bluuebunny/crossref_metadata_2025_split huggingface dataset:
Decreased metalloproteinase production as a response to mechanical pressure in human cartilage: a mechanism for homeostatic regulation
Authors: Monfort Jordi , Garcia-Giralt Natalia , López-Armada María J , Monllau Joan C , Bonilla Angeles , Benito Pere , Blanco Francisco J 
Published: September 2006

AbstractArticular cartilage is optimised for bearing mechanical loads. Chondrocytes are the only cells present in mature cartilage and are responsible for the synthesis and integrity of the extracellular matrix. Appropriate joint loads stimulate chondrocytes to maintain healthy cartilage with a concrete protein composition according to loading demands. In contrast, inappropriate loads alter the composition of cartilage, leading to osteoarthritis (OA). Matrix metalloproteinases (MMPs) are involved in degradation of cartilage matrix components and have been implicated in OA, but their role in loading response is unclear. With this study, we aimed to elucidate the role of MMP-1 and MMP-3 in cartilage composition in response to mechanical load and to analyse the differences in aggrecan and type II collagen content in articular cartilage from maximum- and minimum-weight-bearing regions of human healthy and OA hips. In parallel, we analyse the apoptosis of chondrocytes in maximal and minimal load areas. Because human femoral heads are subjected to different loads at defined sites, both areas were obtained from the same hip and subsequently evaluated for differences in aggrecan, type II collagen, MMP-1, and MMP-3 content (enzyme-linked immunosorbent assay) and gene expression (real-time polymerase chain reaction) and for chondrocyte apoptosis (flow cytometry, bcl-2 Western blot, and mitochondrial membrane potential analysis). The results showed that the load reduced the MMP-1 and MMP-3 synthesis (p < 0.05) in healthy but not in OA cartilage. No significant differences between pressure areas were found for aggrecan and type II collagen gene expression levels. However, a trend toward significance, in the aggrecan/collagen II ratio, was found for healthy hips (p = 0.057) upon comparison of pressure areas (loaded areas > non-loaded areas). Moreover, compared with normal cartilage, OA cartilage showed a 10- to 20-fold lower ratio of aggrecan to type II collagen, suggesting that the balance between the major structural proteins is crucial to the integrity and function of the tissue. Alternatively, no differences in apoptosis levels between loading areas were found – evidence that mechanical load regulates cartilage matrix composition but does not affect chondrocyte viability. The results suggest that MMPs play a key role in regulating the balance of structural proteins of the articular cartilage matrix according to local mechanical demands.
Administration of antibiotics via the respiratory tract for the prevention of ICU-acquired pneumonia: a meta-analysis of comparative trials
Authors: Falagas Matthew E , Siempos Ilias I , Bliziotis Ioannis A , Michalopoulos Argyris 
Published: September 2006

Abstract
Introduction
The administration of prophylactic antibiotics via the respiratory tract is one of several strategies for the prevention of intensive care unit (ICU)-acquired pneumonia. We systematically examined the available evidence regarding the effect of prophylactic antibiotics administered via the respiratory tract on the development of ICU-acquired pneumonia, mortality, colonization of the respiratory tract, emergence of antimicrobial resistance, and toxicity.

Methods
We searched the PubMed database (January 1950 to September 2005) and references from relevant articles to identify trials that provided comparative data regarding the above-mentioned outcomes. Two investigators independently performed the data extraction to calculate the effect of the studied intervention on clinically relevant outcomes.

