Effects of platelet-rich plasma and triamcinolone acetonide on interleukin-1ß-stimulated human rotator cuff-derived cells.

OBJECTIVES: Triamcinolone acetonide (TA) is widely used for the treatment of rotator cuff injury because of its anti-inflammatory properties. However, TA can also produce deleterious effects such as tendon degeneration or rupture. These harmful effects could be prevented by the addition of platelet-rich plasma (PRP), however, the anti-inflammatory and anti-degenerative effects of the combined use of TA and PRP have not yet been made clear. The objective of this study was to determine how the combination of TA and PRP might influence the inflammation and degeneration of the rotator cuff by examining rotator cuff-derived cells induced by interleukin (IL)-1ß. METHODS: Rotator cuff-derived cells were seeded under inflammatory stimulation conditions (with serum-free medium with 1 ng/ml IL-1ß for three hours), and then cultured in different media: serum-free (control group), serum-free + TA (0.1mg/ml) (TA group), serum-free + 10% PRP (PRP group), and serum-free + TA (0.1mg/ml) + 10% PRP (TA+PRP group). Cell morphology, cell viability, and expression of inflammatory and degenerative mediators were assessed. RESULTS: Exposure to TA significantly decreased cell viability and changed the cell morphology; these effects were prevented by the simultaneous administration of PRP. Compared with the control group, expression levels of inflammatory genes and reactive oxygen species production were reduced in the TA, PRP, and TA+PRP groups. PRP significantly decreased the expression levels of degenerative marker genes. CONCLUSIONS: The combination of TA plus PRP exerts anti-inflammatory and anti-degenerative effects on rotator cuff-derived cells stimulated by IL-1ß. This combination has the potential to relieve the symptoms of rotator cuff injury.Cite this article: T. Muto, T. Kokubu, Y. Mifune, A. Inui, R. Sakata, Y. Harada, F. Takase, M. Kurosaka. Effects of platelet-rich plasma and triamcinolone acetonide on interleukin-1ß-stimulated human rotator cuff-derived cells. Bone Joint Res 2016;5:602-609. DOI: 10.1302/2046-3758.512.2000582.

Profiling microRNA expression in fracture nonunions: Potential role of microRNAs in nonunion formation studied in a rat model.

MicroRNAs (miRNAs ) are small non-coding RNAs that regulate gene expression. We hypothesised that the functions of certain miRNAs and changes to their patterns of expression may be crucial in the pathogenesis of nonunion. Healing fractures and atrophic nonunions produced by periosteal cauterisation were created in the femora of 94 rats, with 1:1 group allocation. At post-fracture days three, seven, ten, 14, 21 and 28, miRNAs were extracted from the newly generated tissue at the fracture site. Microarray and real-time polymerase chain reaction (PCR) analyses of day 14 samples revealed that five miRNAs, miR-31a-3p, miR-31a-5p, miR-146a-5p, miR-146b-5p and miR-223-3p, were highly upregulated in nonunion. Real-time PCR analysis further revealed that, in nonunion, the expression levels of all five of these miRNAs peaked on day 14 and declined thereafter. Our results suggest that miR-31a-3p, miR-31a-5p, miR-146a-5p, miR-146b-5p and miR-223-3p may play an important role in the development of nonunion. These findings add to the understanding of the molecular mechanism for nonunion formation and may lead to the development of novel therapeutic strategies for its treatment.

Depletion of SIRT6 causes cellular senescence, DNA damage, and telomere dysfunction in human chondrocytes.

