bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parameter selection for and implementation of a web-based decision-support tool to predict extubation outcome in premature infants
Authors: Mueller Martina , Wagner Carol L , Annibale David J , Knapp Rebecca G , Hulsey Thomas C , Almeida Jonas S 
Published: March 2006

Abstract
Background
Approximately 30% of intubated preterm infants with respiratory distress syndrome (RDS) will fail attempted extubation, requiring reintubation and mechanical ventilation. Although ventilator technology and monitoring of premature infants have improved over time, optimal extubation remains challenging. Furthermore, extubation decisions for premature infants require complex informational processing, techniques implicitly learned through clinical practice. Computer-aided decision-support tools would benefit inexperienced clinicians, especially during peak neonatal intensive care unit (NICU) census.

Methods
A five-step procedure was developed to identify predictive variables. Clinical expert (CE) thought processes comprised one model. Variables from that model were used to develop two mathematical models for the decision-support tool: an artificial neural network (ANN) and a multivariate logistic regression model (MLR). The ranking of the variables in the three models was compared using the Wilcoxon Signed Rank Test. The best performing model was used in a web-based decision-support tool with a user interface implemented in Hypertext Markup Language (HTML) and the mathematical model employing the ANN.

Results
CEs identified 51 potentially predictive variables for extubation decisions for an infant on mechanical ventilation. Comparisons of the three models showed a significant difference between the ANN and the CE (p = 0.0006). Of the original 51 potentially predictive variables, the 13 most predictive variables were used to develop an ANN as a web-based decision-tool. The ANN processes user-provided data and returns the prediction 0–1 score and a novelty index. The user then selects the most appropriate threshold for categorizing the prediction as a success or failure. Furthermore, the novelty index, indicating the similarity of the test case to the training case, allows the user to assess the confidence level of the prediction with regard to how much the new data differ from the data originally used for the development of the prediction tool.

Conclusion
State-of-the-art, machine-learning methods can be employed for the development of sophisticated tools to aid clinicians' decisions. We identified numerous variables considered relevant for extubation decisions for mechanically ventilated premature infants with RDS. We then developed a web-based decision-support tool for clinicians which can be made widely available and potentially improve patient care world wide.
Seasonality of service provision in hip and knee surgery: A possible contributor to waiting times? A time series analysis
Authors: Upshur Ross EG , Moineddin Rahim , Crighton Eric J , Mamdani Muhammad 
Published: March 2006

Abstract

Background
The question of how best to reduce waiting times for health care, particularly surgical procedures such as hip and knee replacements is among the most pressing concern of the Canadian health care system. The objective of this study was to test the hypothesis that significant seasonal variation exists in the performance of hip and knee replacement surgery in the province of Ontario.

Methods
We performed a retrospective, cross-sectional time series analysis examining all hip and knee replacement surgeries in people over the age of 65 in the province of Ontario, Canada between 1992 and 2002. The main outcome measure was monthly hospitalization rates per 100 000 population for all hip and knee replacements.

Results
There was a marked increase in the rate of hip and knee replacement surgery over the 10-year period as well as an increasing seasonal variation in surgeries. Highly significant (Fisher Kappa = 16.05, p < 0.01; Bartlett-Kolmogorov-Smirnov Test = 0.31, p < 0.01) and strong (R2
Autoreg = 0.85) seasonality was identified in the data.

Conclusion
Holidays and utilization caps appear to exert a significant influence on the rate of service provision. It is expected that waiting times for hip and knee replacement could be reduced by reducing seasonal fluctuations in service provision and benchmarking services to peak delivery. The results highlight the importance of system behaviour in seasonal fluctuation of service delivery.
Part-time and full-time medical specialists, are there differences in allocation of time?
Authors: de Jong Judith D , Heiligers Phil , Groenewegen Peter P , Hingstman Lammert 
Published: March 2006

Abstract

Background
An increasing number of medical specialists prefer to work part-time. This development can be found worldwide. Problems to be faced in the realization of part-time work in medicine include the division of night and weekend shifts, as well as communication between physicians and continuity of care. People tend to think that physicians working part-time are less devoted to their work, implying that full-time physicians complete a greater number of tasks. The central question in this article is whether part-time medical specialists allocate their time differently to their tasks than full-time medical specialists.

