ADAR2 deficiency ameliorates non-alcoholic fatty liver disease and muscle atrophy through modulating serum amyloid A1

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. Sarcopenia is a syndrome characterized by progressive and generalized loss of skeletal muscle mass and strength, which is commonly associated with NAFLD. Adenosine-to-inosine editing, catalysed by adenosine deaminase acting on RNA (ADAR), is an important post-transcriptional modification of genome-encoded RNA transcripts. Three ADAR gene family members, including ADAR1, ADAR2 and ADAR3, have been identified. However, the functional role of ADAR2 in obesity-associated NAFLD and sarcopenia remains unclear.

METHODS

ADAR2+/+/GluR-BR/R mice (wild type [WT]) and ADAR2-/-/GluR-BR/R mice (ADAR2 knockout [KO]) were subjected to feeding with standard chow or high-fat diet (HFD) for 20 weeks at the age of 5 weeks. The metabolic parameters, hepatic lipid droplet, grip strength test, rotarod test, muscle weight, fibre cross-sectional area (CSA), fibre types and protein associated with protein degradation were examined. Systemic and local tissues serum amyloid A1 (SAA1) were measured. The effects of SAA1 on C2C12 myotube atrophy were investigated.

RESULTS

ADAR2 KO mice fed with HFD exhibited lower body weight (-7.7%, P < 0.05), lower liver tissue weight (-20%, P < 0.05), reduced liver lipid droplets in concert with a decrease in hepatic triglyceride content (-24%, P < 0.001) and liver injury (P < 0.01). ADAR2 KO mice displayed protection against HFD-induced glucose intolerance, insulin resistance and dyslipidaemia. Skeletal muscle mass (P < 0.01), muscle strength (P < 0.05), muscle endurance (P < 0.001) and fibre size (CSA; P < 0.0001) were improved in ADAR2 KO mice fed with HFD compared with WT mice fed with HFD. Muscle atrophy-associated transcripts, such as forkhead box protein O1, muscle atrophy F-box/atrogin-1 and muscle RING finger 1/tripartite motif-containing 63, were decreased in ADAR2 KO mice fed with HFD compared with WT mice fed with HFD. ADAR2 deficiency attenuates HFD-induced local liver and skeletal muscle tissue inflammation. ADAR2 deficiency abolished HFD-induced systemic (P < 0.01), hepatic (P < 0.0001) and muscular (P < 0.001) SAA1 levels. C2C12 myotubes treated with recombinant SAA1 displayed a decrease in myotube length (-37%, P < 0.001), diameter (-20%, P < 0.01), number (-39%, P < 0.001) and fusion index (-46%, P < 0.01). Myogenic markers (myosin heavy chain and myogenin) were decreased in SAA1-treated myoblast C2C12 cells.

CONCLUSIONS

These results provide novel evidence that ADAR2 deficiency may be important in obesity-associated sarcopenia and NAFLD. Increased SAA1 might be involved as a regulatory factor in developing sarcopenia in NAFLD.

A novel smart somatosensory wearable assistive device for older adults' home rehabilitation during the COVID-19 pandemic

Background

Due to the Coronavirus disease 19 (COVID-19) related social distancing measures and health service suspension, physical activity has declined, leading to increased falling risk and disability, and consequently, compromising the older adult health. How to improve the quality of older adult life has become a crucial social issue.

Objective

In traditional rehabilitation, manual and repetitive muscle training cannot identify the patient's rehabilitation effect, and increasing the willingness to use it is not easy. Therefore, based on the usability perspective, this study aims to develop a novel smart somatosensory wearable assistive device (called SSWAD) combined with wireless surface electromyography (sEMG) and exergame software and hardware technology. The older adult can do knee extension, ankle dorsiflexion, and ankle plantar flexion rehabilitation exercises at home. Meanwhile, sEMG values can be digitally recorded to assist physicians (or professionals) in judgment, treatment, or diagnosis.

Methods

To explore whether the novel SSWAD could improve the older adult willingness to use and motivation for home rehabilitation, 25 frail older adult (12 males and 13 females with an average age of 69.3) perform the rehabilitation program with the SSWAD, followed by completing the system usability scale (SUS) questionnaire and the semi-structured interview for the quantitative and qualitative analyses. In addition, we further investigate whether the factor of gender or prior rehabilitation experience would affect the home rehabilitation willingness or not.

Results

According to the overall SUS score, the novel SSWAD has good overall usability performance (77.70), meaning that the SSWAD makes older adult feel interested and improves their willingness for continuous rehabilitation at home. In addition, the individual item scores of SUS are shown that female older adult with prior rehabilitation experience perform better in "Learnability" (t = 2.35, p = 0.03) and "Confidence" (t = -3.24, p = 0.01). On the contrary, male older adult without rehabilitation experience are more willing to adopt new technologies (t = -2.73, p = 0.02), and perform better in "Learnability" (t = 2.18, p = 0.04) and "Confidence" (t = -3.75, p < 0.001) with the SSWAD. In addition, the result of the semi-structured interview shows that the operation of the SSWAD is highly flexible, thus reducing older adult burden during the rehabilitation exercise and using them long-term.

Conclusion

This novel SSWAD receives consistently positive feedback regardless of the gender or prior rehabilitation experience of elders. The SSWAD could be used as a novel way of home rehabilitation for elders, especially during the COVID-19 pandemic. Older adult can do rehabilitation exercises at home, and physicians could make proper judgments or adjust suitable treatments online according to the sEMG data, which older adult can know their rehabilitation progress at the same time. Most importantly, older adult do not have to go to the hospital every time for rehabilitation, which significantly reduces time and the risk of infection.

Photonic crystal enhanced immunofluorescence biosensor integrated with a lateral flow microchip: Toward rapid tear-based diabetic retinopathy screening

Diabetic retinopathy (DR) has accounted for major loss of vision in chronic diabetes. Although clinical statistics have shown that early screening can procrastinate or improve the deterioration of the disease, the screening rate remains low worldwide because of the great inconvenience of conventional ophthalmoscopic examination. Instead, tear fluid that contains rich proteins caused by direct contact with eyeballs is an ideal substitute to monitor vision health. Herein, an immunofluorescence biosensor enhanced by a photonic crystal (PhC) is presented to handle the trace proteins suspended in the tear fluid. The PhC was constructed by self-assembled nanoparticles with a thin layer of gold coated on top of it. Then, the PC substrate was conjugated with antibodies and placed in a microchannel. When the capillary-driven tear sample flew over the PC substrate, the immunoassay enabled the formation of a sandwich antibody-antigen-antibody configuration for PhC-enhanced immunofluorescence. The use of PhC resulted in a concentration enhancement of more than tenfold compared to non-PhC, while achieving an equivalent signal intensity. The limit of detection for the target biomarker, lipocalin-1 (LCN-1), reached nearly 3 μg/ml, and the turnaround time of each detection was 15 min. Finally, a preclinical evaluation was conducted using ten tear samples. A clear trend was observed, showing that the concentrations of LCN-1 were at least twofold higher in individuals with chronic diabetes or DR than in healthy individuals. This trend was consistent with their medical conditions. The results provided a direct proof-of-concept for the proposed PhC biosensor in rapid tear-based DR screening.

Osteoregenerative efficacy of a novel synthetic, resorbable Ca/P/S-based bone graft substitute in intra- and peri-articular fractures: a brief medical image-based report

Background

When a fracture goes into or around a joint, it usually damages the cartilage at the ends of bones and other joint tissue. As a result, the affected joints are prone to traumatic arthritis, leading to stiffness. Repairing bone damage, maintaining joint integrity, and avoiding subchondral and metaphyseal defects caused by comminuted fractures is often a great challenge for orthopedic surgeons. Tissue engineering of synthetic bone substitutes has proven beneficial to the attachment and proliferation of bone cells, promoting the formation of mature tissues with sufficient mechanical strength and has become a promising alternative to autograft methods. The purpose of this study is to retrospectively evaluate the clinical outcome and efficacy of a novel synthetic, highly biocompatible, and fully resorbable Ca/P/S-based bone substitute based on medical image findings.

Materials and methods

A synthetic, inorganic and highly porous Ca/P/S-based bone-substituting material (Ezechbone® Granule, CBS-400) has been developed by National Cheng-Kung University. We collected fourteen cases of complex intra- and peri-articular fractures with Ezechbone® Granule bone grafting between 2019/11 and 2021/11. We studied the evidence of bone healing by reviewing, interpreting and analyzing the medical image recordings.

Results

In the present study, CBS-400 was observed to quickly integrate into surrounding bone within three weeks after grafting during the initial callus formation of the early stage of repair. All of these cases healed entirely within three months. In addition, the patient may return to daily life function after 3.5 months of follow-up and rehabilitation treatment.

Conclusions

Ezechbone® Granule CBS-400 was proved capable of promoting bone healing and early rehabilitation to prevent soft tissue adhesions and joint contractures. Moreover, it has a high potential for avoiding ectopic bone formation or abnormal synostosis.

