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Bone morphogenic proteins (BMPs) may have neurotrophic functions but there is limited evidence of these functions in the peripheral nervous system. We therefore investigated the expression of BMPs and BMP receptors (BMPRs) in normal and injured peripheral nerves. In 10 of 15 Sprague-Dawley rats, a 3-mm segment of sciatic nerve was resected at the trifurcation in the thigh. One day (n = 5) and 7 days (n = 5) after transection, proximal and distal stumps were removed and immunohistochemically analyzed for BMP-2, -7, BMPR-1A, -1B, and -2. The other five animals served as normal controls. In normal nerves, BMP-2 expression was localized at Ranvier's node, and BMP-7 and BMPR-1B were expressed in several axon-Schwann cell units, whereas other receptors were not expressed. After nerve transection, BMP-7 expression was upregulated at both proximal and distal stumps along with Schwann cell columns during Wallerian degeneration. BMPRs were also upregulated compared with the normal nerve. The upregulation in BMP expression after nerve transection suggests that BMPs may play a role in the healing response of the peripheral nerve. [ABSTRACT FROM AUTHOR]

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.

We report a case of recurrent knee valgus deformity in a patient with Ellis-van Creveld syndrome. Varus osteotomy, distraction osteogenesis, or epiphyseal stapling is one treatment option for valgus malalignment to improve appearance, gait, and function. However, surgical correction of valgus knee deformity by varus osteotomies of the proximal tibia was not maintained postoperatively, necessitating additional varus osteotomies of the distal femur in this case. The main cause of recurrence was attributed to large bony defect of the anterior segment of the proximal tibia, in addition to depression of the lateral tibial plateau.

Study Design: A case of primary Ewing sarcoma of the lumbar spine is presented., Objective: To present and review a rare case of primary Ewing sarcoma of the lumbar spine that required differentiation from spinal infection., Summary of Background Data: Primary Ewing sarcoma originating from the spinal column is very rare. Because Ewing sarcoma is one of the most aggressive bone tumors with high proliferative and invasive potential, its clinical symptoms and variety of imaging manifestations can mimic the pathologic findings of other diseases, including infectious diseases., Methods: The clinical course, radiologic features, pathology and treatment outcome of a patient with primary Ewing sarcoma of the lumbar spine was documented., Results: The magnetic resonance imaging findings showed an abnormal marrow signal at the L2 vertebra and significant enlargement of the unilateral iliopsoas muscle. Immunologic and molecular analysis of the surgical specimen provided a diagnosis of Ewing sarcoma. Laminotomy followed by multidisciplinary therapy including chemotherapy and radiation therapy was effective for treating this case., Conclusion: We report a case of Ewing sarcoma that mimicked a psoas abscess secondary to spinal infection. Abnormal magnetic resonance imaging images, as well as a confusing clinical course, made diagnosis difficult. When enlargement of the iliopsoas with a vertebral lesion is detected in a child with low back pain, Ewing sarcoma should be included in the differential diagnosis.

Ochronotic arthropathy is a manifestation of long-standing alkaptonuria, a rare hereditary metabolic disorder characterized by the absence of the enzyme homogentisic acid oxidase. We describe a patient who developed rapidly progressive destructive ochronotic arthropathy in his knee and hip joints and underwent successful bilateral total knee and hip arthroplasties.