Methods
A questionnaire was sent by mail to all internists (N = 817), surgeons (N = 693) and radiologists (N = 621) working in general hospitals in the Netherlands. Questions were asked about the actual situation, such as hours worked and night and weekend shifts. The response was 53% (n = 411) for internists, 52% (n = 359) for surgeons, and 36% (n = 213) for radiologists. Due to non-response on specific questions there were 367 internists, 316 surgeons, and 71 radiologists included in the analyses. Multilevel analyses were used to analyze the data.

Results
Part-time medical specialists do not spend proportionally more time on direct patient care. With respect to night and weekend shifts, part-time medical specialists account for proportionally more or an equal share of these shifts. The number of hours worked per FTE is higher for part-time than for full-time medical specialists, although this difference is only significant for surgeons.

Conclusion
In general, part-time medical specialists do their share of the job. However, we focussed on input only. Besides input, output like the numbers of services provided deserves attention as well. The trend in medicine towards more part-time work has an important consequence: more medical specialists are needed to get the work done. Therefore, a greater number of medical specialists have to be trained. Part-time work is not only a female concern; there are also (international) trends for male medical specialists that show a decline in the number of hours worked. This indicates an overall change in attitudes towards the number of hours medical specialists should work.
Protein cleavage strategies for an improved analysis of the membrane proteome
Authors: Fischer Frank , Poetsch Ansgar 
Published: March 2006

Abstract

Background
Membrane proteins still remain elusive in proteomic studies. This is in part due to the distribution of the amino acids lysine and arginine, which are less frequent in integral membrane proteins and almost absent in transmembrane helices. As these amino acids are cleavage targets for the commonly used protease trypsin, alternative cleavage conditions, which should improve membrane protein analysis, were tested by in silico digestion for the three organisms Saccharomyces cerevisiae, Halobacterium sp. NRC-1, and Corynebacterium glutamicum as hallmarks for eukaryotes, archea and eubacteria.

Results
For the membrane proteomes from all three analyzed organisms, we identified cleavage conditions that achieve better sequence and proteome coverage than trypsin. Greater improvement was obtained for bacteria than for yeast, which was attributed to differences in protein size and GRAVY. It was demonstrated for bacteriorhodopsin that the in silico predictions agree well with the experimental observations.

Conclusion
For all three examined organisms, it was found that a combination of chymotrypsin and staphylococcal peptidase I gave significantly better results than trypsin. As some of the improved cleavage conditions are not more elaborate than trypsin digestion and have been proven useful in practice, we suppose that the cleavage at both hydrophilic and hydrophobic amino acids should facilitate in general the analysis of membrane proteins for all organisms.
Tumor-associated endothelial cells display GSTP1 and RARβ2 promoter methylation in human prostate cancer
Authors: Grover Amelia C , Tangrea Michael A , Woodson Karen G , Wallis Benjamin S , Hanson Jeffrey C , Chuaqui Rodrigo F , Gillespie John W , Erickson Heidi S , Bonner Robert F , Pohida Thomas J , Emmert-Buck Michael R , Libutti Steven K 
Published: March 2006

Abstract

Background
A functional blood supply is essential for tumor growth and proliferation. However, the mechanism of blood vessel recruitment to the tumor is still poorly understood. Ideally, a thorough molecular assessment of blood vessel cells would be critical in our comprehension of this process. Yet, to date, there is little known about the molecular makeup of the endothelial cells of tumor-associated blood vessels, due in part to the difficulty of isolating a pure population of endothelial cells from the heterogeneous tissue environment.

Methods
Here we describe the use of a recently developed technique, Expression Microdissection, to isolate endothelial cells from the tumor microenvironment. The methylation status of the dissected samples was evaluated for GSTP1 and RARβ2 promoters via the QMS-PCR method.

Results
Comparing GSTP1 and RARβ2 promoter methylation data, we show that 100% and 88% methylation is detected, respectively, in the tumor areas, both in epithelium and endothelium. Little to no methylation is observed in non-tumor tissue areas.