Trial registration

The Institutional Review Board at National Cheng Kung University Hospital (NCKUH) approved the study protocol (A-ER-109-031, 3-13-2020).

Muscle Mass Measurement Using Machine Learning Algorithms with Electrical Impedance Myography

Sarcopenia is a wild chronic disease among elderly people. Although it does not entail a life-threatening risk, it will increase the adverse risk due to the associated unsteady gait, fall, fractures, and functional disability. The import factors in diagnosing sarcopenia are muscle mass and strength. The examination of muscle mass must be carried in the clinic. However, the loss of muscle mass can be improved by rehabilitation that can be performed in non-medical environments. Electronic impedance myography (EIM) can measure some parameters of muscles that have the correlations with muscle mass and strength. The goal of this study is to use machine learning algorithms to estimate the total mass of thigh muscles (MoTM) with the parameters of EIM and body information. We explored the seven major muscles of lower limbs. The feature selection methods, including recursive feature elimination (RFE) and feature combination, were used to select the optimal features based on the ridge regression (RR) and support vector regression (SVR) models. The optimal features were the resistance of rectus femoris normalized by the thigh circumference, phase of tibialis anterior combined with the gender, and body information, height, and weight. There were 96 subjects involved in this study. The performances of estimating the MoTM used the regression coefficient (r²) and root-mean-square error (RMSE), which were 0.800 and 0.929, and 1.432 kg and 0.980 kg for RR and SVR models, respectively. Thus, the proposed method could have the potential to support people examining their muscle mass in non-medical environments.

Scaphoid Fracture Detection by Using Convolutional Neural Network

Scaphoid fractures frequently appear in injury radiograph, but approximately 20% are occult. While there are few studies in the fracture detection of X-ray scaphoid images, their effectiveness is insignificant in detecting the scaphoid fractures. Traditional image processing technology had been applied to segment interesting areas of X-ray images, but it always suffered from the requirements of manual intervention and a large amount of computational time. To date, the models of convolutional neural networks have been widely applied to medical image recognition; thus, this study proposed a two-stage convolutional neural network to detect scaphoid fractures. In the first stage, the scaphoid bone is separated from the X-ray image using the Faster R-CNN network. The second stage uses the ResNet model as the backbone for feature extraction, and uses the feature pyramid network and the convolutional block attention module to develop the detection and classification models for scaphoid fractures. Various metrics such as recall, precision, sensitivity, specificity, accuracy, and the area under the receiver operating characteristic curve (AUC) are used to evaluate our proposed method’s performance. The scaphoid bone detection achieved an accuracy of 99.70%. The results of scaphoid fracture detection with the rotational bounding box revealed a recall of 0.789, precision of 0.894, accuracy of 0.853, sensitivity of 0.789, specificity of 0.90, and AUC of 0.920. The resulting scaphoid fracture classification had the following performances: recall of 0.735, precision of 0.898, accuracy of 0.829, sensitivity of 0.735, specificity of 0.920, and AUC of 0.917. According to the experimental results, we found that the proposed method can provide effective references for measuring scaphoid fractures. It has a high potential to consider the solution of detection of scaphoid fractures. In the future, the integration of images of the anterior–posterior and lateral views of each participant to develop more powerful convolutional neural networks for fracture detection by X-ray radiograph is probably important to research.

Effects of a Virtual Reality-Based Mirror Therapy Program on Improving Sensorimotor Function of Hands in Chronic Stroke Patients: A Randomized Controlled Trial

Background. Embedding mirror therapy within a virtual reality (VR) system may have a superior effect on motor remediation for chronic stroke patients. Objective. The objective is to investigate the differences in the effects of using conventional occupational therapy (COT), mirror therapy (MT), and VR-based MT (VR-MT) training on the sensorimotor function of the upper limb in chronic stroke patients. Methods. This was a single-blinded randomized controlled trial. A total of 54 participants, including chronic stroke patients, were randomized into a COT, MT, or VR-MT group. In addition to 20-minute sessions of task-specific training, patients received programs of 30 minutes of VR-MT, 30 minutes of MT, and 30 minutes of COT, respectively, in the VR-MT, MT, and COT groups twice a week for 9 weeks. The Fugl-Meyer motor assessment for the upper extremities (FM-UE; primary outcome), Semmes-Weinstein monofilament, motor activity log, modified Ashworth scale, and the box and block test were recorded at pre-treatment, post-intervention, and 12-week follow-up. Results. Fifty-two participants completed the study. There was no statistically significant group-by-time interaction effects on the FM-UE score (generalized estimating equations, (GEE), P = .075). Meanwhile, there were statistically significant group-by-time interaction effects on the wrist sub-score of the FM-UE (GEE, P = .012) and the result of box and block test (GEE, P = .044). Conclusions. VR-MT seemed to have potential effects on restoring the upper extremity motor function for chronic stroke patients. However, further confirmatory studies are warranted for the rather weak evidence of adding VR to MT on improving primary outcome of this study. Clinical trial registration: NCT03329417.

Estimating the neovascularity of human finger tendon through high frequency ultrasound micro-Doppler imaging

OBJECTIVE

Neovascularization of injured tendons prolongs the proliferative phase of healing, but prolonged neovascularization may cause improper healing and pain. Currently, ultrasound Doppler imaging is used for measuring the neovascularization of injured tendons (e.g., Achilles tendon). However, the resolution of state-of-the-art clinical ultrasound machines is insufficient for visualizing the neovascularization in finger tendons. In this study, a high-resolution micro-Doppler imaging (HFDI) based on 40-MHz ultrafast ultrasound imaging was proposed for visualizing the neovascularization in injured finger tendons during multiple rehabilitation phases.

METHOD

The vessel visibility was enhanced through a block-wise singular value decomposition filter and several curvilinear structure enhancement strategies, including the bowler-hat transform and Hessian-based vessel enhancement filtering. HFDI was verified through small animal kidney and spleen imaging because the related vessel structure patterns of mice are well studied. Five patients with finger tendon injuries underwent HFDI examination at various rehabilitation phases after surgery (weeks 1156), and finger function evaluations were performed for comparisons.

RESULTS

The results of small animal experiments revealed that the proposed HFDI provides excellent microvasculature imaging performance; the contrast-to-noise ratio of HFDI was approximately 15 dB higher than that of the conventional singular value decomposition filter, and the minimum detectable vessel size for mouse kidney was 35 m without the use of contrast agent. In the human study, neovascularization was clearly observed in injured finger tendons during the early phase of healing (weeks 1121), but it regressed from week 52 to 56. Finger rehabilitation appears to help reduce neovascularization; neovascular density decreased by approximately 1.8%8.0% in participants after 4 weeks of rehabilitation.

CONCLUSION

The experimental results verified the performance of HFDI for microvasculature imaging and its potential for injured finger tendon evaluations.

Triangular configuration with headless compression screws in the fixation of transverse patellar fracture

A triangular configuration with three parallel cannulated screws is an established treatment for fixing transverse patellar fractures; however, the stability achieved with this approach is slightly lower than that attained with cannulated screws combined with anterior wiring. In the present study, triangular configurations were modified by partially or totally replacing the cannulated screws with headless compression screws (HCSs). Through finite element simulation involving a model of distal femoral, patellar, and proximal tibial fractures, the mechanical stability levels of the modified triangular configurations were compared with that of two cannulated screws combined with anterior wiring. Four triangular screw configurations were developed: three HCSs in a forward and backward triangular configuration, two deep cannulated screws along with one superficial HCS, and two superficial cannulated screws with one deep HCS. Also considered were two parallel cannulated screws (inserted superficially or deeply) combined with anterior wiring. The six approaches were all examined in full knee extension and 45° flexion under physiological loading. The highest stability was obtained with the three HCSs in a backward triangular configuration, as indicated by the least fragment displacement and the smallest fracture gap size. In extension and flexion, this size was smaller than that observed under the use of two deeply placed parallel cannulated screws with anterior wiring by 50.3% (1.53 vs. 0.76 mm) and 43.2% (1.48 vs. 0.84 mm), respectively. Thus, the use of three HCSs in a backward triangular configuration is recommended for the fixation of transverse patellar fractures, especially without the use of anterior wiring.

Calculation of flexor pollicis longus moment arm for wrist motion in a cadaver model validates the tenodesis effect for therapy

INTRODUCTION

Synergies of fingers and wrist motion have been incorporated into therapies for finger flexor tendon injuries to improve repair outcomes. Similar synergistic therapy strategies have not been well documented for the thumb.

PURPOSE OF THE STUDY

The purpose of this study was to investigate the extent to which wrist motion enables a synergistic effect at the thumb in a cadaveric model by measuring flexor pollicis longus excursion and calculating the moment arm of this tendon at the wrist joint.

STUDY DESIGN

This is a basic science research.

