Activated protein C suppresses osteoclast differentiation via endothelial protein C receptor, protease-activated receptor-1, sphingosine 1-phosphate receptor, and apolipoprotein E receptor 2.

INTRODUCTION: Bone remodeling relies on a delicate balance between formation and resorption of bone tissues, processes in which bone-forming osteoblasts and bone-resorbing osteoclasts play central roles. Recently, we reported that anticoagulant activated protein C (APC) promotes osteoblast proliferation, but the role of the blood coagulation system in bone remodeling remains unclear. In this study, to further elucidate the relationship between bone remodeling and blood coagulation, we investigated the effect of APC on osteoclast differentiation. MATERIALS AND METHODS: Normal human osteoclast precursor cells were cultured in their growth medium including soluble RANKL, M-CSF, and FBS, and on days 4 and 7, the culture medium was replaced with the same medium containing various concentrations of APC, protein C (PC), sphingosine 1-phosphate (S1P) receptor agonist, FTY720, or APC+various substances without FBS. On day 8, TRAP-positive multinucleated cells (≥3 nuclei) were counted manually using a light microscope. The effects of APC on NF-κB and NFATc1 activation were evaluated using specific ELISA. RESULTS: APC suppressed RANKL-induced osteoclast differentiation, and this APC-induced suppression of osteoclast differentiation was inhibited by zymogen protein C and aprotinin, a serine protease inhibitor. Immunohistochemistry and RT-PCR analyses suggested that endothelial protein C receptor (EPCR) and protease-activated receptor-1 (PAR-1) were expressed in osteoclast precursor cells and osteoclasts. Both anti-PAR-1 antibody and anti-EPCR antibody (RCR-252), which blocks APC binding to EPCR, inhibited the APC-induced suppression of osteoclast differentiation. FTY720 had no effect on osteoclast differentiation. However, FTY 720 and S1P receptor antagonist, VP 23019, inhibited the APC-induced suppression of osteoclast differentiation. On the other hand, recombinant soluble human ApoER2 and anti-human ApoER2 inhibited the APC-induced suppression of osteoclast differentiation. Further, APC had no effect on NF-κB and NFATc1 activation. CONCLUSIONS: APC suppresses human osteoclast differentiation mainly by inhibiting the formation of multinucleated cells via EPCR, PAR-1, S1P receptor, and ApoER2 in a manner that depends on APC protease activity.

Vascular safety during arthroscopic all-inside meniscus suture.

PURPOSE: The purpose of the study is to assess the orientation and distance of the popliteal artery (PA) from both the anteromedial and anterolateral portals. METHODS: The records of 97 patients (100 knees) who underwent knee arthroscopy were reviewed. The shortest distance from the posterior tibial cortex to the PA on the lines from both the medial and lateral borders of the patellar tendon to the PA was evaluated by magnetic resonance imaging at full knee extension. The figure-of-four position was compared between patients with intact and deficient anterior cruciate ligaments (ACLs). The shortest distances from the posterior cruciate ligament (PCL) to the lines running from the medial and lateral borders of the patellar tendon to the PA were also measured. RESULTS: The shortest distances from the posterior tibial cortex to the PA were significantly longer in the figure-of-four position than at full knee extension and during extension in the ACL-deficient than intact group. Distances did not significantly differ in the figure-of-four position. The PA was hidden from the anteromedial portal by the PCL, but remained vulnerable from the anterolateral portal. CONCLUSIONS: All-inside meniscus suturing of the posterior horn of the lateral meniscus inserted through the anteromedial portal is safer when the knee is in the figure-of-four position than fully extended. Meniscus repairs should be completed before ACL reconstruction due to vascular positions and the ease of approach. LEVEL OF EVIDENCE: Prospective correlation study, Level IV.

Elevated soluble platelet glycoprotein VI is a useful marker for DVT in postoperative patients treated with edoxaban.

