Biodegradable composites of poly(propylene carbonate) mixed with silicon nitride for osteogenic activity of adipose-derived stem cells and repair of bone defects.

Absorbable polymers have attracted increasing attention in the field of bone regeneration in recent years for their degradation. Compared with other degradable polymers, polypropylene carbonate (PPC) has several advantages such as biodegradation and relatively cheap raw materials. Most importantly, PPC can degrade into water and carbon dioxide totally which does not give rise to local inflammation and bone resorption in vivo. However, pure PPC has not presented excellent osteoinductivity properties. In order to enhance the osteoinductivity of PPC, silicon nitride (SiN) was employed due to its excellent mechanical properties, biocompatibility and osteogenesis compared with the other common materials such as hydroxyapatite and calcium phosphate ceramics. In this study, composites of PPC mixed with different contents of SiN were prepared successfully (PSN10 with 10 wt% SiN content, and PSN20 with 20 wt% SiN content). The characterization of the composites suggested that PPC mixed with SiN evenly and PSN composites presented stable properties. The results in vitro revealed that the PSN20 composite possessed satisfactory biocompatibility and exerted better osteogenic differentiation effects on adipose-derived stem cells (ADSCs). In particular, the PSN20 composite accelerated the healing of bone defects better and degraded with the process of bone healing in vivo. Overall, the PSN20 composite exhibited better biocompatibility, induced osteogenic differentiation of ADSCs and promoted healing of bone defects, due to which the PSN composite is considered as a potential candidate for treating bone defects in the field of bone tissue engineering.

Hydrostatic pressure induces osteogenic differentiation of adipose-derived mesenchymal stem cells through increasing lncRNA-PAGBC.

Induced osteogenesis of adipose-derived mesenchymal stem cells (AMSCs) has been used to facilitate bone regeneration. Specifically, hydrostatic pressure (HP) has been implicated as a key regulator of AMSC differentiation, whereas the mechanisms that underlie the effects of HP on osteogenesis of AMSCs are not fully understood. Long noncoding RNAs (lncRNAs) are emerging regulators for osteogenic differentiation from AMSCs. In the current study, we found that lncRNA-PAGBC was a specific lncRNA that significantly upregulated during osteogenic differentiation of AMSCs based on published database. HP increased lncRNA-PAGBC, which is a competitive endogenous RNA (ceRNA) that binds to the osteogenesis-inhibitory microRNA, miR-133b, to regulate osteogenic differentiation of AMSCs. Moreover, a key osteogenesis-trigger gene, runt-related transcription factor 2 (RUNX2), was identified as a target gene for miR-133b. Suppression of RUNX2 by miR-133b caused impaired osteogenic differentiation of AMSCs. Furthermore, lncRNA-PAGBC overexpression upregulated, whereas lncRNA-PAGBC silencing decreased the expression of RUNX2 through miR-133b. Together, these data suggest that HP induces osteogenic differentiation of AMSCs through increasing lncRNA-PAGBC.

Macro-Microporous Surface with Sulfonic Acid Groups and Micro-Nano Structures of PEEK/Nano Magnesium Silicate Composite Exhibiting Antibacterial Activity and Inducing Cell Responses.

PURPOSE: To improve the surface bio-properties of polyetheretherketone (PEEK)/nano magnesium silicate (n-MS) composite (PC). MATERIALS AND METHODS: The surface of PC was firstly treated by particle impact (PCP) and subsequently modified by concentrated sulfuric acid (PCPS). RESULTS: PCPS surface exhibited not only macropores with sizes of about 150 µm (fabricated by particle impact) but also micropores with sizes of about 2 µm (created by sulfonation of PEEK) on the macroporous walls, and sulfonic acid (-SO3H) groups were introduced on PCPS surface. In addition, many n-MS nanoparticles were exposed on the microporous walls, which formed micro-nano structures. Moreover, the surface roughness and hydrophilicity of PCPS were obviously enhanced as compared with PC and PCP. Moreover, the apatite mineralization of PCPS in simulated body fluid (SBF) was obviously improved as compared with PC. Furthermore, compared with PC and PCP, PCPS exhibited antibacterial performances due to the presence of -SO3H groups. In addition, the responses (eg, adhesion and proliferation as well as differentiation) of bone marrow mesenchymal stem cell of rat to PCPS were significantly promoted as compared with PC and PCP. CONCLUSION: PCPS with macro-microporous surface containing -SO3H groups and micro-nano structures exhibited antibacterial activity and induced cell responses, which might possess large potential for bone substitute and repair.