METHODS

Eight fresh-frozen cadaveric arms were obtained from our anatomical bequest program. The proximal arm was fixed in neutral pronation/supination position, and motion of the wrist was guided through either flexion/extension or radial/ulnar deviation. Fingers were fixed in extension, thumb interphalangeal and metacarpophalangeal joints were fixed in neutral extension, and the carpometacarpal joint was fixed at 30° palmar abduction. The flexor pollicis longus tendon was exposed proximal to the wrist crease and connected to a rotary potentiometer to measure tendon excursion. Optical markers were attached to the hand to capture kinematics. Wrists were moved from a neutral position over the range of flexion and extension and then from the neutral position through the range of radial to ulnar deviation. Moment arms were calculated.

RESULTS

Moment arm calculation indicated that the flexor pollicis longus acts as a wrist flexor over the entire motion range and as a weak radial deviator at ulnarly-deviated positions.

CONCLUSIONS

This study provides a mechanistic rationale for passive interphalangeal joint motion in varying wrist positions when treating thumb flexor tendon injuries, with benefits seen primarily for wrist extension.

Evaluation of Hand Tendon Elastic Properties During Rehabilitation Through High-Frequency Ultrasound Shear Elastography

Tendon injuries lead to tendon stiffness, which impairs skeletal muscle movement. Most studies have focused on patellar or Achilles tendons by using ultrasound elastography. Only a few studies have measured the stiffness of hand tendons because their thickness is only 1-2 mm, rendering clinical ultrasound elastography unsuitable for mapping hand tendon stiffness. In this study, a high-frequency ultrasound shear elastography (HFUSE) system was proposed to map the shear wave velocity (SWV) of hand flexor tendons. A handheld vibration system that was coaxially mounted with an external vibrator on a high-frequency ultrasound (HFUS) array transducer allowed the operators to scan hand tendons freely. To quantify the performance of HFUSE, six parameters were comprehensively measured from homogeneous, two-sided, and three-sided gelatin phantom experiments: bias, precision, lateral resolution, contrast, contrast-to-noise ratio (CNR), and accuracy. HFUSE demonstrated an excellent resolution of [Formula: see text] to distinguish the local stiffness of thin phantom (thickness: 1.2 mm) without compromising bias, precision, contrast, CNR, and accuracy, which has been noted with previous systems. Human experiments involved four patients with hand tendon injuries who underwent ≥2 months of rehabilitation. Using HFUSE, two-dimensional SWV images of flexor tendons could be clearly mapped for healthy and injured tendons, respectively. The findings demonstrate that HFUSE can be a promising tool for evaluating the elastic properties of the injured hand tendon after surgery and during rehabilitation and thus help monitor progress.

A Fully-Automatic Segmentation of the Carpal Tunnel from Magnetic Resonance Images Based on the Convolutional Neural Network-Based Approach

Purpose

Carpal tunnel syndrome is one of the common peripheral neuropathies. For magnetic resonance imaging, segmentation of the carpal tunnel and its contents, including flexor tendons and the median nerve for magnetic resonance images is an important issue. In this study, a convolutional neural network (CNN) model, which was modified by the original DeepLabv3 + model to segment three primary structures of the carpal tunnel: the carpal tunnel, flexor tendon, and median nerve.

Methods

To extract important feature maps for segmentation of the carpal tunnel, flexor tendon, and median nerve, the proposed CNN model termed modified DeepLabv3 + uses DenseNet-121 as a backbone and adds dilated convolution to the original spatial pyramid pooling module. A MaskTrack method was used to refine the segmented results generated by modified DeepLabv3 + , which have a small and blurred appearance. For evaluation of the segmentation results, the average Dice similarity coefficients (ADSC) were used as the performance index.

Results

Sixteen MR images corresponding to different subjects were obtained from the National Cheng Kung University Hospital. Our proposed modified DeepLabv3 + generated the following ADSCs: 0.928 for carpal tunnel, 0.872 for flexor tendons and 0.785 for the median nerve. The ADSC value of 0.8053 generated the MaskTrack that 0.22 ADSC measure were improved for measuring the median nerve.

Conclusions

The experimental results showed that the proposed modified DeepLabv3 + model can promote segmentations of the carpal tunnel and its contents. The results are superior to the results generated by original DeepLabv3 + . Additionally, MaskTrack can also effectively refine median nerve segmentations.

Effect of a monocyte chemoattractant protein-1 synthesis inhibitor on fibroblasts from patients with carpal tunnel syndrome

BACKGROUND

Carpal Tunnel Syndrome (CTS) is an idiopathic fibrotic disorder. Fibrosis in the subsynovial connective tissues (SSCT) of CTS and many other fibrotic diseases is mediated by Transforming growth factor β (TGF-β). Recently monocyte chemoattractant protein-1 (MCP-1) a cytokine involved in cellular recruitment has been suggested to regulate TGF-β activity. It is related to the onset of diseases which are caused by fibrosis, such as idiopathic pulmonary fibrosis, renal fibrosis, and systemic scleroderma. In this study, we evaluated the effect of the MCP-1 synthesis inhibitor, Bindarit, on primary cultures of fibroblasts from the SSCT of five CTS patients.

METHODS

Fibroblasts were treated with Bindarit (10 μM, 50 μM, 100 μM, or 300 μM). Responses to inhibitors were evaluated by regulation of CTS fibrosis-associated genes, fibrosis gene array and Smad luciferase reporter assay. We also assessed the combination effect of Bindarit and SD208, a TGF-β receptor type 1 inhibitor on TGF-β signaling.

RESULTS

Collagen type III A1 (Col3), connective tissue growth factor (CTGF), and SERPINE1 expression were significantly down-regulated by Bindarit (300 μM) compared to vehicle control. In the fibrosis array, expression of inhibin beta E chain precursor (INHBE), beta actin (ACTB), endothelin 1 (EDN1) and hypoxanthine phosphoribosyltransferase 1 (HPRT1) were significantly down-regulated, and integrin beta-3 (ITGB3) was significantly up-regulated by Bindarit (300 μM). Smad signal transduction activation was significantly down-regulated by Bindarit (300 μM) and/or SD208 (1 μM) with TGF-β1 compared to vehicle control with TGF-β1.

CONCLUSIONS

These results suggest that Bindarit in combination with SD208 may be beneficial as medical therapy for the SSCT fibrosis associated with CTS.

Multiple microRNAs regulate tacrolimus metabolism through CYP3A5

The CYP3A5 gene polymorphism accounts for the majority of inter-individual variability in tacrolimus pharmacokinetics. We found that the basal expression of CYP3A5 in donor grafts also played a significant role in tacrolimus metabolism under the same genetic conditions after pediatric liver transplantation. Thus, we hypothesized that some potential epigenetic factors could affect CYP3A5 expression and contributed to the variability. We used a high-throughput functional screening for miRNAs to identify miRNAs that had the most abundant expression in normal human liver and could regulate tacrolimus metabolism in HepaRG cells and HepLPCs. Four of these miRNAs (miR-29a-3p, miR-99a-5p, miR-532-5p, and miR-26-5p) were selected for testing. We found that these miRNAs inhibited tacrolimus metabolism that was dependent on CYP3A5. Putative miRNAs targeting key drug-metabolizing enzymes and transporters (DMETs) were selected using an in silico prediction algorithm. Luciferase reporter assays and functional studies showed that miR-26b-5p inhibited tacrolimus metabolism by directly regulating CYP3A5, while miR-29a-5p, miR-99a-5p, and miR-532-5p targeted HNF4α, NR1I3, and NR1I2, respectively, in turn regulating the downstream expression of CYP3A5; the corresponding target gene siRNAs markedly abolished the effects caused by miRNA inhibitors. Also, the expression of miR-29a-3p, miR-99a-5p, miR-532-5p, and miR-26b-5p in donor grafts were negatively correlated with tacrolimus C/D following pediatric liver transplantation. Taken together, our findings identify these miRNAs as novel regulators of tacrolimus metabolism.

Role of an additional third screw in the fixation of transverse patellar fracture with two parallel cannulated screw and anterior wire

BACKGROUND

Two parallel cannulated screws along with an anterior wire to construct a tension band is a popular approach in transverse patellar fractures. However, the optimal screw proximity, either deep or superficial screw placements, remains controversial. Hence, a new concept of the addition of a third screw to form a triangular configuration along with the original two parallel screws was proposed in this study. Therefore, the biomechanical effect of the additional third screw on the stability of the fractured patella was investigated with finite element (FE) simulation.

METHODS

An FE knee model including the distal femur, proximal tibia, and fractured patella (type AT/OTA 34-C) was developed in this study. Four different screw configurations, including two parallel cannulated screws with superficial (5-mm proximity) and deep (10-mm proximity) placements and two parallel superficial screws plus a third deep screw, and two parallel deep screws plus a third superficial screw, with or without the anterior wire, were considered for the simulation.

