Showing papers by "University of Western Ontario published in 2007"
Veterans Health Administration1, McMaster University2, Vanderbilt University3, University of Western Ontario4, Foothills Medical Centre5, Hartford Hospital6, University of New Mexico7, Saint Louis University8, Cedars-Sinai Medical Center9, Université de Montréal10, Mayo Clinic11, United States Department of Veterans Affairs12, University of Michigan13, Christiana Care Health System14
TL;DR: As an initial management strategy in patients with stable coronary artery disease, PCI did not reduce the risk of death, myocardial infarction, or other major cardiovascular events when added to optimal medical therapy.
Abstract: We conducted a randomized trial involving 2287 patients who had objective evidence of myocardial ischemia and significant coronary artery disease at 50 U.S. and Canadian centers. Between 1999 and 2004, we assigned 1149 patients to undergo PCI with optimal medical therapy (PCI group) and 1138 to receive optimal medical therapy alone (medical-therapy group). The primary outcome was death from any cause and nonfatal myocardial infarction during a follow-up period of 2.5 to 7.0 years (median, 4.6). Results There were 211 primary events in the PCI group and 202 events in the medicaltherapy group. The 4.6-year cumulative primary-event rates were 19.0% in the PCI group and 18.5% in the medical-therapy group (hazard ratio for the PCI group, 1.05; 95% confidence interval [CI], 0.87 to 1.27; P = 0.62). There were no significant differences between the PCI group and the medical-therapy group in the composite of death, myocardial infarction, and stroke (20.0% vs. 19.5%; hazard ratio, 1.05; 95% CI, 0.87 to 1.27; P = 0.62); hospitalization for acute coronary syndrome (12.4% vs. 11.8%; hazard ratio, 1.07; 95% CI, 0.84 to 1.37; P = 0.56); or myocardial infarction (13.2% vs. 12.3%; hazard ratio, 1.13; 95% CI, 0.89 to 1.43; P = 0.33). Conclusions As an initial management strategy in patients with stable coronary artery disease, PCI did not reduce the risk of death, myocardial infarction, or other major cardiovascular events when added to optimal medical therapy. (ClinicalTrials.gov number, NCT00007657.)
4,069 citations
Clark University1, National Institutes of Health2, Louisiana State University3, CABI4, Umeå University5, Field Museum of Natural History6, Duke University7, University of Minnesota8, University of Alabama9, Oregon State University10, Centraalbureau voor Schimmelcultures11, United States Department of Agriculture12, University of Tübingen13, Max Planck Society14, University of Florida15, Pennsylvania State University16, Aberystwyth University17, Complutense University of Madrid18, University of Oslo19, University of Hong Kong20, University of Tartu21, University of Gothenburg22, University of Kansas23, University of Maine24, University of Illinois at Urbana–Champaign25, Royal Ontario Museum26, Georgia State University27, Estonian University of Life Sciences28, Washington State University29, Nova Southeastern University30, Ludwig Maximilian University of Munich31, University of Western Ontario32, Uppsala University33, Brandon University34, Royal Botanic Garden Edinburgh35, State University of New York at Purchase36, Boise State University37, Cornell University38
TL;DR: A comprehensive phylogenetic classification of the kingdom Fungi is proposed, with reference to recent molecular phylogenetic analyses, and with input from diverse members of the fungal taxonomic community.
2,096 citations
TL;DR: Universal economic constraints in healthcare services dictate that further developments in total hip replacement will be governed by their cost-effectiveness, and computer-assisted surgery will contribute to reproducible and accurate placement of implants.
1,917 citations
TL;DR: In this paper, the focus on environmental management and operations is moved from local optimization of environmental factors to consideration of the entire supply chain during the production, consumption, customer service and post-disposal disposition of products.
1,593 citations
TL;DR: Patients with squamous-cell carcinoma of the head and neck who received docetaxel plus cisplatin and fluorouracil induction chemotherapy plus chemoradiotherapy had a significantly longer survival than did patients who received cisPlatin and fluoride induction chemotherapyplus cheMoradiotherapy.
