CircularRNA_104670 plays a critical role in intervertebral disc degeneration by functioning as a ceRNA.

This study was carried out to explore the roles of circular RNAs (circRNAs) in nucleus pulposus (NP) tissues in intervertebral disc degeneration (IDD). Differentially expressed circRNAs in IDD and normal NP tissues were identified based on the results of microarray analysis. Bioinformatics techniques were employed to predict the direct interactions of selected circRNAs, microRNAs (miR), and mRNAs. CircRNA_104670 was selected as the target circRNA due to its large multiplier expression in IDD tissues. After luciferase reporter and EGFP/RFP reporter assays, we confirmed that circRNA_104670 directly bound to miR-17-3p, while MMP-2 was the direct target of miR-17-3p. The receiver-operating characteristic (ROC) curve showed that circRNA_104670 and miR-17-3p had good diagnostic significance for IDD (AUC circRNA_104670 = 0.96; AUC miRNA-17-3p = 0.91). A significant correlation was detected between the Pfirrmann grade and expression of circRNA_104670 (r = 0.63; p = 0.00) and miR-17-3p (r = -0.62; p = 0.00). Flow-cytometric analysis and the MTT assay showed that interfering with circRNA_104670 using small interfering RNA (siRNA) inhibited NP cell apoptosis (p < 0.01), and this inhibition was reduced by interfering with miR-17-3p. Interfering with circRNA_104670 suppressed MMP-2 expression and increased extracellular matrix (ECM) formation, which were also reduced by interfering with miR-17-3p. Finally, an MRI evaluation showed that circRNA_104670 inhibition mice had a lower IDD grade compared with control mice (p < 0.01), whereas circRNA_104670 and miRNA-17-3p inhibition mice had a higher IDD grade compared with circRNA_104670 inhibition mice (p < 0.05). CircRNA_104670 is highly expressed in the NP tissues of IDD and acts as a ceRNA during NP degradation.

Cortical Activation Changes in Hirayama Disease After Anterior Cervical Decompression and Fusion.

BACKGROUND: Spinal cord injury may cause cortical reconstruction. We, therefore explored the changes in cortical activation before and after anterior cervical decompression and fusion surgery in patients with Hirayama disease (HD). METHODS: In total, 17 cases with HD underwent anterior cervical decompression and fusion surgery. Blood oxygenation level-dependent functional magnetic resonance imaging scan was performed preoperatively, 3 months, 6 months, and 1 year after surgery. Activated voxels were compared between both hands after adjusting for head motion, slice timing, spatial normalization, and image smoothing. Grip strength also was tested in both hands. RESULTS: A retrospective review indicated that the grip strength of the asymptomatic hand was significantly stronger than the symptomatic hand at the time point before the surgery, 3 months after surgery, 6 months after surgery, and 1 year after surgery (P < 0.001). The grip strength of both symptomatic and asymptomatic hands continuously increased within 6 months after surgery (P < 0.05), but it stopped at 1 year after the surgery. The symptomatic limb tends to produce bilateral activation in the primary motor area (M1) during motor tasks. Both contralateral and ipsilateral M1 activation were stronger in symptomatic hand tasks preoperatively (P < 0.05). Both contralateral and ipsilateral activation in M1 during symptomatic hand tasks began to reduce after surgery, and statistical significance was observed 6 months after surgery (P < 0.05). Contralateral activation was relatively even over 6 months of the surgery (P > 0.05). CONCLUSIONS: After surgery, pathologic reconstruction may have occurred in the primary motor cortex. Recovery of motor function in the symptomatic limb was accompanied by decreased ipsilateral and contralateral M1 activation, as well as symptom improvement. These findings suggested that postoperative cortical activation changes may reflect functional recovery in HD.

The value of radiographic indexes in the diagnosis of discogenic low back pain: a retrospective analysis of imaging results.

