Effect of Reneurorrhaphy of Distal Coaptation on Nerve Regeneration After Nerve Grafting: Animal Experimental Study

BACKGROUND

Previous studies have shown that reneurorrhaphy of a distal coaptation at an appropriate time after nerve grafting can upregulate neurotrophins in rat spinal cord neurons. The objective of the present study was to evaluate the effect this procedure has on peripheral nerve regeneration.

METHODS

Fifteen Wistar rats were randomly assigned to sham-surgery, control, or experimental (transection and rerepair of the distal coaptation of the grafting nerve) groups. The sciatic nerve was evaluated via electromyogram and histology at 20 weeks.

RESULTS

When crossing the proximal coaptation of the grafting nerve, the electromyogram and histologic evaluations did not significantly differ between experimental and control groups (P > 0.05). In contrast, crossing the distal coaptation yielded significantly better values (P < 0.05) in the experimental group.

CONCLUSIONS

These results indicate that reneurorrhaphy of the distal coaptation at an appropriate time after nerve grafting can improve nerve function and facilitate the regeneration of axons.

Improved functional outcome in NTOS patients following resection of the subclavius muscle with radiological signs of nerve impingement: indication of participation of the subclavius in brachial plexus compression

OBJECTIVE

Both clinical and radiological reports have suggested that the subclavius, a muscle in the costoclavicular space of the thoracic outlet, participates in neurogenic thoracic outlet syndrome (NTOS) in some instances, especially during movements narrowing the costoclavicular space. Magnetic resonance imaging can identify subclavius muscles with signs of nerve impingement, yet the impact of the subclavius in such situations remains unclear. Therefore, the authors investigated whether dividing or sparing the subclavius characterized by nerve impingement on MRI would affect surgical outcomes.

METHODS

In this retrospective nonrandomized study, authors analyzed all NTOS patients with a subclavius muscle characterized by nerve impingement on MRI (loss of normal fat planes surrounding the brachial plexus) in the period between March 2010 and November 2016. Patients were divided into two groups: the sparing group, in which patients had undergone conventional supraclavicular scalenectomy and first rib resection (FRR), and the dividing group, in which patients had undergone scalenectomy, FRR, and subclavius dividing using a modified supraclavicular incision. The Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, a shoulder range of motion subscale (DASH items 6, 12-15, and 19) concerning overhead activities that can significantly narrow the costoclavicular space, postoperative MRI studies, and patient self-assessments were used to assess surgical outcomes. Univariate and multivariate analyses were conducted to identify independent factors associated with subscale scores.

RESULTS

From a total of 261 patients screened, 71 were eligible for study inclusion. Compared with the sparing group (33 patients), the dividing group (38 patients) had similar postoperative DASH scores and self-assessments but better subscale scores (9.50 ± 2.76 vs 11.94 ± 2.87, p = 0.0005). Postoperative MRI on hyperabduction showed that the brachial plexus became surrounded by normal fat tissue in the costoclavicular space in the diving group but still had signs of impingement from the untreated subclavius muscle in the sparing group. This observation agreed with a better functional recovery in terms of overhead activities in the dividing group, which was reflected by better subscale scores. Multivariate analyses indicated that the type of treatment and symptom duration prior to surgery influenced the subscale scores independently.

CONCLUSIONS

This study revealed that an untreated radiological nerve-compressing subclavius muscle could lead to a relatively lower degree of recovery in the ability to perform overhead activities for NTOS patients postoperatively, suggesting that such subclavius muscles may participate in positional brachial plexus compression during movements narrowing the costoclavicular space. Dividing the muscles could decompress the costoclavicular space more effectively and may lead to better functional recovery.

3D-printed scaffolds of mesoporous bioglass/gliadin/polycaprolactone ternary composite for enhancement of compressive strength, degradability, cell responses and new bone tissue ingrowth

BACKGROUND

Due to the increasing number of patients with bone defects, bone nonunion and osteo-myelitis, tumor and congenital diseases, bone repair has become an urgent problem to be solved.

METHODS

In this study, the 3D-printed scaffolds of ternary composites containing mesoporous bioglass fibers of magnesium calcium silicate (mMCS), gliadin (GA) and polycaprolactone (PCL) were fabricated using a 3D Bioprinter.

