MR morphometry of posterior tibialis muscle in adult acquired flat foot

We conducted magnetic resonance imaging of the posterior tibial (PT) and flexor digitorum longus (FDL) muscle bellies in 12 patients undergoing surgical treatment for unilateral posterior tibial tendon (PTT) dysfunction. All patients had atrophy of the PT muscle compared to the normal leg (mean 10.7%, p=0.008). In those patients with a complete rupture of PTT there was replacement of the PT muscle by fatty infiltration. Conversely, the FDL muscle showed a compensatory hypertrophy (mean 17.2%, p

Temporal expression of fibroblast growth factor receptors during primary ligament repair

Following injury, it is inherently difficult to completely restore the biomechanical properties of ligaments. Relatively little is known about the cellular mechanisms controlling ligament healing. Numerous studies have implicated fibroblast growth factors (FGFs) as key molecules during the initiation of the cellular proliferation, differentiation, migration and matrix deposition that characterise wound healing. While current surgical emphasis concentrates on growth factor intervention, the role of their cognate receptors (FGFRs) has largely been overlooked. Following transection of the medial collateral ligament (MCL) in rabbits, we examined FGFR expression over a 14-day healing period. Using semiquantitative RT-PCR, we observed a significant upregulation in FGFR2 expression after 3 days. By 7 days post injury, FGFR2 expression fell to basal levels in line with those of FGFR1 and 3, both of which remained unaffected by surgical transection. These results demonstrate a role for FGFR2 in fibroblast and endothelial cell proliferation in damaged ligament, and suggest a window for FGF therapy.

The effect of weightbearing exercise with low frequency, whole body vibration on lumbosacral proprioception: A pilot study on normal subjects

Patients with low back pain (LBP) often present with impaired proprioception of the lumbopelvic region. For this reason, proprioception training usually forms part of the rehabilitation protocols. New exercise equipment that produces whole body, low frequency vibration (WBV) has been developed to improve muscle function, and reportedly improves proprioception. The aim of this pilot study was to investigate whether weightbearing exercise given in conjunction with WBV would affect lumbosacral position sense in healthy individuals. For this purpose, twenty-five young individuals with no LBP were assigned randomly to an experimental or control group. The experimental group received WBV for five minutes while holding a static, semi-squat position. The control group adopted the same weightbearing position for equal time but received no vibration. A two-dimensional motion analysis system measured the repositioning accuracy of pelvic tilting in standing. The experimental (WBV) group demonstrated a significant improvement in repositioning accuracy over time (mean 0.78 degrees) representing 39% improvement. It was concluded that WBV may induce improvements in lumbosacral repositioning accuracy when combined with a weightbearing exercise. Future studies with WBV should focus on evaluating its effects with different types of exercise, the exercise time needed for optimal outcomes, and the effects on proprioception deficits in LBP patients.

Muscle fiber and motor unit behavior in the longest human skeletal muscle

The sartorius muscle is the longest muscle in the human body. It is strap-like, up to 600 mm in length, and contains five to seven neurovascular compartments, each with a neuromuscular endplate zone. Some of its fibers terminate intrafascicularly, whereas others may run the full length of the muscle. To assess the location and timing of activation within motor units of this long muscle, we recorded electromyographic potentials from multiple intramuscular electrodes along sartorius muscle during steady voluntary contraction and analyzed their activity with spike-triggered averaging from a needle electrode inserted near the proximal end of the muscle. Approximately 30% of sartorius motor units included muscle fibers that ran the full length of the muscle, conducting action potentials at 3.9 +/- 0.1 m/s. Most motor units were innervated within a single muscle endplate zone that was not necessarily near the midpoint of the fiber. As a consequence, action potentials reached the distal end of a unit as late as 100 ms after initiation at an endplate zone. Thus, contractile activity is not synchronized along the length of single sartorius fibers. We postulate that lateral transmission of force from fiber to endomysium and a wide distribution of motor unit endplates along the muscle are critical for the efficient transmission of force from sarcomere to tendon and for the prevention of muscle injury caused by overextension of inactive regions of muscle fibers.

