Osami Suzuki

MicroRNA-146a expresses in interleukin-17 producing T cells in rheumatoid arthritis patients

BackgroundInterleukin (IL)-17 is an important factor in rheumatoid arthritis (RA) pathogenesis. MicroRNA (miRNA)s are a family of non coding RNAs and associated with human diseases including RA. The purpose of this study is to identify the miRNAs in the differentiation of IL-17 producing cells, and analyze their expression pattern in the peripheral blood mononuclear cells (PBMC) and synovium from RA patients.MethodsIL-17 producing cells were expanded from CD4+T cell. MiRNA microarray was performed to identify the miRNAs in the differentiation of IL-17 producing cells. Quantitative polymerase chain reaction was performed to examine the expression patterns of the identified miRNAs in the PBMC and synovium from RA and osteoarthritis (OA) patients. Double staining combining in situ hybridization and immunohistochemistry of IL-17 was performed to analyze the expression pattern of identified miRNA in the synovium.ResultsSix miRNAs, let-7a, miR-26, miR-146a/b, miR-150, and miR-155 were significantly up regulated in the IL-17 producing T cells. The expression of miR-146a and IL-17 was higher than in PBMC in the patients with low score of Larsen grade and short disease duration. MiR-146a intensely expressed in RA synovium in comparison to OA. MiR-146a expressed intensely in the synovium with hyperplasia and high expression of IL-17 from the patients with high disease activity. Double staining revealed that miR-146a expressed in IL-17 expressing cells.ConclusionThese results indicated that miR-146a was associated with IL-17 expression in the PBMC and synovium in RA patients. There is the possibility that miR-146a participates in the IL-17 expression.

Three-dimensional computed tomography imaging: its applicability in the evaluation of extensor tendons in the hand and wrist.

Objective: The purpose of this study was to determine whether 3-dimensional (3D) computed tomography (CT) imaging with volume rendering can accurately evaluate extensor tendons in the hand and wrist. Methods: Three-dimensional CT imaging was used to evaluate 14 cases. The location where the rupture was suspected was the wrist level in all cases. The accuracy of the image diagnosis was confirmed during surgery in 13 cases. Results: Three-dimensional CT could identify all extensor tendons proximal to the metacarpophalangeal joint. In the cases with rupture, the location of the distal stump could be identified, whereas that of the proximal stump was uncertain. The tendon stump location confirmed during surgery correlated well with the images. Conclusions: This study revealed the usefulness of 3D CT imaging in defining extensor tendons proximal to the metacarpophalangeal joint. This method increased the accuracy and ease of diagnosis and was always useful in surgical planning and patient education.

Platelet-rich plasma accelerated surgical angio-genesis in vascular-implanted necrotic bone: an experimental study in rabbits.

Background Platelets contain many kinds of growth factors with the ability to accelerate angiogenesis. We analyzed whether a single injection of platelet-rich plasma (PRP) would accelerate surgical angiogenesis in necrotic bone implanted with vascular tissue. Methods We used 24 Japanese White rabbits. PRP was refined from autologous blood by separation twice with centrifugation. A removed iliac bone was frozen in liquid nitrogen to ensure complete cellular necrosis. A narrow hole was made in the bone and the saphenous vascular bundle was passed through the hole. The bone was wrapped after injection of either 1 mL (1) PRP, or (2) saline solution into the hole, and was placed subcu-taneously in the thigh. In both groups, angiogenesis was compared 1 week and 2 weeks after surgery. Result Angiogenesis was observed along the implanted vascular bundle in both groups. At 1 and 2 weeks after surgery, both the vessel density and the average length of newly formed vessels of the experimental group were significantly greater than in the control group. Both the vessel density and the length were greater after 2 weeks than after 1 week. Interpretation A single injection of PRP accelerates surgical angiogenesis in vascular-implanted necrotic bone.

FREE VASCULARIZED TOE JOINT TRANSFER TO THE HAND. A TECHNIQUE FOR SIMULTANEOUS RECONSTRUCTION OF THE SOFT TISSUE

Twelve patients underwent reconstruction of injured finger joints using our technique of a vascularized transfer of the second toe proximal interphalangeal joint. The age of the patients at operation ranged from 7 to 47 years and the postoperative follow-up was 9 to 48 months. All the joint transfers survived and united with resolution of the preoperative joint pain, deformity and instability. The average range of motion of the reconstructed joints was 59° in the proximal interphalangeal and 54° in the metacarpophalangeal joints. No patient complained of pain or functional deficits in the donor foot.

Human platelet-rich plasma promotes axon growth in brain-spinal cord coculture

Platelet-rich plasma (PRP) contains several growth factors, including platelet-derived growth factor (PDGF), transforming growth factor-&bgr;1 (TGF-&bgr;1), insulin-like growth factor-1 (IGF-1), and vascular endothelial growth factor (VEGF), that are associated with repair processes after central nervous system injury. Although PRP have been applied to some regenerative therapies, the regeneration effects of PRP on spinal cord injury have not been reported. This study applied a rat organ coculture system to examine the ability of PRP to enhance axonal growth in spinal cord tissues and to identify the growth factors in PRP that contribute to the regulation of axon growth. PRP from human peripheral blood was added to organ cocultures. Furthermore, neutralizing antibodies against PDGF-AB, TGF-&bgr;1, IGF-1, or VEGF were added to the cocultures with PRP. Axon growth from the brain cortex into the spinal cord was assessed quantitatively using anterograde axon tracing with DiI. Addition of PRP to the cocultures promoted axon growth, and the axon growth was significantly suppressed by the addition of neutralizing antibodies against IGF-1 and VEGF, but not PDGF-AB. In contrast, axon growth was promoted significantly by the addition of neutralizing antibodies against TGF-&bgr;1. These findings indicate that PRP promotes axon growth in spinal cord tissues through mechanisms associated with IGF-1 and VEGF, and that TGF-&bgr;1 in PRP exerts negative effects on axon growth.