Abstract: Background A randomized phase 3 trial of the treatment of squamous-cell carcinoma of the head and neck compared induction chemotherapy with docetaxel plus cisplatin and fluorouracil (TPF) with cisplatin and fluorouracil (PF), followed by chemoradiotherapy. Methods We randomly assigned 501 patients (all of whom had stage III or IV disease with no distant metastases and tumors considered to be unresectable or were candidates for organ preservation) to receive either TPF or PF induction chemotherapy, followed by chemoradiotherapy with weekly carboplatin therapy and radiotherapy for 5 days per week. The primary end point was overall survival. Results With a minimum of 2 years of follow-up (≥3 years for 69% of patients), significantly more patients survived in the TPF group than in the PF group (hazard ratio for death, 0.70; P=0.006). Estimates of overall survival at 3 years were 62% in the TPF group and 48% in the PF group; the median overall survival was 71 months and 30 months, respectively (P=0.006). There...
1,509 citations
TL;DR: Computer simulations suggest that using only survey responders to calculate Dissimilarity typically results in underestimation of true dissimilarity effects and that these effects can occur even when response rates are high.
Abstract: The extensive research examining relations between group member dissimilarity and outcome measures has yielded inconsistent results. In the present research, the authors used computer simulations to examine the impact that a methodological feature of such research, participant nonresponse, can have on dissimilarity-outcome relations. Results suggest that using only survey responders to calculate dissimilarity typically results in underestimation of true dissimilarity effects and that these effects can occur even when response rates are high.
1,481 citations
TL;DR: The results were summarized in a draft manuscript by the primary authors (G.D. and W.J. as discussed by the authors ) and discussed at the annual IOIBD meetings in 2004 and 2005.
1,064 citations
TL;DR: It is proposed that tetrabutyl ammonium (TBA) cations most probably intercalate into the gaps and the defects during electrochemical cycling and break the tubes near the defects.
Abstract: Blue luminescent nanocrystals (NCs) were prepared electrochemically from multiwalled carbon nanotubes (MWCNTs) for the first time. The carbon NCs were characterized by UV−vis, photoluminescence, Raman, XRD spectroscopy, and high-resolution transmission electron microscopy. The structure evolution of the MWCNTs during electrochemical treatments was monitored by SEM ex situ. Since the MWCNTs were formed with scrolled graphene layers, we propose that tetrabutyl ammonium (TBA) cations most probably intercalate into the gaps and the defects during electrochemical cycling and break the tubes near the defects.
1,055 citations
TL;DR: In patients with moderate-to-severe Crohn's disease, induction and maintenance therapy with certolizumab pegol was associated with a modest improvement in response rates, as compared with placebo, but with no significant improvement in remission rates.
Abstract: In this article we provide a contemporary overview of available clinical data on certolizumab pegol, a pegylated anti-tumor necrosis factor (TNF) alpha agent that comprises a uniquely small protein, and its emerging role as a therapy for Crohn's disease (CD). The results from a comprehensive clinical trial program suggest that certolizumab pegol offers rapid and sustained remission of moderate to severe CD. Certolizumab pegol is an effective and well-tolerated therapy both in patients who have already received biologics and in patients who are anti-TNF naive. Benefits of therapy include a stable dosing regimen, which allows for rapid induction of a clinical response followed by long-term maintenance of response and remission under one fixed dose. Treatment with certolizumab pegol has been shown to improve function and quality of life in patients with CD, and insights into the potential mechanisms by which certolizumab pegol effects a response in CD suggest that this agent may have the potential to slow or even modify disease progression. Early therapy is particularly effective and could help control CD progression and lessen the burden of disease on patients.
1,023 citations
TL;DR: In this paper, the authors present multilevel research on bribery, national identity, team boundary spanning, professional role identity, organizational citizenship, interorganizational exchanges, and divestitures.
Abstract: Most management problems involve multilevel phenomena, yet most management research uses a single level of analysis. A micro or a macro lens alone yields incomplete understanding at either level. Multilevel research addresses the levels of theory, measurement, and analysis required to fully examine research questions. This forum presents multilevel research on bribery, national identity, team boundary spanning, professional role identity, organizational citizenship, interorganizational exchanges, and divestitures. To enrich the impact of future management research, we recommend (1) applying multilevel designs to existing models (2) considering bottom-up effects, (3) collaborating across disciplines on multidisciplinary topics, and (4) addressing major real-world problems via multilevel approaches.
