Mussel inspired sequential protein delivery based on self-healing injectable nanocomposite hydrogel.

Polysaccharide based self-healing and injectable hydrogels with reversible characteristics have widespread potential in protein drug delivery. However, it is a challenge to design the dynamic hydrogel for sequential release of protein drugs. Herein, we developed a novel mussel inspired sequential protein delivery dynamic polysaccharide hydrogel. The nanocomposite hydrogel can be fabricated through doping polydopamine nanoparticles (PDA NPs) into reversible covalent bond (imine bonds) crosslinked polymer networks of oxidized hyaluronic acid (OHA) and carboxymethyl chitosan (CEC), named PDA NPs@OHA-l-CEC. Besides multiple capabilities (i.e., injection, self-healing, and biodegradability), the nanocomposite hydrogel can achieve sustained and sequential protein delivery of vascular endothelial growth factor (VEGF) and bovine serum albumin (BSA). PDA NPs doped in hydrogel matrix serve dual roles, acting as secondary protein release structures and form dynamic non-covalent interactions (i.e., hydrogen bonds) with polysaccharides. Moreover, by adjusting the oxidation degree of OHA, the hydrogels with different crosslinking density could control overall protein release rate. Analysis of different release kinetic models revealed that Fickian diffusion drove rapid VEGF release, while the slower BSA release followed a Super Case II transport mechanism. The novel biocompatible system achieved sequential release of protein drugs has potentials in multi-stage synergistic drug deliver based on dynamic hydrogel.

Lithium promotes recovery after spinal cord injury.

Lithium is associated with oxidative stress and apoptosis, but the mechanism by which lithium protects against spinal cord injury remains poorly understood. In this study, we found that intraperitoneal administration of lithium chloride (LiCl) in a rat model of spinal cord injury alleviated pathological spinal cord injury and inhibited expression of tumor necrosis factor α, interleukin-6, and interleukin 1 ß. Lithium inhibited pyroptosis and reduced inflammation by inhibiting Caspase-1 expression, reducing the oxidative stress response, and inhibiting activation of the Nod-like receptor protein 3 inflammasome. We also investigated the neuroprotective effects of lithium intervention on oxygen/glucose-deprived PC12 cells. We found that lithium reduced inflammation, oxidative damage, apoptosis, and necrosis and up-regulated nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 in PC12 cells. All-trans retinoic acid, an Nrf2 inhibitor, reversed the effects of lithium. These results suggest that lithium exerts anti-inflammatory, anti-oxidant, and anti-pyroptotic effects through the Nrf2/heme oxygenase-1 pathway to promote recovery after spinal cord injury. This study was approved by the Animal Ethics Committee of Xi'an Jiaotong University (approval No. 2018-2053) on October 23, 2018.

[Expression of Semaphorin 3A after spinal cord injury].

OBJECTIVE: To investigate expression of Semaphorin 3A in rats after spinal cord injury and explore possible mechanism of inhibiting of axonal regeneration after SCI. METHODS: Forty healthy female SD rats, 8 weeks old, weighing (210.00±9.88) g, were randomly divided into control group(20 rats in group A) and model group(20 rats in group B). In control group, removal of T10 lamina and partial removal of T9 and T11 lamina were performed, and no further operation was performed on spinal cord (pseudo operation). In model group, the total T10 and partial T9, T11 partial lamina were incised and the spinal cord transection was performed to create animal models of spinal cord injury. The rats were perfused and spinal cord tissue obtained at 3, 7, 14, 28 and 42 days after surgery (4 rats in each group at each time point), respectively, and then HE staining was performed. Meanwhile, the expression of Semaphoring 3A was detected in accordance with the protocol of SP kit. RESULTS: After a simple spinal cord transection injury, hemorrhagic necrosis, localized edema, neurodegeneration, necrosis, and cyst formation occurred in the injured area, and glial scar formation occurred in glial cells. Semaphorin 3A expression levels in control group was low in the gray matter area. There was no expression of Semaphorin 3A in the injured area of spinal cord injury in model group 3 days after operation. On the 14th day, the expression of Semaphorin 3A in the injured area of spinal cord injury increased significantly and was at a high level. On the 28th day, the expression of Semaphorin 3A was moderate. On the 42th day, the positive expression of Semaphorin 3A returned to normal level. CONCLUSION: The increased expression of Semaphorin 3A after spinal cord injury may be one of the mechanisms that inhibit axonal regeneration.