RESULTS

Results indicated that the addition of a third screw increased stability by reducing the dorsal gap opening when two parallel screws were deeply placed, particularly on the fractured patella without an anterior wire. However, the third screw was of little value when two parallel screws were superficially placed. In the existence of two deep parallel screws and the anterior wire, the third screw reduced the gap opening by 23.5% (from 1.15 mm to 0.88 mm) and 53.6% (from 1.21 mm to 0.61 mm) in knee flexion 45° and full extension, respectively. Furthermore, in the absence of the anterior wire, the third screw reduced the gap opening by 73.5% (from 2 mm to 0.53 mm) and 72.2% (from 1.33 mm to 0.37 mm) in knee flexion 45° and full extension, respectively.

CONCLUSION

Based on the results, a third cannulated screw superficially placed (5-mm proximity) is recommended to increase stability and maintain contact of the fractured patella, fixed with two parallel cannulated screws deeply placed (10-mm proximity), particularly when an anterior wire was not used. Furthermore, the third screw deeply placed is not recommended in a fractured patella with two parallel superficial screws.

Computational comparison of different plating strategies in medial open-wedge high tibial osteotomy with lateral hinge fractures

Background

Lateral hinge fracture (LHF) is associated with nonunion and plate breakage in high tibial osteotomy (HTO). Mechanical studies investigating fixation strategies for LHFs to restore stability and avoid plate breakage are absent. This study used computer simulation to compare mechanical stabilities in HTO for different LHFs fixed with medial and bilateral locking plates.

Methods

A finite element knee model was created with HTO and three types of LHF, namely T1, T2, and T3 fractures, based on the Takeuchi classification. Either medial plating or bilateral plating was used to fix the HTO with LHFs. Furthermore, the significance of the locking screw at the combi hole (D-hole) of the medial TomoFix plate was evaluated.

Results

The osteotomy gap shortening distance increased from 0.53 to 0.76, 0.79, and 0.72 mm after T1, T2, and T3 LHFs, respectively, with medial plating only. Bilateral plating could efficiently restore stability and maintain the osteotomy gap. Furthermore, using the D-hole screw reduced the peak stress on the medial plate by 28.7% (from 495 to 353 MPa), 26.6% (from 470 to 345 MPa), and 32.6% (from 454 to 306 MPa) in T1, T2, and T3 LHFs, respectively.

Conclusion

Bilateral plating is a recommended strategy to restore HTO stability in LHFs. Furthermore, using a D-hole locking screw is strongly recommended to reduce the stress on the medial plate for lowering plate breakage risk.

DeepNerve: A New Convolutional Neural Network for the Localization and Segmentation of the Median Nerve in Ultrasound Image Sequences

Carpal tunnel syndrome commonly occurs in individuals working in occupations that involve use of vibrating manual tools or tasks with highly repetitive and forceful manual exertion. In recent years, carpal tunnel syndrome has been evaluated by ultrasound imaging that monitors median nerve movement. Conventional image analysis methods, such as the active contour model, are typically used to expedite automatic segmentation of the median nerve, but these usually suffer from an arduous manual intervention. We propose a new convolutional neural network framework for localization and segmentation of the median nerve, called DeepNerve, that is based on the U-Net model. DeepNerve integrates the characteristics of MaskTrack and convolutional long short-term memory to effectively locate and segment the median nerve. On the basis of experimental results, the proposed model achieved high performance and generated average Dice measurement, precision, recall and F-score values of 0.8975, 0.8912, 0.9119 and 0.9015, respectively. The segmentation results of DeepNerve were significantly improved in comparison with those of conventional active contour models. Additionally, the results of Student's t-test revealed significant differences in four deformation measurements of the median nerve, including area, perimeter, aspect ratio and circularity. We conclude that the proposed DeepNerve not only generates satisfactory results for localization and segmentation of the median nerve, but also creates more promising measurements for applications in clinical carpal tunnel syndrome diagnosis.

Segmentation of finger tendon and synovial sheath in ultrasound image using deep convolutional neural network

BACKGROUND

Trigger finger is a common hand disease, which is caused by a mismatch in diameter between the tendon and the pulley. Ultrasound images are typically used to diagnose this disease, which are also used to guide surgical treatment. However, background noise and unclear tissue boundaries in the images increase the difficulty of the process. To overcome these problems, a computer-aided tool for the identification of finger tissue is needed.

RESULTS

Two datasets were used for evaluation: one comprised different cases of individual images and another consisting of eight groups of continuous images. Regarding result similarity and contour smoothness, our proposed deeply supervised dilated fully convolutional DenseNet (D2FC-DN) is better than ATASM (the state-of-art segmentation method) and representative CNN methods. As a practical application, our proposed method can be used to build a tendon and synovial sheath model that can be used in a training system for ultrasound-guided trigger finger surgery.

CONCLUSION

We proposed a D2FC-DN for finger tendon and synovial sheath segmentation in ultrasound images. The segmentation results were remarkably accurate for two datasets. It can be applied to assist the diagnosis of trigger finger by highlighting the tissues and generate models for surgical training systems in the future.

METHODS

We propose a novel finger tendon segmentation method for use with ultrasound images that can also be used for synovial sheath segmentation that yields a more complete description for analysis. In this study, a hybrid of effective convolutional neural network techniques are applied, resulting in a deeply supervised dilated fully convolutional DenseNet (D2FC-DN), which displayed excellent segmentation performance on the tendon and synovial sheath.

Characterization of the extensor digitorum communis tendon using high-frequency ultrasound shear wave elastography

PURPOSE

Hand tendon injuries caused by various accidents are common in emergency departments. The assessment of tendon properties is crucial for evaluating the effectiveness of therapy or rehabilitation during recovery after hand injuries. Many recent studies have indicated that the shear wave velocity (SWV) of tendons is related to their stiffness. However, measurement of SWV of hand tendon is still a challenge because the small size of tendon and the limitation of existing ultrasound systems for detecting fast SWV.

METHODS

We propose a high-frequency ultrasound (HFUS) elastography system using an external vibrator to measure the SWV of the extensor digitorum communis (EDC) tendon. First, animal studies were performed by measuring the SWV and stress of porcine tendons using the proposed HFUS elastography and materials testing systems respectively. In the human experiment, SWVs were measured during hand extension and flexion. The applied stress from a finger during the movements was recorded synchronously by using a load cell.

RESULTS

The experimental results reveal that a favorable linear correction (R² of 0.96) was obtained between tendon SWV and stress in animal studies. In the human (hand) EDC tendon experiments, the SWV increased with the extension and flexion of the hand. The SWV of the EDC tendon was in the range of 20 to 135 m/s as the applied force from the finger of a healthy human increased to 50% maximal voluntary contraction.

CONCLUSIONS

All the experimental results show that the proposed HFUS elastography system can be used to characterize the EDC tendon and has potential use for evaluating tendon stiffness during recovery after hand injures.

Evaluation of Hand Tendon Movement by Using High-Frequency Ultrasound Vector Doppler Imaging

OBJECTIVE

Injuries to the hands, wrists, and fingers often involve damage to the tendons. The ability to measure tendon movements during the rehabilitation process can provide clinicians with important information in the quantification of tendon injuries. Conventionally, the tendon is considered a single spring-like structure during force transmission, and its twisted structure is neglected. Recently, clinicians believed that the twisted fiber structure (which enables tendon rotation during movement) of the tendon can provide it with a degree of elasticity and improve the efficiency of force transmission. However, observation of the hand tendon rotation in vivo by using the current imaging modalities is difficult.

METHODS

In this study, a 40-MHz high-frequency vector Doppler imaging (HFVDI) was used to visualize the movement of the hand tendon during muscle contraction. The performance of HFVDI was verified using a rotation phantom experiment. Two human experiments were designed in the present study: 1) participants were allowed to bend their distal and proximal interphalangeal (DIP and PIP) joints of fingers freely and 2) the PIP joint of the finger was fixed such that only the DIP could be moved. The HFVDIs of the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendons were obtained in the transverse and longitudinal views to observe the movements of the hand tendon during finger movements.

RESULTS

The average longitudinal displacements of the FDS and FDP were approximately 3-4 mm for free bending of the finger; however, it was reduced when only the DIP was moved. The rotational phenomenon of the FDS and FDP tendons was observed in the transverse view, which demonstrated the different rotational behaviors of the FDS and FDP fibers during muscle contraction.

CONCLUSION

All the results validated the potential of HFVDI as a novel tool for visualizing tendon rotation and would be useful in providing quantitative information regarding tendon function to determine the rehabilitation process following injuries.