Genetic engineering of T cells with chimeric antigen receptors for hematological malignancy immunotherapy.

The host immune system plays an instrumental role in the surveillance and elimination of tumors by recognizing and destroying cancer cells. In recent decades, studies have mainly focused on adoptive immunotherapy using engineered T cells for the treatment of malignant diseases. Through gene engraftment of the patient's own T cells with chimeric antigen receptor (CAR), they can recognize tumor specific antigens effectively and eradicate selectively targeted cells in an MHC-independent fashion. To date, CAR-T cell therapy has shown great clinical utility in patients with B-cell leukemias. Owing to different CAR designs and tumor complex microenvironments, genetically redirected T cells may generate diverse biological properties and thereby impact their long-term clinical performance and outcome. Meanwhile some unexpected toxicities that result from CAR-T cell application have been examined and limited the curative effects. Diverse important parameters are closely related with adoptively transferred cell behaviors, including CAR-T cells homing, CAR constitutive signaling, T cell differentiation and exhaustion. Thus, understanding CARs molecular design to improve infused cell efficacy and safety is crucial to clinicians and patients who are considering this novel cancer therapeutics. In this review, the developments in CAR-T cell therapy and the limitations and perspectives in optimizing this technology towards clinical application are discussed.

Factors associated with development of re-nonunion after primary revision in femoral shaft nonunion subsequent to failed intramedullary nailing.

BACKGROUND: Currently, there remains a lack of consensus regarding factors predictive of complication such as re-nonunion after primary revision in femoral shaft nonunion subsequent to failed intramedullary nailing (IMN). A better understanding of prognostic factors could potentially reduce the risk of re-nonunion happening and allow patients to maximize their recovery in the most expeditious manner. Our study aims to identify risk factors in the development of re-nonunion after primary revision inclusive of exchanging reamed nailing (ERN) and augmentative compression plating (ACP) with IMN in situ for femoral shaft nonunion subsequent to failed IMN. METHODS: A retrospective study was performed for 63 cases (61 patients) of femoral shaft nonunion subsequent to failed IMN, who were made primary revision with either ERN or ACP from June 2007 to June 2015. The following set of variables was selected based on the speculation that they would contribute to the outcome: sex (male or female), age, body mass index(BMI), smoking, alcohol abuse, cause of injury, fracture type, type of IMN (antegrade or retrograde), use of IMN locking screws(dynamic or static), site of nonunion, primary nonunion time, pathological type of nonunion, bone defect (mm), primary revision method (ERN or ACP), and adjuvant autogenous bone grafting (ABG) (yes or no). Univariate analysis and multiple regression were used to identify risk factors in the development of re-nonunion after primary revision with either ERN or ACP for femoral shaft nonunion subsequent to failed IMN. The minimum follow-up time was 1.5 years (standard deviation [SD] = 1.2, range 1.5-8 years). RESULTS: Of 63 cases (61 patients) of femoral shaft nonunion subsequent to failed IMN, primary revision with ERN was performed in 33 (52.4%) cases and primary revision with ACP was performed in 30 (47.6%) cases. Adjuvant ABG procedure was undertaken in 39 (61.9%) cases during primary revisions. Re-nonunion was diagnosed as in 18 (28.6%) cases after primary revision with either ERN or ACP. There was a significant difference in time to union between patients treated with primary ERN and those with primary ACP (log-rank, p = 0.006). Furthermore, the difference was also statistically significant between patients with adjuvant ABG procedure and those without it (log-rank, p = 0.009). The relative risk factors included smoking, BMI, site of nonunion, bone defect, primary revision method, and adjuvant ABG procedure. However, primary revision method and adjuvant ABG procedure were shown to be two independent risk factors in multiple logistic regression analysis. CONCLUSIONS: Patients with excessive tobacco use, BMI ≥ 30 kg/m2, bone defect ≥ 5 mm, primary revision with ERN, and no adjuvant ABG procedure had a higher likelihood of developing re-nonunion. Of these risk factors, primary revision with ERN and no adjuvant ABG procedure were two strongest risk factors.

