Biointerface engineering through amalgamation of gene technology and site-specific growth factor conjugation for efficient osteodifferentiation.

The development of bone implants through bioinspired immobilization of growth factors remains a key issue in the generation of biological interfaces, especially in enhancing osteodifferentiation ability. In this study, we developed a strategy for surface functionalization of poly(lactide-glycolide) (PLGA) and hydroxyapatite (HA) composite substrates through site-specific conjugation of bone morphogenetic protein 2 containing 3,4-hydroxyphenalyalanine (DOPA-BMP2) mediated by tyrosinase and sortase A (SrtA). Firstly, the growth factor BMP2-LPETG containing LPETG motif was successfully expressed in Escherichia coli through recombinant DNA technology. The excellent binding affinity of binding growth factor (DOPA-BMP2) was achieved by converting the tyrosine residue (Y) of YKYKY-GGG peptide into DOPA (X) by tyrosinase, which bound to the substrates. Then its GGG motif was specifically bound to the end of BMP2-LPETG mediated by SrtA. Therefore, the generated bioactive DOPA-BMP2/PLGA/HA substrates significantly promoted the osteogenic differentiation of MC3T3-E1 cells. Thanks to this microbial-assisted engineering approach, our work presents a facile and highly site-specific strategy to engineer biomimetic materials for orthopedics and dentistry by effectively delivering growth factors, peptides, and other biomacromolecules.

Reconstruction of a Complex Foot Injury With Free Remodeled Fibular Osteocutaneous Flap: A Case Report and Literature Review.

Management of complex foot injuries, which involve open fractures and severe trauma to soft tissues, represent a challenge to orthopedic clinicians. In the present case report, we treated a complex foot injury with a remodeled fibular osteocutaneous free flap to reconstruct the anterior and lateral areas of the foot. The flap survived completely. At the 9-month follow-up examination, bony union of the graft bone was identified by radiographic examination. The reconstructed foot could bear body weight, and the patient could maintain a bipedal gait without discomfort. The remodeled fibular osteocutaneous free flap provides an option for functional reconstruction of foot defects.

IFN-γR/STAT1 signaling in recipient hematopoietic antigen-presenting cells suppresses graft-versus-host disease.

The absence of IFN-γ receptor (IFN-γR) or STAT1 signaling in donor cells has been shown to result in reduced induction of acute graft-versus-host disease (GVHD). In this study, we unexpectedly observed increased activation and expansion of donor lymphocytes in both lymphohematopoietic organs and GVHD target tissues of IFN-γR/STAT1-deficient recipient mice, leading to rapid mortality following the induction of GVHD. LPS-matured, BM-derived Ifngr1-/- Stat1-/- DCs (BMDCs) were more potent allogeneic stimulators and expressed increased levels of MHC II and costimulatory molecules. Similar effects were observed in human antigen-presenting cells (APCs) with knockdown of Stat1 by CRISPR/Cas9 and treatment with a JAK1/2 inhibitor. Furthermore, we demonstrated that the absence of IFN-γR/STAT1 signaling in hematopoietic APCs impaired the presentation of exogenous antigens, while promoting the presentation of endogenous antigens. Thus, the indirect presentation of host antigens to donor lymphocytes was defective in IFN-γR/STAT1-deficient, donor-derived APCs in fully donor chimeric mice. The differential effects of IFN-γR/STAT1 signaling on endogenous and exogenous antigen presentation could provide further insight into the roles of the IFN-γ/STAT1 signaling pathway in the pathogenesis of GVHD, organ rejection, and autoimmune diseases.

Effect of Fentanyl as an Adjuvant to Brachial Plexus Block for Upper Extremity Surgeries: A Systematic Review and Meta-Analysis of RCTs.