Characterization of Hand Tendons Through High-Frequency Ultrasound Elastography

Tendon stiffness plays an important role in the tendon healing process, and many studies have indicated that measuring the shear wave velocity (SWV) on tendons relates to their stiffness. Because the thickness of hand tendons is a few millimeters, high-resolution imaging is required for visualizing hand tissues. However, the resolution of current ultrasound elastography systems is insufficient. In this study, a high-frequency (HF) ultrasound elastography system is proposed for measuring the SWVs of hand tendons. The HF ultrasound elastography system uses an external vibrator to create shear waves on hand tendons. Then, it uses a 40-MHz HF ultrasound array transducer with ultrafast ultrasound imaging technology to measure the SWV for characterizing hand tendons. A handheld device that combines a transducer and a vibrator allows the user to scan hand tissues. The biases of HF ultrasound elastography were measured in gelatin phantom experiments and were less than 6% compared to standard mechanical testing approach. Human experiments showed the ability to use HF ultrasound elastography to distinguish different SWVs of hand tendons. The SWVs were 0.73 ± 0.65 m/s and 1 ± 0.54 m/s for flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP), respectively, and 0.52 ± 0.14 m/s and 4.02 ± 0.77 m/s for extensor tendon under stretch and contraction conditions, respectively. The simplicity and convenience of the HF ultrasound elastography system for measuring hand tendon stiffness make it a promising tool for evaluating the severity of hand injuries and the performance of rehabilitation after hand injuries.

[An interlaboratory comparison study on the detection of RUNX1-RUNX1T1 fusion transcript levels and WT1 transcript levels]

Objective: To investigate the current status and real performance of the detection of RUNX1-RUNX1T1 fusion transcript levels and WT1 transcript levels in China through interlaboratory comparison. Methods: Peking University People's Hospital (PKUPH) prepared the samples for comparison. That is, the fresh RUNX1-RUNX1T1 positive (+) bone morrow nucleated cells were serially diluted with RUNX1-RUNX1T1 negative (-) nucleated cells from different patients. Totally 23 sets with 14 different samples per set were prepared. TRIzol reagent was added in each tube and thoroughly mixed with cells for homogenization. Each laboratory simultaneously tested RUNX1-RUNX1T1 and WT1 transcript levels of one set of samples by real-time quantitative PCR method. All transcript levels were reported as the percentage of RUNX1-RUNX1T1 or WT1 transcript copies/ABL copies. Spearman correlation coefficient between the reported transcript levels of each participated laboratory and those of PKUPH was calculated. Results: ①RUNX1-RUNX1T1 comparison: 9 samples were (+) and 5 were (-) , the false negative and positive rates of the 20 participated laboratories were 0 (0/180) and 5% (5/100) , respectively. The reported transcript levels of all 9 positive samples were different among laboratories. The median reported transcript levels of 9 positive samples were from 0.060% to 176.7%, which covered 3.5-log. The ratios of each sample's highest to the lowest reported transcript levels were from 5.5 to 12.3 (one result which obviously deviated from other laboratories' results was not included) , 85% (17/20) of the laboratories had correlation coefficient ≥0.98. ②WT1 comparison: The median reported transcript levels of all 14 samples were from 0.17% to 67.6%, which covered 2.6-log. The ratios of each sample's highest to the lowest reported transcript levels were from 5.3-13.7, 62% (13/21) of the laboratories had correlation coefficient ≥0.98. ③ The relative relationship of the reported RUNX1-RUNX1T1 transcript levels between the participants and PKUPH was not always consistent with that of WT1 transcript levels. Both RUNX1-RUNX1T1 and WT1 transcript levels from 2 and 7 laboratories were individually lower than and higher than those of PKUPH, whereas for the rest 11 laboratories, one transcript level was higher than and the other was lower than that of PKUPH. Conclusion: The reported RUNX1-RUNX1T1 and WT1 transcript levels were different among laboratories for the same sample. Most of the participated laboratories reported highly consistent result with that of PKUPH. The relationship between laboratories of the different transcript levels may not be the same.

Label-Free Monitoring of Microorganisms and Their Responses to Antibiotics Based on Self-Powered Microbead Sensors

Rapid detection of bacteria and their susceptibility to specific antibiotics plays a vital role in microbial infection treatments. Antimicrobial susceptibility testing (AST) is a common measure to select effective drugs. However, the conventional practices, such as broth dilution, E-test, and disk diffusion, in clinical applications require a long turnaround time (∼3 days), thereby compromising treatments and increasing mortality. This study presents self-powered sensors for on-site microorganism monitoring and rapid AST based on functionalized microbeads. The microbead sensors are driven by Brownian motion, rendering external power unnecessary. Fluorescent microbeads ( d_p = 2 μm) were coated with vancomycin to capture bacteria. The growth and responses of Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus under antibiotic treatment were evaluated. The method showed stable selective binding despite the presence of some interferential substances, such as proteins and cells. Diffusivity change was strongly related to bacterial concentration. Accordingly, the diffusivity values of microbeads bound with motile and nonmotile bacteria exhibited specific patterns because of extra motility from microbes and increased particle diameter. Only a drop of microbead-bacteria suspension (∼5 μL) was needed in a microchip for each measurement. The microchip provided a steady environment for measurement over a few hours. By distinguishing the slope of the last four data points in the temporal diffusivity curve, bacterial susceptibility or resistance to specific antibiotics could be determined within a time frame of 2 h. The study provides insights into saving more lives by using a fast and robust AST technique in future clinical practice.

Triamcinolone Acetonide affects TGF-β signaling regulation of fibrosis in idiopathic carpal tunnel syndrome

Background

Fibroblast behavior and cell-matrix interactions of cells from normal and idiopathic carpal tunnel syndrome (CTS) subsynovial connective tissue (SSCT) with and without Triamcinolone Acetonide (TA) were compared in this study. A cell-seeded gel contraction model was applied to investigate the effect of steroid treatment on SSCT fibroblast gene expression and function.

Methods

SSCT cells were obtained from CTS patients and fresh cadavers. Cells were isolated by mechanical and collagenase digestion. Collagen gels (1 mg/ml) were prepared with SSCT cells (1 × 10⁶/mL). A sterile Petri dish with a cloning ring in the center was prepared. The area between the ring and outer dish was filled with cell-seeded collagen solution and gelled for 1 h. The gel was released from the outer way of the petri dish to allow gel contraction. Cell seeded gels were treated with 10 M triamcinolone acetonide (TA) or vehicle (DMSO) in modified MEM. Every 4 h for 3 days the contracting gels were photographed and areas calculated. Duplicate contraction tests were performed with each specimen, and the averages were used in the analyses, which were conducted using two-factor analysis of variance in a generalized linear model framework utilizing generalized estimating equations (GEE) to account for the correlation between samples. The contraction rate was determined by the area change over time, and the decay time constant was calculated. A customized mechanical test system was used to determine gel stiffness and tensile strength. Gene expression was assessed using Human Fibrosis and Cell Motility PCR arrays.

Results

TA-treated gels had a significantly higher contraction rate, tensile strength and stiffness than the untreated gels. Proteinases involved in remodeling had increased expression in TA-treated gels of the patient group. Pro-fibrotic genes and ECM regulators, such as TGF-β, collagens and integrins, were down-regulated by TA, indicating that TA may work in part by decreasing fibrotic gene expression.

Conclusions

This study showed that TA affects cell-matrix interaction and suppresses fibrotic gene expression in the SSCT cells of CTS patients.

Electronic supplementary material

The online version of this article (10.1186/s12891-018-2260-y) contains supplementary material, which is available to authorized users.

Dual Effect of Hepatic Macrophages on Liver Ischemia and Reperfusion Injury during Liver Transplantation

Ischemia-reperfusion injury (IRI) is a major complication in liver transplantation (LT) and it is closely related to the recovery of grafts' function. Researches has verified that both innate and adaptive immune system are involved in the development of IRI and Kupffer cell (KC), the resident macrophages in the liver, play a pivotal role both in triggering and sustaining the sterile inflammation. Damage-associated molecular patterns (DAMPs), released by the initial dead cell because of the ischemia insult, firstly activate the KC through pattern recognition receptors (PRRs) such as toll-like receptors. Activated KCs is the dominant players in the IRI as it can secret various pro-inflammatory cytokines to exacerbate the injury and recruit other types of immune cells from the circulation. On the other hand, KCs can also serve in a contrary way to ameliorate IRI by upregulating the anti-inflammatory factors. Moreover, new standpoint has been put forward that KCs and macrophages from the circulation may function in different way to influence the inflammation. Managements towards KCs are expected to be the effective way to improve the IRI.