[A case-control study of cervical spine Key-hole technique and anterior cervical Zero-P system in the treatment of cervical spondylotic radiculopathy].

OBJECTIVE: To explore the short-term clinical efficacy of single-stage cervical spondylotic radiculopathy (CSR) between the minimally invasive Key-hole technique and anterior cervical Zero profile intervertebral fusion system (Zero-P). METHODS: A retrospective analysis was performed on 45 patients who underwent surgical treatment for CSR from January 2017 to January 2020, including 21 in Key hole group (12 males and 9 females), followed up for 10-22(13.2±2.3) months;24 cases in Zero-P group (14 males and 10 females), and the follow up period was 10 to 23(12.7±1.9) months. Perioperative conditions (incision length, intraoperative blood loss, operation time, length of hospital stay, and complications) were compared between two groups, and X-rays of cervical spine before and after surgery and at the final follow-up were taken to analyzed curvature of the cervical spine, visual analogue scale(VAS) of pain before and after surgery, Oswestry Disability Index(ODI) and Japanese Orthopaedic Association (JOA) score of cervical spine were recorded to evaluate clinical efficacy. RESULTS: In Key-hole group and Zero-P group, the surgical incision length, intraoperative blood loss, operation time, final follow-up Cobb angle and immediate postoperative VAS score respectively were (1.2±0.2) cm, (5.3±0.3) cm;(35.3±9.7) ml, (120.2±13.5) ml;(56.4±11.3) min, (90.6±12.6) min;(3.2±3.9)°, (7.3±3.8)°;(2.8±1.2)points, (3.8±1.1) points;the Zero-P group was larger than the Key hole group, with statistical significance(P<0.05) . There were no statistically significant difference in length of hospital stay, ODI and JOA scores between two groups (P>0.05). After the follow-up, 1 case of neurostimulation symptoms in Key-hole group was relieved by conservative treatment, 2 cases improved after reoperation due to recurrence of cervical disc herniation;2 cases of neurostimulation symptoms in Zero-P group, 2 cases of throat discomfort, and 1 case dural tears were all relieved by conservative treatment. CONCLUSION: The cervical spine Key-hole technology is similar to the anterior cervical Zero-P system in the treatment of CSR. The Key-hole technique has certain advantages in incision length, intraoperative blood loss, and operation time. It is a safe, effective and can be widely used cervical spine surgery method.

[Diagnosis value of serum infection index for early infection of patients undergoing posterior cervical expansive open-door laminoplasty].

