Multidimensional ultrasound imaging of the wrist: Changes of shape and displacement of the median nerve and tendons in carpal tunnel syndrome

Dynamics of structures within the carpal tunnel may alter in carpal tunnel syndrome (CTS) due to fibrotic changes and increased carpal tunnel pressure. Ultrasound can visualize these potential changes, making ultrasound potentially an accurate diagnostic tool. To study this, we imaged the carpal tunnel of 113 patients and 42 controls. CTS severity was classified according to validated clinical and nerve conduction study (NCS) classifications. Transversal and longitudinal displacement and shape (changes) were calculated for the median nerve, tendons and surrounding tissue. To predict diagnostic value binary logistic regression modeling was applied. Reduced longitudinal nerve displacement (p≤ 0.019), increased nerve cross‐sectional area (p≤ 0.006) and perimeter (p≤ 0.007), and a trend of relatively changed tendon displacements were seen in patients. Changes were more convincing when CTS was classified as more severe. Binary logistic modeling to diagnose CTS using ultrasound showed a sensitivity of 70–71% and specificity of 80–84%. In conclusion, CTS patients have altered dynamics of structures within the carpal tunnel. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1332–1340, 2015.     

Doppler imaging of vibrations as a tool for quantifying first tarsometatarsal joint stiffness

Objective. To assess whether first tarsometatarsal joint stiffness can be measured by Doppler imaging of vibrations and if so, to assess reference values.

Design. Repeated in vivo Doppler imaging of vibrations measurements at the first tarsometatarsal joint in healthy persons.

Background. Clinical hypermobility of the first tarsometatarsal joint is an important factor in a hallux valgus deformity. No objective and non-invasive test is available to quantify first tarsometatarsal joint mobility. Doppler imaging of vibrations, a technique recently developed to measure joint stiffness, might be an effective tool to quantify stiffness of this joint.

Methods. Vibrations were applied to the head of the first metatarsal in 46 feet of 23 healthy subjects and picked up by a transducer at both sides of the first tarsometatarsal joint. A pilot study was performed on three patients with hypermobility of the first tarsometatarsal joint. Measurements are expressed in threshold units related to colour Doppler imaging.

Results. The values of the threshold units were found to be very similar in healthy persons, with a good repeatibility; 95% of the healthy persons had a threshold unit below 3.4. No significant difference was found between the left and right foot, or between male and female subjects. Also there was no significant correlation with age or weight of the subjects. In the three patients with first tarsometatarsal hypermobility we found threshold units above 5.

Conclusions. With Doppler imaging of vibrations first tarsometatarsal joint stiffness can be measured in healthy persons in a non-invasive and objective way. In a pilot study, three patients with first tarsometatarsal hypermobility showed lower stiffness values than the healthy subjects.

Relevance This study presents a new method for quantification of first tarsometatarsal joint stiffness and provides reference values in healthy persons. First measurements on patients gave promising results to future use of this method for assessment of clinical hypermobility in hallux valgus patients.     

Lower-leg inertial properties in transtibial amputees and control subjects and their influence on the swing phase during gait

OBJECTIVES: To identify the factors that constitute optimal inertial properties for a lower-limb prosthesis. DESIGN: Experimental, controlled; simulation using a subject-specific double-pendulum model based on individual kinematic data and leg inertial properties. Simulation outcomes were compared with gait analysis data. SETTING: A gait laboratory. PARTICIPANTS: Ten transtibial amputees and 10 matched healthy controls. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Inertial properties of the lower leg; kinematics and kinetics of the swing phase; and kinematics of double-pendulum model simulations. RESULTS: In all amputees, inertial properties were reduced. No between-group differences existed in kinematics; hip and knee joint torques and powers were reduced in the amputees. Deviations between the double-pendulum model and experimental data were larger in the amputees than in the control subjects. CONCLUSIONS: Although current lightweight prostheses have less optimal pendular behavior, their light weight requires smaller joint torques to influence the pendular trajectory. Therefore, optimal inertial properties, in terms of swing phase kinematics and kinetics, will be a compromise between pendular properties and efficient control.     

