardiac anomalies. Children with extra-cardiac anomalies in the absence of Down's syndrome represent a heterogeneous group, with varying patterns of survival. Survival did not improve in these latter patients during the period of our study.
The signalling pathway which causes contraction via P2‐purinoceptors in rat urinary bladder smooth muscle
Authors: Naramatsu Masahiro , Yamashita Toshikazu , Kokubun Shinichiro 
Published: January 2005

The signalling pathway which causes contractions to adenosine 5′‐O‐2‐thiodiphosphate (ADPβS) and α,β‐methylene adenosine 5′‐diphosphate (α,β‐Me ADP) was investigated in rat urinary bladder smooth muscle by measuring isotonic tension.
The responses to 10 μM α,β‐methylene adenosine 5′‐triphosphate (α,β‐Me ATP) in 0 and 3.6 mM Ca2+ were 5.9±1.3 (n=10) and 122.2±6.4 (n=8) % respectively of those obtained in 1.8 mM Ca2+, whereas those to 100 μM ADPβS were 34.6±3.3 (n=8) and 96.8±7.2 (n=8) %, in 0 and 3.6 mM Ca2+, respectively. In both experimental conditions, the responses to the two agonists expressed as % of the control responses were significantly different (P<0.01).
Indomethacin at high concentrations (>1 μM) decreased the responses to α,β‐Me ATP (10 μM), ADPβS (100 μM) and α,β‐Me ADP (100 μM). However, no significant difference was obtained between the responses to all the agonists at 30 μM indomethacin.
2‐Nitro‐4‐carboxphenyl n,n‐diphenylcarbamate (NCDC) at concentrations between 1 μM and 100 μM concentration‐dependently decreased the responses to ADPβS (100 μM) and α,β‐Me ADP (100 μM) and almost completely inhibited them at 100 μM. Although the responses to α,β‐Me ATP (10 μM) were also inhibited by the drug, at 50 and 100 μM NCDC the responses to α,β‐Me ATP were significantly larger than those to ADPβS and α,β‐Me ADP (P<0.01).
NCDC 100 μM significantly inhibited the KCl‐induced contraction to 65.9±4.9% (n=6) of the control (P<0.01).
It is suggested that the contraction via ADPβS‐sensitive receptors in the rat urinary bladder smooth muscle mainly depends on Ca2+ ions liberated from intracellular Ca2+ stores, though the contribution of Ca2+ ions from the extracellular space cannot be neglected. The release of Ca2+ ions from stores is mainly mediated by the production of inositol trisphosphate (IP3) via the activation of phospholipase C.

British Journal of Pharmacology (1997) 122, 558–562; doi:10.1038/sj.bjp.0700157
Evidence for a role for nitric oxide in relaxation of the frog oesophageal body to electrical field stimulation
Authors: Williams S. J. , Parsons M. E. 
Published: January 2005

Electrical field stimulation (EFS) (1–10 Hz, 30 V, 2 ms) of frog oesophageal body strips resulted in frequency‐dependent non‐adrenergic, non‐cholinergic (NANC) relaxations.
Tetrodotoxin (TTX) (10−6–10−5 M) had no effect on EFS evoked relaxations with a 2 ms pulse width. At a pulse width of 0.5 ms only the responses to the highest frequency (10 Hz) were significantly inhibited by TTX at 10−5 M. Relaxations at the 2 ms pulse width were unaffected by ω‐conotoxin (10−6 M), nifedipine (10−6 M) or cobalt (5×10−4 M).
NG‐nitro‐L‐arginine (L‐NOARG) (10−6–10−4 M), a nitric oxide synthase (NOS) inhibitor, caused a concentration‐dependent inhibition of the EFS‐induced NANC relaxant responses. The inhibitory effect of L‐NOARG was both prevented and reversed by L‐arginine but not D‐arginine (5×10−3 M).
The phosphodiesterase type V inhibitor (PDE V), SK&F 96231 (10−7–10−4 M), caused a concentration‐dependent potentiation of both the percentage relaxation and the duration of the relaxant responses to EFS.
ODQ (10−7–10−5 M), a guanylate cyclase inhibitor, produced a concentration‐dependent inhibition of EFS‐evoked NANC relaxations.
Oxyhaemoglobin (10−6 M), which binds nitric oxide (NO), inhibited NANC relaxations to EFS.
The NO donor sodium nitroprusside (SNP) (10−8–10−4 M) produced a concentration‐dependent inhibition of evoked tone. L‐NOARG (10−4 M) had no effect on the SNP evoked relaxations. Preincubation with oxyhaemoglobin (10−6 M) caused a reduction in the SNP (10−6–10−5 M) induced relaxations.
These results suggest NO is the relaxant transmitter of the frog oesophageal body and the source of NO may be non‐neuronal.