Disrupted cortical proprioceptive representation evokes symptoms of peculiarity, foreignness and swelling, but not pain

Objectives. It has been proposed that disruption of the internal proprioceptive representation, via incongruent sensory input, may underpin pathological pain states, but experimental evidence relies on conflicting visual input, which is not clinically relevant. We aimed to determine the symptomatic effect of incongruent proprioceptive input, imparted by vibration of the wrist tendons, which evokes the illusion of perpetual wrist flexion and disrupts cortical proprioceptive representation. Methods. Twenty-nine healthy and naive volunteers reported symptoms during five conditions: control, active and passive wrist flexion, extensor carpi radialis tendon vibration to evoke illusion of perpetual wrist flexion, and ulnar styloid (sham) vibration. No advice was given about possible illusions. Results. Twenty-one subjects reported the illusion of perpetual wrist flexion during tendon vibration. There was no effect of condition or of whether or not subjects reported an illusion on discomfort/pain (P > 0.28). Peculiarity, swelling and foreignness were greater during tendon vibration than during the other conditions, and greater during tendon vibration in those who reported an illusion of wrist flexion than in those who did not (P < 0.05 for all). Symptoms were reported by at least two subjects in each condition and four subjects reported systemic symptoms (e.g. nausea). Conclusions. In healthy volunteers, incongruent proprioceptive input does not cause discomfort or pain but does evoke feelings of peculiarity, swelling and foreignness in the limb.

Preparation and characterisation of novel polycaprolactone-chitosan blends

This research paper reports on the production of a biocompatible and biodegradable material to be used in a polymer stent used for counteracting the occurrence of anastomotic leakage following gastrointestinal surgery. Chitosan was blended with polycaprolactone in a solvent mixture of acetic acid and water. Membranes were formed with a range of 50/50%, 60/40%, 65/35%, 70/30% and 80/20% polycaprolactone/chitosan. The tensile properties of the blends were examined over a time period to access material degradation. In addition the biocompatibilities of the polycaprolactone/chitosan blends were tested for cytotoxic effect using primary tendon fibroblastic cells. This research concluded that the polycaprolactone/chitosan was non-toxic to the fibroblasts cells in-vitro. Analysis of the mechanical properties of the blends showed a range of mechanical strengths and polymer life spans. Overall, blends of 65/35%, 70/30% and 80/20% polycaprolactone/chitosan emerged as possible candidates for the production of a gastrointestinal stent. © 2011 Inderscience Enterprises Ltd.

Efeitos da terapia laser de baixa intensidade associada ao exercício aeróbio no reparo de tenotomia do tendão de aquiles de ratos diabéticos

Diabetes Mellitus (DM ) is a complex disease that requires continuous medical care for the reduction of risk factors in addition to glycemic control. The typical hyperglycemia of this disease produces glycosylation of proteins and so the consequence is the accumulation of glycosylation final products in various human tissues, among them, the tendon. The aerobic exercise (AE) and the low level laser therapy (LLLT) have been used to treat tendinopathies in individuals with or without DM. Objective: The aim of this study was to watch the effect of the LLLT and the AE, in association, in partial tenotomy of the tissue repair of the Achilles tendon (AT) of diabetic rats. Methods: 91 animals were utilized and divided in to the following groups: control group (GC), injured control group (GCL), diabetic group (GD), diabetic group LLLT (GD – TLBI), diabetic group trained (GD - EX) and diabetic group trained laser (GD-EX+TLBI). The animals were submitted to intervention with AE, using a protocol with a progressive increase of time (12 to 60 min) and speed of (4 to 9 m/min), and the LLLT (660 nm laser, 10mW, 4 J/cm², single point for 16 seconds, three times for week). It was analyzed morphological, biomechanical and molecular characteristics. For data showing normal distribution was used one-way ANOVA test and post hoc Tukey and data without normal distribution was used Mann Whitney test and post hoc Dunn's. It was accepted p <0.05 for statistical significance Results: The biomechanical tests indicated major improvement in the GC and GD-EX+TLBI groups when compared with the diabetic groups in the following variables: maximum load, strain, absorbed energy, stress, cross section area, elastic modulus and energy density (p<0.05). The analysis through molecular biology indicated that the association of aerobic exercise and LLLT generated an increase of the collagen I gene expression and modulated the expression of the MMP2 and MMP9 (p<0.05). No observed any major improvement in the morphological variable studied. Conclusion: the LLLT associated with aerobic exercise promotes and increase of the mechanical properties, in the control of collagen I gene expression and of the MMP2 and MMP9 of the diabetic rats.

Dynamic effects of anchor positional tolerance on tension moored floating wind turbine

For water depths greater than 60m floating wind turbines will become the most economical option for generating offshore wind energy. Tension mooring stabilised units are one type of platform being considered by the offshore wind energy industry. The complex mooring arrangement used by this type of platform means that the dynamics are greatly effected by offsets in the positioning of the anchors. This paper examines the issue of tendon anchor position tolerances. The dynamic effects of three positional tolerances are analysed in survival state using the time domain FASTLink. The severe impact of worst case anchor positional offsets on platform and turbine survivability is shown. The worst anchor misposition combinations are highlighted and should be strongly avoided. Novel methods to mitigate this issue are presented.