Licorice consumption as a cause of posterior reversible encephalopathy syndrome: a case report

Introduction  

A 49-year-old woman was admitted to our hospital because of thunderclap headache and blurred vision. At the time of presentation, her blood pressure was 219/100 mmHg, her arterial pH was 7.64 and her potassium level was 2.7 mM/l.     

Impact of chronic pain on everyday physical activity.

Although patients with chronic pain are often considered to have reduced levels of everyday physical activity, data on their activity levels are scarce and inconclusive. Therefore, this study explored whether patients with chronic pain have reduced activity levels, as objectively measured with an activity monitor. The activity monitor is based on long-term ambulatory monitoring of signals from body-fixed accelerometers during everyday life, aimed at assessment of mobility-related activities. Measurements with the monitor were performed during a weekday (24 h) in 18 patients with chronic pain and compared with measurements obtained from 18 gender and age matched healthy comparison subjects. The mean (SD) age of the patients was 44 (11) years, and the mean (SD) duration of their complaints was 8 (7) years. Compared with the healthy subjects, the duration of dynamic activities was not significantly reduced (p=0.10) in the patient group. Mean (SD) intensity of everyday physical activity was lower (p=0.03) in the patients than in the healthy comparison subjects (0.021 [0.006] g versus 0.026 [0.004] g), and patients spent more time lying down (47.0 [10.2]% versus 34.3 [5.6] %; p=0.000) and less time sitting (29.2 [8.9]% versus 36.4 [9.3]%; p=0.03) than the healthy comparison subjects. In spite of significant differences between patients and healthy comparison subjects for some aspects of the activity pattern (which may reflect pain behaviour), the impact of chronic pain on everyday physical activity was relatively small.     

Determinants of functioning of adolescents and young adults with cerebral palsy

Purpose. To describe the level of functioning of adolescents and young adults with cerebral palsy (CP) and study determinants of their level of functioning.

Method. In the CP Transition study, adolescents and young adults aged 16 - 20 years, diagnosed with CP without severe learning disabilities (n = 103) participated. In this group we assessed subject characteristics, i.e., age, type of CP, gross motor function (GMFCS), level of education as well as outcome measures on functioning in daily activities and social participation (Life Habits questionnaire, Vineland Adaptive Behavior Scale, Functional Independence Measure). Multivariate regression analyses were performed.

Results. About 20 - 30% of the participants encountered restrictions in daily activities (mobility, self-care, nutrition) and social participation (taking responsibility, community living, leisure activities and employment). The GMFCS level, level of education, and age proved to be important determinants of functioning in daily activities and social participation, explaining 70% and 66% of the variance in outcome respectively.

Conclusion. A significant number of adolescents and young adults with CP without severe learning disabilities are restricted in daily activities and social participation. These problems are mainly attributable to restricted gross motor functioning, a low level of education and younger age.     

Bacterial genome reduction using the progressive clustering of deletions via yeast sexual cycling