Objective: To assess if the addition of fentanyl to brachial plexus block has an impact on anesthetic outcomes and complication rates in patients undergoing upper extremity surgeries. Methods: We explore the PubMed, Embase, ScienceDirect, CENTRAL, and Google Scholar databases for all randomized controlled trials (RCTs) comparing adjuvant fentanyl with placebo/no drug for patients undergoing upper extremity surgery under brachial plexus block. Outcomes assessed were onset, duration of sensory and motor anesthesia, complications, and postoperative analgesia scores. Meta-analysis was conducted utilizing a random-effects model. The risk of bias was assessed using the Cochrane Collaboration's risk of bias assessment tool 2. Certainty of evidence was assessed using GRADE. Subgroup analysis was conducted depending upon the approach of brachial plexus block and type of local anesthetic. Results: Twelve RCTs with 660 patients were included. Addition of fentanyl had no effect on onset of sensory anesthesia (11 studies; MD: 0.48; 95% CI: -1.81, 0.85; I 2 = 96%; p=0.48) but significantly shortened onset of motor anesthesia (8 studies; MD: -2.36; 95% CI: -3.99, -0.74; I 2 = 96%; p=0.48). Duration of sensory anesthesia (9 studies; MD: 82.81; 95% CI: 41.81, 123.81; I 2 = 99%; p < 0.0001) and motor anesthesia (7 studies; MD: 93.41; 95% CI: 42.35, 144.46; I 2 = 99%; p=0.0003) was significantly increased with addition of fentanyl. The certainty of evidence-based on GRADE was deemed to be moderate for both onset and duration of anesthesia. The incidence of overall complications (nausea/vomiting and pruritis) was significantly higher in the fentanyl group (7 studies; OR: 2.14; 95% CI: 1.04, 4.40; I 2 = 8%; p=0.04) but with low certainty of evidence. Conclusions: Adjuvant fentanyl with brachial plexus block improves the onset of motor anesthesia but not sensory anesthesia. The duration of both sensory and motor anesthesia is significantly prolonged with fentanyl by around 83-93 minutes. However, clinicians should be aware that complications such as nausea/vomiting and pruritis are increased twofold with the addition of the drug. Current evidence is limited risk of bias in the RCTs and high heterogeneity in the meta-analyses.

The homodigital neurovascular antegrade island flap for fingertip reconstruction in children.

We describe a homodigital neurovascular island flap for fingertip reconstruction in children and review the appearance and function of the reconstructed fingertips. Eleven children, with a mean age of 4 years (range: 2-7),who had sustained a fingertip injury with total or subtotal pulp loss were treated with a homodigital neurovascular island flap between 2007 and 2009. The flaps were harvested based on a single digital neurovascular bundle without further shortening of the distal phalanx. The average follow-up period was 15 months (range: 10-32 months). The clinical outcome evaluations included the defect size of the flap, the static two-point discrimination, total active motion (TAM) of the PIP and DIP joints and time to return to daily activities. Patient satisfaction with function and cosmesis were also evaluated. All of the flaps survived without any painful scar formation, hypersensitivity or cold intolerance and no interphalangeal joint contractures were noted. The average two point discrimination ranged from 3 to 4 mm, with an average of 3.4 mm. All the patients were satisfied with the function and appearance of the involved finger. Our study suggests that the homodigital neurovascular is a reliable choice of treatment for children fingertip defects.

Author Correction: Enhancing Cell Proliferation and Osteogenic Differentiation of MC3T3-E1 Pre-osteoblasts by BMP-2 Delivery in Graphene Oxide-Incorporated PLGA/HA Biodegradable Microcarriers.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

LncRNA XIST knockdown suppresses the malignancy of human nasopharyngeal carcinoma through XIST/miRNA-148a-3p/ADAM17 pathway in vitro and in vivo.