Mechanical properties and cellular response of novel electrospun nanofibers for ligament tissue engineering: Effects of orientation and geometry

Electrospun nanofibers are a promising material for ligamentous tissue engineering, however weak mechanical properties of fibers to date have limited their clinical usage. The goal of this work was to modify electrospun nanofibers to create a robust structure that mimics the complex hierarchy of native tendons and ligaments. The scaffolds that were fabricated in this study consisted of either random or aligned nanofibers in flat sheets or rolled nanofiber bundles that mimic the size scale of fascicle units in primarily tensile load bearing soft musculoskeletal tissues. Altering nanofiber orientation and geometry significantly affected mechanical properties; most notably aligned nanofiber sheets had the greatest modulus; 125% higher than that of random nanofiber sheets; and 45% higher than aligned nanofiber bundles. Modifying aligned nanofiber sheets to form aligned nanofiber bundles also resulted in approximately 107% higher yield stresses and 140% higher yield strains. The mechanical properties of aligned nanofiber bundles were in the range of the mechanical properties of the native ACL: modulus=158±32MPa, yield stress=57±23MPa and yield strain=0.38±0.08. Adipose derived stem cells cultured on all surfaces remained viable and proliferated extensively over a 7 day culture period and cells elongated on nanofiber bundles. The results of the study suggest that aligned nanofiber bundles may be useful for ligament and tendon tissue engineering based on their mechanical properties and ability to support cell adhesion, proliferation, and elongation.

Human Fetal Progenitor Tenocytes for Regenerative Medicine.

Tendon injuries are very frequent and affect a wide and heterogeneous population. Unfortunately, the healing process is long with outcomes that are not often satisfactory due to fibrotic tissue appearance, which leads to scar and adhesion development. Tissue engineering and cell therapies emerge as interesting alternatives to classical treatments. In this study, we evaluated human fetal progenitor tenocytes (hFPTs) as a potential cell source for treatment of tendon afflictions, as fetal cells are known to promote healing in a scarless regenerative process. hFPTs presented a rapid and stable growth up to passage 9, allowing to create a large cell bank for off-the-shelf availability. hFPTs showed a strong tenogenic phenotype with an excellent stability, even when placed in conditions normally inducing cells to differentiate. The karyotype also indicated a good stability up to passage 12, which is far beyond that necessary for clinical application (passage 6). When placed in coculture, hFPTs had the capacity to stimulate human adult tenocytes (hATs), which are responsible for the deposition of a new extracellular matrix during tendon healing. Finally, it was possible to distribute cells in porous or gel scaffolds with an excellent survival, thus permitting a large variety of applications (from simple injections to grafts acting as filling material). All of these results are encouraging in the development of an off-the-shelf cell source capable of stimulating tendon regeneration for the treatment of tendon injuries.

Cerebrotendinous xanthomatosis with bradyphrenia and psychiatric disorders: a case with 18F-FDG PET imaging and a literature review

Background and Objectives: Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive lipid-storage disease caused by mutations in the CYP27A1. The purpose of this study is to determine the clinical characteristics, neuroimaging and mutation detect in a family with CTX systematically. Methods: Collecting history materials and detecting the routine clinical biochemical tests and imaging examination, and for the first time taking the whole body positron emission tomography (PET)-CT examination for probed in the world to research abnormal metabolism activities in CTX. To observe the effect of treatment with chenodeoxycholic acid (CDCA) and stains before and after the intervention, using serum lipid level detection and neuropsychological evaluation. Genetic testing was carried out to screen the nine exons and exon-intron boundaries about 200-300bq of CYP27A1. Results: A 37-year-old woman with typical clinical characteristics of CTX. Magnetic resonance imaging (MRI) of brain showed bilateral lesions in the dentate nucleus of the cerebellum, then, PET images revealed multiple abnormal hypermetabolism areas at distal tendon, and multifocal areas of hypometabolism in bilateral sides of cerebellar hemispheres, the frontal lobe and temporal lobe. Histopathology reveals accumulation of xanthoma cells and dispersed lipid crystal clefts in xanthomas. In genetic analysis, it shown an insertion of cytosine (77-78insC) located in the first exon of CYP27A1 in the proband. Conclusions: We found that a Chinese patient presented a typical clinical feature of CTX along with clear correlation on both structural and functional imaging had a novel mutation in the CYP27A1 gene.