To explore value of different radiographic indexes in the diagnosis of discogenic low back pain (LBP). A total number of 120 cases (60 patients diagnosed with discogenic LBP and 60 healthy people) were retrospectively analysed to identify factors in the diagnosis of discogenic LBP by using univariate and multivariate analyses. A receiver operating characteristic (ROC) curve was drew to show the predictive accuracy of the finally enrolled factors. Among all the included patients, 60 were strictly admitted in the discogenic LBP group while the other 60 were enrolled in the control group. Five results shows significant differences between discogenic LBP and control groups, including Cobb angle, lumbar stability, height of the disc, Modic change and High intense zone (HIZ) based on the results of univariate analysis; lumbar stability, Modic change and HIZ show high value in the diagnosis of lumbar discogenic pain based on the multivariate logistic analysis. The ROC curve shows that good diagnostic accuracy was obtained from the enrolled diagnostic factors including lumbar stability (Angular motion, more than 14.35°), Modic change and HIZ.

Electrophysiological differences between Hirayama disease, amyotrophic lateral sclerosis and cervical spondylotic amyotrophy.

BACKGROUND: Hirayama disease (HD), amyotrophic lateral sclerosis (ALS) or cervical spondylotic amyotrophy (CSA) may result in atrophy of intrinsic hand and forearm muscles. The incidence of HD is low, and it is rarely encountered in the clinical setting. Consequently, HD is often misdiagnosed as ALS or CSA. It is important to differentiate these diseases because HD is caused by a benign focal lesion that is limited to the upper limbs. METHODS: The thenar and hypothenar compound muscle action potential (CMAP) amplitude of the upper limbs of 100 HD, 97 ALS and 32 CSA cases were reviewed; 35 healthy individuals were included as controls. Seventy-eight percent, 38% and 69% of patients with HD, ALS or CSA had unilateral involvement; the remaining patients were affected bilaterally. Thenar and hypothenar CMAP amplitude evoked by ulnar stimulation was compared with CMAP evoked by median stimulation. RESULTS: The ulnar/median CMAP ratio was found to be lower in HD (0.55 ± 0.41, P<0.0001), higher in ALS (2.28 ± 1.15, P<0.0001) and no different in CSA (1.21 ± 0.53, P>0.05) compared with the normal range from previous studies (0.89-1.60) and with the healthy controls (1.15 ± 0.23). Conduction velocities of the sensory and motor nerves, the amplitude of the sensory nerve action potential, and the CMAP amplitude of the unaffected limb were all normal. CONCLUSIONS: The hand muscles were differentially affected between patients with HD, ALS and CSA. The ulnar/median CMAP ratio could be used to distinguish these three diseases.

Evaluation of characteristics and surgical outcomes in cervical spondylotic amyotrophy.

BACKGROUND: Cervical spondylotic amyotrophy (CSA) is a rare clinical syndrome resulting from cervical spondylosis. Surgical treatment includes anterior cervical decompression and fusion (ACDF), and laminoplasty with or without foraminotomy. Some studies indicate that ACDF is an effective method for treating CSA because anterior decompression with or without medial foraminotomy can completely eliminate anterior and/or anterolateral lesions. We retrospectively evaluated outcome of surgical outcome by anterior cervical decompression and fusion (ACDF). MATERIALS AND METHODS: 28 CSA patients, among whom 12 had proximal type CSA and 16 had distal type CSA, treated by ACDF, were evaluated clinicoradiologically. The improvement in atrophic muscle power was assessed by manual muscle testing (MMT) and the recovery rate of the patients was determined on the basis of the Japanese Orthopedic Association (JOA) scores. Patient satisfaction was also examined. RESULTS: The percentage of patients, who gained 1 or more grades of muscle power improvement, as determined by MMT, was 91.7% for those with proximal type CSA and 37.5% for those with distal type CSA (P < 0.01). The JOA score-based recovery rates of patients with proximal type and distal type CSA were 60.8% and 41.8%, respectively (P < 0.05). Patient satisfaction was 8.2 for those with proximal type CSA and 6.9 for those with distal type CSA (P < 0.01). A correlation was observed among the levels of improvement in muscle power, JOA score based recovery rate, patient satisfaction and course of disease (P < 0.05). CONCLUSION: ACDF can effectively improve the clinical function of patients with CSA and result in good patient satisfaction despite the surgical outcomes for distal type CSA being inferior to those for proximal type CSA. Course of disease is the fundamental factor that affects the surgical outcomes for CSA. We recommend that patients with CSA undergo surgical intervention as early as possible.