OBJECTIVE: To investigate the diagnosis value of white blood cell (WBC) count, C-reactive protein (CRP), serum procalcitonin (PCT) and erythrocyte sedimentation rate (ESR) levels for early infection after posterior cervical expansive open-door laminoplasty. Discover, prevent, and treat postoperative infections promptly. METHODS: The clinical data of 120 patients with early fever after posterior cervical laminoplasty from January 2010 to April 2019 were retrospectively analyzed. According to the results of bacteriological culture of wound exudate, the patients were divided into infected group(53 cases) and non-infected group(67 cases). In infection group, there were 32 males and 21 females, aged from 48 to 63 years old, with an average of(52.28±6.36) years. In non-infected group, there were 37 males and 30 females, aged from 46 to 62 years old, with an average of(51.63±5.82) years. According to the postoperative infection types, the patients in infection group were divided into 30 cases of deep surgical site infection group and 23 cases of superficial surgical site infection group. In deep surgical site infection group, there were 19 males and 11 females, aged from 50 to 63 years old with an average of (53.16±5.62) years. In superficial surgical site infection group, there were 13 males and 10 females, aged from 48 to 61 years old with an average of (52.15±5.68) years. WBC count, CRP, PCT and ESR serum infection indexes were compared between groups and within groups before and after surgery. The serum infective index data of 120 patients were collected and the sensitivity and specificity of the serum infectious index were used to diagnose the infection. Accuracy assessment of early infection diagnosis of WBC count, CRP, PCT and ESR serum infection indexes by plotting the receiver operating characteristic(ROC) curve with 1-specificity as the abscissa and sensitivity as the ordinate. RESULTS: There were no significant difference in WBC count, CRP, PCT and ESR serum infection indexes between infected group and non-infected group before operation(P>0.05). Postoperative WBC count, CRP, PCT and ESR infection indexes in infection group were higher than in non-infected group(P<0.05). Among patients with postoperative infection, WBC count, CRP, PCT and ESR serum infection index levels were significantly different in the different postoperative infection types (P<0.05). In non-infected group, WBC count, CRP, PCT and ESR serum infection indexes showed an overall trend of rising first and then falling. The area under curve (AUC) of WBC count infection index was 0.637(P<0.05). The AUC of CRP infection index was 0.792 (P<0.05). The AUC of PCT infection index was 0.774 (P<0.05). The AUC of ESR infection index was 0.783(P<0.05). CONCLUSIONS: WBC count, CRP, PCT and ESR serum infection indexes can be used for the diagnosis of early infection after posterior cervical expansive open-door laminoplasty. In addition, the comprehensive analysis of the changes of the four infection indexes can be used for the identification of different postoperative infection types. WBC count index is less accurate for early infection diagnosis, and CRP, PCT, and ESR indexes are more accurate for early infection diagnosis. In general, CRP, PCT and ESR serum infection indexes have important clinical significance for the diagnosis of early infection after posterior cervical open-door laminoplasty, which helps clinicians to detect early postoperative infection as early as possible to facilitate subsequent treatment.

[Depressant effect of Lithium on apoptosis of nerve cells of adult rats after spinal cord injury].

OBJECTIVE: To study whether lithium agent produces neuroprotective effect by inhibiting the nerve cell apoptosis of rats after spinal cord injury. METHODS: Forty-two male SD rats weighing 200 to 250 g were randomly divided into 3 groups: blank control group(n=6) without surgery, normal saline(NS) group(n=18) with intraperitoneal injection of NS (40 mg/kg); and Lithium chloride (Licl) group (n=18) with intraperitoneal injection of Licl (40 mg/kg). After Allen method modeling, Licl group started intraperitoneal injection of Licl solution (40 mg·kg⁻¹·d⁻¹) within 15 min after operation to the second week. NS group, during the same interval, was injected with a same amount of NS. Postoperative 3, 7, 14 d, BBB scores in each group were measured;the expression of Bcl-2 and Bax protein were observed by immunohistochemisty staining;TUNEL staining was used to observe the nerve cell apoptosis. RESULTS: The BBB scores in blank control group were 21. Postoperative 7, 14 d, BBB scores of Licl group were higher than that of NS group(P<0.05). As for the Bcl-2 protein expression, black control group has a level of 0.081±0.003;7 d and 14 d postoperatively, the level in Licl group was 0.151±0.003, 0.163±0.003 and in NS group, 0.143±0.003, 0.154±0.002, respectively. Licl group showed significantly increased Bcl-2 protein expression(P<0.05). As for the Bax protein expression, black control group showed a level of 0.071±0.003; 7 d and 14 d postoperatively, the level in Licl group was 0.121±0.002, 0.106±0.002 and in NS group was 0.126±0.001, 0.120±0.002, respectively. The Bax protein expression is significantly inhibited in the Licl group(P<0.05). In nerve cell apoptosis by TUNEL staining, the positive cells were fewer in the black control group with apoptosis index (AI) of 1.98±0.19;while 7d and 14d postoperatively, the AI of Licl group was 13.12±0.69, 4.29±1.00 and of NS group, 18.26±0.87, 5.48±0.70, respectively. Licl group showed significant inhibition of the cell apoptosis(P<0.05). CONCLUSIONS: Licl can promote the Bcl-2 protein expression and inhibit the Bax proteins expression in nerve cells of rat after SCI, thereby playing a role in the inhibition of nerve cell apoptosis. This may be one of the mechanisms that Licl can promote the recovery of motor function of rats after SCI.