1,002 citations
TL;DR: In this article, the authors reviewed the empirical literature on the relations between the Big Five personality dimensions and post-secondary academic achievement, and found some consistent results, such as Conscientiousness, Openness to Experience, Extraversion, and Extraversion was sometimes negatively related to the same criterion, although the empirical evidence regarding these latter two dimensions was somewhat mixed.
TL;DR: This poster presents a poster presented at the American Society of Echocardiography’s annual meeting in Los Angeles, California, on Wednesday, 3 March 2016, featuring presentations by Scott T. Reeves, MD, FASE and Kathryn E. Reeves.
Abstract: Scott T. Reeves, MD, FASE, Kathryn E. Glas, MD, FASE, Holger Eltzschig, MD, Joseph P. Mathew, MD, FASE, David S. Rubenson, MD, FASE, Gregg S. Hartman, MD, and Stanton K. Shernan, MD, FASE, for the Council for Intraoperative Echocardiography of the American Society of Echocardiography, Charleston, South Carolina; Atlanta, Georgia; Tubingen, Germany; Durham, North Carolina; La Jolla, California; and Lebanon, New Hampshire
TL;DR: It appears that levels of physical activity vary with seasonality, and the ensuing effect of poor or extreme weather has been identified as a barrier to participation in physical activity among various populations.
TL;DR: It is suggested that a greater percentage of patients will achieve normal functioning with longer nightly CPAP durations, but what constitutes adequate use varies between different outcomes.
Abstract: CONTINUOUS POSITIVE AIRWAY PRESSURE (CPAP) CURRENTLY IS CONSIDERED THE MOST EFFECTIVE TREATMENT FOR OBSTRUCTIVE SLEEP APNEA (OSA) THIS device provides a pneumatic splint to prevent nocturnal airway collapse In randomized clinical trials that included use of sham CPAP as a placebo, treatment with this device has been shown to produce improvements in symptoms, quality of life, sleepiness, neuropsychological performance, and hypertension1 It has also been established that optimal effectiveness depends on consistent use Skipping even 1 night of treatment reverses improvements in daytime sleepiness, response performance, and the physiologic measure of disease severity, the apnea-hypopnea index (AHI)2–4
Although these benefits have been shown in randomized clinical trials, there is considerable variation in use of CPAP by patients in routine clinical practice,5–8 with approximately half using it consistently every night on average 6 hours per night and the other half skipping from 1 to 7 nights per week using it on average 35 hours per night5 It is not known, however, what the impact of differential use of CPAP is on effectiveness of therapy in routine clinical practice It may be that individuals with shorter hours of use are, in general, less well treated with respect to improvements in outcomes such as sleepiness, than are those with longer durations of use Alternatively, there might be individual variation in need for CPAP so that, even though some individuals have shorter hours of CPAP use, they are effectively treated with respect to sleepiness This individual variation might be mediated by biologic mechanisms similar to those of the recently described individual variation in response to sleep deprivation9
To address this question, we conducted a multisite effectiveness study in which we evaluated clinical status outcomes before and after 3 months of routine clinical care that included measurement of CPAP adherence during the entire follow-up period This multisite international study capitalized on patient heterogeneity with regard to average nightly use of CPAP, in order to estimate relationships between the likelihood of achieving a “normal” value on salient clinical measures of sleepiness and functional status and the “dose” of CPAP treatment received (ie, hours of CPAP use per night) Because there is no consensus regarding which outcomes are primary with regard to the assessment of CPAP treatment response, we chose those deemed most applicable to the clinical management of OSA—subjective sleepiness (Epworth Sleepiness Scale [ESS]10), physiologic sleepiness (Multiple Sleep Latency Test [MSLT]11), and disease-specific functional status (Functional Outcomes of Sleep Questionnaire [FOSQ]12) By evaluating the nightly duration of CPAP relative to obtaining normal values in those impaired on each of these measures, we provide data that the clinician can employ in determining optimal treatment response within the context of treatment goals, eg, to reduce daytime sleepiness, improve daily functioning, or both
TL;DR: In this paper, the effect of investments in enterprise resource planning (ERP), supply chain management (SCM), and CRM systems on a firm's long-term stock price performance and profitability measures such as return on assets and return on sales was analyzed.