Potential advantages of the H-reflex of the biceps femoris-long head in documenting S1 radiculopathy.

PURPOSE: A novel H-reflex method using the biceps femoris-long head (BF-LH) was investigated to collect the normative data for this reflex arc and assess its clinical utility for S1 radiculopathy evaluation. Comparability with conventional tibial and Sol H-reflex findings was also determined. METHODS: BF-LH H-reflexes were recorded using surface electrodes to S1-root stimulation in 43 unilateral S1 radiculopathy patients (radiculopathy group) and 34 normal subjects (control group) from March 2009 to December 2011. H-M interval and peak-to-peak amplitudes were measured. The BF-LH H-reflex and the H-reflex from the soleus muscle (Sol H-reflex) to both tibial nerve stimulation (tibial H-reflex) and S1-root stimulation were used and compared for application in S1 radiculopathy evaluation. RESULTS: BF-LH H-reflexes were reliably recorded for all control group subjects. Abnormal BF-LH H-reflexes were recorded for 40 (93.0%) radiculopathy group patients in the involved extremity, and abnormal involved side tibial H-reflexes and Sol H-reflexes were recorded in 31 (72.1%) and 41 (95.3%) radiculopathy group patients, respectively. The BF-LH H-reflex exhibited significantly higher sensitivity for evaluation of S1 radiculopathy, accurate in 40 (93.0%) radiculopathy group patients, than that provided by the conventional tibial H-reflex of only 31 (72.1%) (P < 0.05). CONCLUSIONS: The BF-LH H-reflex is a highly sensitive and reliable clinical tool for evaluation of the S1 spinal reflex pathway in radiculopathy that is distinct from the Sol H-reflex and conventional tibial H-reflex arcs.

Minimally invasive lumbar interbody fusion via MAST Quadrant retractor versus open surgery: a prospective randomized clinical trial.

BACKGROUND: In recent years, a variety of minimally invasive lumbar surgery techniques have achieved desirable efficacy, but some dispute remains regarding the advantages over open surgery. This study aimed to compare minimally invasive lumbar interbody fusion via MAST Quadrant retractor with open surgery in terms of perioperative factors, postoperative back muscle function, and 24-month postoperative follow-up results. METHODS: From September 2006 to June 2008, patients with single-level degenerative lumbar spine disease who were not responsive to conservative treatment were enrolled in this study. Patients were randomized to undergo either minimally invasive surgery (MIS, transforaminal lumbar interbody fusion via MAST Quadrant retractor, 41 cases) or open surgery (improved transforaminal lumbar interbody fusion, 38 cases). RESULTS: The MIS group had longer intraoperative fluoroscopy time than the open surgery group, and the open surgery group had significantly increased postoperative drainage volume and significantly prolonged postoperative recovery time compared with the MIS group (P < 0.05 for all). MRI scanning showed that the T2 relaxation time in the multifidus muscle was significantly shorter in the MIS group than in the open surgery group at 3 months after surgery (P < 0.01). Surface electromyography of the sacrospinalis muscle showed that the average discharge amplitude and frequency were significantly higher in the MIS group than in the open surgery group (P < 0.01). The Oswestry disability index and visual analog scale scores were better at 3, 6, 12 and 24 months postoperatively than preoperatively in both groups. Both groups of patients met the imaging convergence criteria at the last follow-up. CONCLUSIONS: MIS can effectively reduce sacrospinalis muscle injury compared with open surgery, which is conducive to early functional recovery. In the short term, MIS is superior to open surgery, but in the long term there is no significant difference between the two procedures.