Image-guided minimally invasive percutaneous treatment of spinal metastasis.

In order to provide effective options for minimally invasive treatment of spinal metastases, the present study retrospectively evaluated the efficacy and safety of image-guided minimally invasive percutaneous treatment of spinal metastases. Image-guided percutaneous vertebral body enhancement, radiofrequency ablation (RFA) and tumor debulking combined with other methods to strengthen the vertebrae were applied dependent on the indications. Percutaneous vertebroplasty (PVP) was used when vertebral body destruction was simple. In addition, RFA was used in cases where pure spinal epidural soft tissue mass or accessories (spinous process, vertebral plate and vertebral pedicle) were destroyed, but vertebral integrity and stability existed. Tumor debulking (also known as limited RFA) combined with vertebral augmentation were used in cases presenting destruction of the epidural soft tissue mass and accessories, and pathological vertebral fractures. A comprehensive assessment was performed through a standardized questionnaire and indicators including biomechanical stability of the spine, quality of life, neurological status and tumor progression status were assessed during the 6 weeks-6 months follow-up following surgery. After the most suitable treatment was used, the biomechanical stability of the spine was increased, the pain caused by spinal metastases within 6 weeks was significantly reduced, while the daily activities and quality of life were improved. The mean progression-free survival of tumors was 330±54 days, and no associated complications occurred. Therefore, the use of a combination of image-guided PVP, RFA and other methods is safe and effective for the treatment of spinal metastases.

[Application of 360 degree circular decompression and transpedicle screw fixation in the treatment of ossification of thoracic posterior longitudinal ligament by posterior approach].

OBJECTIVE: To investigate the clinical effects of 360 degree circular decompression and transpedicle screw fixation to treat the ossification of thoracic posterior longitudinal ligament by posterior approach. METHODS: From December 2009 to November 2013, 18 patients with ossification of thoracic posterior longitudinal ligament ossification were treated with 360 degree circle decompression and transpedicle screw fixation by posterior approach. There were 8 males and 10 females,ranging in age from 32 to 67 years old, with an average of 51 years old. Four patients were accompanied with ligamentum flavum ossification. Longitudinal ossifications in 5 cases were located in the upper thoracic vertebra and 13 cases in the middle and lower thoracic vertebra. Five cases were typical type, 4 cases were segmental type, 6 cases were continuous type and 3 cases were mixed type. All the patients had the posterior spinal canal decompression combined with longitudinal ligament resection, interbody fusion with bone graft and internal fixation surgeries. The operation time,blood loss and complications were recorded. JOA score were applied to evaluate the neurological function recovery pre-surgery, 2 days post-surgery and the latest follow-up. The surgery effects were evaluated by Epstein-Schwall method. RESULTS: The operation time ranged from 3 to 6 hours (mean, 4.2 hours). The blood loss ranged from 800 to 4 000 ml (mean, 1 800 ml). All the patients were followed up, and the duration ranged from 6 months to 3 years, with a mean of 1.8 years. The JOA score increased from preoperative 4.30 ± 2.60 to 7.60 ± 2.40 2 days after surgery, and 7.80 ± 1.90 at the latest follow-up (t = 4.61, P < 0.001). The JOA scores between 2 days after surgery and the latest follow-up had no significant differences (t = 0.28,P = 0.78). The neurological recovery rate was 74% 2 days after surgery and 71% at the latest follow-up. There were 4 cases got an excellent result,10 good,3 fair and 1 poor according to Epstein-Schwall evaluation method. Four patients had cerebrospinal fluid leakage, 3 patients had intercostal nerve paralysis or pain, and 1 patient had superficial incision infection. The neurological function in 3 patients became worse in the second day posteratively , and among them, 2 patients were recovered at the latest follow-up and 1 patient had no changes. All the patients got fusion of bone graft and no internal fixation loosening and fractures occurred. CONCLUSION: 360 degree circular decompression and transpedicle screw fixation can resect different types of thoracic longitudinal ligament ossification, and can achieve a good clinical effect.

