Remission of hypersensitivity by simple weight load stimuli in a complex regional pain syndrome mouse model.

Painful sensitivity of the hand or foot are the most common and debilitating symptoms of complex regional pain syndrome (CRPS). Physical therapy is standard treatment for CRPS, but evidence supporting its efficacy is minimal and it can be essentially impossible for CRPS patients to actively exercise the painful limb. Using the well-characterized distal tibial fracture CRPS mouse model, we compared the therapeutic effects of several weeks of daily hindlimb loading versus rotarod walking exercise. The effects of loading and exercise were evaluated by weekly testing of hind-paw withdrawal thresholds to von Frey fibers and radiant heat, as well as measurements of paw and ankle edema. At 6 weeks after fracture, the mice were killed and the ipsilateral femur, spinal cord and L4/5 dorsal root ganglia, and hind-paw skin collected for PCR assays and paw skin Immunohistochemistry evaluation. Hindlimb loading reduced hind-paw von Frey allodynia and heat hyperalgesia and edema within a week and these effects persisted for at least a week after discontinuing treatment. These therapeutic effects of loading exceeded the beneficial effects observed with rotarod walking exercise in fracture mice. Levels of nerve growth factor and transient receptor potential vanilloid 1 (TRPV1) immunostaining in the hind-paw skin were increased at 6 weeks after fracture, and both loading and exercise treatment reduced increases. Collectively, these results suggest that loading may be an effective and possibly curative treatment in CRPS patients with sensitivity in the affected limb.

Delayed tendon healing after injury in tetranectin-deficient mice.

BACKGROUND: Tetranectin, a plasminogen-binding protein, is present in human serum and has a role in tissue remodeling. The wound healing process is established and follows a similar cascade in tendon tissue as in other tissues. In this study, we investigated whether tetranectin has a role in regulating tissue formation of injured tendon. METHODS: Using the patella tendon injury model in the tetranectin-null mice, healing processes of the injured tendon were evaluated by histological and immunohistochemical analyses, and measurement of the expression of tetranectin, type 1 collagen (Col 1), tenomodulin, scleraxis, TGFß, IL-1ß, IL-6 and TNF-α. RESULTS: At the inflammatory phase within 7 days after the injury, involvement of inflammatory cells and the expressions of IL-1ß, IL-6 and TNF-α were significantly decreased in tetranectin-null mice. Tetranectin expression increased at 1 day and peaked at 3 days, and finally disappeared at 7 days after the injury in wild-type mice. The tendon healing period and maturity were significantly delayed in the tetranectin-null mice. Expression levels of type 1 collagen and tenomodulin in tetranectin-null mice were significantly lower than those in the wild-type mice until 70 days after injury. With regard to the long-term processes, the healing and maturation of the injured tendon in tetranectin-null mice were eventually completed. CONCLUSION: We believe that tetranectin might have a potential role in enhancing tissue formation of healing tendon at the inflammatory phase after injuries. The characteristics of tetranectin as a purified protein from human serum could be interested in an attractive candidate as a potential agent to enhance tendon healing after injury.

The First Fatal Case of Chromobacterium violaceum Infection in Japan.

BACKGROUND Chromobacterium violaceum (C. violaceum) is a gram-negative and facultative anaerobic oxidase-positive bacillus generally seen in tropical or subtropical areas (latitudes between 35°N and 35°S). C. violaceum infection is a rare but serious infection with high morbidity and mortality rates. Most clinicians practicing in non-tropical counties, such as Japan, are unfamiliar with it. CASE REPORT We report the first fatal case of a 49-year-old man infected with C. violaceum after a traffic accident in Japan (latitude 34.8°N). The patient reported brief submergence in a marshy muddy rice field after the accident. There was some evidence of soil and water contamination of the patient's skin and clothing, but he denied swallowing water or soil. There were no findings of pneumonitis or severe open wounds on admission. Until the night of the 7th day of hospitalization, his general conditions remained stable despite a persistent fever. However, he suddenly collapsed on the 8th day of hospitalization and died. C. violaceum bacteremia led to fatal sepsis on dissemination to the iliopsoas abscess, which is a rare combination for this infection. CONCLUSIONS Episodes of exposure to contaminated water or soil, especially in summer, are important predisposing factors for C. violaceum infection. Thus, it is vital to include C. violaceum infections as a differential diagnosis, since the mortality rate of C. violaceum infections is high and the cases of this infection have increased in non-tropical counties.

Surgical Procedures Based on the Arthrographic Findings of the Fifth MTP Joint With Proximal Phalanx Duplication in Postaxial Polydactyly of the Foot.