Prevention of deep vein thrombosis (DVT) is important in patients undergoing major orthopedic surgery. Although the detection of an elevated D-dimer level is useful for predicting DVT, it is not efficacious in postoperative patients being treated with anti-Xa agents. The soluble platelet glycoprotein VI (sGPVI) level is a marker of activated platelets, but not bleeding. Therefore, sGPVI levels are usually examined as a predictor of DVT in such patients. In the present study, 83 orthopedic patients were treated with 30 mg of edoxaban for prophylaxis of DVT. Fourteen patients developed DVT and 17 patients discontinued the prophylaxis due to decreased hemoglobin levels. Plasma levels of sGPVI in the patients were significantly higher after surgery than before surgery. On day 1, the sGPVI levels increased, while the platelet counts decreased. There were no significant differences in D-dimer, soluble fibrin, or FDP levels in orthopedic patients with and without DVT before surgery and on days 1, 4, and 8. Plasma sGPVI levels were significantly higher in the patients with DVT than in those without DVT on days 1 and 4. Plasma levels of D-dimer were significantly higher in patients with withdrawal than in those without. However, there were no significant differences in sGPVI levels between those with and without withdrawal. As D-dimer levels are known to increase in patients with withdrawal, this parameter is not useful for evaluating the risk of DVT in these patients. In contrast, the sGPVI level is not increased in those with withdrawal and may therefore be useful for evaluating the risk of DVT in postoperative patients treated with an anticoagulant.

Determination of the LD50 of acridine orange via intravenous administration in mice in preparation for clinical application to cancer therapy.

AIM: We undertook studies to determine the lethal dose 50 (LD50) of acridine orange (AO) using mice in order to confirm the safety of intravenous administration of AO. MATERIALS AND METHODS: We used 40 mice and AO was administered once intravenously. General behavior and mortality were continuously observed for 14 days. At the end of the experiment, all animals were sacrificed for subsequent studies. RESULTS: The LD50 for AO in male and female mice was determined to be 32 mg/kg and 36 mg/kg, respectively. Histopathological abnormalities were observed in only one mouse which died three days after the administration of AO. The other nine mice which died immediately after the administration of AO had no pathological findings in major organs. CONCLUSION: The clinical use of AO can be kept at 1.0 mg/kg or below and, therefore, intravenous administration of AO might be safe for use as cancer therapy.

Role of high-sensitivity C-reactive protein in the differentiation of benign and malignant soft tissue tumors.

The aim of the present study was to determine whether serum high-sensitivity CRP (hs-CRP) levels can be used to predict the differentiation of benign soft tissue tumors and soft tissue sarcomas (STS) and whether there are any links between increased hs-CRP levels and patients' characteristics. Serum samples were collected from 14 healthy subjects, 35 patients with benign soft tissue tumors and 60 patients with STS. The Hs-CRP levels in the patients with STS were statistically higher than those observed in patients with benign soft tissue tumors (p<0.0001) and control subjects (p<0.0001). There were no significant differences in the hs-CRP levels between patients with benign soft tissue tumors and control subjects (p=0.16). In the receiver operating characteristic analysis, a value of 0.95 µg/ml was found to be an appropriate threshold for identifying patients at-risk for STS. The area under the curve was 0.747. The serum hs-CRP level exhibited a sensitivity and specificity STS of 50% and 94.3%, respectively, for identifying. The current analyses showed that an elevated hs-CRP level is associated with the presence of STS and may, therefore, be used as an additional marker for the differential diagnosis of soft tissue tumors.

Osteoporosis, vertebral fractures and mortality in a Japanese rural community.

OBJECTIVES: The present study aims to determine the relationship between osteoporosis (OP), vertebral fracture (VF) and mortality. METHODS: We followed up 1024 residents of Miyagawa village every 2 years for a mean of 8.4 years between 1997 and 2009. The residents were assessed every 2 years. We defined OP as T scores for bone mineral density that were < 2.5 standard deviations below peak bone mass. VF was assessed by lateral radiography of the thoracic and lumbar spine. The participants were allocated as follows depending on the presence or absence of OP and VF: with OP and without VF (OP group), with VF and without OP (VF group), with OP and VF (OP + VF group) and without OP and VF (Control group). We determined survival/mortality rates until 2011 by reviewing medical histories and death certificates. RESULTS: By 2011, 304 participants had died. The respective 5-year survival rates for the OP + VF, OP, VF and Control groups were 80.6%, 93.7%, 87.8% and 94.2%. Mortality rates were significantly worse for the OP + VF group than the Control group (OP + VF Hazard Ratio: 1.89; 95% CI, 1.27-2.77). CONCLUSION: Prevention of osteoporotic VF in elderly persons is very important from the viewpoint of increasing life expectancy.

