scholarly journals Diagnosing Syndesmotic Instability with Dynamic Ultrasound: Establishing Natural Variations in Normal Motion

2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0019
Author(s):  
Noortje Hagemeijer ◽  
Song Ho Chang ◽  
Jirawat Saengsin ◽  
Gregory Waryasz ◽  
Gino Kerkhoffs ◽  
...  
Keyword(s):  
Prone Position ◽  
Applied Stress ◽  
Supine Position ◽  
Sagittal Plane ◽  
Linear Mixed Effect Model ◽  
P Value ◽  
Mixed Effect ◽  
Force Application ◽  
Dynamic Ultrasound ◽  
Left And Right

Category: Ankle Introduction/Purpose: Syndesmotic instability, when subtle, is challenging to diagnose and often requires visualization of the syndesmosis during applied stress. Ultrasound is a dynamic, non-invasive diagnostic tool that can achieve this at the point of care, although accurate assessment requires better understanding of normal physiologic motion. The aim of this study is to assess normal distal tibiofibular motion in the sagittal plane using ultrasound during applied stress. Methods: Patients with no history of injury to either ankle were included in this study. The distal tibiofibular joint was examined using an ultrasound probe placed anteriorly with the patient in supine position and posteriorly with the patient in prone position. Sagittal fibular translation was simulated by applying an increasing manual force to the fibula in the sagittal plane: 1) in the supine position, anterior to posterior (SAP), 2) in the prone position, posterior to anterior (PPA), and 3) in the prone position, anterior to posterior (PAP) (Figure 1). The relative position of the fibula and tibia were subsequently measured without force application and then at maximum force application, defined as the end point at which increased force did not result in additional fibular translation. Fibular displacement in cm was thereafter calculated. A linear mixed effect model was built for analysis, wherein subject, examiner, experiment and side were random factors. Results: A total of 34 ankles were included. Mean age was 25.0±5 years and 71% were male. After adjusting for gender and side, the model showed that the application of force led to fibular motion in the sagittal plane for each measurement technique. SAP, coef. 0.06 [0.06-0.07], p-value < 0.001. PPA, coef. 0.04 [0.03-0.05], p-value < 0.001. PAP, coef. -0.16 [-0.17- -0.15], p-value < 0.001. The model also showed similar fibular motion values for left and right measurements, SAP p-value 0.589, PPA p-value 0.236, PAP p-value 0.104. Fibular movement values also were not influenced by gender, SAP p-value 0.348, PPA p-value 0.613, PAP p-value 0.714. Conclusion: Alterations of syndesmotic motion in the sagittal plane can be successfully identified using dynamic ultrasound under stressed conditions. On average, 0.6 mm of A to P translation and 0.4 mm of P to A translation were found. Equivalent translation values between the left and right side in each patient underscores that, in the injured setting, the contralateral ankle may be used as a reliable control. This establishes a normal value for ultrasound examination of the syndesmosis, allowing future studies examining the injured state.

scholarly journals Reproducibility and Reliability of Dynamic Ultrasound for Evaluating Tibiofibular Translation in the Sagittal Plane

2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0002
Author(s):  
Noortje Hagemeijer ◽  
Song Ho Chang ◽  
Jirawat Saengsin ◽  
Gregory Waryasz ◽  
Gino Kerkhoffs ◽  
...  
Keyword(s):  
Prone Position ◽  
Supine Position ◽  
Sagittal Plane ◽  
Maximum Force ◽  
P Value ◽  
Ultrasound Probe ◽  
Non Invasive ◽  
Force Application ◽  
Tibiofibular Joint ◽  
Dynamic Ultrasound