Study Design: Immunohistochemical and biochemical analyses of proteinase-activated receptor-2 (PAR-2) in rat and human intervertebral discs (IVDs)., Objectives: To examine the expression and function of PAR-2 in rat IVD cells, and to determine if PAR-2 is expressed in human IVDs., Summary of Background Data: PAR-2 is a G protein-coupled receptor that contributes to the regulation of inflammatory reactions and the pathophysiology of inflammatory diseases, including arthritis. The expression of PAR-2 in the IVD has not been determined., Methods: PAR-2 expression by rat IVD cells and tissues was examined using immunohistochemistry and western blot. Rat anulus fibrosus cells in monolayer culture were used to examine the biologic role of PAR-2 in vitro. The effect of PAR-2-activating peptide (PAR-2AP) on the catabolic cascade was assessed by western blot and real-time PCR. The expression of PAR-2 by human IVD tissues at different stages of degeneration was determined by immunohistochemical analyses., Results: PAR-2 was expressed by rat IVD cells and in both anulus fibrosus and nucleus pulposus tissues, PAR-2 expression was up-regulated by interleukin-1beta (IL-1beta). PAR-2AP significantly increased the release of IL-1beta into the medium. Although PAR-2AP had no direct effect on matrix metalloproteinase-3 (MMP-3) and MMP-13 mRNA levels, treatment with PAR-2AP significantly up-regulated the mRNA levels of a disintegrin and metalloproteinase with thrombospondin motif-4. The simultaneous administration of PAR-2AP and IL-1beta synergistically up-regulated the mRNA levels of a disintegrin and metalloproteinase with thrombospondin motif-4, MMP-3, and MMP-13. The expression of PAR-2 was identified in human IVD tissues. The number of PAR-2-expressing cells was significantly elevated in advanced stages of IVD degeneration compared with those in early stages of degeneration., Conclusion: Our results demonstrate for the first time that IVD cells express PAR-2. The expression of PAR-2 is regulated by IL-1beta stimulation. PAR-2 activation accelerates the expression of matrix-degrading enzymes. PAR-2 may play an important role in the cytokine-mediated catabolic cascade and consequently may be involved in IVD degeneration.

Study Design: A case of thoracic myelopathy with alkaptonuria (ochronotic spondyloarthropathy) is presented., Objective: To present and review the first reported case of an alkaptonuric patient with concomitant thoracic myelopathy., Summary of Background Data: Alkaptonuria, a rare hereditary metabolic disease, is characterized by accumulation of homogentistic acid, ochronosis, and destruction of connective tissue resulting in degenerative spondylosis and arthritis. Despite the high incidence of intervertebral disc diseases among patients with alkaptonuria, neurologic symptoms caused by spinal disease are rare. Thoracic myelopathy in a patient with alkaptonuria has not been previously reported., Methods: The clinical course, radiologic features, pathology, and treatment outcome of an alkaptonuria patient with thoracic myelopathy was documented., Results: Myelopathy of the patient was caused by rupture of a thoracic intervertebral disc. The neurologic symptoms of the patient were markedly improved after surgery., Conclusion: We have reported for the first time, that an alkaptonuria patient showed thoracic myelopathy caused by rupture of a thoracic intervertebral disc. Decompression followed by the instrumented fusion of the thoracic spine was effective for improving the neurologic symptoms.

Study Design: Immunohistochemical and biochemical analyses of NG2 proteoglycan in the human intervertebral disc., Objective: To determine if the human intervertebral disc expresses NG2 proteoglycan., Summary of Background Data: In the nervous system, NG2 has been reported to play an important role as an interactive extracellular matrix component and membrane receptor for growth factors. NG2 is also found in non-neuronal tissues, such as cartilage and bone; however, the expression of NG2 within the human intervertebral disc is unknown., Methods: NG2 expression in the intervertebral disc was examined through Western blotting, reverse transcriptase polymerase chain reaction, and immunohistochemistry. Confocal microscopy was used to assess the spatial association of NG2 with type VI collagen. To reveal changes in the content of NG2 with disc degeneration, Western blot analysis was used to assess the relative content of NG2 in human intervertebral disc tissues with varying degrees of degeneration., Results: NG2 was clearly identified in cells from both the anulus fibrosus and nucleus pulposus, and colocalized with both type VI collagen and beta-integrin, located in the inner area of the cell-associated matrix. Throughout the anterior and posterior regions of the disc tissues, most cells were confirmed to be NG2 positive. Cells expressed NG2 messenger ribonucleic acid, and Western blot confirmed the presence of the core protein of the NG2 protein, 250 kDa. A study comparing the different grades of disc degeneration showed that the content of NG2 was elevated in disc tissues in an advanced stage of degeneration compared to tissues in an early stage of degeneration., Conclusions: Although the biologic role of NG2 remains to be elucidated, the colocalization of NG2 with type VI collagen in the pericellular area suggests that NG2 may play an important role in cell-matrix interactions. The high level of NG2 expression in advanced degeneration also suggests an important role of NG2 in the loss of disc integrity.