TL;DR: In this paper, the authors take note of advances in the entrepreneurial cognition research stream and bring increasing attention to the usefulness of entrepreneurship cognition research, and propose a central research question to further enable entrepreneurial cognition inquiry.
Abstract: In this article, we take note of advances in the entrepreneurial cognition research stream. In doing so, we bring increasing attention to the usefulness of entrepreneurial cognition research. First, we offer and develop a central research question to further enable entrepreneurial cognition inquiry. Second, we present the conceptual background and some representative approaches to entrepreneurial cognition research that form the context for this question. Third, we introduce the articles in this Special Issue as framed by the central question and approaches to entrepreneurial cognition research, and suggest how they further contribute to this developing stream. Finally, we offer our views concerning the challenges and opportunities that await the next generation of entrepreneurial cognition scholarship. We therefore invite (and seek to enable) the growing community of entrepreneurship researchers from across multiple disciplines to further develop the “thinking– doing” link in entrepreneurship research. It is our goal to offer colleagues an effective research staging point from which they may embark upon many additional research expeditions and investigations involving entrepreneurial cognition.
TL;DR: Evidence of a positive relationship between relational leadership and a variety of patient outcomes is document, although future testing of leadership models that examine the mechanisms of influence on outcomes is warranted.
Abstract: Aim
Our aim was to describe the findings of a systematic review of studies that examine the relationship between nursing leadership practices and patient outcomes.
Background
As healthcare faces an economic downturn, stressful work environments, upcoming retirements of leaders and projected workforce shortages, implementing strategies to ensure effective leadership and optimal patient outcomes are paramount. However, a gap still exists in what is known about the association between nursing leadership and patient outcomes.
Methods
Published English-only research articles that examined leadership practices of nurses in formal leadership positions and patient outcomes were selected from eight online bibliographic databases. Quality assessments, data extraction and analysis were completed on all included studies.
Results
A total of 20 studies satisfied our inclusion criteria and were retained. Current evidence suggests relationships between positive relational leadership styles and higher patient satisfaction and lower patient mortality, medication errors, restraint use and hospital-acquired infections.
Conclusions
The findings document evidence of a positive relationship between relational leadership and a variety of patient outcomes, although future testing of leadership models that examine the mechanisms of influence on outcomes is warranted.
Implications for nursing management
Efforts by organisations and individuals to develop transformational and relational leadership reinforces organisational strategies to improve patient outcomes.
TL;DR: Monitoring cerebral rSO2 in coronary artery bypass patients avoids profound cerebral desaturation and is associated with significantly fewer incidences of major organ dysfunction.
Abstract: BACKGROUND:Cerebral deoxygenation is associated with various adverse systemic outcomes. We hypothesized, by using the brain as an index organ, that interventions to improve cerebral oxygenation would have systemic benefits in cardiac surgical patients.METHODS:Two-hundred coronary artery bypass patie
TL;DR: A survey of the current state of research on needle insertion in soft tissue is presented, e.g. modeling needle insertion forces, modeling tissue deformation and needle deflection during insertion, robot-assisted needle insertion, and the effect of different trajectories on tissueDeformation.
TL;DR: Specialized techniques to measure tissue elasticity of breast normal tissues and tumour specimens and applied them to 169 fresh ex vivo breast tissue samples as well as a range of benign and malignant breast tumour types show that, under small deformation conditions, the elastic modulus of normal breast fat and fibroglandular tissues are similar while fibroadenomas were approximately twice the stiffness.
Abstract: Understanding and quantifying the mechanical properties of breast tissues has been a subject of interest for the past two decades. This has been motivated in part by interest in modelling soft tissue response for surgery planning and virtual-reality-based surgical training. Interpreting elastography images for diagnostic purposes also requires a sound understanding of normal and pathological tissue mechanical properties. Reliable data on tissue elastic properties are very limited and those which are available tend to be inconsistent, in part as a result of measurement methodology. We have developed specialized techniques to measure tissue elasticity of breast normal tissues and tumour specimens and applied them to 169 fresh ex vivo breast tissue samples including fat and fibroglandular tissue as well as a range of benign and malignant breast tumour types. Results show that, under small deformation conditions, the elastic modulus of normal breast fat and fibroglandular tissues are similar while fibroadenomas were approximately twice the stiffness. Fibrocystic disease and malignant tumours exhibited a 3-6-fold increased stiffness with high-grade invasive ductal carcinoma exhibiting up to a 13-fold increase in stiffness compared to fibrogalndular tissue. A statistical analysis showed that differences between the elastic modulus of the majority of those tissues were statistically significant. Implications for the specificity advantages of elastography are reviewed.