BACKGROUND: Long non-coding RNA (lncRNA) X inactivate-specific transcript (XIST) has been verified as an oncogenic gene in human cancers, including nasopharyngeal carcinoma (NPC). However, the role of XIST in NPC remains to be largely uncovered, as well as its underlying mechanism. METHODS: Expression of XIST, miR-148a-3p and ADAM17 was detected using qPCR and western blot assay. Cell proliferation and apoptosis assay were measured with MTT and flow cytometry, separately. Migration and invasion abilities were examined by transwell assays. Epithelial-mesenchymal transition (EMT) was assessed by western blot analyzing levels of E-cadherin, N-cadherin and vimentin. The potential binding between miR-148a-3p and XIST/ADAM17 was validated by luciferase reporter assay, Ago2-RNA immunoprecipitation and RNA pull-down assay. Xenograft experiments were conducted to measure tumor growth. RESULTS: XIST was upregulated and miR-148a-3p was downregulated in NPC tissues and cell lines. Both XIST knockdown and miR-148a-3p overexpression promoted apoptosis, suppressed cell proliferation, migration, invasion, and EMT of NPC cells in vitro. In addition, miR-148a-3p was validated as a target of XIST, and silencing of miR-148a-3p could reverse XIST knockdown-mediated functions in SUNE-1 and CNE2 cells. Furthermore, miR-148a-3p was identified to target ADAM17, and ectopic expression of ADAM17 could abate miR-148a-3p-induced effects as well. Notably, ADAM17 was downregulated by XIST knockdown through upregulating miR-148a-3p. In vivo, XIST knockdown resulted in a slower tumor growth. CONCLUSION: Knockdown of XIST suppresses the malignant progression of NPC cells through targeting miR-148a-3p/ADAM17 axis both in vitro and in vivo.

Spontaneous peripheral nerve palsy with hourglass-like fascicular constriction in the upper extremity.

OBJECTIVE: Spontaneous paralysis from hourglass-like fascicular constriction of peripheral nerves is rare, its clinical manifestations are not well documented, and its pathogenesis remains unknown. The unclear origin of this disorder and difficulty in diagnosis result in its uncertain management. The authors sought to gain a more thorough understanding of this condition through describing the anatomy, clinical features, etiology, and treatment of hourglass-like constriction. METHODS: The authors retrospectively reviewed 20 patients (22 nerves) with hourglass-like constriction. The patients' clinical information was reviewed. Preoperative sonographic assessment and electrophysiological examination of involved nerves were performed. Surgical treatments included interfascicular neurolysis and neurorrhaphy. Samples of tissue subjected to resected constriction were sent for pathological analysis. The patients had regular face-to-face follow-up visits. RESULTS: Acute pain was always the first symptom and was followed by paralysis. Paralysis progression was rapid and serious. Surgical exploration indicated an hourglass-like constricted segment completely unrelated to the compressive structures. Electrophysiological analysis showed severe denervation, and histopathological examination showed inflammatory cell infiltration, demyelination, and reduction of nerve fibers. CONCLUSIONS: Hourglass-like fascicular constrictive neuropathy has an integrative effect from multiple different mechanisms. Surgical intervention is beneficial for selected patients who do not recover in a timely fashion and have hourglass-like lesions confirmed by preoperative ultrasound imaging. The authors recommend that early surgical intervention of the nerve be offered to patients who do not show any signs of recovery 3 months after onset. Both interfascicular neurolysis and neurorrhaphy are effective treatment methods. Mild to moderate constriction can usually be treated successfully by interfascicular neurolysis alone, whereas more advanced lesions with loss of fascicle continuity (severe constriction) may be best treated with resection and direct neurorrhaphy.

ARF influences diabetes through promoting the proliferation and malignant development of ß cells.

OBJECTIVE: Diabetes is a common chronic disease. ARF is a new tumor suppressor, which is one hotspot of cell cycle regulators. The mutation of ARF is absent in nearly 50% of tumors. ARF plays an important role in many physiological processes, such as cell proliferation, cell senescence and cell cycle arrest. However, the molecular mechanism of ARF regulating is not clear at present. Our study aims to explore the mechanism of ARF in diabetes. METHODS: ARF-Tg mice and C57 mice were fasted for 12 hours before the experiment. STZ was injected at a dose of 45-65 mg/kg. The model was established for blood glucose ≥16.7 mmol/L, the level of sugar in urine was at 3 + -4+. The experiment was carried out when the mice was eight weeks. The levels of glucagon with or without doxycycline mice, the proliferation and apoptosis of ß-cell after immunosuppressive therapy were determined by immunofluorescence assay. Immunofluorescence and immunohistochemistry were used to observe the changes of insulin and glucagon. RESULTS: Forty-eight model mice (96%) were divided into two groups, each group has 24 mice, respectively. There was not significant difference of insulin and glucagon in both groups without induction. After induction, the level of insulin was increased in ARF-Tg mice, the neonatal ß cells were not increased but the number of proliferation cells and apoptotic cells was increased. Sirolimus combined with tacrolimus can effectively inhibit the reversal of the development of diabetes, but the conclusions need to be further confirmed in clinical. CONCLUSIONS: High expression of ARF can promote the occurrence of diabetes by accelerating cell proliferation and apoptosis. Immunosuppressive agents can effectively reverse this phenomenon.