Study Design: A retrospective study., Objective: To examine the frequency and current status of the incidence of deaths by suicide of patients with spinal diseases during hospitalization., Summary of Background Data: It was reported that most cases of deaths by suicide during hospitalization were patients admitted to the psychiatric ward. There were no reports to the incidence of death by suicide during hospitalization in patients with spinal diseases., Methods: Of 69,861 patients admitted to the Department of Orthopedics of 28 affiliated hospitals of our university between September 1997 and August 2002, 14,987 patients with spinal diseases were targeted for this study. We examined the number of deaths by suicide during hospitalization., Results: Of the 14,987 patients with spinal diseases, there were 5 deaths (0.03%) by suicide during hospitalization. There were no deaths by suicide in 54,874 patients with orthopedic diseases other than spinal diseases., Conclusion: In the treatment of patients with spinal diseases, it seemed important for spinal surgeons to provide comprehensive treatment for the whole patient by paying attention to the relationship between a patient and a physician, in particular, by carefully observing the psychologic status of a patient.

Study Design: In vitro assessment of the effects of platelet-rich plasma on the extracellular matrix metabolism of porcine intervertebral disc cells., Objectives: To determine whether platelet-rich plasma is effective in stimulating cell proliferation and extracellular matrix metabolism by porcine disc cells cultured in alginate beads., Summary of Background Data: Platelet-rich plasma is used to accelerate wound healing and tissue regeneration. Activated platelets release multiple growth factors that regulate cell proliferation, differentiation, and morphogenesis. Individual growth factors present in platelet-rich plasma have been demonstrated to affect the metabolism of intervertebral disc cells., Methods: Platelet-poor and platelet-rich plasma was isolated from fresh porcine blood using a commercially available platelet concentration system. After preculture for 7 days and serum starvation for 24 hours, the beads containing nucleus pulposus and anulus fibrosus cells were then cultured for another 72 hours in serum-free medium, 10% fetal bovine serum, 10% platelet-poor plasma, or 10% platelet-rich plasma. The synthesis of proteoglycans and collagen, the accumulation of proteoglycans, and the DNA content were biochemically assessed., Results: Platelet-rich plasma had a mild stimulatory effect on cell proliferation of intervertebral disc cells. Platelet-rich plasma treatment significantly upregulated proteoglycan and collagen synthesis and proteoglycan accumulation when compared with platelet-poor plasma., Conclusions: Platelet-rich plasma was effective in stimulating cell proliferation and extracellular matrix metabolism. The response to platelet-rich plasma was greater in the case of anulus fibrosus cells than of nucleuspulposus cells. The local administration of platelet-rich plasma might stimulate intervertebral disc repair. In addition, given the risks of using animal serum for tissue engineering, autologous blood may gain favor as a source of growth factors and serum supplements needed for stimulating cells to engineer intervertebral disc tissues.