Ultrasound elastography for carpal tunnel pressure measurement: A cadaveric validation study

Carpal tunnel pressure is a key factor in the etiology of carpal tunnel syndrome. Numerous approaches have been conducted to measure carpal tunnel pressure. However, most techniques are invasive and take time and effort. We have developed an innovative approach to noninvasively assess the tunnel pressure by using the ultrasound surface wave elastography (USWE) technique. In a previous study it was shown that the shear wave speed in a tendon increased linearly with increasing tunnel pressure enclosed the tendon in a simple tendon model. This study aimed to examine the relationship between the carpal tunnel pressure and the shear wave speeds inside and outside the carpal tunnel in a human cadaveric model. The result showed that the shear wave speed inside the carpal tunnel increased linearly with created carpal tunnel pressure, while the shear wave speed outside the carpal tunnel remained constant. These findings suggest that noninvasive measurement of carpal tunnel pressure is possible by measuring the shear wave speed in the tendon. After fully establishing this technology and being applicable in clinic, it would be useful in the diagnosis of carpal tunnel syndrome. For that reason, further validation with this technique in both healthy controls and patients with carpal tunnel syndrome is required. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:477-483, 2018.

Blocking fibrotic signaling in fibroblasts from patients with carpal tunnel syndrome

Fibrosis of the subsynovial connective tissue (SSCT) in carpal tunnel syndrome (CTS) patients is increasingly recognized as an important aspect of CTS pathophysiology. In this study, we evaluated the effect of blocking profibrotic pathways in fibroblasts from the SSCT in CTS patients. Fibroblasts were stimulated with transforming growth factor β1 (TGF-β1), and then treated either with a specific fibrosis pathway inhibitor targeting TGF-β receptor type 1 (TβRI), platelet-derived growth factor receptor (PDGFR), epidermal growth factor receptor (EGFR), or vascular endothelial growth factor receptor (VEGFR). Fibrosis array and quantitative real-time polymerase chain reaction of fibrotic genes were evaluated. Array gene expression analysis revealed significant down-regulation of multiple fibrotic genes after treatment with TβRI, PDGFR, and VEGFR inhibitors. No array fibrotic genes were significantly down-regulated with EGFR inhibition. Further gene expression analysis of known CTS fibrosis markers collagen type I A2 (Col1), collagen type III A1 (Col3), connective tissue growth factor (CTGF), and SERPINE1 showed significantly down-regulation after TβRI inhibition. In contrast, VEGFR inhibition significantly down-regulated CTGF and SERPINE1, whereas, PDGFR and EGFR inhibition significantly down-regulated Col3. Taken together the inhibition of TβRI appears to be the primary mediator of fibrotic gene expression in fibroblasts from CTS patients. TGF-β/Smad activity was further evaluated, and as expected inhibition of Smad activity was significantly down-regulated after inhibition of TβRI, but not with PDGFR, VEGFR, or EGFR inhibition. These results indicate that local therapies specifically targeting TGF-β signaling alone or in combination offer the potential of a novel local antifibrosis therapy for patients with CTS.

Immunohistochemical localization of sex hormone receptors in two Raillietina tapeworms

Sex hormone receptors play critical roles in development and reproduction. However, it is not known whether they exist in Raillietina tapeworms, and if they do, whether they have a similar function to that in vertebrates. We examined the immunohistochemical distributions of androgen receptors (ARs), estrogen receptors (ERs), and progesterone receptors (PRs) in the tissues of two tapeworm species: Raillietina echinobothrida and Raillietina tetragona. Immunopositive ARs were found in the entire reproductive system of R. echinobothrida, including the testes, ovaries, and oocysts, and weakly immunopositive ERs and PRs were found in the testes, ovaries, and oocysts. Immunopositive ARs were also found throughout the entire reproductive system of R. tetragona, including the testes, ovaries, and oocysts, and weakly immunopositive ERs were in the testes and oocysts; the PRs were distributed in an immunonegative manner. The results show that androgens and their receptors play critical roles in reproductive system development in the two tapeworms. The immunoreactivity and tissue localizations of the sex hormone receptors suggest that, in both species, they have similar functions as in vertebrates, and modulate reproduction.

Effect of wrist and interphalangeal thumb movement on zone T2 flexor pollicis longus tendon tension in a human cadaver model

INTRODUCTION

Therapy after flexor pollicis longus (FPL) repair typically mimics finger flexor management, but this ignores anatomic and biomechanical features unique to the FPL.

PURPOSE OF THE STUDY

We measured FPL tendon tension in zone T2 to identify biomechanically appropriate exercises for mobilizing the FPL.

METHODS

Eight human cadaver hands were studied to identify motions that generated enough force to achieve FPL movement without exceeding hypothetical suture strength.

RESULTS

With the carpometacarpal and metacarpophalangeal joints blocked, appropriate forces were produced for both passive interphalangeal (IP) motion with 30° wrist extension and simulated active IP flexion from 0° to 35° with the wrist in the neutral position.

DISCUSSION

This work provides a biomechanical basis for safely and effectively mobilizing the zone T2 FPL tendon.

CONCLUSION

Our cadaver study suggests that it is safe and effective to perform early passive and active exercise to an isolated IP joint.

LEVEL OF EVIDENCE

NA.

Assessing Finger Joint Biomechanics by Applying Equal Force to Flexor Tendons In Vitro Using a Novel Simultaneous Approach

Background

The flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) are critical for finger flexion. Although research has recently focused on these tendons’ coactivity, their contributions in different tasks remain unclear. This study created a novel simultaneous approach to investigate the coactivity between the tendons and to clarify their contributions in different tasks.

Methods

Ten human cadaveric hands were mounted on our custom frame with the FDS and FDP of the third finger looped through a mechanical pulley connected to a force transducer. Joint range of motion, tendon excursion and loading force were recorded during individual joint motion and free joint movement from rest to maximal flexion. Each flexor tendon’s moment arm was then calculated.

Results

In individual motions, we found that the FDP contributed more than the FDS in proximal interphalangeal (PIP) joint motion, with an overall slope of 1.34 and all FDP-to-FDS excursion (P/S) ratios greater than 1.0 with force increase. However, the FDP contributed less than the FDS in metacarpophalangeal (MCP) joint motion, with an overall slope of 0.95 and P/S ratios smaller than 1.0 throughout the whole motion except between 1.9% and 13.1% force. In free joint movement, the FDP played a greater role than the FDS, with an overall ratio of 1.37 and all P/S ratios greater than 1.0.

Conclusions

The new findings include differences in finger performance and excursion amounts between the FDS and FDP throughout flexion. Such findings may provide the basis for new hand models and treatments.

Identification of the Position and Thickness of the First Annular Pulley in Sonographic Images

The purpose was to identify the A1 pulley's exact location and thickness by comparing measurements from a clinical high-frequency ultrasound scanner system (CHUS), a customized high-frequency ultrasound imaging research system (HURS) and a digital caliper. Ten cadaveric hands were used. We explored the pulley by layers, inserted guide pins and scanned it with the CHUS. After identifying the pulley, we measured each long finger's thickness using the CHUS and excised the pulley to measure its thickness with a digital caliper and the HURS. The thin hypo-echoic layer was revealed to be the synovial fluid space, and the pulley appears hyper-echoic regardless of scan direction. We also defined the pulley's boundaries. Moreover, the CHUS provided a significantly lower measurement of the pulley's thickness than the digital caliper and HURS. Likewise, based on the digital caliper's measurement, the HURS had significantly lower mean absolute and relative errors than the CHUS.

PAPP-A affects tendon structure and mechanical properties

Pregnancy-associated plasma protein-A (PAPP-A) serves to increase local insulin-like growth factor (IGF) stimulation of proliferation and differentiation in many tissues through proteolysis of inhibitory IGF-binding proteins. The purpose of this study was to investigate the effects of PAPP-A on tendon structure and mechanical properties. A total of 30 tails from 6-month-old mice were tested with 10 tails in each of following groups: PAPP-A knockout (KO), skeletal-specific PAPP-A overexpressing transgenic (Tg) and wild type (WT). Morphologically, the total tail cross-sectional area (CSA), individual tissue CSAs of bone, muscle and tendon, and fascicle diameter were measured. A fascicle pullout test was performed to assess stiffness and strength of interfascicular structures. Fascicles were mechanically characterized through low and high displacement rate uniaxial tension tests providing modulus at each rate, hysteresis area and stress relaxation ratio. The KO mice had a smaller total tail CSA (p<0.05), fascicle diameter (p<0.05), absolute tendon CSA (p<0.05), fast and slow stiffness (p<0.05 for both) and larger hysteresis area (p<0.05) compared to WT and Tg mice. On the other hand, the Tg mice had a larger fascicle diameter (p<0.05), absolute tendon CSA (p<0.05), higher interfascicular strength and stiffness (p<0.05) and lower fascicular modulus at low displacement rates (p<0.05) compared to WT and KO mice. Tg mice also had larger total tail CSA area (p<0.05) and smaller hysteresis area (p<0.05) than KO mice, and larger normalized tendon CSA (p<0.05) than WT mice. Based on these data, we conclude that PAPP-A affects fascicle structure, thereby affecting tendon phenotype.