RESULTS

The compressive strength and in vitro degradability of the mMCS/GA/PCL composites (MGPC) scaffolds were improved with the increase of mMCS content. In addition, the attachment and proliferation of MC3T3-E1 cells on the scaffolds were significantly promoted with the increase of mMCS content. Moreover, the cells with normal phenotype attached and spread well on the scaffolds surfaces, indicating good cytocompatibility. The scaffolds were implanted into the femur defects of rabbits, and the results demonstrated that the scaffold containing mMCS stimulated new bone formation and ingrowth into the scaffolds through scaffolds degradation in vivo. Moreover, the expression of type I collagen into scaffolds was enhanced with the increase of mMCS content.

CONCLUSION

The 3D-printed MGPC scaffold with controllable architecture, good biocompatibility, high compressive strength, proper degradability and excellent in vivo osteogenesis has great potential for bone regeneration.

[Technical specification for clinical application of critical ultrasonography]

Critical ultrasonography(CUS) is different from the traditional diagnostic ultrasound, the examiner and interpreter of the image are critical care medicine physicians. The core content of CUS is to evaluate the pathophysiological changes of organs and systems and etiology changes. With the idea of critical care medicine as the soul, it can integrate the above information and clinical information, bedside real-time diagnosis and titration treatment, and evaluate the therapeutic effect so as to improve the outcome. CUS is a traditional technique which is applied as a new application method. The consensus of experts on critical ultrasonography in China released in 2016 put forward consensus suggestions on the concept, implementation and application of CUS. It should be further emphasized that the accurate and objective assessment and implementation of CUS requires the standardization of ultrasound image acquisition and the need to establish a CUS procedure. At the same time, the standardized training for CUS accepted by critical care medicine physicians requires the application of technical specifications, and the establishment of technical specifications is the basis for the quality control and continuous improvement of CUS. Chinese Critical Ultrasound Study Group and Critical Hemodynamic Therapy Collabration Group, based on the rich experience of clinical practice in critical care and research, combined with the essence of CUS, to learn the traditional ultrasonic essence, established the clinical application technical specifications of CUS, including in five parts: basic view and relevant indicators to obtain in CUS; basic norms for viscera organ assessment and special assessment; standardized processes and systematic inspection programs; examples of CUS applications; CUS training and the application of qualification certification. The establishment of applied technology standard is helpful for standardized training and clinical correct implementation. It is helpful for clinical evaluation and correct guidance treatment, and is also helpful for quality control and continuous improvement of CUS application.

Transcriptomic Landscapes of Immune Response and Axonal Regeneration by Integrative Analysis of Molecular Pathways and Interactive Networks Post-sciatic Nerve Transection

Potential interaction between immune response and axonal regeneration has recently attracted much attention in peripheral nervous system (PNS). Previously, global mRNA expression changes in proximal nerve segments were profiled and merely focused on the differentially change of the key biological processes. To further uncover molecular mechanisms of peripheral nerve regeneration, here we focused on the interaction between immune response and axonal regeneration that associated with specific molecular pathways and interactive networks following sciatic nerve transection. To offer an outline of the specific molecular pathways elaborating axonal regeneration and immune response, and to figure out the molecular interaction between immune response and axonal regeneration post-sciatic nerve transection, we carried out comprehensive approaches, including gene expression profiling plus multi-level bioinformatics analysis and then further experimental validation. Alcam, Nrp1, Nrp2, Rac1, Creb1, and Runx3 were firstly considered as the key or hub genes of the protein-protein interaction (PPI) network in rat models of sciatic nerve transection, which are highly correlated with immune response and axonal regeneration. Our work provide a new way to figure out molecular mechanism of peripheral nerve regeneration and valuable resources to figure out the molecular courses which outline neural injury-induced micro-environmental variation to discover novel therapeutic targets for axonal regeneration.

Matrine inhibits TPC-1 human thyroid cancer cells via the miR-21/PTEN/Akt pathway