Background: Considerable controversy exists concerning the mechanism of axonal regeneration in end-to-side neurorrhaphy. The authors studied the mode of axonal regeneration in end-to-side neurorrhaphy without a perineurial window using a rat sciatic nerve model., Methods: Twenty-seven rats were used. A 10-mm segment of peroneal nerve was harvested and coapted to the ipsilateral tibial nerve in end-to-side fashion using a T-shaped silicone chamber to minimize the tibial nerve damaged by surgery. To explain the role of nerve damage on axonal regeneration in end-to-side neurorrhaphy, we also used an isogenic nerve transplantation model in which the peroneal nerve remained intact. The mode of axonal regeneration was studied with electron microscopy, morphometric analysis, immunofluorescence, and immunohistochemistry., Results: Both morphometric analysis and immunolabeling of neurofilaments demonstrated that regenerating axons emerge at sites far proximal to the coaptation site, travel within the tibial nerve, traverse the perineurium circumferentially around the coaptation site, and then invade into the peroneal nerve. Electron microscopy and a double-labeled immunofluorescence study with antibodies against neurofilament and tenascin-C confirmed large-scale axonal penetration into the perineurium around the coaptation site. Immunofluorescence with antibody against NG2, a marker of axonal regeneration, prevented the possibility of collateral sprouting at the coaptation site. In addition, an end-to-side neurorrhaphy model with an isogenic peroneal nerve clearly demonstrated that nerve damage is a prerequisite for axonal regeneration through end-to-side neurorrhaphy., Conclusions: The authors could not locate the site of axonal sprouting in end-to-side neurorrhaphy without a perineurial window; however, this study cast doubts on current hypothesis on the mode of axonal regeneration in end-to-side neurorrhaphy.

Background: Alginates have a wide variety of potential clinical applications, including use in cell encapsulation, drug delivery, and tissue engineering. Although the compounds are typically used in the form of a calcium hydrogel, alginates in this form possess several disadvantages, including low biodegradability, induction of foreign body reactions, and cytotoxicity secondary to Ca2+ efflux and contamination with bioincompatible substances. Thus, the goal of the present study was to develop a new method of obtaining sterilized, pure, highly viscous alginate sol from seaweed alginates and to determine its utility as an injectable antiadhesion drug., Methods: Viscous injectable pure alginate sol was produced from a commercially available sodium alginate, and its molecular and physical characteristics were analyzed. The biological properties of the viscous injectable pure alginate sol were analyzed using cultured fibroblasts prepared from the dorsal skin of neonatal rats to determine its biocompatibility and its effects on cell proliferation, cell migration, and collagen lattice contraction., Results: The mannuronic acid-to-glucuronic acid ratio of viscous injectable pure alginate sol, as determined by nuclear magnetic resonance studies, was 1.2, and its viscosity at 5 percent was 17,800 mPa. Purification used to produce viscous injectable pure alginate sol decreased contamination by insoluble particles by 20 percent and decreased polyphenol concentration by 17 percent. In vitro analyses with cultured fibroblasts demonstrated that viscous injectable pure alginate sol had excellent biodegradability and biocompatibility and that viscous injectable pure alginate sol inhibited fibroblast proliferation and migration. Furthermore, assessment of collagen contraction with floating fibroblast-loaded collagen lattices indicated that viscous injectable pure alginate sol enhanced wound healing in surrounding connective tissues., Conclusions: The authors conclude that viscous injectable pure alginate sol can inhibit scar formation by presenting a physical barrier to invading fibroblasts and by enhancing wound healing of surrounding tissues.

Background: Clinical treatment of recurrent symptoms following peripheral nerve decompression is problematic. Removal of scar tissue can produce an inappropriately pronounced healing response and thereby lead to more serious tethering or compression of the nerve. The goal of the present study was to test the ability of viscous injectable pure alginate sol to prevent perineurial adhesion using a rat neurolysis model., Methods: The antiadhesive effect of viscous injectable pure alginate sol after neurolysis was evaluated histologically and biomechanically. A total of 40 rats were used in this study. The viscous injectable pure alginate sol was applied topically on the right side after external (six rats) or extensive internal (six rats) neurolysis, whereas the left side received no treatment. The nerves were harvested over 6 weeks, and histologic analysis was performed with hematoxylin and eosin staining and Masson trichrome staining. Functional analysis of the blood and perineurial barriers was also evaluated with Evans blue albumin (four rats). Sixteen rats were used for biomechanical analysis, and eight rats were used as a control group. The results were analyzed statistically using a post hoc test., Results: Histologic examination showed that the use of viscous injectable pure alginate sol was associated with excellent biocompatibility and strong inhibition of perineurial granulation. Viscous injectable pure alginate sol was absorbed completely within 6 weeks without inducing inflammation. In addition, viscous injectable pure alginate sol enhanced repair of the perineurium associated with regeneration of epithelial-like cell layers, a key structure necessary for barrier function of the inner layer of the perineurium. Functional analysis with Evans blue albumin clearly demonstrated that, although blood nerve barrier function recovered by 6 weeks postoperatively in all nerves, the perineurial barrier function recovered only in the sol-treated nerves. Biomechanical study showed a significant antiadhesive effect of viscous injectable pure alginate sol., Conclusions: Viscous injectable pure alginate sol inhibited adhesion formation around nerves and enhanced regeneration of the perineurium with barrier function. Because excessive perineurial fibrosis and tethering at the neurolysis or neurorrhaphy site is a common postoperative problem in peripheral nerve surgery, viscous injectable pure alginate sol appears to have potentially broad clinical applications.