OBJECTIVE: SIRT6, a member of the sirtuin family of nicotinamide adenine dinucleotide (NAD(+))-dependent protein deacetylases, has been implicated as a key factor in aging-related diseases. However, the role of SIRT6 in chondrocytes has not been fully explored. The purpose of this study was to examine the role of SIRT6 in human chondrocytes by inhibiting SIRT6 in vitro. DESIGN: First, the localization of SIRT6 and proliferation cell nuclear antigen (PCNA) in human cartilages was examined by immunohistochemistry. Next, SIRT6 was depleted by RNA interference (RNAi), and the effect of SIRT6 depletion on changes in gene expression, protein levels, proliferation, and senescence in human chondrocytes was assessed. Furthermore, to detect DNA damage and telomere dysfunction, γH2AX foci and telomere dysfunction-induced foci (TIFs) were examined using immunofluorescence microscopy. The protein levels of two mediators for DNA damage induced-senescence, p16 and p21, were examined by western blotting. RESULTS: Immunohistochemical analysis showed SIRT6 was preferentially expressed in the superficial zone chondrocytes and PCNA-positive cluster-forming chondrocytes in the osteoarthritic cartilage tissue samples. Real-time PCR analysis showed that matrix metalloproteinase 1 (MMP-1) and MMP-13 mRNA were significantly increased by SIRT6 inhibition. Moreover, SIRT6 inhibition significantly reduced proliferation and increased senescence associated ß-galactosidase (SA-ß-Gal)-positive chondrocytes; it also led to increased p16 levels. Immunofluorescence microscopy showed that γH2AX foci and TIFs were increased by SIRT6 inhibition. CONCLUSION: Depletion of SIRT6 in human chondrocytes caused increased DNA damage and telomere dysfunction, and subsequent premature senescence. These findings suggest that SIRT6 plays an important role in the regulation of senescence of human chondrocytes.

A radiographic analysis of alignment of the lower extremities--initiation and progression of varus-type knee osteoarthritis.

OBJECTIVE: This study aimed to investigate alignment based on age in normal knees and alignment based on deformity in osteoarthritis (OA) knees using detailed radiographic parameters. DESIGN: Various parameters were measured from weight-bearing long leg radiographs of 1251 legs (797 normal and 454 OA knees) as a cross-sectional study. Normal knees were classified by age (young, middle aged, aged, and elderly) and symptomatic OA knees on the basis of the alignment (femorotibial angle (FTA): mild, moderate, severe and profound). The mean measurements in each group were calculated and compared within each group. RESULTS: The femoral shaft showed medially bowed curvature (femoral bowing) of approximately 2° in the young normal group, which shifted to lateral bowing with age. However, OA knees showed larger lateral bowing with OA grade, which might reduce the condylar-shaft angle and subsequently shifted the mechanical axis medially. Progression of mild to moderate OA might be associated with a decreasing condylar-shaft angle (femoral condylar orientation) and widening condylar-plateau angle (joint space narrowing) rather than decreasing tibial plateau flattering. Steeping of the tibial plateau inclination due to increasing tibial plateau shift (tibial plateau compression) rather than medial tibial bowing might be the main contributor to worsening of varus deformity in knees with severe and profound OA. CONCLUSIONS: This cross-sectional study might provide the possibility of OA initiation and progression. The lateral curvature of the femoral shaft associated with aging may contribute to the initiation of varus-type OA of the knee. These changes in the femur may be followed by secondary signs of OA progression including varus femoral condylar orientation, medial joint space narrowing, and tibial plateau compression.

Dose- and time-dependent effects of triamcinolone acetonide on human rotator cuff-derived cells.

OBJECTIVES: To investigate the appropriate dose and interval for the administration of triamcinolone acetonide (TA) in treating tendinopathy to avoid adverse effects such as tendon degeneration and rupture. METHODS: Human rotator cuff-derived cells were cultured using three media: regular medium (control), regular medium with 0.1 mg/mL of TA (low TA group), and with 1.0 mg/mL of TA (high TA group). The cell morphology, apoptosis, and viability were assessed at designated time points. RESULTS: In the low TA group, the cells became flattened and polygonal at seven days then returned to normal at 21 days. The cell apoptosis ratio and messenger ribonucleic acid expression of caspase-3, 7, 8, and 9 increased, and viability was reduced in the low and high groups at seven days. In the low TA group, apoptosis and viability returned to normal at 21 days, however, in the high TA group, the cell morphology, apoptosis ratio, caspase-3, 7, 8, and 9 and viability did not return by day 21. Re-administration was performed in the low TA group at 7-, 14-, and 21-day intervals, and cell viability did not return to the control level at the 7- and 14-day intervals. CONCLUSION: A 0.1 mg/mL dose of TA temporarily decreased cell viability and increased cell apoptosis, which was recovered at 21 days, however, 1 mg/mL of TA caused irreversible damage to cell morphology and viability. An interval > three weeks was needed to safely re-administer TA. These findings may help determine the appropriate dose and interval for TA injection therapy. Cite this article: Bone Joint Res 2014;3:328-34.