Radiographic findings in several atypical cases of postaxial polydactyly of the foot do not provide sufficient information to assess the cartilaginous structures or duplicated digit connections at the MTP joint. The purpose of this study was to demonstrate the surgical procedures using arthrography for the cartilaginous structures of the MTP joint in postaxial polydactyly of the foot. We performed arthrography in 7 feet of 7 patients with postaxial polydactyly of the foot in which duplication of the proximal phalanx was observed at the fifth MTP joint on the basis of radiographic evaluation. The average age at surgery was 13.5 months and average duration of postsurgical follow-up was 36 months. Individual surgical procedures were confirmed or modified during the operation by reference to the arthrographic findings. Radiographic and arthrographic findings were assessed in relation to the findings from direct observation of the cartilaginous structures at surgery. Postoperative malalignment, functional disturbance and pain in the reconstructed toe were evaluated. The arthrographic findings provided different forms of cartilaginous structures that could be categorized in 4 types, and reflected the cartilaginous connection visualized at surgery that could not be detected on radiographs in each case. No cases revealed any deformities, functional disturbance, or pain in the reconstructed toe after surgery. The parents' evaluation in each case was "very satisfied" or "satisfied." The arthrographic findings provided additional information regarding variations in the cartilaginous structures of the fifth MTP joint and for determining individual surgical procedure for postaxial polydactyly of the foot.

Long-term outcomes after phalangeal distraction lengthening in patients with constriction band syndrome.

We investigated the long-term post-operative outcomes, more than 10 years after surgery, of distraction lengthening of phalanges in patients with congenital constriction band syndrome. Five shortened digits of two patients with congenital constriction band syndrome underwent distraction lengthening of the proximal phalanges using external fixator for the reconstruction of grasp and pinch at age of 53 and 41 months. The post-operative followed-up was 126 and 124 months. Subjective evaluation of hand function was performed using the tape measure method and Functional Dexterity Test pre-operatively and at 1 year after surgery. The parameters for proximal phalangeal distraction and the changes in the length ratio of the phalanges were evaluated. Grasp and pinch function was markedly improved after phalangeal lengthening. Regarding the radiographic findings, the length of distraction was 9.7 mm, % increase of lengthening: 52%, duration of distraction: 28 days, duration of fixation: 83 days, and healing index: 90 days. At the latest follow-up, the relative length of the proximal phalanx did not change significantly (-6%) during the 10 years after distraction lengthening. Patients with constriction band syndrome obtained favorable hand function and preserved those functions for more than 10 years after distraction lengthening of short phalanges using an external fixator.

Soft tissue injury in the limbs increased regional bone turnover.

BACKGROUND: Pathological conditions after skeletal tissue injury such as trauma and surgical intervention are often accompanied with regional osteoporotic changes, which are recognized to be mainly caused by limb immobility after injury. However, the mechanisms for the progression of regional osteoporotic changes related to the injury remains unknown. Previous studies reported that the pathophysiological conditions related to tissue injury include the acidic micro-environment formation and increased ATP levels. In addition, we previously demonstrated that those changes in the micro-environment induced a high bone turnover state through the activation of TRPV1, ASICs and P2X expressed in bone cells. We, therefore, hypothesized that tissue injury could enhance a high bone turnover state due to those pathophysiological changes in soft tissue in the injured limb. The aim of this study was to examine whether soft tissue injury associated with cutaneous incisions in a limb affects regional bone turnover. METHODS: Eight-week-old male C57BL/6 J mice underwent soft tissue injury associated with cutaneous incisions in the right femoral skin. During the 14 days after the incision, changes in the expression of osteoblast and osteoclast differentiation regulators and ATP were evaluated in comparison with those in uninjured mice. The pain-like behaviors and the expression of those differentiation regulators with and without treatment with bisphosphonate and Cox2 inhibitor were assessed in the injured limb. RESULTS: Consistent with the wound healing process, the expression levels of Osterix, osteocalcin and RANKL in the femur of the incised limb were significantly increased up to 7 days, and then decreased to the same level as those in the control limbs by 14 days after the incisions. The levels of TRAP 5b and ATP were initially significantly increased, and then decreased to the same level as before injury by day 14. Bisphosphonate significantly improved the pain-like behaviors in the injured limb associated with the inhibition of osteoblast and osteoclast differentiation regulators. CONCLUSION: We believe that the pathophysiological changes in soft tissue resulting from cutaneous incisions could be related to the induction of osteoblast and osteoclast differentiation regulators.

High bone turnover state under osteoporotic changes induces pain-like behaviors in mild osteoarthritis model mice.