Value of preoperative magnetic resonance imaging measurements in thoracic percutaneous vertebroplasty using unilateral.

BACKGROUND: Increasing the successful puncture rate of the percutaneous vertebroplasty (PVP) in thoracic vertebral compression fracture by unilateral puncture is a problem that spinal surgeons are trying to solve. The aim of this study was to assess the value of preoperative MRI imaging measurements for PVP using a unilateral puncture. METHODS: We performed a retrospective, comparative study of two groups of osteoporotic thoracic vertebral compression fracture patients who had received a PVP using a unilateral puncture. Group A (22 patients with 27 valid vertebrae) received PVP with a unilateral puncture between October 2005 and February 2007. Group B (18 patients with 24 valid vertebrae) received a routine MRI imaging measurements before a PVP between March 2007 and June 2008. We determined the target area to puncture based on the preoperative MRI cross-sectional images of vertebra. The PVP used a simultaneous puncture through a unilateral posterolateral approach, so the vertical distance from the point of skin puncture to the posterior median line, as well as the puncture angle, were measured using the MRI. The results were used to guide the PVP operation. We compared these two groups based on the average time for a single vertebra operation, the achievement ratio of puncture, and the incidence of bone cement leakage during surgery. The mean follow-up period was 14.2 months (range 12 - 23 months). The pre- and post-operative visual analogue score (VAS) (3 and 12 months post-surgery), the variation of Oswestry disability index (ODI) and the incidence of long-term complications were also compared. RESULTS: The average time of a single vertebra operation in groups A and B were (34.7 ± 5.4) and (23.3 ± 4.2) minutes, respectively. In groups A and B, the success rates of puncture were 74.1% and 91.7%, respectively. Postoperative reduction of the average VAS scores in groups A and B at 3 and 12 months post-surgery were 5.8 ± 2.1, 6.1 ± 1.8, 6.1 ± 2.0, 6.2 ± 1.6, respectively. However, the ODI increase was 41.6% ± 5.7%, 40.6% ± 6.0%, 46.3% ± 5.2%, 46.1% ± 6.7%. Paired t test evaluation of the values above showed a significant difference in the time of single-vertebra operation and the success rates between groups A and B (P < 0.05), but no significant difference was seen in the reduction of VAS scores and ODI (P > 0.05). There was no statistically significant difference in the complication rate between the two groups. CONCLUSIONS: A preoperative MRI measurement effectively reduced the time of PVP with a unilateral puncture, which improved the success rate of the puncture without an additional risk of operation related complication.

H-reflex to S1-root stimulation improves utility for diagnosing S1 radiculopathy.