TL;DR: This study demonstrates a direct role of the IGF-II/IGF1R axis on human ES cell physiology and establishes that hdFs produced by human ES cells themselves define the stem cell niche of pluripotent human stem cells.
Abstract: Distinctive properties of stem cells are not autonomously achieved, and recent evidence points to a level of external control from the microenvironment. Here, we demonstrate that self-renewal and pluripotent properties of human embryonic stem (ES) cells depend on a dynamic interplay between human ES cells and autologously derived human ES cell fibroblast-like cells (hdFs). Human ES cells and hdFs are uniquely defined by insulin-like growth factor (IGF)- and fibroblast growth factor (FGF)-dependence. IGF 1 receptor (IGF1R) expression was exclusive to the human ES cells, whereas FGF receptor 1 (FGFR1) expression was restricted to surrounding hdFs. Blocking the IGF-II/IGF1R pathway reduced survival and clonogenicity of human ES cells, whereas inhibition of the FGF pathway indirectly caused differentiation. IGF-II is expressed by hdFs in response to FGF, and alone was sufficient in maintaining human ES cell cultures. Our study demonstrates a direct role of the IGF-II/IGF1R axis on human ES cell physiology and establishes that hdFs produced by human ES cells themselves define the stem cell niche of pluripotent human stem cells.
University of Massachusetts Amherst1, University of Toledo2, Miami University3, Food and Drug Administration4, Yale University5, University of Louisville6, University of Western Ontario7, Taipei Medical University8, University of Rochester9, University of South Florida10, Eli Lilly and Company11, United States Department of Agriculture12, University of Düsseldorf13, Harvard University14, College of the Holy Cross15, University of Colorado Boulder16, Michigan State University17, Indiana University18, Jilin University19, University of Texas Health Science Center at San Antonio20, University of Louisiana at Monroe21, McMaster University22, RTI International23, University of Florida24, Kansas State University25, University of California, Irvine26, University of Michigan27, Aarhus University28, North Carolina State University29, Stanford University30, Lovelace Respiratory Research Institute31, University of Wyoming32, University of Tasmania33, Binghamton University34, New York Medical College35, National Institutes of Health36
TL;DR: This article offers a set of recommendations that scientists believe can achieve greater conceptual harmony in dose-response terminology, as well as better understanding and communication across the broad spectrum of biological disciplines.
TL;DR: Data demonstrate that, in the ewe, a high percentage of ARC kisspeptin neurons also produce dynorphin and NKB, and it is proposed that a single subpopulation of ARC neurons contains all three neuropeptides.
Abstract: Kisspeptin is a potent stimulator of GnRH secretion that has been implicated in the feedback actions of ovarian steroids. In ewes, the majority of hypothalamic kisspeptin neurons are found in the arcuate nucleus (ARC), with a smaller population located in the preoptic area. Most arcuate kisspeptin neurons express estrogen receptor-alpha, as do a set of arcuate neurons that contain both dynorphin and neurokinin B (NKB), suggesting that all three neuropeptides are colocalized in the same cells. In this study we tested this hypothesis using dual immunocytochemistry and also determined if kisspeptin neurons contain MSH or agouti-related peptide. To assess colocalization of kisspeptin and dynorphin, we used paraformaldehyde-fixed tissue from estrogen-treated ovariectomized ewes in the breeding season (n = 5). Almost all ARC, but no preoptic area, kisspeptin neurons contained dynorphin. Similarly, almost all ARC dynorphin neurons contained kisspeptin. In experiment 2 we examined colocalization of kisspeptin and NKB in picric-acid fixed tissue collected from ovary intact ewes (n = 9). Over three quarters of ARC kisspeptin neurons also expressed NKB, and a similar percentage of NKB neurons contained kisspeptin. In contrast, no kisspeptin neurons stained for MSH or agouti-related peptide. These data demonstrate that, in the ewe, a high percentage of ARC kisspeptin neurons also produce dynorphin and NKB, and we propose that a single subpopulation of ARC neurons contains all three neuropeptides. Because virtually all of these neurons express estrogen and progesterone re-ceptors, they are likely to relay the feedback effects of these steroids to GnRH neurons to regulate reproductive function.