Complete traumatic backout of the blade of proximal femoral nail antirotation: a case report.

This article presents a rare case of traumatic complete expulsion of the helical blade after successful treatment of an intertrochanteric fracture with proximal femoral nail antirotation (PFNA). A 94-year-old woman sustained an intertrochanteric fracture of the left femur. Fracture fixation was performed by using PFNA-II. At six months FU, the patient presented with pain at the proximal lateral left thigh after she had fallen. A protrusion was noted. Radiographs showed a complete expulsion of the helical blade with a healed intertrochanteric fracture. The PFNA-II was removed and a cemented bipolar hemiarthroplasty was performed. At 5 months after surgery, the patient was able to walk with a walker without pain. Traumatic complete expulsion of the blade should be considered as a possible complication of PFNA/PFNA-II.

The osteogenic activity of human mandibular fracture haematoma-derived cells is stimulated by low-intensity pulsed ultrasound in vitro.

Low intensity pulsed ultrasound (LIPUS) stimulation is a clinically established treatment method used to accelerate long bone fracture healing; however, this method is currently not applied to mandibular fractures. In this study, we investigated the effects of LIPUS on human mandibular fracture haematoma-derived cells (MHCs) in order to explore the possibility of applying LIPUS treatment to mandibular fractures. MHCs were isolated from five patients. The cells were divided into two groups: (1) LIPUS (+) group: MHCs cultured in osteogenic medium with LIPUS treatment; and (2) LIPUS (-) group: MHCs cultured in osteogenic medium without LIPUS treatment. The osteogenic differentiation potential and proliferation of the MHCs were compared between the two groups. The waveform used was equal to the wave conditions of a clinical fracture healing system. The gene expression levels of ALP, OC, Runx2, OSX, OPN, and PTH-R1 and mineralization were increased in the LIPUS (+) group compared to the LIPUS (-) group. There were no significant differences in cell proliferation between the two groups. These findings demonstrate the significant effects of LIPUS on the osteogenic differentiation of MHCs. This study provides significant evidence for the potential usefulness of the clinical application of LIPUS to accelerate mandibular fracture healing.

Interleukin-6-induced satellite cell proliferation is regulated by induction of the JAK2/STAT3 signalling pathway through cyclin D1 targeting.

OBJECTIVES: To determine whether interleukin-6 (IL-6) stimulates rat muscle satellite cell proliferation in culture, and if so, to clarify the signalling mechanisms. MATERIALS AND METHODS: Primary satellite cells were isolated from thirty male F344 rats, 11 weeks of age. IL-6 at concentrations of 0.01, 0.1, 1, 10 or 100 ng/ml was added to culture media. RESULTS: IL-6 at 0.01-1 ng/ml induced dose-dependent increase in cell proliferation. After treatment with 1 ng/ml IL-6, cell proliferation increased by 31%, and p-STAT3(+) /MyoD(+) cells increased in number compared to those in control media (P < 0.05). Inhibitors of JAK2 (AG 490) and STAT3 (STAT3 peptide) blocked the increase in BrdUrd(+) cell numbers at 6 h post stimulation with 1 ng/ml IL-6 (P < 0.05). Furthermore, cyclin D1 mRNA expression and cyclin D1(+) /MyoD(+) cell numbers significantly increased in cultures treated with 1 ng/ml IL-6 compared to those in control media (P < 0.05). In contrast, treatment with 10 and 100 ng/ml IL-6 did not stimulate cell proliferation. Treatment with 10 ng/ml IL-6 induced greater SOCS3 mRNA expression than with 1 ng/ml IL-6 and control media. Moreover, co-localization of SOCS3 and myogenin was observed after treatment with 10 ng/ml IL-6. CONCLUSIONS: IL-6 induced dose-dependent increase in satellite cell proliferation by activating the JAK2/STAT3/cyclin D1 pathway.