Prevalence of hallux valgus and risk factors among Japanese community dwellers.

BACKGROUND: To investigate the prevalence and severity of radiographically detected hallux valgus (HV) as well as associated risk factors among Japanese residents of Miyagawa, a mountain village located in the center of Mie Prefecture. METHODS: The height, weight and body mass index (BMI) of 403 participants (male n = 135, female n = 268) recruited from among the residents of Miyagawa Village, Japan aged ≥65 years were measured, and baseline data, including age, sex and medical history were obtained from interviews and questionnaires. Knee osteoarthritis (KOA) was determined from radiographs of the feet and knees, and osteoporosis was determined by measuring bone mineral density. Hallux valgus, defined as angulation of the big toe at the first metatarsophalangeal joint of >20°, was classified as: mild (20°-30°), moderate (30°-40°) or severe (>40°). Risk factors for HV were calculated using multivariate logistic regression analysis that included age, sex, obesity (BMI ≥25), KOA, osteoporosis, Heberden's nodes and low back pain as variables. RESULTS: The overall prevalence of definite radiographic HV was 22.8 % (184/806), and mild, moderate and severe HV was found in 66.3, 27.2 and 6.5 % of the participants, respectively. Hallux valgus was found in at least one foot in 120 (29.8 %) of the participants and the prevalence significantly differed between females with and without HV and KOA (odds ratios: 2.54 and 1.71, respectively). CONCLUSIONS: The prevalence of definite radiographic HV was 29.8 %. Female sex and KOA were significantly associated with increased risk for radiographic HV.

Clinical outcomes of Kyocera Modular Limb Salvage system after resection of bone sarcoma of the distal part of the femur: the Japanese Musculoskeletal Oncology Group study.

PURPOSE: The Japanese Musculoskeletal Oncology Group have developed an original prosthesis called the Kyocera Modular Limb Salvage system (KMLS system). This prosthesis has a semi-rotating hinge joint and is particularly designed for people with an Asian body type. The metallic parts of the prosthesis are made entirely of titanium alloy. The purpose of this study is to evaluate the clinical outcomes of treatment using this system following tumour resection of primary bone sarcoma of the distal femur. METHODS: Between 2002 and 2010, 82 patients with primary bone sarcomas of the distal femur were treated. Seventeen patients underwent stem cementation, while 65 patients were treated with cementless prostheses. The mean follow-up period after surgery was 61 months. RESULTS: Complications were observed in 28 of the 82 patients. Forty-one complications occurred in these 28 patients. Thirteen prostheses (16%) required revision surgery due to complications, including five cases of stem breakage, three deep infections, three cases of aseptic loosening, one case of displacement of the shaft cap and one case of breakage of the tibial tray. The five-year overall prosthetic survival rate was 80.0%. Four of the 82 patients underwent subsequent amputation due to local recurrence. The five-year limb salvage rate was 94.5%. The mean function score according to the scoring system of the Musculoskeletal Tumour Society was 21.8 points (72.5%). CONCLUSIONS: Although further follow-up is required to determine the performance, this prosthesis is considered to be satisfactory for reconstruction of the distal femur after resection of bone sarcoma.

Ewing's sarcoma with an uncommon clinical course: A case report.

Here, a case of Ewing's sarcoma family of tumors (ESFT) of the femur with an unusual clinical course is reported. At 20 years of age, the patient had undergone curettage of a bone tumor of the right femur which was diagnosed as ESFT. One cycle of chemotherapy with vincristine and cyclophosphamide and radiotherapy for a total dose of 40 Gy was administered. The patient did not develop any recurrence or metastases for the following 18 years, in spite of the inadequacy of the initial treatment. At 38 years of age, he was referred to our institution with right thigh pain that had persisted for several months. Radiographs and magnetic resonance imaging findings showed a mass lesion in his proximal femur extending to the soft tissue. An open biopsy was performed and the lesion was diagnosed as recurrence of ESFT, although a molecular biological investigation did not reveal any expression of the characteristic fusion genes that have previously been reported. The patient received standard multimodal therapy employing standard combination chemo-therapy for ESFT and wide surgical excision. The patient has been disease-free for 9 years since the treatment. This patient may have a rare subtype of ESFT with an unknown chromosomal translocation and relatively non-aggressive biological behavior.