[Case-control study of anterior cervical decompression plus sublevel fusion and posterior cervical laminoDIastv for the treatment of multilevel cervical spondylotic myelopathy].

OBJECTIVE: To compare the clinical outcomes of anterior cervical decompression plus sublevel fusion and posterior cervical laminoplasty in treating multilevel cervical spondylotic myelopathy. METHODS: The clinical data of 56 patients with multilevel cervical spondylotic myelopathy were retrospectively analyzed from July 2009 to June 2012. There were 32 males and 24 females, aged from 42 to 79 years old with an average of (56.9 +/- 12.8) years. All patients had the typical clinical features of cervical spondylotic myelopathy,radiological evidences, and courses of disease were from 2 months to 16 years with an average of (10.6 +/- 3.2)years. Of them,34 patients were treated with anterior cervical decompression plus sublevel fusion (anterior fusion group) and 22 patients with posterior cervical laminoplasty (posterior laminoplasty group). JOA score and radiological data were used to evaluate the clinical results: RESULTS: No complications about nerve and blood vessel was found and the patients were followed up from 24 to 36 months with an average of 28.6 months. In anterior fusion group, the cervical anterior column height was significantly increased and the anterior cervical curvature angle was significantly decreased at 2 weeks after surgery (P < 0.05). In posterior laminoplasty group, there was no significant difference in above items between preoperative and postoperative at 2 weeks,final follow-up. Postoperative at 2 weeks and final follow-up, there was significant difference in anterior cervical curvature angle between two groups (P<0.05). Postoperative JOA score had obviously improved in all patients, at 3 months after operation and final follow-up, anterior fusion group was better than that of posterior laminoplasty group (P < .05). CONCLUSION: The anterior sublevel fusion can effectively restore cervical anterior column height, and compared with the posterior cervical laminoplasty, it can obviously improve the spinal cord function. It is an effective method for the multilevel cervical spondylotic myelopathv.

[Unilateral versus bilateral pedicle screw fixation in minimally invasive transforaminal lumbar interbody fusion(MIS-TLIF): a Meta analysis].

OBJECTIVE: To compare the clinical outcome between unilateral and bilateral pedicle screw fixation in minimally invasive transforaminal lumbar interbody fusion(MIS-TLIF) for the treatment of lumbar degenerative diseases. METHODS: The studies concerning unilateral or bilateral pedicle screw fixation in MIS-TLIF for the treatment of lumbar degenerative diseases from January 2000 to October 2015 were searched from Medline, Embase, The Cochrane Library, China Biology Medicinedisc and Wanfang database, China National Knowledge Internet (CNKI). The data of the studies were collected, risk of bias of the included RCTs were assessed according to Cochrane handbook 5.1.0, risk of bias of the included retrospective or prospective studies were assessed according to MINORS. The Oswestry Disability Index (ODI), visual analogue scale(VAS), lumbar lordosis angle, segmental lordosis angle, lumbar scoliosis angle, segmental scoliosis angle, fusion rate, complication rate, hospitalization time, operative time and blood loss data were Meta analyzed by RevMan 5.2.0 software. RESULTS: Nine studies were included, containing 4 randomized controlled trials (RCT), 2 prospective studies and 3 retrospective studies, there were 451 patients in total. The results showed that there was no significant difference between the two methods in VAS of back pain, VAS of leg pain, ODI, lumbar lordosis angle, segmental lordosis angle, lumbar scoliosis angle, segmental scoliosis angle, fusion rate, complication rate, hospitalization time. There was significant difference in operative time and blood loss between unilateral and bilateral pedicle screw fixation. CONCLUSIONS: Using unilateral or bilateral pedicle screw fixation in MIS-TLIF for lumbar degenerative diseases can achieve the same clinical effects, and there was no significant difference in complication rate. Unilateral pedicle screw fixation is safer than bilateral fixation because of less operative time and blood loss. However, the number and quality of the literatures may result in low reliability, so greater sample size and high quality RCTs are needed in future.