Orientin-mediated Nrf2/HO-1 signal alleviates H2O2-induced oxidative damage via induction of JNK and PI3K/AKT activation.

Oxidative stress is closely associated with the pathogenesis of various diseases. Orientin (Ori), a flavonoid component isolated from natural plants, possesses antioxidant activity. Accordingly, we focused on exploring the potential therapeutic effects of Ori on hydrogen peroxide (H2O2)-induced oxidative impairment in RAW 264.7 cells and the underlying antioxidative mechanisms. Our findings suggested that Ori exposure effectively alleviated H2O2-stimulated cytotoxicity, inhibited reactive oxygen species (ROS) generation, and glutathione (GSH) depletion, which were involved in induction of heme oxygenase-1 (HO-1) by enhancing the nuclear factor-erythroid 2-related factor 2 (Nrf2) translocation, decreasing the Keap1 protein expression, and increasing the antioxidant response element (ARE) activity. However, knockdown of Nrf2 and HO-1 with siRNA mostly abolished the cytoprotective effects against H2O2-induced cell oxidative injury, reduced the expression of Nrf2 and HO-1, respectively. Moreover, Ori exposure significantly induced a c-Jun NH2-terminal kinase (JNK) and phosphatidylinositol 3-kinase (PI3K)/serine/threonine kinase (AKT) phosphorylation, but JNK and PI3K/AKT inhibitors treatment effectively reduced levels of Ori-enhanced Nrf2 nuclear translocation and HO-1 protein expression, and blocked Ori-inhibited cytotoxicity and ROS accumulation triggered by H2O2 respectively. Taken together, Ori might exhibit a protective role against H2O2-stimulated oxidative damage by the induction of HO-1 expression through the activation of the JNK- and PI3K/AKT-Nrf2 signaling pathways.

Enhancing Cell Proliferation and Osteogenic Differentiation of MC3T3-E1 Pre-osteoblasts by BMP-2 Delivery in Graphene Oxide-Incorporated PLGA/HA Biodegradable Microcarriers.

Lack of bioactivity has seriously restricted the development of biodegradable implants for bone tissue engineering. Therefore, surface modification of the composite is crucial to improve the osteointegration for bone regeneration. Bone morphogenetic protein-2 (BMP-2), a key factor in inducing osteogenesis and promoting bone regeneration, has been widely used in various clinical therapeutic trials. In this study, BMP-2 was successfully immobilized on graphene oxide-incorporated PLGA/HA (GO-PLGA/HA) biodegradable microcarriers. Our study demonstrated that the graphene oxide (GO) facilitated the simple and highly efficient immobilization of peptides on PLGA/HA microcarriers within 120 min. To further test in vitro, MC3T3-E1 cells were cultured on different microcarriers to observe various cellular activities. It was found that GO and HA significantly enhanced cell adhesion and proliferation. More importantly, the immobilization of BMP-2 onto the GO-PLGA/HA microcarriers resulted in significantly greater osteogenic differentiation of cells in vitro, as indicated by the alkaline phosphate activity test, quantitative real-time polymerase chain reaction analysis, immunofluorescence staining and mineralization on the deposited substrates. Findings from this study revealed that the method to use GO-PLGA/HA microcarriers for immobilizing BMP-2 has a great potential for the enhancement of the osseointegration of bone implants.

Posterior Thigh Flap Pedicled on the Cutaneous Vessels Arising From the Popliteo-posterior Intermediate Artery: A Report of 5 Cases.