The relationships among hemostatic markers, the withdrawal of fondaparinux due to a reduction in hemoglobin and deep vein thrombosis in Japanese patients undergoing major orthopedic surgery.

BACKGROUND: The relationships among the hemostatic markers, the development of deep vein thrombosis (DVT) and the withdrawal of fondaparinux due to a reduction in the hemoglobin levels were examined. METHODS: Two-hundred twenty-one Japanese patients who underwent major orthopedic surgery and were treated with 1.5mg of fondaparinux instead of 2.5mg of fondaparinux were studied. Forty-seven of 221 patients discontinued fondaparinux treatment (withdrawal group) and 37 patients developed DVT. RESULTS: The age, frequency of total knee arthroplasty (TKA), withdrawal of fondaparinux, reduction of hemoglobin and the plasma levels of soluble fibrin (SF), D-dimer and fibrinogen and fibrin degradation product (FDP) on day 1 after the operation were significantly higher in the patients with DVT. Elevated SF, D-dimer or FDP levels were associated with the risk for DVT. The age, frequency of TKA or DVT, anti-Xa activity and the creatinine, FDP and D-dimer levels were significantly higher in the withdrawal group. An anti-Xa level >0.33 mg/l and an elevated D-dimer or FDP level were associated with the risk of withdrawal. CONCLUSION: The age and SF levels, TKA and withdrawal of fondaparinux were related to the risk of DVT, and the anti-Xa activity, creatinine level and DVT were related to the risk of withdrawal of fondaparinux due to a reduction in hemoglobin.

Soluble Neural-cadherin as a novel biomarker for malignant bone and soft tissue tumors.

BACKGROUND: Neural-cadherin (N-cadherin) is one of the most important molecules involved in tissue morphogenesis, wound healing, and the maintenance of tissue integrity. Recently, the cleavage of N-cadherin has become a focus of attention in the field of cancer biology. Cadherin and their ectodomain proteolytic shedding play important roles during cancer progression. The aims of this study are to investigate the serum soluble N-cadherin (sN-CAD) levels in patients with malignant bone and soft tissue tumors, and to evaluate the prognostic significance of the sN-CAD levels. METHODS: We examined the level of serum sN-CAD using an ELISA in 80 malignant bone and soft tissue tumors (bone sarcoma, n = 23; soft tissue sarcoma, n = 50; metastatic cancer, n = 7) and 87 normal controls. The mean age of the patients was 51 years (range, 10-85 years) and the mean follow-up period was 43 months (range, 1-115 months). RESULTS: The median serum sN-CAD level was 1,267 ng/ml (range, 135-2,860 ng/ml) in all patients. The mean serum sN-CAD level was 1,269 ng/ml (range, 360-2,860 ng/ml) in sarcoma patients, otherwise 1,246 ng/ml (range, 135-2,140 ng/ml) in cancer patients. The sN-CAD levels in patient were higher than those found in the controls, who had a median serum level of 108 ng/ml (range, 0-540 ng/ml). The patients with tumors larger than 5 cm had higher serum sN-CAD levels than the patients with tumors smaller than 5 cm. The histological grade in the patients with higher serum sN-CAD levels was higher than that in the patients with lower serum sN-CAD levels. A univariate analysis demonstrated that the patients with higher serum sN-CAD levels showed a worse disease-free survival rate, local recurrence-free survival rate, metastasis-free survival rate, and overall survival rate compared to those with lower serum sN-CAD levels. In the multivariate analysis, sN-CAD was an independent factor predicting disease-free survival. CONCLUSIONS: sN-CAD is a biomarker for malignant bone and soft tissue tumors, and a potentially valuable pre-therapeutic prognostic factor in patients with bone and soft tissue sarcoma.

Clinical significance of radiofrequency ablation and metastasectomy in elderly patients with lung metastases from musculoskeletal sarcomas.