Results
Our meta-analysis includes 8 comparative trials (5 randomized controlled trials (RCTs) and 3 non-randomized trials) studying gentamicin (3 trials), polymyxins (3 trials), tobramycin (1 trial), and ceftazidime (1 trial) that studied 1,877 patients. Our primary analysis, which included the 5 RCTs, revealed that ICU-acquired pneumonia was less common in the group of patients that received the antibiotic prophylaxis (odds ratio (OR) = 0.49, 95% confidence interval (CI) 0.32–0.76). No difference in mortality was found between the compared groups (OR = 0.86, 95% CI 0.55–1.32). Data were too limited to permit an analysis of colonization with Pseudomonas aeruginosa. A secondary analysis, adding the three non-randomized comparative trials, did not reveal substantially different results regarding ICU-acquired pneumonia and mortality, while fewer patients were colonized with P. aeruginosa in the group that received prophylaxis, compared to the group of patients that received no prophylaxis (OR = 0.51, 95% CI 0.30–0.86). No serious drug-related toxicity was noted. No meaningful systematic analysis of the evidence regarding the emergence of resistance could be performed in the studies included in our meta-analysis.

Conclusion
The limited available evidence supports that prophylactic administration of antibiotics via the respiratory tract is associated with reduction of occurrence of ICU-acquired pneumonia. However, there is evidence from non-comparative studies that this preventive strategy may lead to an increase in the emergence of resistant bacteria. Thus, further investigation, at least in ICU patients at high risk for development of ICU-acquired pneumonia, is warranted, including a more systematic evaluation of issues related to the emergence of resistance.
Length of Stay by Route of Contrast Administration for Diagnosis of Appendicitis by Computed‐tomography Scan
Authors: Berg Evan R. , Mehta Supriya D. , Mitchell Patricia , Soto Jorge , Oyama Leslie , Ulrich Andrew 
Published: September 2006

Abstract Objectives Studies show equivalent accuracy of abdominal computed tomography (CT) using rectal contrast compared with oral contrast for diagnosing appendicitis. The authors evaluated whether emergency department (ED) length of stay and satisfaction differed by route of contrast administration for abdominal CT. Methods This before‐and‐after intervention evaluated adult patients in an urban academic ED who were undergoing abdominal CT to screen for suspected appendicitis. Phase 1 subjects had a CT after oral contrast. Phase 2 patients had a CT after rectal contrast infused by gravity drip. Patients were interviewed after CT scan to assess satisfaction and discomfort. The primary outcome was ED length of stay. Medians, 95% binomial confidence intervals (CI), and Wilcoxon rank sum test of differences were calculated. Results One hundred twelve patients were enrolled; half received rectal contrast. There was a significant decrease in length of stay for patients who were administered rectal contrast (261 min, 95% CI = 236 to 305 min) vs. oral contrast (332 min, 95% CI = 299 to 362 min), p = 0.009. Although subjects in the rectal‐contrast group waited 65 minutes longer than did oral‐contrast patients before receiving contrast after the CT order, the time from contrast administration to CT was 13 minutes, vs. 150 minutes for patients receiving oral contrast (p < 0.001). Patient satisfaction and discomfort did not differ by route of contrast administration. Conclusions Rectal contrast for patients undergoing abdominal CT to rule out appendicitis reduced ED length of stay by more than an hour and did not affect patient satisfaction or discomfort. Rectal‐contrast administration for abdominal CT may significantly shorten patient throughput time for individuals undergoing evaluation for appendicitis.
Digital versus Local Anesthesia for Finger Lacerations: A Randomized Controlled Trial
Authors: Chale Stuart , Singer Adam J. , Marchini Scott , McBride Mary Jo , Kennedy David 
Published: September 2006