Akt phosphorylation in human chondrocytes is regulated by p53R2 in response to mechanical stress.

OBJECTIVE: The p53 tumor-suppressor protein p53R2 is activated in response to various stressors that act on cell signaling. When DNA is damaged, phosphorylation of p53 at its Ser 15 residue induces p53R2 production. The role of p53R2 in chondrocytes remains poorly understood. In this study, we evaluated in chondrocytes, p53R2 expression and its regulation in response to mechanical stress. Furthermore, we investigated the function of p53R2 in relation to mechanotransduction. METHODS: Osteoarthritis (OA) cartilage obtained from total knee replacements and normal cartilage obtained from femoral neck fractures was used to measure p53R2 expression by using immunohistochemistry, western blotting, and real-time polymerase chain reaction (PCR). The OA chondrocytes were subjected to a high magnitude of cyclical tensile strain by using an FX-2000 Flexercell system. Next, sulfated glycosaminoglycan (sGAG) production was quantified in these cells. Protein expression of p53R2, and phosphorylation of Akt, p38MAPK, ERK1/2, and JNK was also detected using western blotting. Moreover, Akt phosphorylation was detected after transfecting the cells with p53R2-specific small interfering RNA (siRNA). RESULTS: Expression of p53R2 was significantly increased in OA chondrocytes and in chondrocytes after applying 5% tensile strain to the cells. However, Akt phosphorylation was down-regulated in OA chondrocytes after the strain, and was up-regulated after transfection of p53R2. sGAG protein as well as collagen type II and aggrecan mRNA was increased following transfection of p53R2-specific siRNA after 5% tensile strain. CONCLUSIONS: p53R2 could regulate matrix synthesis via Akt phosphorylation during chondrocyte mechanotransduction. Down-regulation of p53R2 may be a new therapeutic approach in OA therapy.

Satellite cell pool enhancement in rat plantaris muscle by endurance training depends on intensity rather than duration.

AIM: Increases in the number of satellite cells are necessary for the maintenance of normal muscle function. Endurance training enhances the satellite cell pool. However, it remains unclear whether exercise intensity or exercise duration is more important to enhance the satellite cell pool. This study examined the effects of different intensity and duration of endurance training on the satellite cell pool in rat skeletal muscle. METHODS: Forty-one 17-week-old female Sprague-Dawley rats were assigned to control (n = 8), high intensity and high duration (n = 7), high intensity and low duration (n = 8), low intensity and high duration (n = 9) and low intensity and low duration (n = 9) groups. Training groups exercised 5 days per week on a motor driven treadmill for 10 weeks. After the training period, animals were anaesthetized and the plantaris muscles were removed, weighed and analysed for immunohistochemical and histochemical properties. RESULTS: Although no significant differences were found in muscle mass, mean fibre area and myonuclei per muscle fibre between all groups, the percentage of satellite cells was significantly higher in the high-intensity groups than in the other groups (P < 0.05). CONCLUSION: Increases in the satellite cell pool of skeletal muscle following endurance training depend on the intensity rather than duration of exercise.

An analysis of bone regeneration at a segmental bone defect by controlled release of bone morphogenetic protein 2 from a biodegradable sponge composed of gelatin and ß-tricalcium phosphate.