BACKGROUND: The incidence of sarcoma diagnosed in the elderly population may be rising due to the increasing life expectancy. The purpose of our study was to evaluate the efficacy of lung metastasectomy and radiofrequency (RF) ablation in elderly sarcoma patients (65 years or older) with lung metastases, compared with adult sarcoma patients younger than 65 years (20-64 years). MATERIALS AND METHODS: We retrospectively evaluated the clinical efficacy of metastasectomy and lung RF ablation in sarcoma patients with lung metastases. RESULTS: Between 2001 and 2010, lung metastases were detected in 66 adult patients with musculoskeletal sarcomas. Twenty-five patients with lung metastasis were elderly. Twelve of the 25 patients were treated with lung metastasectomy and/or RF ablation. In contrast, 41 patients were adult patients younger than 65 years. Twenty of these 41 patients were treated with lung metastasectomy and/or RF ablation. The 1 and 3-year survival rates after initial treatment for lung metastases were 81.8% and 38.4% in 12 elderly patients, respectively. Compared with the control group, the survival rate in the elderly patients was not significantly different. CONCLUSION: We conclude that elderly sarcoma patients with lung metastases should always be considered for either metastasectomy or RF ablation.

Protective effect of edaravone for tourniquet-induced ischemia-reperfusion injury on skeletal muscle in murine hindlimb.

BACKGROUND: Studies have shown that ischemia-reperfusion (I/R) produces free radicals leading to lipid peroxidation and damage to skeletal muscle. The purposes of this study were 1) to assess the histological findings of gastrocnemius muscle (GC) and tibialis anterior muscle (TA) in I/R injury model mice, 2) to histologically analyze whether a single pretreatment of edaravone inhibits I/R injury to skeletal muscle in murine models and 3) to evaluate the effect of oxidative stress on these muscles. METHODS: C57BL6 mice were divided in two groups, with one group receiving 3 mg/kg intraperitoneal injections of edaravone (I/R + Ed group) and the other group receiving an identical amount of saline (I/R group) 30 minutes before ischemia. Edaravone (3-methy-1-pheny1-2-pyrazolin-5-one) is a potent and novel synthetic scavenger of free radicals. This drug inhibits both nonenzymatic lipid peroxidation and the lipoxygenase pathway, in addition to having potent antioxidant effects against ischemia reperfusion. The duration of the ischemia was 1.5 hours, with reperfusion at either 24 or 72 hours (3 days). Specimens of gastrocnemius (GC) and anterior tibialis (TA) were removed for histological evaluation and biochemical analysis. RESULTS: This model of I/R injury was highly reproducible in histologic muscle damage. In the histologic damage score, the mean muscle fibers and inflammatory cell infiltration in the I/R + Ed group were significantly less than the corresponding values of observed in the I/R group. Thus, pretreatment with edaravone was observed to have a protective effect on muscle damage after a period of I/R in mice. In addition, the mean muscle injury score in the I/R + Ed group was also significantly less than the I/R group. In the I/R + Ed group, the mean malondialdehyde (MDA) level was lower than in the I/R group and western-blotting revealed that edaravone pretreatment decreased the level of inducible nitric oxide synthase (iNOS) expression. CONCLUSIONS: Edaravone was found to have a protective effect against I/R injury by directly inhibiting lipid peroxidation of the myocyte by free radicals in skeletal muscles and may also reduce the secondary edema and inflammatory infiltration incidence of oxidative stress on tissue.

The efficacy of rebamipide add-on therapy in arthritic patients with COX-2 selective inhibitor-related gastrointestinal events: a prospective, randomized, open-label blinded-endpoint pilot study by the GLORIA study group.

OBJECTIVE: We aimed to confirm the effect of combined treatment with celecoxib and rebamipide would be more effective than celecoxib alone for prevention of upper gastrointestinal (GI) events. METHODS: Patients with rheumatoid arthritis, osteoarthritis, and low back pain were enrolled in this study. Patients were randomized to two groups: a monotherapy group (100 mg celecoxib twice daily) and a combination therapy group (add on 100 mg of rebamipide three times a day). The GI mucosal injury was evaluated by endoscopic examination before treatment and at 3 months. The primary endpoint was to evaluate the preventive effect of the combination therapy group for GI events, endoscopic upper GI ulcers and intolerable GI symptoms, compared with the monotherapy group. RESULTS: Seventy-five patients were enrolled. Sixty-five patients were analyzed (16 males, 49 females; mean age: 67 ± 13 years). The prevalence of upper GI events, five of endoscopic GI ulcers and one of intolerable GI symptoms, were 6/34 (17.6%) in the monotherapy group and 0/31 in the combination therapy group, p = 0.0252. CONCLUSIONS: The combination therapy group was more effective than the monotherapy group for prevention of upper GI events in this study. Rebamipide might be a candidate for an option to prevent COX-2 selective inhibitor-induced upper GI events.