[Posterior spinal transpedicular wedge osteotomy for kyphosis due to delayed osteoporotic vertebral fracture in elderly].

OBJECTIVE: To evaluate the clinical effects of posterior spinal transpedicular wedge osteotomy for kyphosis due to delayed osteoporotic vertebral fracture in elderly. METHODS: From July 2009 to February 2014,26 patients with kyphosis caused by delayed osteoporotic vertebral fracture were treated with transpedicular wedge osteotomy. There were 10 males and 16 females,aged from 55 to 75 years old with an average of 67 years. There were 1 osteotomy in thoracic vertebra,21 osteotomies in thoracolumbar vertebrae and 4 in lumbar vertebrae. Total 29 vertebrae were involved, 23 cases with single vertebral fracture and 3 cases with double vertebral fractures. Preoperative Cobb angles were 32°~51° with the mean of (42.00 ± 4.75) ° and VAS scores were 6 to 9 points with an average of (8.40 ± 0.75) points. According to the Frankel grade of spinal cord function, 4 cases were grade D and 22 cases were grade E. Intraoperative bleeding, operation time and perioperative complications were recorded, and improvements of Cobb angle were evaluated by X-rays. VAS score and Frankel grade were respectively used to evaluate the pain and nerve function. RESULTS: The average operation time were 155 min (ranged, 120 to 175) and the mean intraoperative bleeding were 1 100 ml (ranged,800 to 1 500). Postoperative at 2 days, Cobb angle and VAS score were (9.60 ± 2.50) ° and (4.00 ± 1.00) points, respectively, ranged from 5° to 15° and 1 to 5 points. VAS score and Cobb angle improved obviously compared with preoperative (P < 0.05), and the improvement rate of Cobb angle was 76%. Frankel grade of 1 case changed from grade E to C, and the others did not become worse. The follow-up period ranged from 3 to 24 months with an average of 16.4 months. At the final follow-up, Cobb angles and VAS score were (11.00 ± 3.50)° and (4.40 ± 1.25) points, respectively, ranged from 5° to 19° and 1 to 6 points. The patient whose Frankel grade E changed to C at 2 days after surgery and changed to grade D at the latest follow-up. Vertebral body fracture below the fusion level happened in 1 case at 3 months after surgery, vertebral body fracture above the fusion level happened in 1 case at 5 months after surgery, and their chest pain symptoms were relieved after symptomatic treatment and anti osteoporosis treatment. All osteotomy levels obtained fusion which confirmed by X-ray and no internal fixation loosening and breakage were found. CONCLUSION: The clinical effect of posterior transpedicular wedge osteotomy for kyphosis due to delayed osteoporotic vertebral fracture was satisfactory, but manipulation during the operation should be cautious and prevent adjacent vertebral body fracture should be pay attention to prevent.

[Total vertebral column resection combined with anterior mesh cage support for the treatment of severe congenital kyphoscoliosis].