Reactivation of denervated Schwann cells by neurons induced from bone marrow-derived mesenchymal stem cells.

The use of neurons induced from stem cells has been introduced as an effective strategy for promoting peripheral nerve regeneration (PNR). The evolution and role of native denervated Schwann cells (SCs) were often ignored when exploring the mechanisms underlying neural transplantation therapy for PNR. The aim of this study was to understand if following injury, native denervated SCs could be reactivated by transplanting of neurons induced from bone marrow-derived mesenchymal stem cells (NI-BMSCs) to promote PNR. We co-cultured denervated SCs with NI-BMSCs in vitro, tested the proliferation of denervated SCs, and measured the expression and secretion of neurotrophic factors and neural adhesion molecules of the denervated SCs. Concurrently, 48 adult male Sprague-Dawley rats were randomly divided into 4 even groups of 12 rats each: normal group, phosphate-buffered saline (PBS) injection group, BMSCs transplantation group and NI-BMSCs transplantation group. PBS injection and cells transplantation were performed 4 weeks post-injury. After 4 weeks of NI-BMSCs transplantation, the survival of seeded NI-BMSCs was examined, proliferation and ultrastructure of native denervated SCs were detected, and myelination, axonal regeneration and the sciatic functional index measurements were also determinated. Our results demonstrated that NI-BMSCs reactivated denervated SCs both in vitro and in vivo and promoted sciatic nerve regeneration.

Augmentative locking plate with autologous bone grafting for distal femoral nonunion subsequent to failed retrograde intramedullary nailing.

OBJECTIVE: To explore the indications and efficacy of augmentative locking compression plate (LCP) or less invasive stabilization system (LISS)with autogenous bone grafting (BG) in treating distal femoral nonunion subsequent to failed retrograde intramedullary nailing (RIN). METHODS: A retrospective study was performed for 21 patients with distal femoral nonunion subsequent to failed RIN, who received therapy with either augmentative LCP (n = 11) or LISS with autogenous BG (n = 13). Operation time, time to union, union rate, time to renonunion, complication rate and SF-36 scores a year after hardware removal were compared between the two groups. RESULTS: The bone union occurred in 13/13 (100%) cases in augmentative LISS group versus 9/11 (81.8%) cases in augmentative LCP group [odds ratio (OR) = 3.21, 95% confidence interval (CI) 0.7-13]. Time to union, time to renonunion, complication rate of the augmentative LCP group were significantly more than that of the augmentative LISS with autogenous BG group (p = 0.023, p = 0.021 and p = 0.033). No significant difference was found in the average operation time of two groups (p = 0.121). At the follow-up a year after hardware removal, statistically significant HRQOL improvement in the augmentive LISS group was measured at the level of pain (p = 0.003) and general health perception (p = 0.011), as compared to the augmentive LCP group. CONCLUSIONS: We suggest augmentative LCP, for distal femoral nonunios after RIN, may be optimal for that of typeAO33A fractures, whereas augmentative LISS for that of typeAO33C fractures more.

Exchanging reamed nailing versus augmentative compression plating with autogenous bone grafting for aseptic femoral shaft nonunion: a retrospective cohort study.