Abstract Objectives To compare the pain of needle insertion, anesthesia, and suturing in finger lacerations after local anesthesia with prior topical anesthesia with that experienced after digital anesthesia. Methods This was a randomized controlled trial in a university‐based emergency department (ED), with an annual census of 75,000 patient visits. ED patients aged ≥8 years with finger lacerations were enrolled. After standard wound preparation and 15‐minute topical application of lidocaine‐epinephrine‐tetracaine (LET) in all wounds, lacerations were randomized to anesthesia with either local or digital infiltration of 1% lidocaine. Pain of needle insertion, anesthetic infiltration, and suturing were recorded on a validated 100‐mm visual analog scale (VAS) from 0 (none) to 100 (worst); also recorded were percentage of wounds requiring rescue anesthesia; time until anesthesia; percentage of wounds with infection or numbness at day 7. Outcomes were compared by using Mann‐Whitney U and chi‐square tests. A sample of 52 patients had 80% power to detect a 15‐mm difference in pain scores. Results Fifty‐five patients were randomized to digital (n= 28) or local (n= 27) anesthesia. Mean age (±SD) was 38.1 (±16.8) years, 29% were female. Mean (±SD) laceration length and width were 1.7 (±0.7) cm and 2.0 (±1.0) mm, respectively. Groups were similar in baseline patient and wound characteristics. There were no between‐group differences in pain of needle insertion (mean difference, 1.3 mm; 95% confidence interval [CI] =−17.0 to 14.3 mm); anesthetic infiltration (mean difference, 2.3 mm; 95% CI =−19.7 to 4.4 mm), or suturing (mean difference, 7.6 mm; 95% CI =−3.3 to 21.1 mm). Only one patient in the digital anesthesia group required rescue anesthesia. There were no wound infections or persistent numbness in either group. Conclusions Digital and local anesthesia of finger lacerations with prior application of LET to all wounds results in similar pain of needle insertion, anesthetic infiltration, and pain of suturing.
Prognostic Value of Symptoms during a Normal or Nonspecific Electrocardiogram in Emergency Department Patients with Potential Acute Coronary Syndrome
Authors: Chase Maureen , Brown Aaron M. , Robey Jennifer L. , Pollack Charles V. , Shofer Frances S. , Hollander Judd E. 
Published: September 2006

Abstract Objectives Emergency department (ED) patients with symptoms concerning for acute coronary syndrome (ACS) and a normal electrocardiogram (ECG) are at risk for adverse cardiovascular events. The authors hypothesized that patients with a normal or nonspecific ECG during symptoms have a lower risk for ACS than do those who are asymptomatic. Methods This was a prospective cohort study of ED patients with potential ACS. Outcomes were acute myocardial infarction (AMI), ACS, and 30‐day cardiovascular events (death, AMI, revascularization). Fisher's exact test, t‐tests, and logistic regression were used for data analysis. Results Of 2,593 patient visits, 2,007 patients had normal or nonspecific ECG findings. There were 1,196 who had symptoms during ECG, whereas 811 did not. Patients with symptoms at ECG acquisition were younger (49.9 vs. 55.2 years; p < 0.001) and were more likely to be black (70% vs. 64%; p = 0.002), female (63% vs. 58%; p = 0.03), and to have used cocaine (5% vs. 2%; p = 0.004). They were less likely to have hypertension (49% vs. 58%; p < 0.001), and diabetes (22% vs. 17%; p = 0.002). Patients with and without symptoms were equally likely to have AMI (both 2.8%; p > 0.99), ACS (10.1% vs. 11.5%; p = 0.34), and 30‐day adverse outcomes (both 5.3%; p > 0.99). After adjustment for baseline cardiovascular‐risk factors, odds ratios for patients with symptoms at the time of ECG acquisition were not significantly different for any of the outcomes: AMI (1.1; 95% confidence interval [CI] = 0.6 to 1.9); ACS (1.1; 95% CI = 0.8 to 1.4); or 30‐day events (1.2; 95% CI = 0.8 to 1.9). Conclusions Patients who are symptomatic during acquisition of a normal or nonspecific ECG have rates of adverse cardiovascular events similar to those of patients without symptoms. Clinicians should not rely on the absence of ECG abnormalities during symptoms to help exclude ACS.
R‐wave Amplitude in Lead II of an Electrocardiograph Correlates with Central Hypovolemia in Human Beings
Authors: McManus John G. , Convertino Victor A. , Cooke William H. , Ludwig David A. , Holcomb John B. 
Published: September 2006