Category: Ankle Introduction/Purpose: Syndesmotic instability, when subtle, is challenging to diagnose and requires visualization of the syndesmosis during an applied stress. Ultrasound is a dynamic, non-invasive diagnostic tool that can do so at the point of care, but its reliability and reproducibility remain unclear. The aim of this study is to evaluate reliability and reproducibility of the dynamic use of ultrasonography, a safe and non-invasive imaging technique, for evaluating tibiofibular translation in the sagittal plane. Methods: Patients with no history of injury to either ankle were included in this study. The distal tibiofibular joint was examined using an ultrasound probe placed anteriorly with the patient in supine position, and posteriorly with the patient in prone position. Sagittal fibular translation was simulated by applying an increasing manual force to the fibula in the sagittal plane: 1) in supine position, anterior to posterior (SAP), 2) in prone position, posterior to anterior (PPA), and 3) in prone position, anterior to posterior (PAP) (Figure 1). Two examiners performed the dynamic examination independently to investigate reproducibility of the test. To test for reliability, the relative position of the fibula and tibia were subsequently measured by three observers; with no force application and at maximum force application, defined as the end point at which increased force did not result in additional fibular translation. Interrater reliability was tested using intraclass correlation coefficients (ICC). Results: In total 34 ankles among 17 patients were included, of which 24 ankles were male (71%). Mean subject age was 25.0 ± 5 years. Substantial agreement was found for all measurements. Anterior measurements of the distance between the ultrasound probe and the tibia and fibula demonstrated ICC’s of 0.98 and 0.98, respectively. PPA demonstrated ICC’s of 0.99 and 0.99, and PAP ICC’s of 0.99, and 0.99. To test for reproducibility the mean tibiofibular delta values of SAP, PPA, and PAP in neutral, and after maximum force application were compared between exams. Exam 1 vs exam 2: SAPneutral, coef. -0.001, p-value 0.895. PPAneutral, coef. -0.06, p-value 0.076. PAPneutral, coef. -0.01, p-value 0.957. SAPmaxforce, coef. -0.03, p-value 0.365. PAPmaxforce, coef. <-0.01, p-value 0.910, PPAmaxforce, coef. -0.08, p-value 0.028. Conclusion: Use of dynamic ultrasound is a reliable and accurate technique for measuring changes in sagittal translation of the tibiofibular joint. Substantial variation between right and left ankles of an individual subject is rare, underscoring the significant utility of the contralateral ankle as a control in the injury setting. This test affords a non-invasive means of diagnosing syndesmotic instability in the sagittal plane.

scholarly journals Percutaneous Nephrolithotomy in Supine versus Prone Position in Tertiary Hospital in Mysore: A Prospective Cohort Study

2021 ◽  
Author(s):  
Ravikumar Banavase Ramesh ◽  
R Vijayakumar ◽  
V Manjunath ◽  
Abhilash Gautham ◽  
Amruthraj Gowda
Keyword(s):  
Cohort Study ◽  
Prone Position ◽  
Percutaneous Nephrolithotomy ◽  
Supine Position ◽  
Surgical Outcomes ◽  
Operative Time ◽  
P Value ◽  
Vas Score ◽  
Stone Free Rate ◽  
Free Rate

Introduction: Percutaneous Nephrolithotomy (PCNL) is a procedure of choice for large renal calculi. It is a common urological procedure. PCNL can be performed in various positions. Aim: To determine the surgical outcomes in patients undergoing PCNL in supine and prone positions. Materials and Methods: A cohort study was conducted on patients with renal and upper ureteral stones who underwent PCNL in either prone or supine position between August 2019 to August 2020 at Urology Department, JSS Hospital, Mysuru. Supine PCNL was done in the flank Free Oblique Supine Modified Lithotomy (FOSML) position. All the procedures were performed under fluoroscopy guidance. Surgical outcomes including operative time, length of hospital stay, Stone Free Rate (SFR), radiation dose, and postoperative complications were evaluated. The collected data was tabulated and frequency (n) and percentage (%) analysis was performed. The Chi-square test was used to find the level of significance. Results: A total of 70 patients were included in the study and out of which 35 patients were in the supine (46.37±14.73 years, 28 males and 7 females) and 35 patients (47.54±12.45 years, 23 males and 12 females) were in the prone PCNL groups. Statistically significant difference was observed in the mean operating time in the supine and prone PCNL groups (81.43 vs 127.71 minutes; p-value=0.001), with a higher stone-free rate (94.29% vs 91.43%; p-value=0.643) observed in the supine PCNL group. One patient in supine group had postoperative sepsis and one patient in prone group had bleeding requiring transfusion. The Visual Analog Scale (VAS) score in supine PCNL was (5.08±0.32) less than in prone group (8.03±0.40) (p-value <0.001). Conclusion: PCNL in the supine position compared with the prone position demonstrates significantly lower operative time with similar SFR and lower VAS score.

scholarly journals MegaLMM: Mega-scale linear mixed models for genomic predictions with thousands of traits

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Daniel E. Runcie ◽  
Jiayi Qu ◽  
Hao Cheng ◽  
Lorin Crawford
Keyword(s):  
Genomic Prediction ◽  
Large Scale ◽  
Mixed Model ◽  
Human Genetics ◽  
Linear Mixed Effect Model ◽  
Mixed Effect ◽  
Statistical Framework ◽  
Effect Model ◽  
Plant Data ◽  
Genetic Value

AbstractLarge-scale phenotype data can enhance the power of genomic prediction in plant and animal breeding, as well as human genetics. However, the statistical foundation of multi-trait genomic prediction is based on the multivariate linear mixed effect model, a tool notorious for its fragility when applied to more than a handful of traits. We present , a statistical framework and associated software package for mixed model analyses of a virtually unlimited number of traits. Using three examples with real plant data, we show that can leverage thousands of traits at once to significantly improve genetic value prediction accuracy.