OBJECTIVE: The purpose of this study was to compare the outcomes of exchanging reamed nailing (ERN) and augmentative compression plating (ACP) with autogenous bone grafting (BG) for the treatment of aseptic femoral shaft nonunion secondary to the treatment of intramedullary nailing (IMN). METHODS: A multicenter retrospective study was performed for 178 patients (180 cases) of aseptic femoral shaft nonunion secondary to first treatment of IMN. All cases were fixed with either ERN (n=87) or ACP (n=93). In the ERN group, 42 cases (48.3%) were nonisthmal nonunions and 45 (51.7%) were isthmal nonunions. In the ACP group, 46 cases (49.5%) were nonisthmal nonunions, and 47 (50.5%) were isthmal nonunions. Operation time, blood loss, time to union, union rate, volume of drainage, time to renonunion, and complication rate were compared between the 2 groups. RESULTS: All patients were followed up, with a mean period of 4.1 years (range: 1-7.1 years). Bone union occurred in 93/93 cases (100%) in the ACP group versus 75/87 cases (86.2%) in the ERN group (odds ratio [OR]=3.28, 95% confidence interval [CI] 0.8-14). Of the 12 cases involved with renonunion in the ERN group, 10 were nonisthmal nonunions, and 2 were isthmal nonunions with cortical bone defect >3 cm. The union time, blood loss, and complication rate of the ERN group were significantly higher than those of the ACP group (p=0.028, p=0.035, and p=0.021, respectively). No significant difference was found in the average operation time of the 2 groups (p=0.151). However, for the nonisthmal nonunions, a significant difference was found between the ERN and ACP groups (p=0.018). CONCLUSION: ACP with autogenous BG can obtain a higher bone union rate and shorter time to union than ERN in the treatment of aseptic femoral shaft nonunion after failed IMN. Especially for nonisthmal femoral shaft nonunions or isthmal nonunions with larger bone defects, ACP with autogenous BG can be more advantageous than ERN for patients. A future prospective observational study should be conducted.

Mesoporous magnesium silicate-incorporated poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) bioactive composite beneficial to osteoblast behaviors.

Mesoporous magnesium silicate (m-MS) and poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) (PCL-PEG-PCL) composite (m-MPC) was synthesized by solvent casting method. The results suggest that the mechanical properties of compressive strength and elastic modulus, as well as hydrophilicity, of the m-MPC increased with increase of m-MS content in the composites. In addition, the weight loss of the m-MPC improved significantly with the increase of m-MS content during composite soaking in phosphate-buffered saline for 10 weeks, indicating that incorporation of m-MS into PCL-PEG-PCL could enhance the degradability of the m-MPC. Moreover, the m-MPC with 40 w% m-MS could induce a dense and continuous apatite layer on its surface after soaking in simulated body fluid for 5 days, which was better than m-MPC 20 w% m-MS, exhibiting excellent in vitro bioactivity. In cell cultural experiments, the results showed that the attachment and viability ratio of MG63 cells on m-MPC increased significantly with the increase of m-MS content, showing that the addition of m-MS into PCL-PEG-PCL could promote cell attachment and proliferation. The results suggest that the incorporation of m-MS into PCL-PEG-PCL could produce bioactive composites with improved hydrophilicity, degradability, bioactivity, and cytocompatibility.

Tissue engineering scaffolds of mesoporous magnesium silicate and poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) composite.

Mesoporous magnesium silicate (m-MS) and poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) (PCL-PEG-PCL) composite scaffolds were fabricated by solvent-casting and particulate leaching method. The results suggested that the incorporation of m-MS into PCL-PEG-PCL could significantly improve the water adsorption of the m-MS/PCL-PEG-PCL composite (m-MPC) scaffolds. The in vitro degradation behavior of m-MPC scaffolds were determined by testing weight loss of the scaffolds after soaking into phosphate buffered saline (PBS), and the result showed that the degradation of m-MPC scaffolds was obviously enhanced by addition of m-MS into PCL-PEG-PCL after soaking for 10 weeks. Proliferation of MG63 cells on m-MPC was significantly higher than MPC scaffolds at 4 and 7 days. ALP activity on the m-MPC was obviously higher than MPC scaffolds at 7 days, revealing that m-MPC could promote cell differentiation. Histological evaluation showed that the introduction of m-MS into PCL-PEG-PCL enhanced the efficiency of new bone formation when the m-MPC scaffolds implanted into bone defect of rabbits. The results suggested that the inorganic/organic composite of m-MS and PCL-PEG-PCL scaffolds exhibited good biocompatibility, degradability and osteogenesis.