Conclusion
We applied an accurate microdissection technique to isolate endothelial cells from tissues, enabling DNA analysis such as promoter methylation status. The observations suggest that epigenetic alterations may play a role in determining the phenotype of tumor-associated vasculature.
The effects of sex and hormonal status on restraint-stress-induced working memory impairment
Authors: Shansky Rebecca M , Rubinow Katya , Brennan Avis , Arnsten Amy FT 
Published: March 2006

Abstract

Background
Restraint stress has been shown to elicit numerous effects on hippocampal function and neuronal morphology, as well as to induce dendritic remodeling in the prefrontal cortex (PFC). However, the effects of acute restraint stress on PFC cognitive function have not been investigated, despite substantial evidence that the PFC malfunctions in many stress-related disorders.

Methods
The present study examined the effects of restraint stress on PFC function in both male rats and cycling female rats in either the proestrus (high estrogen) or estrus (low estrogen) phase of the estrus cycle. Animals were restrained for 60 or 120 minutes and then tested on spatial delayed alternation, a PFC-mediated task. Performance after stress was compared to performance on a different day under no-stress conditions, and analyzed using analysis of variance (ANOVA).

Results
Sixty minutes of restraint impaired only females in proestrus, while 120 minutes of restraint produced significant impairments in all animals. Increases in task completion times did not affect performance.

Conclusion
These results demonstrate an interaction between hormonal status and cognitive response to stress in female rats, with high estrogen levels being associated with amplified sensitivity to stress. This effect has been previously observed after administration of a pharmacological stressor (the benzodiazepine inverse agonist FG7142), and results from both studies may be relevant to the increased prevalence of stress-related disorders, such as major depressive disorder, in cycling women. Overall, the results show that restraint stress has important effects on the cognitive functions of the PFC, and that hormonal influences in the PFC are an important area for future research.
Changes in farmers' knowledge of maize diversity in highland Guatemala, 1927/37-2004
Authors: van Etten Jacob 
Published: March 2006

Abstract
Small-scale studies on long-term change in agricultural knowledge might uncover insights with broader, regional implications. This article evaluates change in farmer knowledge about crop genetic resources in highland Guatemala between 1927/37 and 2004. It concentrates on maize (Zea mays ssp. mays L.) in one Guatemalan township, Jacaltenango, an area with much ecological and maize diversity. It relies on a particular type of baseline information: lists of farmer-defined cultivars drawn up by ethnographers in the first half of the twentieth century. A questionnaire format based on two independent lists of local farmer cultivars dating from 1927 and 1937 was used to assess changes in maize diversity. Comparisons between attributes given to each cultivar in the past and in 2004 were used as a partial test of the stability of cultivar identity. In farmers' perceptions, cultivar loss was low and limited to certain cultivars adapted to the warmer environments. Crop production problems were mentioned as the main motives for change. No evidence for a loss of cultivars due to the political violence of the 1980s was found. In the lower areas many newly introduced cultivars were found, which reportedly provide solutions for the production problems the older cultivars have. The article contrasts these findings with those of an earlier study which suggested much cultivar loss due to political violence, and draws conclusions about the methodological implications.
Does prophylactic sotalol and magnesium decrease the incidence of atrial fibrillation following coronary artery bypass surgery: a propensity-matched analysis
Authors: Aerra V , Kuduvalli M , Moloto AN , Srinivasan AK , Grayson AD , Fabri BM , Oo AY 
Published: March 2006

Abstract

Background
Atrial fibrillation can occur in up to 40% of patients undergoing coronary surgery.

Methods
We retrospectively analysed 103 consecutive coronary surgery patients under the care of one surgeon between April 2003 and September 2003. These patients received 40 mg of sotalol orally twice daily from the first post-operative day for 6 weeks and 2 g of magnesium intravenously immediately post surgery and on the first post-operative day. We developed a propensity score for the probability of receiving sotalol and magnesium after coronary surgery. 89 patients from the sotalol and magnesium group were successfully matched with 89 unique coronary surgery patients who did not receive either sotalol or magnesium with an identical propensity score.

Results
Preoperative characteristics were well matched between groups. There was no significant difference with respect to in-hospital mortality between groups (sotalol and magnesium 1.1% versus control 4.5%; p = 0.17). The incidence of atrial fibrillation in the sotalol and magnesium group was 13.5% compared to 27.0% in the controls (p = 0.025).