scholarly journals Sept8/SEPTIN8 involvement in cellular structure and kidney damage is identified by genetic mapping and a novel human tubule hypoxic model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gregory R. Keele ◽  
Jeremy W. Prokop ◽  
Hong He ◽  
Katie Holl ◽  
John Littrell ◽  
...  
Keyword(s):  
Complex Traits ◽  
Genetic Model ◽  
Association Studies ◽  
Model Systems ◽  
Linear Mixed Effect Model ◽  
Genome Wide Association Studies ◽  
Tubulointerstitial Injury ◽  
Heritable Variation ◽  
Mixed Effect

AbstractChronic kidney disease (CKD), which can ultimately progress to kidney failure, is influenced by genetics and the environment. Genes identified in human genome wide association studies (GWAS) explain only a small proportion of the heritable variation and lack functional validation, indicating the need for additional model systems. Outbred heterogeneous stock (HS) rats have been used for genetic fine-mapping of complex traits, but have not previously been used for CKD traits. We performed GWAS for urinary protein excretion (UPE) and CKD related serum biochemistries in 245 male HS rats. Quantitative trait loci (QTL) were identified using a linear mixed effect model that tested for association with imputed genotypes. Candidate genes were identified using bioinformatics tools and targeted RNAseq followed by testing in a novel in vitro model of human tubule, hypoxia-induced damage. We identified two QTL for UPE and five for serum biochemistries. Protein modeling identified a missense variant within Septin 8 (Sept8) as a candidate for UPE. Sept8/SEPTIN8 expression increased in HS rats with elevated UPE and tubulointerstitial injury and in the in vitro hypoxia model. SEPTIN8 is detected within proximal tubule cells in human kidney samples and localizes with acetyl-alpha tubulin in the culture system. After hypoxia, SEPTIN8 staining becomes diffuse and appears to relocalize with actin. These data suggest a role of SEPTIN8 in cellular organization and structure in response to environmental stress. This study demonstrates that integration of a rat genetic model with an environmentally induced tubule damage system identifies Sept8/SEPTIN8 and informs novel aspects of the complex gene by environmental interactions contributing to CKD risk.

scholarly journals Limited not lazy: a quasi-experimental secondary analysis of evidence quality evaluations by those who hold implausible beliefs

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Kristy A. Martire ◽  
Bethany Growns ◽  
Agnes S. Bali ◽  
Bronte Montgomery-Farrer ◽  
Stephanie Summersby ◽  
...  
Keyword(s):  
Secondary Analysis ◽  
Past Research ◽  
Linear Mixed Effect Model ◽  
High Quality ◽  
Mixed Effect ◽  
High Quality Evidence ◽  
Effect Model ◽  
Evidence Quality ◽  
Quasi Experimental ◽  
Quality Evidence

AbstractPast research suggests that an uncritical or ‘lazy’ style of evaluating evidence may play a role in the development and maintenance of implausible beliefs. We examine this possibility by using a quasi-experimental design to compare how low- and high-quality evidence is evaluated by those who do and do not endorse implausible claims. Seven studies conducted during 2019–2020 provided the data for this analysis (N = 746). Each of the seven primary studies presented participants with high- and/or low-quality evidence and measured implausible claim endorsement and evaluations of evidence persuasiveness (via credibility, value, and/or weight). A linear mixed-effect model was used to predict persuasiveness from the interaction between implausible claim endorsement and evidence quality. Our results showed that endorsers were significantly more persuaded by the evidence than non-endorsers, but both groups were significantly more persuaded by high-quality than low-quality evidence. The interaction between endorsement and evidence quality was not significant. These results suggest that the formation and maintenance of implausible beliefs by endorsers may result from less critical evidence evaluations rather than a failure to analyse. This is consistent with a limited rather than a lazy approach and suggests that interventions to develop analytical skill may be useful for minimising the effects of implausible claims.

Influence of submaximal isometric contractions of the hamstrings on electromyography activity and force while functioning as hip extensors

2020 ◽  
pp. 1-8
Author(s):  
Dasom Oh ◽  
Wootaek Lim
Keyword(s):  
Prone Position ◽  
Supine Position ◽  
Isometric Contraction ◽  
Muscle Length ◽  
Biceps Femoris ◽  
Emg Activity ◽  
Isometric Contractions ◽  
Significant Difference ◽  
Extension Force ◽  
Long Head