Gene expression profile analysis of human intervertebral disc degeneration.

In this study, we used microarray analysis to investigate the biogenesis and progression of intervertebral disc degeneration. The gene expression profiles of 37 disc tissue samples obtained from patients with herniated discs and degenerative disc disease collected by the National Cancer Institute Cooperative Tissue Network were analyzed. Differentially expressed genes between more and less degenerated discs were identified by significant analysis of microarray. A total of 555 genes were significantly overexpressed in more degenerated discs with a false discovery rate of < 3%. Functional annotation showed that these genes were significantly associated with membrane-bound vesicles, calcium ion binding and extracellular matrix. Protein-protein interaction analysis showed that these genes, including previously reported genes such as fibronectin, COL2A1 and ß-catenin, may play key roles in disc degeneration. Unsupervised clustering indicated that the widely used morphology-based Thompson grading system was only marginally associated with the molecular classification of intervertebral disc degeneration. These findings indicate that detailed, systematic gene analysis may be a useful way of studying the biology of intervertebral disc degeneration.

Comparison of the pedicle screws placement between electronic conductivity device and normal pedicle finder in posterior surgery of scoliosis.

STUDY DESIGN: Prospective randomized clinical trial. OBJECTIVE: To compare the accuracy and time using of pedicle screw placement between electronic conductivity device (ECD) and normal pedicle finder (NPF) in posterior surgery of scoliosis, through a randomized clinical trial. SUMMARY OF BACKGROUND DATA: Pedicle screw insertion for scoliosis correction can be associated with increased pedicle perforations. The malposition rates using various techniques in different region of the spine have been reported to occur with a frequency of 3.3%-43%. An ECD has been reported in spine surgeries, but its accuracy and surgical time comparing with NPF in the presence of scoliosis has not been reported. METHODS: The 42 patients of adolescent idiopathic scoliosis with average major Cobb angle of 55.3±7 degrees (range, 45-78 degrees), who received posterior correction surgeries using pedicle screws system only were divided into 2 groups by random: group NPF (22 patients); and group ECD (20 patients). NPF group had 332 screws and ECD group had 362 screws. The 2 groups were compared for accuracy of screw placement, time for screw insertion, and the number of times the C-arm had to be brought into the field. RESULTS: There were 47 (14.2%) pedicle perforation in the NPF group as compared with only 15 (4.1%) in the ECD group (P<0.001). Although in different region of the spine, screw accuracy showed discrepant statistical result, with upper (T1-T3), middle (T4-T7), and lower thoracic (T8-T10) comparison showing significant statistical difference (P=0.010, 0.001, and 0.041, respectively) and thoracolumbar (T11-L2) and lower lumbar (L3-L5) comparison showing no significant statistical difference (P=0.278 and 0.292, respectively). Average screw insertion time in the NPF group was 241±61 seconds compared with 204±33 seconds in the ECD group (P=0.009). The C-arm had to be moved into the operation field on an average of 1.59±0.67 times in the NPF group compared with 1.20±0.52 in the ECD group (P=0.040). CONCLUSIONS: ECD increases pedicle screw accuracy, especially in T1-T10, and reduces insertion time and radiation in posterior adolescent idiopathic scoliosis.

Treatment of bone nonunion and bone defects associated with unsuccessful humeral condylar fracture repair with autogenous iliac bone reconstruction.