Acute phase proteins and biomarkers for health in chickens

Acute phase proteins (APPs) are proteins synthesised predominantly in the liver, whose plasma concentrations increase (positive APP) or decrease (negative APP) as a result of infection, inflammation, trauma and tissue injury. They also change as a result of the introduction of immunogens such as bacterial lipopolysaccharide (LPS), turpentine and vaccination. While publications on APPs in chickens are numerous, the limited availability of anti-sera and commercial ELISAs has resulted in a lot of information on only a few APPs. Disease is a threat to the poultry industry, as pathogens have the potential to evolve, spread and cause rapid onset of disease that is detrimental to the welfare of birds. Low level, sub-acute disease with non-specific, often undiagnosed causes can greatly affect bird health and growth and impact greatly on productivity and profitability. Developing and validating methods to measure and characterise APPs in chickens will allow these proteins to be used diagnostically for monitoring flock health. Using immune parameters such as APPs that correlate with disease resistance or improvements in production and welfare will allow the use of APPs as selection parameters for breeding to be evaluated. For APPs to be useful parameters on which to evaluate chicken health, information on normal APP concentrations is required. Ceruloplasmin (Cp) and PIT54 concentrations were found to be much lower in healthy birds form commercial production farms than the reported normal values obtained from the literature. These APPs were found to be significantly higher in culled birds from a commercial farm and Cp, PIT54 and ovotransferrin (Ovt) were significantly higher in birds classified as having obvious gait defects. Using quantitative shotgun proteomics to identify the differentially abundant proteins between three pools: highly acute phase (HAP), acute phase (AP) and non-acute phase (NAP), generated data from which a selection of proteins, based on the fold difference between the three pools was made. These proteins were targeted on a individual samples alongside proteins known to be APPs in chickens or other species: serum amyloid A (SAA), C-reactive protein (CRP), Ovt, apolipoprotein A-I (apo-AI), transthyretin (Ttn), haemopexin (Hpx) and PIT54. Together with immunoassay data for SAA, Ovt, alpha-1-acid glycoprotein (AGP) and Cp the results of this research reveal that SAA is the only major APP in chickens. Ovotransferrin and AGP behave as moderate APPs while PIT54 and Cp are minor APPs. Haemopexin was not significantly different between the three acute phase groups. Apolipoprotein AI and Ttn were significantly lower in the HAP and AP groups and as such can be classed as negative APPs. In an effort to identify CRP, multiple anti-sera cross reacting with CRP from other species were used and a phosphorylcholine column known to affinity purify CRP were used. Enriched fractions containing low molecular weight proteins, elutions from the affinity column together with HAP, AP and NAP pooled samples were applied to a Q-Exactive Hybrid Quadrupole–Orbitrap mass spectrometer (Thermo Scientific) for Shotgun analysis and CRP was not identified. It would appear that CRP is not present as a plasma protein constitutively or during an APR in chickens and as such is not an APP in this species. Of the proteins targeted as possible novel biomarkers of the APR in chickens mannan binding lectin associated serine protease-2, α-2-HS-glycoprotein (fetuin) and major facilitator superfamily domain-containing protein 10 were reduced in abundance in the HAP group, behaving as negative biomarkers. Myeloid protein and putative ISG(12)2 were positively associated with the acute phase being significantly higher in the HAP and AP groups. The protein cathepsin D was significantly higher in both HAP and AP compared to the NAP indicating that of all the proteins targeted, this appears to have the most potential as a biomarker of the acute phase, as it was significantly increased in the AP as well as the HAP group. To evaluate APPs and investigate biomarkers of intestinal health, a study using re-used poultry litter was undertaken. The introduction of litter at 12 days of age did not significantly increase any APPs measured using immunoassays and quantitative proteomics at 3, 6 and 10 days post introduction. While no APP was found to be significantly different between the challenged and control groups at anytime point, the APPs AGP, SAA and Hpx did increase over time in all birds. The protein apolipoprotein AIV (apo-AIV) was targeted as a possible APP and because of its reported role in controlling satiety. An ELISA was developed, successfully validated and used to measure apo-AIV in this study. While no significant differences in apo-AIV plasma concentrations between challenged and control groups were identified apo-AIV plasma concentrations did change significantly between certain time points in challenged and control groups. Apoliporotein AIV does not appear to behave as an APP in chickens, as it was not significantly different between acute phase groups. The actin associated proteins villin and gelsolin were investigated as possible biomarkers of intestinal health. Villin was found not to be present in the plasma of chickens and as such not a biomarker target. Gelsolin was found not to be differentially expressed during the acute phase or as a result of intestinal challenge. Finally a proteomic approach was undertaken to investigate gastrocnemius tendon (GT) rupture in broiler chickens with a view of elucidating to and identify proteins associated with risk of rupture. A number of proteins were found to be differentially expressed between tendon pools and further work would enable further detailing of these findings. In conclusion this work has made a number of novel findings and addressed a number of data poor areas. The area of chicken APPs research has stagnated over the last 15 years with publications becoming repetitive and reliant on a small number of immunoassays. This work has sought to characterise the classic APPs in chickens, and use a quantitative proteomic approach to measure and categorise them. This method was also used to take a fresh approach to biomarker identification for both the APR and intestinal health. The development and validation of assays for Ovt and apo-AIV and the shotgun data mean that these proteins can be further characterised in chickens with a view of applying their measurement to diagnostics and selective breeding programs.