BACKGROUND: Although the medial and lateral hamstrings are clearly distinct anatomically and have different functions in the transverse plane, they are often considered as one muscle during rehabilitation. OBJECTIVE: The purpose of the study was to compare the electromyographic (EMG) activity between the prone position and the supine position during maximal isometric contraction and to additionally confirm the effect of submaximal isometric contractions on EMG activity of medial and lateral hamstrings, and force. METHODS: In the prone position, EMG activities of the long head of biceps femoris (BFLH) and semitendinosus (ST) were measured during the maximal isometric contraction. In the supine position, hip extension force with EMG activity were measured during the maximal and the submaximal isometric contractions. RESULTS: EMG activity in the prone position was significantly decreased in the supine position. In the supine position, there was a significant difference between the BFLH and ST during the maximal isometric contraction, but not during the submaximal isometric contractions. CONCLUSIONS: The dependence on the hamstrings could be relatively lower during hip extensions. When the medial and lateral hamstrings are considered separately, the lateral hamstrings may show a more active response, with increased muscle length, in clinical practice.

scholarly journals Associations between the Bovine Myostatin Gene and Milk Fatty Acid Composition in New Zealand Holstein-Friesian × Jersey-Cross Cows

Animals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1447
Author(s):  
Ishaku L. Haruna ◽  
Yunhai Li ◽  
Ugonna J. Ekegbu ◽  
Hamed Amirpour-Najafabadi ◽  
Huitong Zhou ◽  
...  
Keyword(s):  
Fatty Acid ◽  
New Zealand ◽  
Nucleotide Sequence ◽  
Milk Fat ◽  
Linear Mixed Effect Model ◽  
Polymorphism Analysis ◽  
Mixed Effect ◽  
Myostatin Gene ◽  
Holstein Friesian ◽  
Nucleotide Sequence Variation

The myostatin gene (MSTN), which encodes the protein myostatin, is pleiotropic, and its expression has been associated with both increased and decreased adipogenesis and increased skeletal muscle mass in animals. In this study, the polymerase chain reaction, coupled with single strand conformation polymorphism analysis, was utilized to reveal nucleotide sequence variation in bovine MSTN in 410 New Zealand (NZ) Holstein-Friesian × Jersey (HF × J)-cross cows. These cows ranged from 3 to 9 years of age and over the time studied, produced an average 22.53 ± 2.18 L of milk per day, with an average milk fat content of 4.94 ± 0.17% and average milk protein content of 4.03 ± 0.10%. Analysis of a 406-bp amplicon from the intron 1 region, revealed five nucleotide sequence variants (A–E) that contained seven nucleotide substitutions. Using general linear mixed-effect model analyses the AD genotype was associated with reduced C10:0, C12:0, and C12:1 levels when compared to levels in cows with the AA genotype. These associations in NZ HF × J cross cows are novel, and they suggest that this variation in bovine MSTN could be explored for increasing the amount of milk unsaturated fatty acid and decreasing the amount of saturated fatty acid.

scholarly journals Dynamic Regional Brain Atrophy Rates in the First Year After Ischemic Stroke

Stroke ◽  
2020 ◽  
Vol 51 (9) ◽  
Author(s):  
Amy Brodtmann ◽  
Mohamed Salah Khlif ◽  
Natalia Egorova ◽  
Michele Veldsman ◽  
Laura J. Bird ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cortical Thickness ◽  
Brain Atrophy ◽  
Brain Volume ◽  
Linear Mixed Effect Model ◽  
First Year ◽  
Intracranial Volume ◽  
Mixed Effect ◽  
Time Points ◽  
Regional Brain

Background and Purpose: Brain atrophy can be regarded as an end-organ effect of cumulative cardiovascular risk factors. Accelerated brain atrophy is described following ischemic stroke, but it is not known whether atrophy rates vary over the poststroke period. Examining rates of brain atrophy allows the identification of potential therapeutic windows for interventions to prevent poststroke brain atrophy. Methods: We charted total and regional brain volume and cortical thickness trajectories, comparing atrophy rates over 2 time periods in the first year after ischemic stroke: within 3 months (early period) and between 3 and 12 months (later period). Patients with first-ever or recurrent ischemic stroke were recruited from 3 Melbourne hospitals at 1 of 2 poststroke time points: within 6 weeks (baseline) or 3 months. Whole-brain 3T magnetic resonance imaging was performed at 3 time points: baseline, 3 months, and 12 months. Eighty-six stroke participants completed testing at baseline; 125 at 3 months (76 baseline follow-up plus 49 delayed recruitment); and 113 participants at 12 months. Their data were compared with 40 healthy control participants with identical testing. We examined 5 brain measures: hippocampal volume, thalamic volume, total brain and hemispheric brain volume, and cortical thickness. We tested whether brain atrophy rates differed between time points and groups. A linear mixed-effect model was used to compare brain structural changes, including age, sex, years of education, a composite cerebrovascular risk factor score, and total intracranial volume as covariates. Results: Atrophy rates were greater in stroke than control participants. Ipsilesional hemispheric, hippocampal, and thalamic atrophy rates were 2 to 4 times greater in the early versus later period. Conclusions: Regional atrophy rates vary over the first year after stroke. Rapid brain volume loss in the first 3 months after stroke may represent a potential window for intervention. Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02205424.

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