Surgical repair of soft tissue defects of the knee and leg remains challenging. Using a case study approach, the anatomy of the popliteo-posterior intermediate cutaneous artery was examined, and a reverse island flap method was developed and implemented. After obtaining informed consent, 5 patients (1 woman, 4 men, age range 31 to 57 years) underwent the experimental use of a reverse island flap with a posterior thigh flap pedicled on the cutaneous vessels arising from the popliteo-posterior intermediate artery to repair soft-tissue defects of the knee and leg. The defects were caused by burned skin below the knee (n = 1), progressive skin necrosis in the knee after fracture surgery (n = 2), and skin infections associated with diabetes mellitus (n = 2). Skin defect sizes ranged from 15 cm x 5 cm to 30 cm x 12 cm. These large defects did not heal spontaneously; wound duration ranged from 1 week to 1 year, and all patients had refused defect repair with free flaps. Patients received posterior thigh flaps pedicled on the popliteo-posterior intermediate artery with areas ranging from 17 cm x 6 cm to 25 cm x 12 cm. All patients were treated with antibiotics and local dressings (iodoform and alcohol) changed daily post surgery, and blood supply was monitored by assessing the texture and color of the flap and venous regurgitation (ie, vein drainage disturbance). Four (4) of the five flaps survived completely. In 1 patient, partial survival of the flap, which had a good blood supply despite a venous circulation disorder, occurred: in this case, complete survival was achieved after treatment with a retrograde fascial flap and skin grafting. The appearance and texture of all flaps were satisfactory (ie, patients underwent only 1 operation, healing time was approximately 2 weeks, flap quality was close to normal skin, the donor site closed directly, and the shape and function of the knee and leg recovered well). No donor site abnormality was observed, and no postsurgical infection occurred. More research is needed, but the use of a reverse island flap with a posterior thigh flap pedicled on the cutaneous vessels arising from the popliteo-posterior intermediate artery may be a feasible option to repair soft tissue defects of the knee and leg.

Differentiation of endogenous neural stem cells in adult versus neonatal rats after brachial plexus root avulsion injury.

An experimental model of brachial plexus root avulsion injury of cervical dorsal C5-6 was established in adult and neonatal rats. Real-time PCR showed that the levels of brain-derived neurotrophic factor, nerve growth factor and neurotrophin-3 in adult rats increased rapidly 1 day after brachial plexus root avulsion injury, and then gradually decreased to normal levels by 21 days. In neonatal rats, levels of the three neurotrophic factors were decreased on the first day after injury, and then gradually increased from the seventh day and remained at high levels for an extended period of time. We observed that greater neural plasticity contributed to better functional recovery in neonatal rats after brachial plexus root avulsion injury compared with adult rats. Moreover, immunohistochemical staining showed that the number of bromodeoxyuridine/nestin-positive cells increased significantly in the spinal cords of the adult rats compared with neonatal rats after brachial plexus root avulsion injury. In addition, the number of bromodeoxyuridine/glial fibrillary acidic protein-positive cells in adult rats was significantly higher than in neonatal rats 14 and 35 days after brachial plexus injury. Bromodeoxyuridine/ß-tubulin-positive cells were not found in either adult or neonatal rats. These results indicate that neural stem cells differentiate mainly into astrocytes after brachial plexus root avulsion injury. Furthermore, the degree of neural stem cell differentiation in neonatal rats was lower than in adult rats.

Anatomical characteristics of deer and sheep lumbar spines: comparison to the human lumbar spine / Características anatómicas de la columna vertebral de ciervos y ovejas: comparación con la columna vertebral humana

Deer and sheep spines are often used as models of the human spine. A prerequisite for the use of animal models is information regarding the interspecies differences in the parameters of general interest. This would clarify the limitations of each animal model and substantiate the applicability of the obtained results to humans. Since sufficient data appear to be currently unavailable, we sought to investigate the feasibility of using deer and sheep as animal models for studies on the human spine. The objective of this study was a thorough comparison of the anatomical parameters of deer and sheep spines with those of the human spine. We employed three-dimensional reconstructions of computed tomography images, generated using figure analysis software, which facilitated quantitative analysis of the linear and curvature parameters and the geometric index of the vertebral bodies. Our findings represent a comprehensive database of the anatomical characteristics of the deer and sheep lumbar spines and their comparisons with those of the human lumbar spine. This study provides insight into the similarities and differences in the vertebral geometries between the human spine and the deer and sheep spines. We found that the differences are minimal and that they do not greatly compromise the utility of deer and sheep lumbar spines as models of the human lumbar spine.