OBJECTIVE: The H-reflex on stimulation of the tibial nerve in the popliteal fossa is routinely used in the diagnosis of first sacral (S1) nerve-root radiculopathy. The H-reflex latency, however, is considered to lack sensitivity since a small change from the focal root pathology can be diluted in a relatively long reflex latency. We have studied the soleus H-reflex elicited by stimulation of the S1 nerve root at the S1 foramen. The normal values for the S1-foramen H-reflex have been reported in a previous study, but there are no definitive reports in patients with S1 radiculopathy. This study was undertaken to determine whether stimulating at the S1 nerve root can improve the utility of the H-reflex for detecting an S1-root lesion. METHODS: A randomised paired-study design was utilised to evaluate two H-reflexes: one elicited with tibial nerve stimulation and one elicited with S1-root stimulation. Fifty-five patients with unilateral S1 radiculopathy, confirmed by clinical, electrodiagnostic and magnetic resonance imaging (MRI) evidences were studied. A high-voltage electrical stimulator was used to elicit H-reflexes bilaterally at the S1 foramen and L4/L5 spine level. Latencies were compared with previously generated normal values and similar responses from the asymptomatic leg, focussing on the interval between the peak of M- and H-waves (HMI). RESULTS: On the symptomatic side, 39 of the 55 patients had abnormal tibial H-reflex latencies and 54 patients had abnormal responses on S1-foramen stimulation (absent in 18; HMI prolonged >0.4ms in 36). On the asymptomatic side, all 55 patients had normal tibial H-reflexes, and 52 had normal responses on S1-foramen stimulation. In three patients, the HMI was abnormal on S1-foramen stimulation. In 46 patients tested with L4/L5-level stimulation, H-reflex was present in 39 and absent in seven. The latency of the M-wave to S1 stimulation was normal. CONCLUSIONS: Abnormal S1-root H-reflexes reveal lesions at the S1 root in patients with normal tibial H-reflexes; therefore, enhancing diagnostic sensitivity. The appearance of the H-reflex to L4/L5-level stimulation in patient with absent H-reflex to S1-foramen stimulation further localises the site of S1 nerve-root lesion to the L5/S1 spine level. Thus, H-reflex to S1-root stimulation significantly increases the diagnostic sensitivity for S1 radiculopathy. SIGNIFICANCE: In our study, the S1-root H-reflex with high-voltage electrical stimulation has shown greater sensitivity than the tibial H-reflex in evaluating S1 compressive radiculopathies. An abnormal S1-root H-reflex helps to localise the lesion to the S1 root in patients with concurrent abnormal tibial nerve H-reflex, which may increase diagnostic specificity.

[The anatomic study and clinical significance of the modified transforaminal lumbar interbody fusion].

OBJECTIVE: To put some improvements to the traditional transforaminal lumbar interbody fusion (TLIF) and discuss its clinical significance. METHODS: Completed the traditional posterior lumbar interbody fusion (PLIF) and TLIF procedure in 12 fresh cadavers, dissect further to expose the surrounding anatomical structures, and put the modified TLIF surgery according to the anatomical findings. And simulated the operation in 12 fresh cadavers, analyzed its feasibility and potential advantages. RESULTS: The early anatomical study found that the related nerve root was in a state of high tension and certain risk of injury when completed the traditional PLIF and TLIF surgery, and found certain operational area between the superior articular process and the midline structures of the spinous processes and interspinous ligaments. Put the modified TLIF surgical approach according to the anatomical findings, which the operating area is located in PLIF outside and TLIF inside. As the following words: Take a posterior-middle incision, preserve the supraspinous and interspinous ligaments, and the spinous processes, dissect the bilateral paravertebral muscle, expose lamina and facet joints, not including transverse process, and remove unilateral inferior two third lamina, inferior articular process and expose the articular surface of the superior articular process, then dispose the intervertebral space for interbody fusion obliquely in the unilateral approach. Successfully completed the modified TLIF procedure in 12 fresh cadavers, the results showed that the technique has the following advantages. (1) Only remove unilateral inferior two third lamina and inferior articular process, preserve the supraspinous and interspinous ligaments, and the spinous processes, not expose the transverse process. (2) Both central canal, and lateral recess and nerve root canal of the operative side can be decompressed effectively simultaneously. (3) Avoid excessive traction to the thecal sac and traversing nerve roots and decrease the injury rate due to the reservation of the midline structures and the oblique manipulation, and less injury rate of the exiting nerve root, because of not necessary to expose it routinely. CONCLUSIONS: The modified TLIF is safe and feasible, could effectively reduce the nerve roots injuries. Maybe it's a better choice for most of the Chinese patients at present.

[Comparison of 3D C-arm fluoroscopy-based and CT-based navigation systems in the lumbar pedicle puncture: in vitro experiment on a cadaveric lumbar trunk specimen].