OBJECTIVE: To explore the clinical effects of total vertebral column resection combined with anterior mesh cage support in treating severe congenital kyphoscoliosis. METHODS: From April 2008 to April 2012,21 patients with severe congenital kyphoscoliosis were treated with total vertebral column resection and internal fixation through posterior approach combined with anterior mesh cage support. There were 8 males and 13 females with an average age of 19.4 years old (ranged from 10 to 35). And 6 cases were thoracic segments deformity,13 cases were thoracolumbar segments and 2 cases were lumbar segments, of them, 2 cases were accompanied with Chairs deformity, 6 cases with diastematomyelia, 4 cases with syringomyelia,and 1 case with neurofibromatosis. According to the Frankel grade system, 3 cases were grade C, 5 cases grade D and 13 cases grade E. Blood loss, operative time, and perioperative complications were recorded. Coronal and sagittal Cobb angle, apical vertebral offset distance, sagittal offset, the relative height of shoulders, razor back deformities were measured and analyzed before and after operation. RESULTS: The average operative time was 5.2 h (3.5 to 6.5 h) and blood loss was 2,500 ml (1,400 to 4,900 ml). The 2nd day after operation, apical vertebral offset distance, sagittal offset, the relative height of shoulders, razor back deformities had obviously improved than preoperative (P < 0.05). There was no significant difference in above items between postoperative on the 2nd day and final follow-up (P > 0.05). The corrective rate of kyphosis and scoliosis were (60.97 +/- 6.30)% and (62.24 +/- 5.82)%, respectively. On the first day after surgery,2 cases of Frankel grade E aggravated to grade D, and obtained recovery at 2 week after conservative treatment. And 1 case palinesthesia later,grade D aggravated to grade C and obtained recovery after revision surgery in time. One case complicated with permanent blindness of left eye, 1 case occurred injury of pleura and 2 cases had cerebrospinal fluid leak during operation. All patients were followed up from 9 to 31 months with an av- erage of 18.6 months. At final follow-up,all patients obtained bone union, Frankel grade D in 4 cases and grade E in 17 cases, no correction loss and internal fixation loosening was found. CONCLUSION: Total vertebral column resection combined with anterior mesh cage support can effectively correct kyphosis and scoliosis in severe congenital kyphoscoliosis and can avoid injury of spine cord by spinal crispation, but intraoperative position and neurologic complications should still be considered.

[Repair of subacute spinal cord crush injury by bone marrow stromal cell transplantation and chondroitinase ABC microinjection in adult rats].

OBJECTIVE: To investigate the possibility of repairing spinal cord injury by bone marrow stromal cell (MSC) transplantation and microinjection of chondroitinase ABC (ChABC) in adult rats. METHODS: MSCs isolated from the femoral and tibial bones of new-born Wistar rats were cultured and the cell density was adjusted to 1×10(5)µl before transplantation. SD rats with T8 spinal cord crush injury were divided into 4 groups, namely group A (control) and groups B, C and D with injections of the MSCs, ChABC and MSCs+ChABC at the injury site, respectively. At 0 h, 1 day, 2 days, 3 days, 1 week, and 2 weeks after the injury, the BBB score system was used to evaluate the motion function. At 14 days after the injury, the maximal transverse diameter and actual area of necrosis were evaluated on HE stained sections. GFAP-CS56, GFAP-GAP43 and GFAP-NF160 immunofluorescence double labeling staining were carried out to evaluate the regeneration of the nerve fibers. RESULTS: At the 14th day after the injury, BBB scores showed significant differences between group A and groups B, C and D (P<0.05), between the groups B and D and between groups C and D, butnot between groups B and C. HE staining showed cavity formation at the injury site in each group, with significant differences between group A and groups B, C and D and also between the latter 3 groups. Immunofluorescence staining revealed more intense expression of GFAP in group A than in the other groups with apparent cavity formation at the lesion site, which was only moderate in groups B and C. The expression of GAP-43 was more intense in group D than in groups B and C. The expression of NF-160 was more intense in group D than in the other 3 groups. CONCLUSION: The strategy of MSC transplantation combined with ChABC can be effective for repairing spinal cord injury in adult rats.

Increased expression of collagens, transforming growth factor-beta1, and -beta3 in gluteal muscle contracture.