Pollicization of the index finger for traumatic thumb amputation.

Background: Indications for pollicization of the index finger have decreased since the toe-to-thumb transfer and wraparound flap have been developed for thumb reconstruction. Pollicization, however, remains a useful method of thumb reconstruction depending on the amputation level, age, and patients’ requests. The purpose of this study was to evaluate the authors’ results and to clarify indications for pollicization. Methods: Eight patients treated by pollicization of the index finger after thumb amputation were reviewed retrospectively. Five men and three women were included. The age at surgery ranged from 24 to 66 years, with a mean age of 43 years. Amputation levels included the metacarpophalangeal joint in four patients, the first metacarpal in three, and the carpometacarpal joint in one. The period between injury and pollicization ranged from 0 days to 4 years. Postoperative evaluations included thumb range of motion, opposition and pinch function, grasp and pinch strength, sensation, conversion of position sense, a “picking-up” test, and appearance. Results: The follow-up period ranged from 5 to 28 years, with an average of 15 years, excluding one patient who died during the follow-up period. The thenar muscles were retained in four patients, who had excellent postoperative function and satisfactory results. Conclusions: Pollicization gives excellent results if the thenar muscles can be retained; opposition can be expected after this procedure. However, if the thenar muscles cannot be preserved, the reconstructed thumb may function as a post against the fingers to regain grasping and pinching functions.

Short Interposed Pedicle of Flow-Through Anterolateral Thigh Flap for Reliable Reconstruction of Damaged Upper Extremity

In microvascular reconstructive surgery, the recipient vessel in free flap transfer is often sacrificed to provide the vascular pedicle anastomosis. As the recipient vessel is likely to be necessary for distal circulation in the damaged upper extremity, preserving its patency is critical. Flow-through anastomosis is one method that preserves the recipient vessels patency. We present here eight patients who underwent upper-extremity reconstructions with a free flow-through anterolateral thigh flap. The flaps short vascular pedicle was interposed into a division of the radial artery and anastomosed on both sides of the pedicles T-shaped arterial segment. The flow-through flap has various advantages, not only making it possible to reconstruct both vessels and soft tissues but also preserving recipient vessels and balancing the blood supply or pressure in the flap. In clinical situations that do not require reconstruction of the artery, the short interposed pedicle of the free anterolateral thigh flow-through flap offers a versatile and reliable option for microsurgical reconstruction of defects in the upper extremities.

In vivo bioluminescence imaging of magnetically targeted bone marrow-derived mesenchymal stem cells in skeletal muscle injury model.

The purpose of this study is to clarify the kinetics of transplanted mesenchymal stem cells (MSCs) in rat skeletal muscle injury model and the contribution of the magnetic cell delivery system to muscle injury repair. A magnetic field generator was used to apply an external magnetic force to the injury site of the tibia anterior muscle, and 1 × 106 MSCs labeled with ferucarbotran–protamine complexes, which were isolated from luciferase transgenic rats, were injected into the injury site. MSCs were injected with and without an external magnetic force (MSC M+ and MSC M− groups, respectively), and phosphate‐buffered saline was injected into injury sites as a control. In vivo bioluminescence imaging was performed immediately after the transplantation and, at 12, 24, and 72 h, and 1 and 4 weeks post‐transplantation. Also, muscle regeneration and function were histologically and electromechanically evaluated. In vivo bioluminescence imaging showed that the photon of the MSC M+ group was significantly higher than that of the MSC M− group throughout the observation period. In addition, muscle regeneration and function in the MSC M+ group was histologically and functionally better than that of the MSC M− group. The results of our study indicated that magnetic cell delivery system may be of use in directing the transplanted MSCs to the injury site to promote skeletal muscle regeneration.

Surgical angiogenesis: a new approach to maintain osseous viability in xenotransplantation

Chung Y‐G, Bishop AT, Giessler GA, Suzuki O, Platt JL, Pelzer M, Friedrich PF, Kremer T. Surgical angiogenesis: a new approach to maintain osseous viability in xenotransplantation. Xenotransplantation 2010; 17: 38–47.

Osteochondral flap fracture of the olecranon in a child.

Osteochondral flap fracture in a child is rare. A 7 year-old boy with an osteochondral flap fracture is reported. Intraoperatively, the osteochondral fragment in the olecranon fossa was connected to a part of the medial collateral ligament. The authors suppose that this type of fracture occur not only as a result of a shearing force of the trochlea but also by a traction force through the medial collateral ligament when a complete tear of the medial collateral ligament was avoided for any reason. Furthermore, the immaturity of bone of the child may result in avulsion fracture, not in injury of the distal part of the ligament. Osteosynthesis with poly-L-lactic acid pins was useful to reacquire good elbow function.