OBJECTIVE: To compare the accuracy and operating features of 3D C-arm fluoroscopy-based and CT-based navigation systems in the lumbar pedicle punctures. METHODS: A specimen of cadaveric lumbar trunk underwent lumbar pedicle punctures at the levels of L3, L4, and L5 under the guidance of the 3D C-arm fluoroscopy-based and CT-based navigation systems. During the procedure C-arm fluoroscopy was used to monitor the accuracy of the puncture. Generally, in comparison with the 3D C-arm fluoroscopy-based navigation system, the best operation route and protocol could be drawn up pre-operatively, matched registration needed to be renewed for each vertebra, and the images thus obtained were of high quality in CT-based navigation. RESULTS: Both navigation systems had excellent accuracy in the guidance of lumbar pedicle punctures, and had different operating features. CONCLUSION: Both navigation systems had its special advantages. The operating process of the 3D C-arm fluoroscopy-based navigation system was more convenient and rapid, and suitable for percutaneous vertebral puncture. CT based navigation system had clearer pictures, especially for the osteoporotic vertebral bodies, and it had less requirements for the equipments.

[Appraise operative outcome for acute central cervical spinal cord injuries without fracture and dislocation].

OBJECTIVE: To evaluate the surgical outcome for acute central cervical spinal cord injuries without fracture and dislocation. METHODS: A retrospective study was performed on 52 patients with acute central cervical cord injuries without fracture and dislocation from 2000 to 2005. All of patients underwent cervical anterior or posterior decompression, fusion and inter fixation. Spinal function was evaluated by ASIA (American Spinal Injury Association) guidelines. Pre- and post-operation ASIA scores were analyzed using liner correlation and regression. The neurological function was recorded during followed-up. The average follow-up was 29 months (range, 12 to 42). RESULTS: After operation, the ASIA scores increased significantly (P<0.01). Finally, ASIA motor, pin pricking and light touching scores of the 41 patients were 91 +/- 7, 107 +/- 6 and 107 +/- 6 respectively. CONCLUSION: Decompression and inter fixation for injured segment can make a stable and broad space for spinal cord, promoting early neurological recovery and long-term improvement.

[Transduction of recombinant marrow stem cells using lentiviral vector and adenoviral vector: a comparative study].

OBJECTIVE: To compare the efficiency of transfection of marrow stem cells (MSCs) by using lentiviral vector and adenoviral vector. METHODS: MSCs were obtained from the femur bone marrow of rat and cultured. Recombinant plasmid pHIV-CS-CG-PRE containing green fluorescent protein (GFP) gene, and package plasmids pRSV-Rev, pMDLg/pPRE, and pMD.G were infected into the human embryonic kidney cells of the line 293T. The rat MSCs were transfected with the DFP recombinant lentiviral particles, and flow cytometry was used to detect the expression of GFP 1, 3, and 5 weeks later. Full-length human bone morphogenetic protein = 2 (hBMP2) gene was searched out from the GenBank and isolated from human liver cDNA from a sample of liver tissue resected from a patient with liver rupture and then cloned. Thus the lentiviral vector with BMP-2 gene, pHIV-CS-CDF-CG-PRE-BMP-2 was constructed and transfected into 293 cells. Indirect immunofluorescence assay, ELISA, and Western blotting were used to detect the expression of hBMP2 gene. RESULTS: After infected by the viral vectors the GFP expression was significantly better in the lentiviral vector-infected rMSCs than in the adenoviral vector-infected ones. FCM showed that the GFP expression rates of the lentiviral vector-infected rMSCs 1, 3, and 5 weeks after the infection were 90%, 83.2%, and 79% respectively, and he GFP expression rates of the adenoviral vector-infected rMSCs 1, 3, and 5 weeks after the infection were 71%, 0.13%, and 0.05% respectively, all significantly lower than on the former group. Indirect immunofluorescence assay, ELISA, and Western blotting showed that the recombinant lentivirus successfully expressed the target protein in the transfected 293T cells. CONCLUSION: Lentiviral vector with hBMP2 gene can be constructed successfully. The transfection efficiency of BMP2 gene by lentivirus is significantly higher than that of adenovirus.