INTRODUCTION: Our previous studies demonstrated that a high bone turnover state under osteoporotic changes decreased the threshold of skeletal pain. Recent studies reported that the incidence of joint pain due to osteoarthritis (OA) in postmenopausal women was higher than that in males even with the same radiographic OA grade. The aim of this study was to evaluate whether a high bone turnover state affects the induction of pain-like behaviors in mild OA model mice. MATERIALS AND METHODS: We established mild OA model mice with accompanying osteoporotic changes by monosodium iodoacetate injection after ovariectomy. We assessed pain-like behaviors by von Frey test and paw-flick test; histological changes in OA joints; the expression of Runx2, Osterix, Osteocalcin, and Rankl; bone micro-architecture by µCT and measured serum tartrate-resistant acid-phosphatase 5b levels in the model mice. RESULTS: Pain-like behaviors in mice with OA and osteoporotic changes were significantly increased in comparison with those in OA mice without osteoporotic changes. The severity of histological OA changes did not differ significantly between the OA mice with and without osteoporotic changes. Bisphosphonate significantly improved pain-like behaviors accompanied with improvement in the high bone turnover state in the OA mice with osteoporosis, while it had no significant effect on pain-like behaviors in the OA mice without osteoporosis. In addition, the improvement was maintained for more than 4 weeks even after the discontinuation of bisphosphonate treatment. CONCLUSION: These results indicated that a high bone turnover state under osteoporotic changes could affect the induction of pain-like behaviors in mild OA model mice.

Hypersensitivity to cold stimulation associated with regional osteoporotic changes in tail-suspended mice.

INTRODUCTION: Cold intolerance is defined as abnormal pain resulting from exposure to cold stimulation after trauma. However, the pathophysiology remains unclear. We recently demonstrated that regional osteoporotic changes accompanied by high bone turnover were involved in causing pain-like behaviors in the unloaded hind limbs of tail-suspended mice. Bisphosphonate prevented pain-like behaviors and high bone turnover conditions in tail-suspended mice. The aims of this study were to examine the relationship between regional osteoporotic changes and the induction of hypersensitivity to cold stimulation. MATERIALS AND METHODS: The hind limbs of tail-suspended mice were unloaded for 2 weeks. The von Frey test and paw-flick test assessed pain-like behaviors and cold plate test evaluated cold escape behaviors. Furthermore, we examined whether cold hypersensitivity associated with regional osteoporotic changes could be improved by bisphosphonate, TRPV1 and TRPA1 antagonists. RESULTS: Hypersensitivity to cold stimulation was induced more noticeably in the tail-suspended mice, and this effect was related to the increased expression of bone metabolism markers. In addition, the cold hypersensitivity was improved by the resumption of weight bearing and prevented by bisphosphonate or a TRPV1 antagonist, and was accompanied with a decrease in the expression of bone metabolism markers. TRPA1 antagonist significantly improved the cold escape behavior, but had no significant effects on the expression of those markers. CONCLUSION: We demonstrated that the regional osteoporotic changes accompanying a high bone turnover state could be involved in the induction of hypersensitivity to cold stimulation in the tail-suspended mice.

Midterm and Long-term Follow-up After Surgical Reconstruction for Lateral Polydactyly of the Foot With Mosaic-like Alignment of the Phalanx Bones.

BACKGROUND: The phalanx bones in several cases of lateral polydactyly of foot revealed complicated alignment with radiographic findings revealing medial-protrusion and lateral deviation of the middle phalanx. We previously defined such cases as showing "mosaic-like alignment" and demonstrated favorable postoperative outcomes using our surgical procedure. The aim of this study was to evaluate the midterm and long-term postoperative outcomes in such cases. METHODS: The study included 17 feet from 16 patients; 5 male and 11 female, with one bilateral case. The radiographic findings in all cases revealed a mosaic-like alignment of phalanges. Average age of the patients at the initial surgery was 12 months and average duration of post-operative follow-up was 89 months (60 to 132 mo). The surgical procedures were focused on the alignment between the distal and proximal phalanges independent of the middle phalanx alignment. Ligamentous joint stability was restored using collateral ligament reconstruction. We retrospectively evaluated post-operative outcomes, and subjective evaluation by the patients and parents was carried out. RESULTS: No cases revealed either varus or valgus deformities, pigmentation of the grafted skin, or functional disturbance. As for postoperative complications, we observed visible thickening in 7 toes, 3 of which further underwent partial resection of the middle phalanx. Subjective evaluation of the postoperative results by the patients and parents was "very satisfied" or "satisfied" in 15 of 16 cases. CONCLUSION: On the basis of our midterm to long-term postoperative outcomes, we believe that our method of surgical reconstruction provides a new option for the treatment of lateral polydactyly of the foot with mosaic-like alignment of the phalanx bones. LEVEL OF EVIDENCE: Level IV-therapeutic studies.

Signal turn-on probe for nucleic acid detection based on (19)F nuclear magnetic resonance.

To image gene expression in vivo, we designed and synthesized a novel signal turn-on probe for (19)F nuclear magnetic resonance (MR) imaging based on paramagnetic relaxation enhancement. The stem-loop structured oligodeoxyribonucleotide (ODN) having a molecular beacon sequence for point mutated K-ras mRNA was doubly labeled with bis(trifluoromethyl)benzene moiety and Gd-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid chelate moiety at the each termini of the ODN probe, respectively. We found that the (19)F MR signal of the bis(trifluoromethyl)benzene moiety tethered at the 5' termini of the probe turned on by the addition of complementary ODN. The probe has the potential to image gene expressions in vivo.