To treat large bone defects is a clinically challenging problem and utilizing tissue engineering technology is an attractive approach for overcoming such a problem. Previously, a biodegradable sponge incorporating bone morphogenic protein-2 (BMP-2), which can control the release of BMP-2 for a prolonged time in an in vivo environment, was reported. In addition, a biodegradable sponge composed of gelatin and ß-tricalcium phosphate (ßTCP), gelatin-ßTCP sponge to develop a more ideal scaffold for enhancing bone regeneration was also created and previously reported. The purpose of this study was to investigate the effectiveness of the gelatin-ßTCP sponge for the promotion of bone regeneration in a critical-sized bone defect site in vivo. Apparent bone regeneration was induced by the gelatin sponge incorporating BMP-2 and the gelatin-ßTCP sponge with BMP-2 incorporation. In contrast, no apparent bone formation was induced by either the gelatin sponge only or the gelatin-ßTCP sponge without BMP-2. To investigate the quality of the regenerated bone, we conducted a biomechanical evaluation with a three-point bending test. We found no significant difference between the gelatin sponge incorporating BMP-2 and the gelatin-ßTCP sponge incorporating BMP-2 groups. Incorporation of ßTCP into the gelatin sponge was expected to enhance biomechanical strength during the initial bone regeneration. However, our observations showed that the gelatin-ßTCP sponge did not significantly improve the quality of regenerated bone from the viewpoint of biomechanical assessment, even though it did not impair the effectiveness of the promotion of bone regeneration by BMP-2 in the bone defect.

Effects of ageing and endurance exercise training on alpha-actinin isoforms in rat plantaris muscle.

AIM: We recently reported that α-actinin adaptation occurs at the isoform level. This study was undertaken to clarify the effects of: (1) ageing-induced shift of myosin heavy chain (MyHC) composition and (2) endurance exercise training on α-actinin isoforms in rat plantaris muscle. METHODS: Adult (18 mo) and old (28 mo) male Fischer 344 rats were assigned to either sedentary control or endurance exercise training groups. Animals in the training groups ran on a treadmill for 8 week with training intensity adjusted to be equal for adult and old groups. After the training was completed, the plantaris muscles were taken for analyses of α-actinin-2, α-actinin-3, and MyHC composition and metabolic enzyme activities. RESULTS: The proportion of type IIb MyHC was lower, and that of type I MyHC was higher in old animals than in adult animals. α-actinin-3 was significantly lower in old animals than in adult animals. No significant difference was found in α-actinin-2 and citrate synthase (CS) activity between adult and old animals. Citrate synthase activity was higher in trained animals than in sedentary animals. Endurance training produced a fast-to-slow shift within type II MyHC isoforms in both adult and old animals. α-actinin-2 was significantly higher in trained animals than in sedentary animals. No significant difference was found in α-actinin-3 between trained and sedentary animals. CONCLUSION: These results support the α-actinin adaptation at the isoform level and show that the α-actinin-3 expression depends on the amount of type II MyHC, whereas α-actinin-2 expression is associated with improvement of muscular aerobic capacity.

Evaluation of BPA uptake in clear cell sarcoma (CCS) in vitro and development of an in vivo model of CCS for BNCT studies.

Clear cell sarcoma (CCS), a rare malignant tumor with a predilection for young adults, is of poor prognosis. Recently however, boron neutron capture therapy (BNCT) with the use of p-borono-L-phenylalanine (BPA) for malignant melanoma has provided good results. CCS also produces melanin; therefore, the uptake of BPA is the key to the application of BNCT to CCS. We describe, for the first time, the high accumulation of boron in CCS and the CCS tumor-bearing animal model generated for BNCT studies.

Boron neutron capture therapy for clear cell sarcoma (CCS): biodistribution study of p-borono-L-phenylalanine in CCS-bearing animal models.

Clear cell sarcoma (CCS) is a rare melanocytic malignant tumor with a poor prognosis. Our previous study demonstrated that in vitro cultured CCS cells have the ability to highly uptake l-BPA and thus boron neutron capture therapy could be a new option for CCS treatment. This paper proved that a remarkably high accumulation of (10)B (45-74 ppm) in tumor was obtained even in a CCS-bearing animal with a well-controlled biodistribution followed by intravenous administration of L-BPA-fructose complex (500 mg BPA/kg).

DcR3 induces cell proliferation through MAPK signaling in chondrocytes of osteoarthritis.