BACKGROUND: Our preliminary study retrospectively assessed outcomes after the use of autogenous iliac bone grafts combined with internal fixation to repair refractory bone nonunions and bone defects associated with supracondylar or intracondylar humeral fractures, or both. MATERIALS AND METHODS: We identified 22 patients (14 men and 8 women) with a mean age of 33.8 years (range, 17-60 years) with bone nonunion and severe bone defects associated with supracondylar or intercondylar humerus fractures, or both. The humeral condyle in each patient was anatomically reconstructed using autologous iliac bone grafts and internal fixation. Active functional exercise was initiated 3 to 4 weeks after surgery. The following variables were assessed: preoperative and postoperative elbow range of motion, Mayo Elbow Performance Score (MEPS), and postoperative complications. RESULTS: Mean follow-up was 38.6 months. Mean duration until bone union was 5.6 months. Preoperatively, 16 patients had a fair or poor MEPS (<75). At final follow-up MEPS was excellent (>90) in 8, good (75-90) in 9, fair (60-74) in 4, and poor (<60) in 1 patient. Postoperative heterotopic ossification anterior to the elbow joint occurred in 2 patients. CONCLUSIONS: Our preliminary results suggest that anatomic reconstruction of the humeral condyle using autogenous iliac bone grafting with internal fixation can improve elbow joint function in patients with bone nonunion and bone defects associated with supracondylar or intracondylar humeral fractures, or both. Larger scale studies are warranted to confirm our findings and compare the efficacy of this vs other surgical approaches.

Treatment of lower extremity long bone nonunion with expandable intramedullary nailing and autologous bone grafting.

BACKGROUND: Nonunion of long bones in lower limbs is a common complication of orthopedic trauma that can be extremely debilitating. This retrospective study describes our experience using expandable intramedullary nails and autologous bone grafting in treating lower limb long bone nonunion with bone defects. METHODS: Nineteen patients (mean age 38.9 years, range 18-61) with lower limb long bone nonunion and defects caused by femoral or tibial fracture types were as follows: A2 (3 femoral, 1 tibial), A3 (1 femoral, 2 tibial), B2 (3 femoral, 4 tibial), and B3 (1 femoral, 4 tibial). Expandable intramedullary nailing and autologous bone (iliac and/or fibular) grafting were used for the treatment. Postoperative bone healing as determined by analysis of standard anteroposterior and lateral X-ray films every 4 weeks. Complications were noted. RESULTS: The average number of previous surgeries was 1.9 (range 1-4). The mean duration from original injury to treatment was 17.6 months (range 9-40 months). Femoral shaft nonunion healed on average of 26.5 weeks (range 16-60 weeks) after surgery, while tibial shaft nonunion healed on average of 23.6 weeks (range 12-40 weeks) after surgery. Class I healing occurred in all but two patients who experienced chronic postoperative osteomyelitis and delayed wound healing, respectively. Two patients complained of postoperative donor site pain. CONCLUSIONS: The use of expandable intramedullary nails and autologous bone grafts was an effective method for repair of nonunion of lower limb fractures combining with bone defects with minimal complications.

[Application of acetabular tridimensional memory alloy-fixation system in treatment of old acetabular posterior wall fracture with bone defect].