Abstract Objectives Previous animal and human experiments have suggested that reduction in central blood volume either increases or decreases the amplitude of R waves in various electrocardiograph (ECG) leads depending on underlying pathophysiology. In this investigation, we used graded central hypovolemia in adult volunteer subjects to test the hypothesis that moderate reductions in central blood volume increases R‐wave amplitude in lead II of an ECG. Methods A four‐lead ECG tracing, heart rate (HR), estimated stroke volume (SV), systolic blood pressure, diastolic blood pressure, and mean arterial pressure were measured during baseline supine rest and during progressive reductions of central blood volume to an estimated volume loss of >1,000 mL with application of lower‐body negative pressure (LBNP) in 13 healthy human volunteer subjects. Results Lower‐body negative pressure resulted in a significant progressive reduction in central blood volume, as indicated by a maximal decrease of 65% in SV and maximal elevation of 56% in HR from baseline to −60 mm Hg LBNP. R‐wave amplitude increased (p < 0.0001) linearly with progressive LBNP. The amalgamated correlation (R2) between average stroke volume and average R‐wave amplitude at each LBNP stage was −0.989. Conclusions These results support our hypothesis that reduction of central blood volume in human beings is associated with increased R‐wave amplitude in lead II of an ECG.
Earning and learning: Role congruence, state/trait factors and adjustment to university life
Authors: Swanson Vivien , Broadbridge Adelina , Karatzias Athanasios 
Published: September 2006

Background. Undertaking term‐time employment is increasingly commonplace for university students. Much research suggests that combining ‘earning and learning’ may be detrimental to university life, generating role conflicts, increasing stress and reducing academic success, participation and overall adjustment to university. Potential positive effects of term‐time employment on well‐being are often neglected.Aims. This study adopted a balanced perspective, investigating the relationship between role congruence in academic, social and career domains and adjustment, with state and trait psychological factors as mediators/moderators.Methods. A questionnaire measuring perceived role congruence, adjustment to university life and psychological state and trait characteristics was mailed to all undergraduates at a Scottish university during term‐time.Sample. Results for a subsample of 625 university students currently in term‐time employment were included in this paper.Results. Findings suggested that students generally perceived employment and university roles to be in balance, and there was no difference in adjustment for students whether currently in term‐time employment or not. However, psychological factors, particularly positive affectivity and stress were important mediators of the relationship between role congruence and adjustment.Conclusions. Since promoting role congruence may enhance students' adjustment and well‐being, the study has implications for universities, student welfare organizations and employers offering term‐time employment.
The effects of an early history of otitis media on children's language and literacy skill development
Authors: Winskel Heather 
Published: September 2006

Background. Otitis media (OM) or middle ear infection is a common childhood illness and is most frequent during the crucial first 3 years of life when speech and language categories are being established, which could potentially have a long‐term effect on language and literacy skill development.Aims. The purpose of the current study was to ascertain the effects of a history of OM in early childhood on later language and literacy skill development.Sample. Forty‐three children from Grade 1 and Grade 2, between 6 and 8 years old with an early history of OM and 43 control children, matched for chronological age, gender and socio‐economic status, participated in this study.Methods. Children were tested on multiple measures of phonological awareness, semantic knowledge, narration and reading ability. The performance of children with and without a history of OM was compared on the different measures.Results. There was a general tendency for children with a history of OM to achieve lower scores on phonological awareness skills of alliteration, rhyme and non‐word reading, semantic skills of expressive vocabulary and word definitions and reading than non‐OM children.Conclusion. These findings highlight the potential problems an early history of middle ear infection can have on school‐aged children's later language and literacy development.
Arithmetic problems at school: When there is an apparent contradiction between the situation model and the problem model
Authors: Coquin‐Viennot Danièle , Moreau Stéphanie 
Published: September 2006