Papillary thyroid cancer (PTC) is the primary type of thyroid cancer and the most widespread endocrine malignancy. Matrine is a traditional Chinese medicine and has been demonstrated as a promising alternative drug for the treatment of TPC-1 human PTC. In the present study, the therapeutic effects and the underlying molecular mechanisms of matrine on TPC-1 cells were investigated. Treatment with matrine at the concentrations of 1, 2, 5, 10 and 20 mg/ml inhibited TPC-1 cell proliferation by up to 95.8% (for 20 mg/ml matrine). Flow cytometry indicated that treatment with 10 mg/ml matrine induced up to 61.8% apoptosis of the TPC-1 cells and the cell cycle was arrested at the G0/G1 phase following treatment with matrine (2, 5 and 10 mg/ml) for 48 h. Quantitative polymerase chain reaction indicated that the expression of microRNA (miR)-21 was downregulated and phosphatase and tensin homolog (PTEN) mRNA levels increased up to 1.66-fold following treatment with matrine, and RAC-α serine/threonine-protein kinase (Akt) mRNA levels were downregulated 0.34-fold following treatment with 5 mg/ml matrine, compared with the normal control group. Western blot analysis indicated that matrine at 2 and 5 mg/ml increased levels of the miR-21 target PTEN and decreased the levels of phosphorylated (p)Akt. Furthermore, miR-21 mimic transfection decreased the expression levels of PTEN and increased the levels of pAkt. These results suggested that the miR-21/PTEN/Akt pathway may be one of the mechanisms by which matrine induces apoptosis and cell cycle arrest in TPC-1 thyroid cancer cells. Matrine is an alternative potential drug for the treatment of thyroid cancer.

Fas Ligand Gene (Faslg) Plays an Important Role in Nerve Degeneration and Regeneration After Rat Sciatic Nerve Injury

Wallerian degeneration (WD) is associated with changes in the expression levels of a large number of genes. However, the effects of these up- or down-regulated genes are poorly understood. We have reported some key factors that are differentially regulated during WD in our previous research. Here, we explored the roles of Fas ligand gene (Faslg) in WD after rat sciatic nerve injury. The data showed that Faslg was up-regulated in injured nerves. Expression changed of Faslg in Schwann cells (SCs) resulted in alterations in the release of related factors. Silencing or overexpression of Faslg affected SC proliferation, migration, and apoptosis through β-catenin, nuclear factor-κB (NF-κB), and caspase-3 pathways in vivo and in vitro. Our data suggest that Faslg is a key regulatory gene that affects nerve repair and regeneration in peripheral nerve injury. This study sheds new light on the effects of Faslg on peripheral nerve degeneration and/or regeneration.

[The expressions of VEGF and VEGFR signaling pathway in the bone marrow mononuclear cells with chronic mountain sickness]

Objective: This study was aimed at investigating the levels and relationships of vascular endothelial growth factor (VEGF) and its receptor(VEGFR) in the bone marrow mononuclear cells (MNC) of chronic mountain sickness (CMS). Methods: A total of 34 patients with CMS and 30 controls residing at altitudes of 3 000-4 500 m were recruited for this study. The levels of VEGF, VEGFR1 and VEGFR2 in bone marrow MNC were detected by flow cytometry technique and RT-qPCR. Results: The percentage of VEGFR2 positive cells in the bone marrow MNC of CMS were higher than that of the controls[20.7% (8.1%, 67.6%) vs 8.1% (2.2%, 14.9%), P<0.05], but that of VEGFR1-positive and VEGF-positive were similar in CMS and controls. The mRNA levels of VEGFR2 were higher in the bone marrow MNC of CMS than in the controls[1.7(1.0, 5.1) vs 1.0(0.4, 2.7), P<0.05], while VEGF and VEGFR1 mRNA levels were similar between the two groups. The percentage of VEGFR2 positive cells in CMS were significantly correlated with hemoglobin (r=0.453, P=0.007) and the percentage of VEGF-positive cells (r=0.373, P=0.030). Conclusions: Bone marrow MNC of CMS may show enhanced activity of the VEGF-VEGFR2 pathway, and it appears to be involved in the pathogenesis of CMS.

miR-182 promotes cell proliferation and invasion by inhibiting APC in melanoma

OBJECTIVE

Common treatment methods have shown a lack of therapeutic effect in melanoma, a type of malignant tumor. The pathogenesis of melanoma is not yet fully clear, therefore, search for a new treatment strategy is urgent. Recent studies have demonstrated that miR-182 is remarkably over-expressed in human melanoma. Our study aimed to explore the underlying mechanism of miR-182 on melanoma.

METHODS

In this study, the expression level of miR-182 was detected using RT-PCR in melanoma and adjacent tissues as well as in HEM-m, A375, A2058, and WM35 cell lines. Functions of miR-182 were investigated by using CCK-8 on cell proliferation, apoptosis, invasion, and cell cycle on A375 cells. Moreover, expression levels of Frz, Dsh, β-catenin, APC, Axin, GSK-3β, and CK1 were detected by Western blotting after knockdown and overexpression of miR-182. Overexpression of miR-182 and knockdown of APC was used to demonstrate regulated functions in melanoma.