Characterization and gene transfer in mesenchymal stem cells derived from human umbilical-cord blood.

It has been shown that the stromal-cell population found in bone marrow can be expanded and differentiated into cells with the phenotypes of bone, cartilage, muscle, neural, and fat cells. However, whether mesenchymal stem cells (MSCs) are present in human umbilical-cord blood (UCB) has been the subject of ongoing debate. In this study, we report on a population of fibroblastlike cells derived from the mononuclear fraction of human UCB with osteogenic and adipogenic potential, as well as the presence of a subset of cells that have been maintained in continuous culture for more than 6 months. These cells were found to express CD29, CD44, CD90, CD95, CD105, CD166, and MHC class, but not CD14, CD34, CD40, CD45, CD80, CD86, CD117, CD152, or MHC class II. We also compared gene expression after gene transfer using lenti- and adenoviral vectors carrying the green fluorescence protein to the MSCs derived from UCB because a reliable gene-delivery system is required to transfer target genes into MSCs, which have attracted attention as potential platforms for the systemic delivery of therapeutic genes. The lentiviral vectors can transduce these cells more efficiently than can adenoviral vectors, and we maintained transgene expression for at least 5 weeks. This is the first report showing that UCB-derived MSCs can express exogenous genes by way of a lentivirus vector. These results demonstrate that human UCB is a source of mesenchymal progenitors and may be used in cell transplantation and a wide range of gene-therapy treatments.

Long-term gene expression using the lentiviral vector in rat chondrocytes.

The optimal approach to a long-term stable transgene expression in chondrocytes has not been established. Recently, lentiviral vectors have been used for transfection of some cultured cell lines. Our study tests the hypothesis that lentiviral vectors lead to longer gene expression in primary chondrocytes. We transfected lentiviral and adenoviral vectors carrying the green fluorescence protein gene to chondrocytes at different infection rates and cultured them in collagen Type I gel for up to 6 weeks. We also transplanted the cells of gel-suspended chondrocytes into the backs of nude mice. The mRNA expression of collagen Type II and aggrecan core protein was tested by real time polymerase chain reaction. The morphologic features and proliferation of chondrocytes were observed. Lentiviral vectors could transfect the green fluorescence protein gene to chondrocytes and the adenoviral vector, and there was no influence on the proliferation and phenotype of the chondrocytes. The percentage of lentiviral green fluorescence protein positive cells was much greater than the adenoviral green fluorescence protein at the end of 6 weeks. Stable green fluorescence protein expression was observed only in the lentivirus-transfected implants. The gene transfected by the lentiviral vector can be expressed efficiently for a long time and may be useful for gene transfer in cartilage defect repair.

Biodegradable microsphere-loaded tacrolimus enhanced the effect on mice islet allograft and reduced the adverse effect on insulin secretion.

The adverse effects of tacrolimus have limited the use of this potent immunosuppressive drug in clinical transplantation. To improve the therapeutic effects, we developed a new type of tacrolimus with biodegradable microsphere technology and examined the immunosuppressive effects on allogeneic islet transplantation and the side-effects on insulin secretion in vivo. With a single subcutaneous injection, mouse blood concentrations of tacrolimus (M-FK) carried in biodegradable microspheres remained flat for 2 weeks (only 10 h for conventional tacrolimus). A single subcutaneous administration of 20 mg/kg of M-FK significantly prolonged the survival of islet allografts (MST = 28 days) compared with the control group (MST = 10 days). Series administration of 10 mg/kg of M-FK at 7-day intervals markedly prolonged the survival of islet grafts, and resulted in 60% allograft acceptance. In mice with syngeneic islet transplantations, a single administration of 30 mg/kg of tacrolimus inhibited insulin secretion, whereas a single administration of an equal dosage of M-FK did not. The results suggested that M-FK enhanced the immunosuppressive effects on islet allograft rejection more effectively with reduced side-effects on insulin secretion.