Conclusion
The combination of sotalol and magnesium can significantly reduce the incidence of post-operative atrial fibrillation following coronary surgery.
Ultrasonography of the metacarpophalangeal and proximal interphalangeal joints in rheumatoid arthritis: a comparison with magnetic resonance imaging, conventional radiography and clinical examination
Authors: Szkudlarek Marcin , Klarlund Mette , Narvestad Eva , Court-Payen Michel , Strandberg Charlotte , Jensen Karl E , Thomsen Henrik S , Østergaard Mikkel 
Published: March 2006

AbstractSigns of inflammation and destruction in the finger joints are the principal features of rheumatoid arthritis (RA). There are few studies assessing the sensitivity and specificity of ultrasonography in detecting these signs. The objective of the present study was to investigate whether ultrasonography can provide information on signs of inflammation and destruction in RA finger joints that are not available with conventional radiography and clinical examination, and comparable to the information provided by magnetic resonance imaging (MRI). The second to fifth metacarpophalangeal and proximal interphalangeal joints of 40 RA patients and 20 control persons were assessed with ultrasonography, clinical examination, radiography and MRI. With MRI as the reference method, the sensitivity, specificity and accuracy of ultrasonography in detecting bone erosions in the finger joints were 0.59, 0.98 and 0.96, respectively; they were 0.42, 0.99 and 0.95 for radiography. The sensitivity, specificity and accuracy of ultrasonography, with signs of inflammation on T1-weighted MRI sequences as the reference method, were 0.70, 0.78 and 0.76, respectively; they were 0.40, 0.85 and 0.72 for the clinical examination. With MRI as the reference method, ultrasonography had higher sensitivity and accuracy in detecting signs of inflammation and destruction in RA finger joints than did clinical and radiographic examinations, without loss of specificity. This study shows that ultrasonography has the potential to improve assessment of patients with RA.
Expression of the inflammatory chemokines CCL5, CCL3 and CXCL10 in juvenile idiopathic arthritis, and demonstration of CCL5 production by an atypical subset of CD8+ T cells
Authors: Pharoah Daniel S , Varsani Hemlata , Tatham Richard W , Newton Katy R , de Jager Wilco , Prakken Berent J , Klein Nigel , Wedderburn Lucy R 
Published: March 2006

AbstractThis study focuses upon three chemokines, namely CCL5, CXCL10 and CCL3, which are potential novel therapeutic targets in arthritis. The aim of the study was to analyse the expression and production of these three chemokines within the joints of children with juvenile idiopathic arthritis (JIA) of the oligoarticular and polyarticular subtypes. All three of these chemokines are highly expressed at the level of mRNA, with the most significant increase in mRNA levels being demonstrated for CCL5 when compared with matched peripheral blood samples and controls. We show that high levels of all three chemokines are present in synovial fluid of children with JIA. We investigate the major source of CCL5 from inflammatory synovial cells, which we show to be CD8+ T cells. This CD8+ synovial T cell population has an unexpected phenotype that has not been described previously, being CCR7- yet predominantly CD28+ and CD45RA-. These cells contain high levels of stored intracellular CCL5, and rapid release of CCL5 takes place on T cell stimulation, without requiring new protein synthesis. In addition, we demonstrate that CCL5 is present in synovial biopsies from these patients, in particular on the endothelium of small and medium sized vessels. We believe this to be the first in depth analysis of these mediators of inflammation in JIA.
Lack of association of a variable number of aspartic acid residues in the asporin gene with osteoarthritis susceptibility: case-control studies in Spanish Caucasians
Authors: Rodriguez-Lopez Julio , Pombo-Suarez Manuel , Liz Myriam , Gomez-Reino Juan J , Gonzalez Antonio 
Published: March 2006