Collagen gel contraction as a measure of fibroblast function in an animal model of subsynovial connective tissue fibrosis

Carpal tunnel syndrome (CTS) is a peripheral neuropathy characterized by non-inflammatory fibrosis of the subsynovial connective tissues (SSCT). A rabbit model of CTS was developed to test the hypothesis that SSCT fibrosis causes the neuropathy. We used a cell-seeded collagen-gel contraction model to characterize the fibrosis in this model in terms of cellular mechanics, specifically to compare the ability of SSCT cells from the rabbit model and normal rabbits to contract the gel, and to assess the effect of transforming growth factor-β1,which is upregulated in CTS, on these cells. SSCT fibrosis was induced in six retired breeder female rabbits which were sacrificed at 6 weeks (N = 3) and 12 weeks (n = 3). An additional two rabbits served as controls. SSCT was harvested according to a standard protocol. Gels seeded with SSCT cells from rabbits sacrificed at 6 weeks had significantly higher tensile strength (p < 0.001) and Young's modulus (p < 0.001) than gels seeded with cells from rabbits sacrificed at 12 weeks or control animals. TGF-β1 significantly increased the decay time constant (p < 0.001), tensile strength (p < 0.001), and Young's modulus (p < 0.001) regardless of the cell source. This model may be useful in screening therapeutic agents that may block SSCT fibrosis, identifying possible candidates for CTS treatment.

Efficacy of intervertebral disc regeneration with stem cells - a systematic review and meta-analysis of animal controlled trials

Management of intervertebral disc (IVD) degenerative disease is challenging, as it is accompanied by irreversible loss of IVD cells. Stem cell transplantation to the disc has shown promise in decelerating or arresting the degenerative process. Multiple pre-clinical animal trials have been conducted, but with conflicting outcomes. To assess the effect of stem cell transplantation, a systematic review and meta-analysis was performed. A comprehensive literature search was conducted through Week 3, 2015. Inclusion criteria consisted of controlled animal trials. Two reviewers screened abstracts and full texts. Disagreements were resolved by a third reviewer. Random effects models were constructed to pool standardized mean difference (SMD). Twenty two studies were included; nine of which were randomized. Statistically significant differences were found with the stem cell group exhibiting increased disc height index (SMD=3.64, 95% confidence interval (CI): 2.49, 4.78; p<0.001), increased MRI T2 signal intensity (SMD=2.28, 95% CI: 1.48, 3.08; p<0.001), increased Type II collagen mRNA expression (SMD=3.68, 95% CI: 1.66, 5.70; p<0.001), and decreased histologic disc degeneration grade (SMD=-2.97, 95% CI: -3.97, -1.97; p<0.001). There was statistical heterogeneity between studies that could not be explained with pre-planned subgroup analyses based on animal species, study designs, and transplanted cell types. Stem cells transplanted to the IVD in quadruped animals decelerate or arrest the IVD degenerative process. Further studies in human clinical trials will be needed to understand if such benefit can be translated to bipedal humans.

Effects of different extents of pulley release on tendon excursion efficiency and tendon moment arms

To compare the excursion efficiency and moment arms of flexor digitorum superficialis (FDS) and profundus (FDP) among different conditions of pulley integrity related to trigger finger treatment, cadaveric fingers were first tested with an intact pulley system, and then the first (A1) and second (A2) annular pulleys were released gradually from the proximal to distal part. Linear position sensors and a motion capture system were used to measure the tendon excursion and joint rotation simultaneously. The tendon excursion efficiency was defined as the range of motion of the involved joints per unit of tendon excursion, and the tendon moment arm was determined by the slope of the linear fitting result of tendon excursion versus metacarpophalangeal (MCP) joint rotation. No significant differences were found between the release of the A1 pulley and the release extending to half the proximal part of the A2 pulley in the FDP excursion efficiency and the moment arms of FDS and FDP with respect to the MCP joint. These results imply that the release could extend to half the proximal A2 pulley, if necessary, without significantly decreasing the FDP excursion efficiency and increasing the moment arms of FDS and FDP with respect to the MCP joint.

TGF-β signaling regulates fibrotic expression and activity in carpal tunnel syndrome

Fibrosis of the subsynovial connective tissue (SSCT) is a predominant feature of carpal tunnel syndrome (CTS). While the nature of CTS has been extensively studied, little is known about the etiology of this disease. We investigated SSCT tissue from patients with CTS and control subjects using fibrosis arrays and cell culture analysis. Twofold changes in fibrotic gene expression were found in multiple genes from patient SSCT using fibrosis arrays. This data was confirmed via qRT-PCR on a subset of genes; collagen I (Col1), collagen III (Col3), connective tissue growth factor (CTGF), transforming growth factor β (TGF-β), and SMAD3 (P < 0.05) which significantly corroborate the fold changes found in the fibrosis arrays. To further explore the nature of SSCT fibrosis, cells were isolated from patient and control tissue. Col1, Col3, TGF-β, and SMAD3 were highly expressed in patient SSCT fibroblasts as compared to control (P < 0.05). Further, fibrotic genes expression was decreased by inhibiting TGF-β receptor I (TβRI) activity (P < 0.05). TGF-β second messenger SMAD activity was significantly activated in SSCT fibroblasts from patients and this activation was abrogated by inhibiting TβRI signaling (P < 0.05). These findings suggest that blocking TGF-β signaling may be an important therapeutic approach to treating the underlying fibrosis of SSCT in CTS patients.

Clinical and pathological correlates of severity classifications in trigger fingers based on computer-aided image analysis

Background

The treatment of trigger finger so far has heavily relied on clinicians’ evaluations for the severity of patients’ symptoms and the functionality of affected fingers. However, there is still a lack of pathological evidence supporting the criteria of clinical evaluations. This study’s aim was to correlate clinical classification and pathological changes for trigger finger based on the tissue abnormality observed from microscopic images.

Methods

Tissue samples were acquired, and microscopic images were randomly selected and then graded by three pathologists and two physicians, respectively. Moreover, the acquired images were automatically analyzed to derive two quantitative parameters, the size ratio of the abnormal tissue region and the number ratio of the abnormal nuclei, which can reflect tissue abnormality caused by trigger finger. A self-developed image analysis system was used to avoid human subjectivity during the quantification process. Finally, correlations between the quantitative image parameters, pathological grading, and clinical severity classification were assessed.

Results

One-way ANOVA tests revealed significant correlations between the image quantification and pathological grading as well as between the image quantification and clinical severity classification. The Cohen’s kappa coefficient test also depicted good consistency between pathological grading and clinical severity classification.

Conclusions

The criteria of clinical classification were found to be highly associated with the pathological changes of affected tissues. The correlations serve as explicit evidence supporting clinicians in making a treatment strategy of trigger finger. In addition, our proposed computer-aided image analysis system was considered to be a promising and objective approach to determining trigger finger severity at the microscopic level.

Collagen gel contraction as a measure of fibroblast function in carpal tunnel syndrome

Noninflammatory subsynovial connective tissue (SSCT) fibrosis with nerve compression is a prominent feature of carpal tunnel syndrome (CTS). Studies have shown that SSCT matrix synthesis and material property changes in CTS are associated with increased activity of transforming growth factor (TGF)-β1. The aim of this study were to (1) investigate the ability of SSCT fibroblasts from CTS patients and unaffected individuals to contract a collagen gel ring and (2) determine how the addition of TGF-β1 affects this ability. SSCT fibroblasts from three normal cadavers and three age-matched female patients who had undergone surgery for CTS were used. Results showed patient cell-seeded gels had a significantly higher contraction rate (p < 0.001) than control cells, and fully contracted gel rings possessed a significantly higher tensile strength (p = 0.003) and stiffness (p < 0.001). Furthermore, TGF-β1 significantly intensified contraction rate (p < 0.001), tensile strength (p < 0.001), and stiffness (p < 0.001). In conclusion, SSCT cells from normal donors and CTS patients contract collagen gel rings differently, and this ability is affected by TGF-β1 treatment. This cell-seeded collagen gel model may be useful for developing new methods of stopping or eliminating the effect of TGF-β1 on the SSCT fibroblasts and surrounding matrix, which might aid in the identification of medical treatment for CTS.

The effect of low- and high-velocity tendon excursion on the mechanical properties of human cadaver subsynovial connective tissue

Fibrosis of the subsynovial connective tissue (SSCT) in the carpal tunnel is the most common histological finding in carpal tunnel syndrome (CTS). Fibrosis may result from damaged SSCT. Previous studies found that with low-velocity (2 mm/s), tendon excursions can irreversibly damage the SSCT. We investigated the effect of tendon excursion velocity in the generation of SSCT damage. Nine human cadaver wrists were used. Three repeated cycles of ramp-stretch testing were performed simulating 40%, 60%, 90%, and 120% of the middle finger flexor tendon superficialis physiological excursion with an excursion velocity of 60 mm/s. Energy and force were calculated and normalized by values obtained in the first cycle for each excursion level. Data were compared with low-velocity excursion data. For high-velocity excursions, a significant drop in the excursion energy ratio was first observed at an excursion level of 60% physiological excursion (p < 0.024) and that for low-velocity excursions was first observed at 90% physiological excursion (p < 0.038). Furthermore, the energy ratio was lower at 60% for high velocities (p ≤ 0.039). Increasing velocity lowers the SSCT damage threshold. This finding may be relevant for understanding the pathogenesis of SSCT fibrosis, such as that accompanying CTS, and a relationship with occupational factors.