OBJECTIVE: To investigate the effectiveness of acetabular tridimensional memory alloy-fixation system (ATMFS) combined with autologous iliac bone in the treatment of old acetabular posterior wall fracture with bone defect. METHODS: Between January 2002 and February 2009, 17 patients with old acetabular posterior wall fracture and bone defect were treated, including 11 males and 6 females with an average age of 41.7 years (range, 20-60 years). The time from fracture to admission was 14-180 days (mean, 63 days). The displacement of the acetabular articular surface was more than or equal to 3 mm. According to the America Association of Orthopedic Surgeon (AAOS) acetabular fracture and defect classification standard, there were 4 cases of type I, 6 cases of type II, 5 cases of type III, and 2 cases of type IV. After the residual fracture fragments of the acetabular posterior wall and soft tissue hyperplasia were removed, the femoral head was reduced, and posterior wall defect was repaired with autologous iliac bone graft; ATMFS was used to fix acetabular posterior wall and artificial capsular ligament to reconstruct the hip so as to prevent re-dislocation of the femoral head. RESULTS: According to Matta imaging assessment standard, the results were excellent in 8 cases, good in 6 cases, fair in 2 cases, and poor in 1 case with an excellent and good rate of 82.3%. All incisions healed by first intention, and no sciatic nerve injury occurred. All patients were followed up 1-8 years (mean, 3.9 years). The mean time of fracture union was 3.6 months (range, 2-6 months). Avascular necrosis of femoral head occurred in 1 case, heterotopic ossification around the acetabulum in 1 case. According to Merle d'Aubigné-Postel scoring system evaluation, the clinical results were excellent in 9 cases, good in 6 cases, fair in 1 case, and poor in 1 case with an excellent and good rate of 88.2%. CONCLUSION: ATMFS combined with autologous iliac bone graft and artificial ligament reconstruction of the hip joint capsule is a good choice for the treatment of old acetabular posterior wall fractures with bone defect, which can resume the posterior hip joint stability and prevent re-dislocation of the femoral head.

Central administration of kisspeptin-10 inhibits water and sodium excretion of anesthetized male rats and the involvement of arginine vasopressin.

AIM: To investigate the effect of hypothalamus kisspeptin on water and sodium excretion and the possible mechanism. METHOD: The intracerebroventricular (icv) administration and radioimmunoassay were used to observe the effect of kisspeptin-10 on urine flow, sodium and potassium excretion, plasma arginine vasopressin (AVP), and atrial natriuretic peptide (ANP) concentrations in anesthetized male rats. The mediation of renal sympathetic nerve was also investigated by studies conducted on rats with bilateral renal sympathetic denervation. RESULTS: The urine flow, sodium excretion, and free water clearance decreased significantly by icv injection of 5 nmol kisspeptin-10 (p < 0.05) from 30 to 60 min post-injection. Meanwhile, plasma AVP concentrations increased significantly 30 min after the icv injection of 5 nmol kisspeptin-10 (p < 0.05), whereas the equal dose of kisspeptin-10 did not significantly change plasma ANP concentrations. The mean arterial blood pressure, heart rate, and potassium excretion did not significantly change during the experiment. Furthermore, pretreatment with 5 nmol kisspeptin-10 could still significantly decrease urine flow and sodium excretion in renal sympathetic denervated rats. CONCLUSION: Central administration of kisspeptin-10 could inhibit sodium excretion and urine flow in anesthetized male rats, which is probably mediated by increasing the plasma AVP concentration and is independent of plasma ANP concentration and renal sympathetic nerve activity.

Orphanin FQ and glutamate connection in the regulation of gonadotropin-releasing hormone secretion in the preoptic area of conscious male rats.

Utilizing the method of push-pull perfusion and radioimmunoassay (RIA), the secretory profile of gonadotropin-releasing hormone (GnRH) in the preoptic area (POA) and serum-luteinizing hormone (LH) levels were examined in conscious male rats after administration of [Nphe(1)]NC(1-13)NH(2), a competitive antagonists of the opioid receptor-like 1 receptor (ORL1 receptor) which is endogenous receptor for Orphanin FQ (OFQ). Glutamate release in the POA was also measured by high-performance liquid chromatography (HPLC) after perfusion of [Nphe(1)]NC(1-13)NH(2), i.e. NC13. The results showed that GnRH secretion from the POA and serum LH levels was increased significantly 40 min and 60 min, respectively after perfusion of 2 and 20 mmol/L NC13 in freely moving male rats (p<0.05). Pretreatment with a glutamate, N-methyl-D-aspartate (NMDA) receptor antagonist (MK-801, s.c., 0.2 mg/kg) abolished the increase of GnRH release in the POA induced by 2 mmol/L NC13. Additionally, 20 mmol/L NC13 significantly enhanced glutamate release in the POA at 40 min post-perfusion in a dose-dependent manner. These findings suggest that hypothalamic OFQ/ORL1 receptor system plays a role in the physiological inhibitory control of GnRH secretion in the POA of male rats, and provide evidence for involvement of an OFQ and glutamate pathway in the control of GnRH secretion.