RESULTS

Expression levels of miR-182 were significantly upregulated in melanoma tissues and cell lines. Overexpression of miR-182 promoted cell proliferation, migration, and invasion while inhibiting cell apoptosis and cell cycle in S phase. Overexpression of miR-182 upregulated expression levels of β-catenin and APC. Overexpression of miR-182 and knockdown of APC inhibited proliferation of melanoma cells and tumors.

CONCLUSION

Overexpression of miR-182 promotes cell proliferation and invasion by targeting to APC in melanoma. The pathogenesis of miR-182 and APC might provide therapeutic targets for treatment of melanoma in the molecular level.

[Value of evaluating the coronary collateral circulation by transluminal attenuation gradient in patients with chronic total occlusion and related influencing factors]

Objective: To observe the value of evaluating the coronary collateral circulation of chronic total occlusion (CTO) by transluminal attenuation gradient (TAG) and Rentrop grading, and analyze the influencing factors for coronary collateral circulation. Methods: A total of 179 CTO patients admitted to Beijing Anzhen hospital during June 2013 to August 2016 were included in this study.All patients received coronary computed tomographic angiography (CCTA) examination before coronary angiography.Finally, 75 patients (79 vessels) were enrolled.Patients were divided into two groups on the basis of Rentrop classification.The Rentrop 3 was defined as a well-developed coronary collateral circulation group, including 50 CTO vessels, Rentrop 2 or below was defined as poorly-developed collateral circulation group, including 29 vessels.TAG values in patients with various Rentrop grades were analyzed.Univariate and multivariate analysis were used to determine the predictors of collateral circulation. Results: TAG increased consistently in proportion to the angiographic extent of collateral flow (TAG was (-33.6±24.4), (-16.5±15.7) and (-12.8±15.8) HU/10 mm in patients with Rentrop grade 0 or 1, 2 and 3, respectively, P=0.007). Number of good collateral circulation vessels predicted by TAG≥15.6 HU/10 mm was 45(57.0%, 45/79), and 50 (63.3%, 50/79) by Rentrop grade (P=0.383). Prevalence of diabetes was significantly lower (20.8%(10/48) vs. 48.1%(13/27), P=0.01), while history of previous myocardial infarction (MI) was significantly higher (35.4%(17/48) vs. 11.1%(3/27), P=0.02) in patients with good collateral circulation than in patients with poor collateral circulation.The TAG of the good collateral circulation group was significantly higher than in poorly collateral circulation group ((-12.8±15.8) HU/10 mm vs. (-21.2±19.6) HU/10mm, P=0.041). Multiple logistic regression analysis revealed that history of MI (OR=0.196, 95%CI 0.041-0.936, P=0.041) and diabetes(OR=6.604, 95%CI 1.726-25.274, P=0.006) were independent predictors of coronary collateral circulation. Conclusions: TAG could be used to evaluate status of coronary collateral circulation.Presence of MI history and absence of diabetes history are the two independent predictors of well-developed coronary collateral circulation in CTO patients.

Effect of Spp1 on nerve degeneration and regeneration after rat sciatic nerve injury

BACKGROUND

Wallerian degeneration (WD) in injured peripheral nerves is associated with a large number of up- or down-regulated genes, but the effects of these changes are poorly understood. In our previous studies, we reported some key factors that are differentially expressed to activate nerve degeneration and regeneration during WD. Here, we determined the effects of secreted phosphoprotein 1 (Spp1) on WD after rat sciatic nerve injury.

RESULTS

Spp1 was upregulated from 6 h to 14 days after sciatic nerve injury. Altered expression of Spp1 in Schwann cells (SC) resulted in altered mRNA and protein expression levels for cytokines, c-Fos, PKCα and phospho-ERK/ERK and affected SC apoptosis in vitro. Silencing of Spp1 expression in SCs using siRNA technology reduced proliferation and promoted migration of SCs in vitro. By contrast, overexpression of Spp1 promoted proliferation and reduced migration in SCs in vitro. Differential expression of Spp1 after sciatic nerve injury in vivo altered the expression of cytokines, c-Fos, PKCα, and the p-ERK/ERK pathway.

CONCLUSIONS

Spp1 is a key regulatory factor that affects nerve degeneration and regeneration through c-Fos, PKCα and p-ERK/ERK pathways after rat sciatic nerve injury. These results shed new light on the role of Spp1 in nerve degeneration and regeneration during WD.