BACKGROUND: Gluteal muscle contracture (GMC) is a multi-factor human chronic fibrotic disease of the gluteal muscle. Fibrotic tissue is characterized by excessive accumulation of collagen in the muscle's extracellular matrix. Transforming growth factor (TGF)-beta1 and -beta2 are thought to play an important role in fibrogenesis, while TGF-beta3 is believed to have an anti-fibrotic function. We hypothesize that the expression of collagen and TGF-betas would be up-regulated in GMC patients. METHODS: The expression of collagen type I, type III and TGF-betas were studied in 23 fibrotic samples and 23 normal/control samples in GMC patients using immunohistochemistry, reverse transcription and polymerase chain reaction (RT-PCR) and western bolt analysis. RESULTS: Compared to the unaffected adjacent muscle, increased expression of TGF-beta1 and -beta3 was associated with deposition of collagen type I and type III in the fibrotic muscle of the GMC patients at the mRNA level. Strong up-regulation of these proteins in fibrotic muscle was confirmed by immunohistochemical staining and western blot analysis. TGF-beta2 was not up-regulated in relation to GMC. CONCLUSION: This study confirmed our hypothesis that collagen types I, III, TGF-beta1 and TGF-beta3 were up-regulated in biopsy specimens obtained from patients with GMC. Complex interaction of TGF-beta1 with profibrotic function and TGF-beta3 with antifibrotic function may increase synthesis of collagens and thereby significantly contribute to the process of gluteal muscle scarring in patients with GMC.

[Effects of total flavonoids from Rhizoma Drynariae medicated serum on proliferation, differentiation, cell cycle and apoptosis of osteoblasts in vitro].

OBJECTIVE: To observe the effects of total flavonoids from Rhizoma Drynariae medicated serum on cell proliferation, differentiation, cell cycle and apoptosis of rats' osteoblasts cultured in vitro. METHODS: The osteoblasts from cranium of newborn SD rats were cultured by collagenase method. MTT, PNPP, PI and Annexin V/PI methods were used to observe the proliferation, activity of alkaline phosphatase (ALP), every stage cells in the cell cycle, and the ratio of apoptosis cells by different concentrations of total flavonoids from Rhizoma Drynariae medicated serum at different time points. RESULTS: Different concentrations of total flavonoids from Rhizoma Drynariae medicated serum could significantly enhance the cell proliferation rate and ALP activity (P < 0.05), more cells in S stage and less cells apoptosised than that of the untreated osteoblasts (P < 0.05). CONCLUSION: Total flavonoids from Rhizoma Drynariae medicated serum could promote the proliferation, differentiation, increase S stage cells, and reduce the ratio of apoptosis cells, which reveals that they have anti-osteoporosis activity.

[Biomechanical evaluation of anterior cervical spine stabilization with step-cut grafting and absorbable screw fixation].

OBJECTIVE: To determine the initial stability of a novel construct in cadaveric cervical spine in comparison with a conventional method. METHODS: Twelve specimens of fresh human cadaveric cervical spines (C(3)-C(7)) were randomly divided into the test group and control group. In the former group, one-level corpectomy of C(5) and three cortical iliac step-cut grafting with absorbable screw fixation was performed, and one-level corpectomy of C(5) and three cortical iliac strut grafting with anterior plate fixation in the control group. Flexibility test and graft push of strength test were carried out before and after grafting and fixation to determine the range of motion (ROM), neutral zone (NZ) and graft push out strength (POS). RESULTS: The cervical spines of the two groups all had increased initial stability in all 6 rotational degrees of freedom with also enhanced graft POS after fixation. Compared with the control group, the test group had higher stability in extension and comparable stability in flexion and axial rotation, but lower stability in lateral bending. The graft POS after fixation in the test group, however, was lowered in comparison with the control group. CONCLUSION: Step-cut grafting and absorbable screw fixation provides sufficient stability potential for the cervical spine in vitro and allows optimum biomechanical and biological environments to enhance graft fusion and reduce complications.