[Reconstruction of condyle in treatment of refractory condylar nonunion and defect of humerus].

OBJECTIVE: To discuss the strategy of condylar reconstruction in the treatment of refractory condylar nonunion and defect of humerus. METHODS: From September 1998 to September 2005, 18 patients with refractory condylar nonunion concomitant withdefect of humerus were treated. The series included 12 males and 6 females, aged 18 to 60 years. According to AO/ASIF system, primal fractures were classified, including 5 cases of type A3, 2 cases of type B1, 4 cases of type C2 and 7 cases of type C3 fractures. Condylar nonunion and defect of humerus were confirmed by preoperative X-ray. Defective bone mass was 1-4 cm2. The mean extension and flexion of elbow joint was 21.5 degrees (5-65 degrees) and 95.8 degrees (85.0-123.5 degrees) respectively. According to Cassebaum scoring system, the excellent and good rate was 27.8% (excellent in 1 case and good in 4 cases). Time from injury to operation averaged 22.8 months (7-52 months). All patients were operated with approach of olecranon osteotomy. Bone defect was reconstructed with iliac autograft. Shape memory compressive connector, Kirschner wire, cannulated nail, anatomic plates and reconstruction plates were used to fix. RESULTS: Eighteen patients were followed up 12-86 months (mean 27.6 months). All the incisions healed by first intention. No bone block displacement,loosening or breakage of internal fixation occurred. The time of bone union averaged 5.7 months (4-8 months). The mean extension and flexion of elbow joint were 11.4 degrees (0-44.5 degrees) and 128.6 degrees (105.5-144.5 degrees) 1 year after operation. Ectopicossification formed in 1 case at anterior part of elbow 4 months after operation. According to Cassebaum scoring system,the results were excellent in 8 cases, good in 6 cases, fair in 3 cases and poor in 1 case. The excellent and good rate was 77.8%. CONCLUSION: The shape of humeral condyle can be reconstructed with iliac autograft. Compressive internal fixation of bone block can promote bone union. Anatomical reconstruction, rigid internal fixation and early function exercise can improve the function of elbow joint evidently.

[Development of a fusion toxin IL15M-PEdelta293 based on a receptor-specific IL-15 antagonist].

IL-15 and IL-15 receptors (IL-15R) play a crucial role in the pathogenesis of adult T-cell leukemia (ATL), multiple myeloma and inflammatory autoimmune diseases. To develop a novel therapeutic agent capable of eliminating IL-15R-over-expressing abnormal cells, the gene coding for human IL-15 antagonist (IL-15M) was fused with a DNA fragment coding for the mutated form of Pseudomonas exotoxin, PEdelta293. The resulting gene fusion was cloned into pET16b under the control of T7 promoter, giving rise to the expression plasmid pET-IL15M-PEdelta293. Using Ni2+ -NTA affinity chromatography, IL15M-PEdelta293 was purified from E. coli BL21 (DE3) pLysS transformed with pET-IL15M-PEdelta293. The fusion toxin showed cytotoxicity to IL-15R-bearing myelogenous leukemia cell line K562 and K562-derived multidrug resistant cell line K562/AO2. However, IL-15R negative cell line Jurkat was insensitive to IL15M-PEdelta293. In addition, the toxic effect of IL15M-PEdelta293 on K562 was completely blocked by excessive amount of recombinant human IL-15. These results demonstrated that the selective cytotoxicity of IL15M-PEdelta293 correlated with the appropriate IL-15R expression on target cells. The present data suggest that the chimeric toxin constructed in this report may have therapeutic potential in the treatment of diseases associated with abnormal expression of IL-15/IL-15R, even in the treatment of chemotherapy refractory tumors.