AbstractA recent genetic association study has identified a microsatellite in the coding sequence of the asporin gene as a susceptibility factor for osteoarthritis (OA). Alleles of this microsatellite determine the variable number of aspartic acid residues in the amino-terminal end of the asporin protein. Asporin binds directly to the growth factor transforming growth factor beta and inhibits its anabolic effects in cartilage, which include stimulation of collagen and aggrecan synthesis. The OA-associated allele, with 14 aspartic acid residues, inhibits the anabolic effects of transforming growth factor beta more strongly than other asporin alleles, leading to increased OA liability. We have explored whether the association found in several cohorts of Japanese hip OA and knee OA patients was also present in Spanish Caucasians. We studied patients that had undergone total joint replacement for primary OA in the hip (n = 303) or the knee (n = 188) and patients with hand OA (n = 233), and we compared their results with controls (n = 294) lacking overt OA clinical symptoms. No significant differences were observed in any of the multiple comparisons performed, which included global tests of allele frequency distributions and specific comparisons as well as stratification by affected joint and by sex. Our results, together with reports from the United Kingdom and Greece, indicate that the stretch of aspartic acid residues in asporin is not an important factor in OA susceptibility among European Caucasians. It remains possible that lifestyle, environmental or genetic differences allow for an important effect of asporin variants in other ethnic groups as has been reported in the Japanese, but this should be supported by additional studies.
Differential Modulation of Estrogen Receptors (ERs) in Ischemic Brain Injury: A Role for ERα in Estradiol-Mediated Protection against Delayed Cell Death
Authors: Dubal Dena B. , Rau Shane W. , Shughrue Paul J. , Zhu Hong , Yu Jin , Cashion Adrienne B. , Suzuki Shotaro , Gerhold Lynnette M. , Bottner Martina B. , Dubal Sam B. , Merchanthaler Istvan , Kindy Mark S. , Wise Phyllis M. 
Published: March 2006

Abstract
Estradiol enhances plasticity and survival of the injured brain. Our previous work demonstrates that physiological levels of estradiol protect against cerebral ischemia in the young and aging brain through actions involving estrogen receptors (ERs) and alterations in gene expression. The major goal of this study was to establish mechanisms of neuroprotective actions induced by low levels of estradiol. We first examined effects of estradiol on the time-dependent evolution of ischemic brain injury. Because estradiol is known to influence apoptosis, we hypothesized that it acts to decrease the delayed phase of cell death observed after middle cerebral artery occlusion (MCAO). Furthermore, because ERs are pivotal to neuroprotection, we examined the temporal expression profiles of both ER subtypes, ERα and ERβ, after MCAO and delineated potential roles for each receptor in estradiol-mediated neuroprotection. We quantified cell death in brains at various times after MCAO and analyzed ER expression by RT-PCR, in situ hybridization, and immunohistochemistry. We found that during the first 24 h, the mechanisms of estradiol-induced neuroprotection after MCAO are limited to attenuation of delayed cell death and do not influence immediate cell death. Furthermore, we discovered that ERs exhibit distinctly divergent profiles of expression over the evolution of injury, with ERα induction occurring early and ERβ modulation occurring later. Finally, we provide evidence for a new and functional role for ERα in estradiol-mediated protection of the injured brain. These findings indicate that physiological levels of estradiol protect against delayed cell death after stroke-like injury through mechanisms requiring ERα.
Electronically Tunable Compact Trialkylphosphines: SMAPs-bridged Bicyclic Phosphines
Authors: Ochida Atsuko , Ito Shinichiro , Miyahara Takahiro , Ito Hajime , Sawamura Masaya 
Published: March 2006

Abstract
A series of silicon-constrained monodentate trialkylphosphines SMAPs bearing a Si substituent with diverse electronic natures were synthesized. DFT calculations and NMR measurements indicated that these compounds constitute a class of electronically tunable trialkylphosphines. The tunable range of donor power overlaps those of tri(tert-butyl)phosphine and monoalkyldiarylphosphines.
Reaction of Allylic-type Diindium Compounds with Electrophiles
Authors: Hirashita Tsunehisa , Arai Shun , Mitsui Kazuma , Makino Hajime , Araki Shuki 
Published: March 2006

Abstract
Allylic-type diindium reagents were prepared from 3-bromo-1-iodopropene (1a), 3-bromo-1-iodo-1-phenylpropene (1b), or 2,4-diiodobut-2-en-1-ol (1c) with metallic indium, and their successive coupling with electrophiles was examined. The coupling behavior of the diindium reagents was found to depend on the electrophiles and the substituent on the diindium compounds.