TL;DR: Patients with a new diagnosis of right-sided, transverse, splenic flexure/descending, rectal or sigmoid CRC in Ontario from April 1, 1997 to March 31, 2002 who had a colonoscopy within the 3 years before their diagnosis are advised to inform patients of the small risk of these cancers after Colonoscopy.
TL;DR: Supervised aerobic exercise training has beneficial effects on physical capacity and FMS symptoms and research on the long-term benefit of exercise for FMS is needed.
Abstract: Background
Fibromyalgia (FM) is a syndrome expressed by chronic widespread body pain which leads to reduced physical function and frequent use of health care services. Exercise training is commonly recommended as a treatment. This is an update of a review published in Issue 2, 2002.
Objectives
The primary objective of this systematic review was to evaluate the effects of exercise training including cardiorespiratory (aerobic), muscle strengthening, and/or flexibility exercise on global well-being, selected signs and symptoms, and physical function in individuals with FM.
Search methods
We searched MEDLINE, EMBASE, CINAHL, SportDiscus, PubMed, PEDro, and the Cochrane Central Register for Controlled Trials (CENTRAL, Issue 3, 2005) up to and including July 2005. We also reviewed reference lists from reviews and meta-analyses of treatment studies.
Selection criteria
Randomized trials that were selected focused on cardiorespiratory endurance, muscle strength and/or flexibility as treatment for FM.
Data collection and analysis
Two of four reviewers independently extracted data for each study. All discrepancies were rechecked and consensus was achieved by discussion. Methodological quality was assessed by two instruments: the van Tulder and the Jadad methodological quality criteria. We used the American College of Sport Medicine (ACSM) guidelines to evaluate whether interventions had provided a training stimulus that would effect changes in physical fitness. Due to significant clinical heterogeneity among the studies we were only able to meta-analyze six aerobic-only studies and two strength-only studies.
Main results
There were a total of 2276 subjects across the 34 included studies; 1264 subjects were assigned to exercise interventions. The 34 studies comprised 47 interventions that included exercise. Effects of several disparate interventions on global well-being, selected FM signs and symptoms, and physical function in individuals with FM were summarized using standardized mean differences (SMD). There is moderate quality evidence that aerobic-only exercise training at recommended intensity levels has positive effects global well-being (SMD 0.49, 95% CI: 0.23 to 0.75) and physical function (SMD 0.66, 95% CI: 0.41 to 0.92) and possibly on pain (SMD 0.65, 95% CI: -0.09 to 1.39) and tender points (SMD 0.23, 95% CI: -0.18 to 0.65). Strength and flexibility remain under-evaluated.
Authors' conclusions
There is 'gold' level evidence (www.cochranemsk.org) that supervised aerobic exercise training has beneficial effects on physical capacity and FM symptoms. Strength training may also have benefits on some FM symptoms. Further studies on muscle strengthening and flexibility are needed. Research on the long-term benefit of exercise for FM is needed.
TL;DR: The authors examined the effects of stress, social support, and self-esteem on adjustment to university and found that increased social support from friends, but not from family, predicted improved adjustment.
Abstract: The current study examined the joint effects of stress, social support, and self-esteem on adjustment to university. First-year undergraduate students (N = 115) were assessed during the first semester and again 10 weeks later, during the second semester of the academic year. Multiple regressions predicting adjustment to university from perceived social support (friends and family), self-esteem (academic, social, and global), and stress were conducted. From the fall to winter semesters, increased social support from friends, but not from family, predicted improved adjustment. Decreased stress predicted improved overall, academic, personal-emotional, and social adjustment. Increased global, academic, and social self-esteem predicted decreased depression and increased academic and social adjustment. Results are discussed with respect to potential mechanisms through which support and self-esteem may operate.
TL;DR: Response and remission rates for natalizumab were superior to those for placebo at Weeks 4, 8, and 12, demonstrating the early and sustained efficacy of natalIZumab as induction therapy in patients with elevated C-reactive protein and active Crohn's disease.