Tissue renin-angiotensin system in the intervertebral disc.

STUDY DESIGN: Immunohistochemical and biochemical analyses of the rat intervertebral disc (IVD) tissue renin-angiotensin system (tRAS). OBJECTIVE: To examine the expression and function of tRAS in the rat IVD. SUMMARY OF BACKGROUND DATA: Angiotensin II (Ang II), the major effector of tRAS, is a hormone that contributes to inflammation and fibrosis in many organs. The expression of tRAS in the rat IVD has not been determined. METHODS: tRAS expression in rat and bovine IVDs was examined using real-time polymerase chain reaction (rat) and immunohistochemistry (rat and bovine). Rat annulus fibrosus cells in monolayer culture were used to examine the biological role of tRAS in vitro. The effect of Ang II peptide on extracellular matrix metabolism was assessed by real-time polymerase chain reaction. RESULTS: mRNA of tRAS components, including angiotensin converting enzyme, Ang II, Ang II receptor type 1, Ang II receptor type 2, and Cathepsin D (a renin-like enzyme), was clearly confirmed by real-time polymerase chain reaction analysis. In rat and bovine annulus fibrosus and nucleus pulposus cells in monolayer culture, immunohistochemical analysis showed that each tRAS component was clearly expressed. In rat IVD tissues, immunoreactivity to each antibody for tRAS components was also observed. Proliferation of rat annulus fibrosus cells was mildly stimulated by Ang II peptide. Ang II peptide also had minor stimulatory effect on the expression of the extracellular matrix components, growth factors, and catabolic proteins. CONCLUSION: Our results demonstrate for the first time that the tRAS components necessary to activate tRAS have been found in the normal rat IVD at both mRNA and protein levels. To elucidate the association between tRAS and the process of IVD degeneration, the expression and function of tRAS in the human degenerated IVD should be examined in a future study.

The thrombin inhibitor, argatroban, inhibits breast cancer metastasis to bone.

BACKGROUND: Breast cancer has the potential to metastasize to bone, causing debilitating symptoms. Although many tumor cells have thrombin-generating systems originating from tissue factor (TF), therapy in terms of the coagulation system is not well established. To elucidate the efficacy of the thrombin inhibitor, argatroban, on bone metastasis, we investigated TF activation and vascular endothelial growth factor (VEGF) secretion on treatment with thrombin and argatroban. METHODS: MDA-231 breast cancer cells were treated with thrombin in presence or absence of argatroban, and TF activity was measured in the form of activated factor X. Enzyme-linked immunosorbent assay (ELISA) was used to measure VEGF concentrations in the medium. MDA-231 cells were injected into the left heart ventricle of mice, and then argatroban or saline was administered intraperitoneally for 28 days. After 28 days, incidence of bone metastasis was evaluated in the limbs by radiography. RESULTS: TF activity and VEGF secretion were upregulated by thrombin. Argatroban inhibited the enhancement of TF activity and VEGF secretion induced by thrombin. In vivo analysis revealed that the number of metastasized limbs in the argatroban group was significantly lower compared with the saline group (P < 0.05). CONCLUSIONS: Thrombin not only enhances VEGF secretion but also has a positive feedback mechanism to reexpress TF. These results indicate that inhibition of thrombin is of great value in suppression of tumor metastasis. Argatroban is a noteworthy and useful thrombin inhibitor because it has already been used in the clinical setting and has antimetastatic effects in vivo.

Effect of autologous platelet-rich plasma-releasate on intervertebral disc degeneration in the rabbit anular puncture model: a preclinical study.