British Journal of Pharmacology (1997) 122, 179–185; doi:10.1038/sj.bjp.0701298
Involvement of cyclic nucleotide‐dependent protein kinases in cyclic AMP‐mediated vasorelaxation
Authors: Eckly‐Michel Anita , Martin Viviane , Lugnier Claire 
Published: January 2005

The involvement of cyclic AMP‐dependent protein kinase (PKA) and cyclic GMP‐dependent protein kinase (PKG) in the effects of cyclic AMP‐elevating agents on vascular smooth muscle relaxation, cyclic nucleotide dependent‐protein kinase activities and ATP‐induced calcium signalling ([Ca2+]i) was studied in rat aorta. Cyclic AMP‐elevating agents used were a β‐adrenoceptor agonist (isoprenaline), a phosphodiesterase 3 (PDE3) inhibitor (SK&F 94120) and a PDE4 inhibitor (rolipram).
In rat intact aorta, the relaxant effect induced by isoprenaline (0.01–0.3 μM) was decreased by a specific inhibitor of PKA, H‐89, whereas a specific inhibitor of PKG, Rp‐8‐Br‐cyclic GMPS, was without effect. No significant difference in PKA and PKG activity ratios was detected in aortic rings when isoprenaline 10 μM was used. At the same concentration, isoprenaline did not modify ATP‐induced changes in [Ca2+]i in smooth muscle cells. Neither H‐89 nor Rp‐8‐Br‐cyclic GMPS modified this response. These findings suggest that PKA is only involved in the relaxant effect induced by low concentrations of isoprenaline (0.01–0.3 μM), whereas for higher concentrations, other mechanisms independent of PKA and PKG are involved.
The relaxant effects induced by SK&F 94120 and rolipram were inhibited by Rp‐8‐Br‐cyclic GMPS with no significant effect of H‐89. Neither SK&F 94120, nor rolipram at 30 μM significantly modified the activity ratios of PKA and PKG. Rolipram inhibited the ATP‐induced transient increase in [Ca2+]i. This decrease was abolished by Rp‐8‐Br‐cyclic GMPS whereas H‐89 had no significant effect. These results suggest that PKG is involved in the vascular effects induced by the inhibitors of PDE3 and PDE4. Moreover, since it was previously shown that PDE3 and PDE4 inhibitors only increased cyclic AMP levels with no change in cyclic GMP level, these data also suggest a cross‐activation of PKG by cyclic AMP in rat aorta.
The combination of 5 μM SK&F 94120 with rolipram markedly potentiated the relaxant effect of rolipram. This relaxation was decreased by H‐89 and not significantly modified by Rp‐8‐Br‐cyclic GMPS. Moreover, the association of the two PDE inhibitors significantly increased the activity ratio of PKA without changing the PKG ratio. The present findings show that PKA rather than PKG is involved in this type of vasorelaxation. The differences in the participation of PKA vs PKG observed when inhibitors of PDE3 and PDE4 were used alone or together could be due to differences in the degree of accumulation of cyclic AMP, resulting in the activation of PKA or PKG which are differently localized in the cell.
These findings support a role for both PKA and PKG in cyclic AMP‐mediated relaxation in rat aorta. Their involvement depends on the cellular pathway used to increase the cyclic AMP level.

British Journal of Pharmacology (1997) 122, 158–164; doi:10.1038/sj.bjp.0701339
Central role of intracellular calcium stores in acute flow‐ and agonist‐evoked endothelial nitric oxide release
Authors: Hutcheson Iain R. , Griffith Tudor M. 
Published: January 2005

We have used a cascade bioassay system and isolated arterial ring preparations to investigate the contribution of Ca2+ release from endothelial intracellular stores to nitric oxide (NO) production evoked by increases in shear stress and by acetylcholine in rabbit aorta.
Experiments were performed before and following incubation with either the endoplasmic reticulum Ca2+‐ATPase inhibitors cyclopiazonic acid (CPA, 10 μM) and thapsigargin (TSG, 1 μM) or ryanodine (30, 100 μM) which binds to a specific endoplasmic reticulum Ca2+‐release channel.
In cascade bioassay all three agents induced relaxations of the recipient ring (CPA, 24.4±3.8%; TSG, 51.5±10.6%; ryanodine, 17.4±1.6%) which were significantly attenuated by preincubation of the donor with 100 μM NG‐nitro‐L‐arginine methyl ester (L‐NAME). However, in isolated rings, only CPA and TSG induced L‐NAME‐sensitive relaxations (CPA 52.7±6.5%; TSG 61.3±7%).
Addition of superoxide dismutase (SOD) to the donor perfusate evoked relaxations of the recipient ring in cascade bioassay (13.3±1.4%, n=22). Prior administration of SOD attenuated relaxations to TSG (23.2±3.8%, n=4) and ryanodine (1.7±0.8%, n=4), and pre‐incubation with TSG and ryanodine blunted SOD‐induced responses (4±1.5%, n=4 and 8.9±1.1%, n=4, respectively). By contrast, no interaction was observed between the relaxations evoked by SOD and CPA. In isolated rings, SOD exerted no direct relaxant action and did not modulate relaxations to CPA, TSG or ryanodine.
In cascade bioassay studies time‐averaged shear stress was manipulated with dextran (1–4% w/v, 80000 MW) to increase perfusate viscosity. NO‐dependent relaxation of the recipient ring induced by increased perfusate viscosity was significantly attenuated by CPA (P<0.01; n=6) and TSG (P<0.05; n=7), but not by ryanodine (n=6).
Endothelium‐dependent relaxations to acetylcholine (0.1–30 μM) in cascade bioassay and in isolated aortic ring preparations were markedly attenuated by pretreatment with CPA and TSG, but were unaffected by ryanodine. Ryanodine and CPA caused only a small attenuation of endothelium‐independent relaxations to sodium nitroprusside (0.001–10 μM), whereas TSG had no effect.
We conclude that release of Ca2+ from CPA‐ and TSG‐sensitive endothelial stores is necessary for NO release evoked by acute flow changes and agonists in rabbit abdominal aorta. Ca2+‐induced Ca2+ release via the ryanodine‐sensitive release channel plays no direct role in these responses. Free radical interactions may complicate the interpretation of findings in cascade bioassay compared with isolated ring preparations.

British Journal of Pharmacology (1997) 122, 117–125; doi:10.1038/sj.bjp.0701340