TL;DR: The results show that the described series of hop tests provide a reliable and valid performance-based outcome measure for patients undergoing rehabilitation following ACL reconstruction, and these findings support the use and facilitate the interpretation ofHop tests for research and clinical practice.
Abstract: Background and Purpose Although various hop tests have been proposed as performance-based outcome measures following anterior cruciate ligament (ACL) reconstruction, limited reports of their measurement properties exist. The purpose of this study was to investigate the reliability and longitudinal validity of data obtained from hop tests during rehabilitation after ACL reconstruction.
Subjects Forty-two patients, 15 to 45 years of age, who had undergone ACL reconstruction participated in the study.
Methods and Measures The study design was prospective and observational with repeated measures. The subjects performed a series of 4 hop tests on 3 separate occasions within the 16th week following surgery and on a fourth occasion 6 weeks later. The tests were a single hop for distance, a 6-m timed hop, a triple hop for distance, and crossover hops for distance. Performance on the ACL-reconstructed limb was expressed as a percentage of the performance on the nonoperative limb, termed the “limb symmetry index.” Subjects also completed the Lower Extremity Functional Scale and a global rating of change questionnaire.
Results Intraclass correlation coefficients for limb symmetry index values ranged from .82 to .93. Standard errors of measurement were 3.04% to 5.59%. Minimal detectable changes, at the 90% confidence level, were 7.05% to 12.96%. Changes in hop test scores on the operative limb were statistically greater than changes on the nonoperative limb. Pearson correlations ( r ) between change in hop performances and self-reported measures ranged from .26 to .58.
Discussion and Conclusion The results show that the described series of hop tests provide a reliable and valid performance-based outcome measure for patients undergoing rehabilitation following ACL reconstruction. These findings support the use and facilitate the interpretation of hop tests for research and clinical practice.
TL;DR: Data from this study suggest significant abnormalities in resting-state neural networks in schizophrenia, and further investigations of spontaneous slow fluctuations of the BOLD signal seem warranted in this population.
Abstract: Spontaneous low-frequency fluctuations in the blood oxygen level–dependent (BOLD) functional magnetic resonance imaging (MRI) signal have been shown to reflect neural synchrony between brain regions. A “default network” of spontaneous low-frequency fluctuations has been described in healthy volunteers during stimulus-independent thought. Negatively correlated with this network are regions activated during attention-demanding tasks. Both these networks involve brain regions and functions that have been linked with schizophrenia in previous research. The present study examined spontaneous slow fluctuations in the BOLD signal at rest, as measured by correlation with low-frequency oscillations in the posterior cingulate, in 17 schizophrenic patients, and 17 comparable healthy volunteers. Healthy volunteers demonstrated correlation between spontaneous low-frequency fluctuations of the BOLD signal in the posterior cingulate and fluctuations in the lateral parietal, medial prefrontal, and cerebellar regions, similar to previous reports. Schizophrenic patients had significantly less correlation between spontaneous slow activity in the posterior cingulate and that in the lateral parietal, medial prefrontal, and cerebellar regions. Connectivity of the posterior cingulate was found to vary with both positive and negative symptoms in schizophrenic patients. Because these data suggest significant abnormalities in resting-state neural networks in schizophrenia, further investigations of spontaneous slow fluctuations of the BOLD signal seem warranted in this population.
TL;DR: The current knowledge of the effects of aging on the human neuromuscular system is summarized, some of the major underlying mechanisms of the aging atrophy are described and the importance of strength training to improve muscle function in older people is focused on.
Abstract: With increasing age, human skeletal muscles gradually decrease in volume, mainly due to a reduced number of motor units and muscle fibers, and a reduced size of type 2 fibers. As a result, progressive weakening and impaired mobility occur. High-resistance strength training is beneficial, even in the very old, and could possibly reverse some of the detrimental effects of age-related weakness. The importance of exercise for older people affords an excellent opportunity for the medicine community as a major source of information and promotion of physical activity for this rapidly growing segment of the population. In this review, we summarize the current knowledge of the effects of aging on the human neuromuscular system, describe some of the major underlying mechanisms of the aging atrophy and focus on the importance of strength training to improve muscle function in older people.