INTRODUCTION: Platelet-rich plasma (PRP) is a fraction of plasma in which several growth factors are concentrated at high levels. The active soluble releasate isolated following platelet activation of PRP (PRP-releasate) has been demonstrated to stimulate the metabolism of IVD cells in vitro. The in vivo effect of PRP-releasate on degenerated IVD remains unknown. The purpose of this study was to determine the reparative effects of autologous PRP-releasate on degenerated intervertebral discs (IVDs). METHODS: To induce disc degeneration, New Zealand white rabbits (n = 12) received anular puncture in two noncontiguous discs. Autologous PRP and PPP (platelet-poor plasma) were isolated from fresh blood using two centrifugation techniques. Four weeks after the initial puncture, releasate isolated from clotted PPP or PRP (PPP- or PRP-releasate), or phosphate-buffered saline (PBS; control) was injected into the punctured discs. Disc height, magnetic resonance imaging (MRI) T2-mapping and histology were assessed. RESULTS: Anular puncture produced a consistent disc narrowing within four weeks. PRP-releasate induced a statistically significant restoration of disc height (PRP vs. PPP and PBS, P<0.05). In T2-quantification, the mean T2-values of the nucleus pulposus (NP) and anulus fibrosus (AF) of the discs were not significantly different among the three treatment groups. Histologically, the number of chondrocyte-like cells was significantly higher in the discs injected with PRP-releasate compared to that with PBS. CONCLUSIONS: The administration of active PRP-releasate induced a reparative effect on rabbit degenerated IVDs. The results of this study suggest that the use of autologous PRP-releasate is safe and can lead to a clinical application for IVD degeneration.

Ultrasonic measurement of bone thickness for spinal surgery.

We measured the thickness of the transverse structures associated with the bovine coccygeal transverse processes (bone specimen) by using ultrasonic waves and examined the reliability of this measurement for use in spinal surgery. We first measured the velocity of ultrasonic waves propagating in the spinous process. We then made a hole in the transverse process with an air drill and placed an ultrasonic transducer with a center frequency of 10 MHz in the hole. The time of reflection of the ultrasonic wave from the underside of the transverse process was detected to estimate the remaining bone thickness. The thickness estimated by using ultrasound was compared with the thickness measured by microscopic examination. We could detect reflection waves from the underside of the transverse process in 91.7% of cases (i.e., 22 of 24 measurements using 6 bones from 3 cows). The thickness of the transverse processes in which we detected the waves varied from 0.24 to 6.8 mm. The 95% limit of agreement between ultrasonic and histological measurement was 0.71 mm. Pearson's correlation coefficient showed a strong and positive relationship between the two measurements (r = 0.97, n = 22, P <0.0001).

Prosthetic limb salvage surgery for bone and soft tissue tumors around the knee.

In this study, we analyzed long-term survival, limb function and associated complications after prosthetic limb salvage treatment in patients with bone and soft tissue tumors around the knee joint. A total of 63 patients treated with prosthetic limb salvage surgery around the knee were reviewed. The bone tumors involved the distal femur in 45 patients, the proximal tibia in 14 patients and the soft tissue tumors of the proximal lower leg in 4 patients. The median follow-up period after the first operation was 8.0 years. The medical records of the patients, surgical reports, radiographs and histological specimens were retrospectively reviewed. The 5-year overall survival rate was 63.2% in the patients with distal femur tumors and 86.2% in those with tumors of the proximal lower leg. The 5­year prosthetic survival rate was 72.8% in the distal femur and 74.6% in the proximal lower leg. The mean functional score according to the scoring system of the Musculoskeletal Tumor Society (MSTS) was 81% in the patients with distal femur tumors and 82% in the patients with proximal lower leg tumors. Post-operative complications occurred in 27 patients. Limb salvage surgery is considered to be an effective treatment option. However, the high complication rate is a major concern for prosthetic replacement. Future improvements of prostheses are very important.

Oncolytic virotherapy for human bone and soft tissue sarcomas using live attenuated poliovirus.

The poliovirus receptor CD155, is essential for poliovirus to infect and induce death in neural cells. Recently, CD155 has been shown to be selectively expressed on certain types of tumor cells originating from the neural crest, including malignant glioma and neuroblastoma. However, the expression pattern of CD155 in soft tissue sarcoma has not been examined. Therefore, we first examined CD155 expression in sarcoma cell lines, and found the expression of both CD155 mRNA and protein in 12 soft and bone tissue sarcoma cell lines. Furthermore, we examined the effect of live attenuated poliovirus (LAPV) on 6 bone and soft tissue sarcoma cell lines in vitro, and found that LAPV induced apoptosis by activating caspases 7 and 3 in all of these cell lines. Furthermore, in BALB/c nu/nu mice xenotransplanted with HT1080 fibrosarcoma cells, administration of live attenuated poliovirus caused growth suppression of the tumors. These results suggest that oncolytic therapy using a LAPV may represent a new option for the treatment of bone and soft tissue sarcomas.