La columna vertebral de ciervos y ovejas se utiliza frecuentemente como modelo de la columna vertebral humana. Un requisito previo para el uso de modelos animales es la información con respecto a las diferencias entre especies en los parámetros de interés general, lo que aclara las limitaciones de cada modelo animal y fundamenta la aplicabilidad de los resultados obtenidos para los seres humanos. Debido a que existen datos suficientes actualmente, hemos intentado investigar la viabilidad de utilizar ciervos y ovejas como modelos animales para los estudios sobre la columna vertebral humana. El objetivo fue realizar una comparación exhaustiva de los parámetros anatómicos de las columnas de ciervos y ovejas, con los de la columna vertebral humana. Empleamos reconstrucciones tridimensionales de imágenes de tomografía computadorizada, mediante un programa de análisis de la figura, lo que facilitó el análisis cuantitativo de los parámetros lineales y de la curvatura y el índice geométrico de las vértebras. Nuestros hallazgos representan una amplia base de datos de las características anatómicas de la columna lumbar de los ciervos y ovejas y sus comparaciones con las de la columna lumbar humana. Este estudio proporciona información sobre las similitudes y diferencias en las geometrías vertebrales entre la columna vertebral humana y las columnas de venado y oveja. Se encontró que las diferencias son mínimas y que no comprometen el uso de la columna de ciervos y ovejas como modelos de la columna lumbar humana.

[Clinical comparative studies on multiphase lipectomy and one-phase lipectomy with skin graft transplantation in skin flap contouring].

OBJECTIVE: To discuss the advantages of two flap contouring methods and to explore the best choice for the flap contouring. METHODS: From March 2002 to March 2006, 59 patients were admitted for a flap-contouring operation. Of the 59 patients, 40 (32 males, 8 females; average age, 34 years) underwent the multiphase lipectomy (the multiphase lipectomy group). The original flaps included the abdominal flap in 19 patients, the groin flap in 10, the thoracic flap in 4, the free anteriolateral thigh flap in 6, and the cross leg flap in 1. The flaps ranged in size from 6 cmX 4 cm to 32 cm x 17 cm. However, the remaining 19 patients (16 males, 3 females; average age, 28 years) underwent the one-phase lipectomy with skin graft transplantation(the one-phase lipectomy group). The original flaps included the abdominal flap in 4 patients, the groin flap in 6, the thoracic flap in 3, and the free anteriolateral thigh flap in 6. The flaps ranged in size from 4 cm x 3 cm to 17 cm x 8 cm. The results were analyzed and compared. RESULTS: In the multiphase lipectomy group, partial flap necrosis developed in 4 patients but the other flaps survived. The followed-up of 27 patients for 3 months to 2 years revealed that the flaps had a good appearance and texture, having no adhesion with the deep tissues. However, the flaps became fattened in 22 patients with their body weight gaining. The patients who had a flap >5 cm x 5 cm in area had their sensation functions recovering more slowly; only part of the sensations to pain and heat recovered. The two point discrimination did not recover. In the one-phase lipectomy group, total graft necrosis developed in 1 patient but the healing was achieved with additional skin graft transplantation; partial graft necrosis developed in 2 patients but the wounds were healed after the dressing changes; the remaining flaps survived completely. The follow-up of the 16 patients for 3 months to 3 years revealed that all the 16 patients had a good sensation recovery, 12 patients had the two point discrimination <15 mm, with no recurrence of the fattening of the flaps; however, the grafted skin had a more severe pigmentation, and no sliding movement developed between the skin and the tissue basement. CONCLUSION: The multiphase lipectomy and the one-phase lipectomy with skin graft transplantation are two skin flap contouring methods, which have their own advantages and disadvantages. Which method is taken should be based on the repair location of the skin flap and the condition of the skin flap.