The availability of genetically tractable organisms with simple genomes is critical for the rapid, systems-level understanding of basic biological processes. Mycoplasma bacteria, with the smallest known genomes among free-living cellular organisms, are ideal models for this purpose, but the natural versions of these cells have genome complexities still too great to offer a comprehensive view of a fundamental life form. Here we describe an efficient method for reducing genomes from these organisms by identifying individually deletable regions using transposon mutagenesis and progressively clustering deleted genomic segments using meiotic recombination between the bacterial genomes harbored in yeast. Mycoplasmal genomes subjected to this process and transplanted into recipient cells yielded two mycoplasma strains. The first simultaneously lacked eight singly deletable regions of the genome, representing a total of 91 genes and ∼10% of the original genome. The second strain lacked seven of the eight regions, representing 84 genes. Growth assay data revealed an absence of genetic interactions among the 91 genes under tested conditions. Despite predicted effects of the deletions on sugar metabolism and the proteome, growth rates were unaffected by the gene deletions in the seven-deletion strain. These results support the feasibility of using single-gene disruption data to design and construct viable genomes lacking multiple genes, paving the way toward genome minimization. The progressive clustering method is expected to be effective for the reorganization of any mega-sized DNA molecules cloned in yeast, facilitating the construction of designer genomes in microbes as well as genomic fragments for genetic engineering of higher eukaryotes.Complexities of natural biological systems make it difficult to understand and define precisely the roles of individual genes and their integrated functions. The use of model organisms with a relatively small number of genes enables the isolation of core biological processes from their complex regulatory networks for extensive characterization. However, even the simplest natural microbes contain many genes of unknown function, as well as genes that can be singly or simultaneously deleted without any noticeable effect on growth rate in a laboratory setting (Hutchison et al. 1999; Glass et al. 2006; Posfai et al. 2006). Ill-defined genes and those mediating functional redundancies both compound the challenge of understanding even the simplest life forms.Toward generating a minimal cell where every gene is essential for the axenic viability of the organism, we are pursuing strategies to reduce the 1-Mb genome of Mycoplasma mycoides JCVI-syn1.0 (Gibson et al. 2010). Because we can (1) introduce this genome into yeast and maintain it as a plasmid (Benders et al. 2010; Karas et al. 2013a); and (2) “transplant” the genome from yeast into mycoplasma recipient cells (Lartigue et al. 2009), genetic tools in yeast are available for reducing this bacterial genome. Several systems offer advanced tools for bacterial genome engineering. Here we further exploit distinctive features of yeast for this purpose.Methods for serially replacing genomic regions with selectable markers are limited by the number of available markers. One effective approach is to reuse the same marker after precise and scarless marker excision (Storici et al. 2001). We have previously used a self-excising marker (Noskov et al. 2010) six times in yeast to generate a JCVI-syn1.0 genome lacking all six restriction systems (JCVI-syn1.0 ∆1-6) (Karas et al. 2013a). Despite the advantages of scarless engineering, sequential procedures are time-consuming. When applied to poorly characterized genes with the potential to interact with other genes, some paths for multigene knockout may lead to dead ends that result from synergistic mutant phenotypes. When a dead end is reached, sequentially returning to a previous genome in an effort to find a detour to a viable higher-order multimutant may be prohibitively time-consuming.An alternative approach to multigene engineering, available in yeast, is to prepare a set of single mutants and combine the deletions into a single strain via cycles of mating and meiotic recombination (Fig. 1A; Pinel et al. 2011; Suzuki et al. 2011, 2012). With a green fluorescent protein (GFP) reporter gene inserted in each deletion locus, the enrichment of higher-order yeast deletion strains in the meiotic population can be accomplished using flow cytometry. Here we apply this method to the JCVI-syn1.0 ∆1-6 exogenous, bacterial genome harbored in yeast to nonsequentially assemble deletions for genes predicted to be individually deletable based on biological knowledge or transposon-mediated disruption data. The functional identification of simultaneously deletable regions is expected to accelerate the effort to construct a minimal genome.Open in a separate windowFigure 1.Progressive clustering of deleted genomic segments. (A) Scheme of the method. Light blue oval represents a bacterial cell. Black ring or horizontal line denotes a bacterial genome, with the orange box indicating the yeast vector used as a site for linearization and recircularization. Gray shape denotes a yeast cell. Green dot in the genome indicates a deletion replaced with a GFP marker. (B) Map of deleted regions. Orange box indicates the yeast vector sequence used for genome linearization and recircularization. Green boxes indicate regions deleted in multimutant mycoplasma strains. Blue boxes denote restriction modification (RM) systems that are also deleted in the strains. (C) Pulsed-gel electrophoresis result for deleted genomes. The starting strain was the JCVI-syn1.0 ∆1–6 strain (1062 kb). Two strains were analyzed for each design of simultaneous deletion (962 kb for eight-deletion or 974 kb for seven-deletion genome). Ladder is a set of yeast chromosomes (New England BioLabs). (D) GFP-RFP ratio sorting result. Standard sorting was compared with sorting based on a GFP-RFP ratio (Methods).     

A qualitative study investigating the meaning of participation to improve the measurement of this construct

Quality of Life Research - The purpose of this study was to improve the measurement of participation. Research questions were as follows: (1) What constitutes participation according to adults? (2)...