INTRODUCTION: Decoy receptor 3 (DcR3), a soluble receptor belonging to the tumor necrosis factor (TNF) receptor superfamily, competitively binds and inhibits the TNF family including Fas-ligand (Fas-L), lymphotoxin-like inducible protein that competes with glycoprotein D for binding herpesvirus entry mediator on T-cells (LIGHT) and TNF-like ligand 1A (TL1A). In this study, we investigated the functions of DcR3 on osteoarthritis (OA) chondrocytes. METHODS: Expressions of DcR3 in chondrocytes were measured by realtime Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR). Expression of DcR3 in sera and joint fluids was measured by enzyme-linked immunosorbent assay (ELISA). Chondrocytes were incubated with DcR3-Fc chimera protein (DcR3-Fc) before induction of apoptosis by Fas-L and apoptosis was detected with terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labelling labeling (TUNEL) staining and Western blotting of caspase 8 and poly (ADP-ribose) polymerase (PARP). Chondrocytes were incubated with DcR3-Fc and the proliferation was analyzed by 4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate (WST) assay. Phosphorylation of Extracellular Signal-Regulated Kinase (ERK), P38 mitogen-activated protein kinase (MAPK) and Jun N-terminal Kinase (JNK) in chondrocytes was measured by Western blotting after incubation with DcR3-Fc, Mitogen-activated protein kinase kinase (MEK1/2) inhibitor, or P38 MAPK inhibitor. Chondrocytes were treated with DcR3-Fc after pre-incubation with blocking antibody of Fas-L, LIGHT and TL1A, and proliferation or phosphorylation of ERK was analyzed. RESULTS: DcR3 was expressed in OA and normal chondrocytes. DcR3-Fc protects chondrocytes from Fas-induced apoptosis. DcR3-Fc increased chondrocytes proliferation and induced the phosphorylation of ERK specifically. DcR3-induced chondrocytes proliferation was inhibited by pre-incubation of PD098059 or blocking Fas-L antibody. DcR3 increased chondrocytes proliferation in OA chondrocytes, but did not in normal. CONCLUSION: DcR3 regulates the proliferation of OA chondrocytes via ERK signaling and Fas-induced apoptosis.

The impact of early rehabilitation on the duration of hospitalization in patients after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: We examined the relationship between the improved physical activity by early rehabilitation and the duration of hospitalization among patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: Thirteen allo-HSCT patients with myeloablative conditioning regimens (group A) and 13 patients with nonmyeloablative conditioning regimens (group B) were assessed retrospectively in this study. All patients received physical exercise immediately after neutrophil engraftment at the class 10,000 bioclean room (class 10,000). The mean daily steps at class 10,000 were measured as a substitute for the amount of physical activity, and the duration of hospitalization as one of the clinical outcomes. RESULTS: The degree of physical activity showed a negative correlation with the duration of hospitalization in group A (r = -.71; P = .0071), regardless of complications such as acute graft-versus-host disease, infections, and cytomegalovirus reactivation. However, there was no significant association in group B (r = .09; P = .77). CONCLUSION: The improved physical activity through early rehabilitation may be an independent, favorable prognostic factor for allo-HSCT patients with myeloablative conditioning regimens.

Acetabular development in the contralateral hip in patients with unilateral developmental dysplasia of the hip.