Background: Endovascular aortic repairs have been developed as less invasive treatments for aortic aneurysms. Some aneurismal cavities, however, remain without organization, causing a re-expansion of the aneurysms. We studied cell transplantation into the aneurismal sac to promote the organization of thrombus for the complete healing of aneurysms., Methods and Results: Skin fibroblasts and skeletal myoblasts were isolated from rats for cell transplantation. An intraarterial thrombus model was made by ligation of the carotid artery. Culture medium (medium group, n=11), collagen gel (gel group, n=11), fibroblasts with collagen gel (F group, n=15), myoblasts with collagen gel (M group, n=12), or mixture of fibroblasts and myoblasts with collagen gel (F+M group, n=14) were injected into the thrombus. After 28 days, histologically, the arterial lumens of the F and M groups were partly filled with fibrous tissues, whereas in the F+M group organization was almost completed and luminal sizes diminished. Immunohistochemical staining demonstrated that alpha-smooth muscle actin-positive cells were more abundantly contained in the organized area of the F+M group than in the other groups. We also analyzed cellular function in vitro with immunofluorescence; coculture of fibroblasts and myoblasts showed that the fraction of alpha-smooth muscle actin-positive fibroblasts increased. This phenomenon accounts for the rapid organization of thrombus in the F+M group in vivo., Conclusions: Cell transplantation accelerated thrombus organization. Especially, myoblasts enhanced differentiation of fibroblasts into myofibroblasts, contributing to rapid thrombus organization. Cell transplantation into unorganized spaces seems applicable to endovascular treatment of aneurysms.

Study Design: A retrospective study of serum and hair metal concentrations in patients with titanium alloy spinal implants was performed., Objective: To determine the incidence and possible causes of abnormal metal concentrations., Summary of Background Data: Several studies have demonstrated that metal debris are present in the tissues surrounding titanium alloy spinal implants. However, few studies suggest that metals dissolve, circulate in the body fluid, and accumulate in remote organs., Methods: Titanium, aluminum, and vanadium concentrations in serum and hair were measured after surgery in 46 patients with titanium alloy spinal implants (12 patients in the implant failure group and 34 patients in the no implant failure group) and 20 patients without spinal implants (control group). All the subjects were examined again 1 year after the first examination or implant removal., Results: Of the 46 patients with titanium alloy spinal implants, 16 patients (34.8%) exhibited abnormal serum metal concentrations and 11 patients (23.9%) exhibited abnormal hair metal concentrations. In the control group, three patients (15%) exhibited only abnormal serum and metal aluminum concentrations at the first examination. In both of the two patients who exhibited abnormal serum titanium concentrations and then had their spinal implants removed, the serum and hair titanium levels decreased to beneath the reference value limit in 1 year after the removal. Comparison of the implant failure and no implant failure groups showed no significant differences in the incidence of abnormal serum concentrations of titanium, aluminum, or both metals. Therefore, serum metal concentrations did not seem to be a useful indicator of hardware loosening or implant failure., Conclusions: Approximately one third of patients with titanium alloy spinal implants exhibited abnormal serum or hair metal concentrations at a mean time of mean 5.1 years after surgery. Titanium or aluminum may travel to distant organs after dissolution of metals from the spinal implants.