Background. Understanding and solving problems involves different levels of representation. On the one hand, there are logico‐mathematical representations, or problem models (PMs), which contain information such as ‘the size of the flock changed from 31 sheep to 42’ while, on the other hand, there are more qualitative representations, or qualitative situation models (QSMs), comprising events expressed in everyday terms, such as ‘a lot of lambs had been born’.Aims. We set out to show that an apparent contradiction between a PM and a QSM can result in poorer performances, especially when the activation of formal representations is not fully automatic.Sample. We tested 44 third years (mean age 8;6) and 46 fourth years (mean age 9; 8) from two primary schools in France.Method. Change problems and compare problems were drafted in two versions: one where the QSM and PM were consistent and one where they appeared to be contradictory but were not (referred to hereafter as the inconsistent version). For example, if the numerical data proved that the size of a flock of sheep had increased (PM), the consistent version would state that a lot of lambs had been born (QSM), whereas the inconsistent version would state that the wolf had devoured some of the sheep (QSM). Each pupil was given 7 consistent problems and 7 ‘inconsistent’ ones to solve.Results. For the change problems, errors were more frequent on the inconsistent versions, especially among the younger subjects. For the compare problems, there were more errors on the inconsistent versions regardless of the subjects' age.Conclusion. It is in situations where the problem schema is not automatically activated (younger subjects or compare problems) that the QSM plays its role of intermediate representation and causes performances to deteriorate if it does not correspond to the PM.
The use of deep and surface learning strategies among students learning English as a foreign language in an Internet environment
Authors: Aharony Noa 
Published: September 2006

Background. The learning context is learning English in an Internet environment. The examination of this learning process was based on the Biggs and Moore's teaching‐learning model (Biggs & Moore, 1993).Aim. The research aims to explore the use of the deep and surface strategies in an Internet environment among EFL students who come from different socio‐economic backgrounds. The results of the research may add an additional level to the understanding of students' functioning in the Internet environment.Sample. One hundred fourty‐eight Israeli junior and high school students participated in this research.Methods. The methodology was based on special computer software: Screen Cam, which recorded the students' learning process. In addition, expert judges completed a questionnaire which examined and categorized the students' learning strategies.Results. The research findings show a clear preference of participants from all socio‐economic backgrounds towards the surface learning strategy. The findings also showed that students from the medium to high socio‐economic background used both learning strategies more frequently than low socio‐economic students.Conclusions. The results reflect the habits that students acquire during their adjustment process throughout their education careers. A brief encounter with the Internet learning environment apparently cannot change norms or habits, which were acquired in the non‐Internet learning environment.
The influence of achievement goals on the constructive activity of low achievers during collaborative problem solving
Authors: Gabriele Anthony J. 
Published: September 2006

Background. Previous research on small‐group learning has found that level of constructive activity (solving or explaining how to solve problems using ideas stated or implied in the explanation provided by a partner) was a better predictor of post‐test achievement than either a student's prior achievement or the quality of help received (Webb, Troper, & Fall, 1995).Aims. The purpose of this study was to extend this research by examining the influence of additional factors, in particular, achievement goals and comprehension monitoring, on low achieving students' constructive activity after receiving help from a high achieving peer.Sample. Thirty‐two low achieving upper elementary students from an urban school district in the mid‐west of the United States were paired with high achieving partners.Methods. Videotape data from a previously reported study on peer collaboration were transcribed and reanalyzed. In that study, dyads were randomly assigned instructions designed to induce either a learning or performance goal and were videotaped as they worked together to solve a set of mathematical word problems. The following day, students were individually post‐tested on problems similar to the ones worked on in pairs.Results. Consistent with previous research, low achieving students' level of constructive activity predicted post‐test performance. In addition, constructive activity was found to mediate the relationship between achievement goals and learning. However, achievement goals were not related to low achievers constructive use of help. Instead, achievement goals were related to low achievers' relative accuracy in comprehension monitoring, which in turn was related to level of constructive activity.Conclusions. The meaning of these results for understanding the processes by which low achievers learn from peer help and implications for classroom practice are discussed.