BACKGROUND: Adult patients may present with acetabular dysplasia without a history of developmental dysplasia of the hip. The purpose of the present study was to clarify the development of primary acetabular dysplasia in patients under the age of eighteen years by evaluating the contralateral hip in those with unilateral developmental dysplasia of the hip. METHODS: Radiographs of the contralateral hip of eighty-eight patients with unilateral developmental dysplasia of the hip were reviewed retrospectively. The center-edge angle was measured at the age of eighteen years. The primary acetabular dysplasia group included hips with a center-edge angle of <20 degrees , and the normal group included hips with an angle of > or =20 degrees . The acetabular index at the age of three years, the center-edge angle between the ages of three and eighteen years, and the acetabular angle of Sharp between the ages of six and eighteen years were measured. RESULTS: According to our classification system, twelve hips (13.6%) were assigned to the primary acetabular dysplasia group. At the age of three years, there were no significant differences between the two groups radiographically. A significant difference in the center-edge angle between the two groups was seen at each evaluation period after the age of six years. However, twenty-two patients in the normal group had poor acetabular coverage and three patients in the primary acetabular dysplasia group had good acetabular coverage at the age of nine years. After the age of nine years, improvements in the center-edge angle and the acetabular angle of Sharp were noted in the normal group, whereas no acetabular growth was seen in the primary acetabular dysplasia group. There was no patient with a center-edge angle of <15 degrees at the age of twelve years in the normal group. CONCLUSIONS: After the age of six years, a difference in acetabular growth develops between patients with primary acetabular dysplasia and those with normal hips. However a final prognosis for acetabular development appears to be difficult to determine until the age of twelve years.

Efficient cell-seeding into scaffolds improves bone formation.

Bone marrow stromal cells (BMSCs)/beta-tricalcium phosphate (beta-TCP) composites have attracted a great deal of attention in bone tissue engineering. If more effective bone regeneration is to be achieved, efficient cell-seeding systems need to be clarified. In this study, we investigated the number of cells contained in composites, and the in vitro/vivo osteogenic differentiation capacity of composites using 4 conventional systems of seeding rat BMSCs into beta-TCP: soak, low-pressure, pipette, and syringe systems. The highest number of cells was contained in the composites from the syringe group. Moreover, after two-week osteogenic induction in vitro, the composites in the syringe group exhibited the highest osteogenic potential, which continued at 8 weeks after subcutaneous implantation in vivo. Our results indicated that efficient and appropriate cell-seeding could improve in vitro/vivo bone formation in composites and thus make a potential clinical contribution to successful bone tissue engineering.

Accumulation of MRI contrast agents in malignant fibrous histiocytoma for gadolinium neutron capture therapy.

Neutron-capture therapy with gadolinium (Gd-NCT) has therapeutic potential, especially that gadolinium is generally used as a contrast medium in magnetic resonance imaging (MRI). The accumulation of gadolinium in a human sarcoma cell line, malignant fibrosis histiocytoma (MFH) Nara-H, was visualized by the MRI system. The commercially available MRI contrast medium Gd-DTPA (Magnevist, dimeglumine gadopentetate aqueous solution) and the biodegradable and highly gadopentetic acid (Gd-DTPA)-loaded chitosan nanoparticles (Gd-nanoCPs) were prepared as MRI contrast agents. The MFH cells were cultured and collected into three falcon tubes that were set into the 3-tesra MRI system to acquire signal intensities from each pellet by the spin echo method, and the longitudinal relaxation time (T1) was calculated. The amount of Gd in the sample was measured by inductively coupled plasma atomic emission spectrography (ICP-AES). The accumulation of gadolinium in cells treated with Gd-nanoCPs was larger than that in cells treated with Gd-DTPA. In contrast, and compared with the control, Gd-DTPA was more effective than Gd-nanoCPs in reducing T1, suggesting that the larger accumulation exerted the adverse effect of lowering the enhancement of MRI. Further studies are warranted to gain insight into the therapeutic potential of Gd-NCT.

The intra-operative joint gap in cruciate-retaining compared with posterior-stabilised total knee replacement.

We have developed a new tensor for total knee replacements which is designed to assist with soft-tissue balancing throughout the full range of movement with a reduced patellofemoral joint. Using this tensor in 40 patients with osteoarthritis we compared the intra-operative joint gap in cruciate-retaining and posterior-stabilised total knee replacements at 0 degrees , 10 degrees , 45 degrees , 90 degrees and 135 degrees of flexion, with the patella both everted and reduced. While the measurement of the joint gap with a reduced patella in posterior-stabilised knees increased from extension to flexion, it remained constant for cruciate-retaining joints throughout a full range of movement. The joint gaps at deep knee flexion were significantly smaller for both types of prosthetic knee when the patellofemoral joint was reduced (p < 0.05).