Automatic and Quantitative Measurement of Collagen Gel Contraction Using Model-Guided Segmentation

Quantitative measurement of collagen gel contraction plays a critical role in the field of tissue engineering because it provides spatial-temporal assessment (e.g., changes of gel area and diameter during the contraction process) reflecting the cell behaviors and tissue material properties. So far the assessment of collagen gels relies on manual segmentation, which is time-consuming and suffers from serious intra- and inter-observer variability. In this study, we propose an automatic method combining various image processing techniques to resolve these problems. The proposed method first detects the maximal feasible contraction range of circular references (e.g., culture dish) and avoids the interference of irrelevant objects in the given image. Then, a three-step color conversion strategy is applied to normalize and enhance the contrast between the gel and background. We subsequently introduce a deformable circular model (DCM) which utilizes regional intensity contrast and circular shape constraint to locate the gel boundary. An adaptive weighting scheme was employed to coordinate the model behavior, so that the proposed system can overcome variations of gel boundary appearances at different contraction stages. Two measurements of collagen gels (i.e., area and diameter) can readily be obtained based on the segmentation results. Experimental results, including 120 gel images for accuracy validation, showed high agreement between the proposed method and manual segmentation with an average dice similarity coefficient larger than 0.95. The results also demonstrated obvious improvement in gel contours obtained by the proposed method over two popular, generic segmentation methods.

Is progressive early digit mobilization intervention beneficial for patients with external fixation of distal radius fracture? A pilot randomized controlled trial

OBJECTIVE

To investigate whether progressive early digit mobilization resulted in better outcomes for hand stiffness and related functional results, as well as the effects on the bone healing process.

DESIGN

Prospective, pilot randomized controlled trial.

SETTING

A university hospital in southern Taiwan.

PARTICIPANTS

Twenty-two patients with distal radius fracture randomized into two groups: early digit mobilization or control.

INTERVENTIONS

The intervention group received 45 minutes per treatment session and three sessions per week until the external fixator was removed 6 weeks after fracture. The control group received usual home programmes. After removing fixators, both groups received regular rehabilitation programmes until 12 weeks after surgery.

MAIN MEASURES

Hand strength, dexterity and functional outcomes were obtained using a dynamometer, Purdue pegboard and self-report assessment, respectively, and X-rays of the distal radius were taken to reveal bone healing 1, 3, 6 and 12 weeks after surgery. A motion tracking system measured various kinematic parameters.

RESULTS

The recovery rates between the groups showed statistically significant differences in both thumb workspace (81.55% vs. 69.54%, P = 0.04) and finger workspace (89.22% vs. 59.97%, P = 0.03) 12 weeks after injury. However, no statistical differences were found in finger dexterity, strength and self-reported outcomes. The radiographic assessment showed no significant differences between the groups for radial inclination, radial height and volar tilt throughout the examinations.

CONCLUSIONS

The findings suggest that early rehabilitative intervention for digits is applicable for distal radius fracture treatment, and does not produce additional bone deformities.

Auditory efferent dysfunction in normal-hearing chronic idiopathic tinnitus

OBJECTIVE

To investigate the function of the auditory efferent system in patients with chronic idiopathic tinnitus, but normal pure-tone audiograms.

METHODS

We studied 15 subjects with normal hearing that had experienced either unilateral or bilateral persistent tinnitus for at least 3 months. The ears of the 15 subjects were classified into tinnitus-positive-ear (TPE) and tinnitus-negative-ear (TNE) groups. The control-ear group (CE) comprised the ears of 15 subjects with normal hearing and no tinnitus. We measured different types of otoacoustic emissions (OAEs), including spontaneous (SOAEs), transient evoked (TEOAEs), and distortion product (DPOAEs). We also analyzed contralateral suppression of OAEs and auditory brainstem responses (ABRs). Data were compared among TPE, TNE, and CE groups.

RESULTS

The data associated with cochlear mechanics, including the prevalence of SOAEs, the number of SOAE peaks, and the overall TEOAE responses in the absence of a contralateral stimulus, were not significantly different among the TPE, TNE, and CE groups. In the TPE group, contralateral stimuli failed to significantly suppress overall TEOAEs, and contralateral suppression of DPOAEs was significantly reduced over a limited frequency range. Furthermore, the TPE group showed prolonged latencies in waves III and V of ABRs.

CONCLUSION

This study demonstrated that abnormal contralateral suppression of OAEs and ABRs indicated a dysfunction in the ipsilateral efferent medial olivocochlear system; this might play a role in normal-hearing tinnitus.

Photoconduction mechanism of oxygen sensitization in InN nanowires

The photoconduction (PC) mechanism in indium nitride (InN) nanowires (NWs) has been investigated via environment-, temperature-, and power-dependent measurements. The adsorbed oxygen-induced modulation of the surface state is proposed to be the leading factor in the long lifetime or high gain transport and in sensitizing photocurrent generation in the InN NWs. The electron trapping effect by adsorbed oxygen can be verified by the increased activation energy from 33 ± 4 (in vacuum) to 58 ± 2 meV (in oxygen). The observed supralinear power dependence of photocurrent also suggests the presence of acceptor states that influence the carrier recombination behavior and compensate the thermal carriers in the InN NWs. The potential influence of native oxide on the molecule-sensitive PC in this nitride nanomaterial is also inferred.

Model-based segmentation of flexor tendons from magnetic resonance images of finger joints

Trigger finger is a common hand disease, causing swelling, painful popping and clicking in moving the affected finger joint. To better evaluate patients with trigger finger, segmentation of flexor tendons from magnetic resonance (MR) images of finger joints, which can offer detailed structural information of tendons to clinicians, is essential. This paper presents a novel model-based method with three stages for automatically segmenting the flexor tendons. In the first stage, a set of tendon contour models (TCMs) is initialized from the most proximal cross-sectional image via two-step ellipse estimation. Each of the TCMs is then propagated to its distally adjacent image by affine registration. The propagation is sequentially performed along the proximal-distal direction until the most distal image is reached, as the second stage of segmentation. The TCMs on each cross-sectional image are refined in the last stage with the snake deformation. MR volumes of three subjects were used to validate the segmentation accuracy. Compared with the manual results, our method showed good accuracy with small average margins of errors (within 0.5 mm) and large overlapping ratio (dice similarity coefficient above 0.8). Overall, the proposed method has great potential for morphological change assessment of flexor tendons and pulley-tendon system modeling for image guided surgery.

Computational modeling of ultraviolet disinfection

The efficient design of ultraviolet light (UV) systems for water and wastewater treatment requires detailed knowledge of the patterns of fluid motion that occur in the disinfection channel. This knowledge is increasingly being obtained using Computational Fluid Dynamics (CFD) software packages that solve the equations governing turbulent fluid-flow motion. In this work, we present predictions of the patterns of flow and the extent of disinfection in a conventional reactor consisting of an open channel with an array of UV lamps placed with their axes perpendicular to the direction of flow. It is shown that the resulting flow is inherently unsteady due to the regular shedding of vortices from the submerged lamps. It is also shown that the accurate prediction of the hydraulic residence time and, consequently, the extent of disinfection is strongly dependent on the ability of the CFD method to capture the occurrence and strength of the vortex shedding, and its effects on the turbulent mixing processes.

Neural correlates of antisaccade deficits in schizophrenia, an fMRI study

Schizophrenia patients were known to have oculomotor abnormalities for decades and several studies had found antisaccade impairment to be a biological marker of schizophrenia. In this study, we used functional magnetic resonance imaging (fMRI) to investigate the neural circuits responsible for antisaccade deficits in schizophrenia. Ten normal controls and 10 DSM-IV schizophrenia patients performed antisaccade tasks and control tasks during fMRI. Data were analyzed and task-specific activations were identified using Statistical Parametric Mapping (SPM-2). In normal subjects, antisaccade tasks activated bilateral frontal eye fields, supplementary eye fields, inferior frontal gyrus, superior parietal lobules, inferior parietal lobules, occipital visual cortex, cerebellum, thalamus, and lentiform nuclei (P<0.001). By contrast, schizophrenia patients failed to show activation in bilateral lentiform nucleus, bilateral thalamus, and left inferior frontal gyrus during antisaccade performance. Our findings suggest that schizophrenic antisaccade deficits are associated with dysfunction of fronto-striatal-thalamo-cortical circuits previously demonstrated to be responsible for suppression of the reflexive saccade. Left inferior frontal gyrus, which was known to be responsible for response inhibition on "go/no-go" testing, also plays an important role in schizophrenic antisaccade deficit.