Feasibility of a novel diagnostic chart of intramedullary spinal cord tumors in magnetic resonance imaging.

STUDY DESIGN: Retrospective chart review. OBJECTIVES: Each type of intramedullary spinal cord tumor (IMSCT) has specific anatomical and pathological features visible on magnetic resonance (MR) imaging. The purpose of this study was to investigate the accuracy of preoperative IMSCT diagnosis using our diagnostic chart of tumor-specific MR imaging findings. SETTING: Hamamatsu, Japan. METHODS: From 2009 to 2013, 28 consecutive patients with IMSCT who underwent surgery in our university hospital were included in this study. There were 17 men and 11 women with an average age of 49 years (12-81). The pathological diagnoses were hemangioblastoma (12), ependymoma (11), astrocytoma (4) and squamous cell carcinoma (1). Tumor-specific MR imaging findings were as follows: ependymoma ((a) spinal cord swelling, (b) contrast effect with necrosis, (c) tumor in the center of the spinal cord), hemangioblastoma ((a) spinal cord swelling, (b) homogeneous contrast effect) and astrocytoma ((a) spinal cord swelling, (b) contrast effect is either, (c) eccentric tumor). Based on these features, we generated a diagnostic chart to investigate the MR imaging diagnosis accuracy for IMSCTs. RESULTS: The accuracy of preoperative diagnosis was 89% (25/28 cases). Correct diagnoses were made in 100% of hemangioblastomas (12/12 cases), 90% of ependymomas (9/11 cases) and 100% of astrocytomas (4/4 cases). CONCLUSIONS: Different types of IMSCTs exhibit unique MR imaging characteristics. These features can be used to preoperatively diagnose IMSCTs with high accuracy.

Robotic assisted spinal surgery--from concept to clinical practice.

After several years of product development, animal trials and human cadaver testing, the SpineAssist--a miniature bone-mounted robotic system--has recently entered clinical use. To the best of the authors' knowledge, this is the only available image-based mechanical guidance system that enables pedicle screw insertion with an overall accuracy in the range of 1 mm in both open and minimally invasive procedures. In this paper, we describe the development and clinical trial process that has brought the SpineAssist to its current state, with an emphasis on the various difficulties encountered along the way and the corresponding solutions. All aspects of product development are discussed, including mechanical design, CT-to-fluoroscopy image registration, and surgical techniques. Finally, we describe a series of preclinical trials with human cadavers, as well as clinical use, which verify the system's accuracy and efficacy.

Highly activated matrix metalloproteinase-2 secreted from clones of metastatic lung nodules of nude mice injected with human fibrosarcoma HT1080.

The promoting effects of matrix metalloproteinase-2 (MMP-2) on lung metastasis of human fibrosarcoma cells (HT1080) were studied using nude mice. The fourth generation of HT1080 was established by consecutive clonal selection of metastatic lung nodules formed by intravenous transplantation. MMP-2 and MMP-9 in the culture supernatants of the first and fourth generation cells were analyzed by gelatin zymography and Western blotting, and quantified by scanning densitometry. In gelatin zymograms, mean ratios of values for the 59-kDa band (the active form of MMP-2) to those for the 72-kDa band (the inactive form of MMP-2) for optical density; area, and volume measured by densitometry were 1.44 +/- 0.12, 0.93 +/- 0.05, and 1.27 +/- 0.20, respectively, in the culture supernatant of fourth generation cells isolated from metastatic lung nodules. These values were significantly (P < 0.01) higher than those of first generation cells (0.70 +/- 0.04, 0.48 +/- 0.01, and 0.57 +/- 0.42). Three weeks after intravenous transplantation of HT1080 cells into nude mice, the incidence of lung metastasis and mean number and diameter of metastatic nodules formed by injection of first generation cells were 20% (2 of 10 mice), 2.9 +/- 0.2 and 2.0 +/- 0.2 mm, respectively; while they were 100%, 99.8 +/- 7.2 and 4.3 +/- 0.3 mm following injection of fourth generation cells. These findings suggest that the active MMP-2 produced by human fibrosarcoma cells is important for the cells to form lung metastatic lesions in nude mice.

Bone graft incorporation in radiographically successful human intervertebral body fusion cages.

STUDY DESIGN: Biopsies were obtained from within radiographically successful human intervertebral body fusion cages to document the histology of remodeling bone graft. OBJECTIVES: The purpose of this study is to describe the tissue within successful human interbody cages with special reference to the viability of bone and the presence or absence of debris particles. SUMMARY OF BACKGROUND DATA: The use of interbody fusion cages is gaining rapid acceptance, but there is little histologic documentation of the nature of tissue within successful human interbody fusion cages. METHODS: Needle biopsies were obtained of tissue within radiographically successful intervertebral body fusion cages at the time of pedicle screw removal for back pain or fusion of adjacent spinal level in nine spinal levels of eight patients. Preoperative diagnoses of these eight adult patients included disease conditions in the sagittal plane: spondylosis (5), degenerative disc disease (6), failed laminectomy and discectomy (2), radiculopathy (1), and spondylolisthesis (1). In all cases the cages had been packed with autograft (iliac crest 7, local 1) at the time of insertion. Cage implantation was performed with anterior (anterior lumbar interbody fusion 4, corpectomy and plate fixation 1), and posterior (posterior lumbar interbody fusion 4), segmental instrumentation (plate 1, or pedicle screws 8). All cases except one cervical case had posterolateral fusion or bilateral facet fusion. The cages were composed of carbon fiber-reinforced polymer (Brantigan cage; DePuy AcroMed, Raynham, MA, n = 5) or titanium mesh (Harms Cage; DePuy AcroMed, Raynham, MA, n = 4). Cages had been in situ from 8 to 72 months (mean 28 months). All nine biopsies from eight patients were obtained from within the center of the cages. Specimens were decalcified, routinely embedded in paraffin, stained with hematoxylin and eosin, and viewed qualitatively with transmitted and polarized light. RESULTS: All needle biopsies were obtained from within the center of the cages, and no patient developed spinal instability after the biopsy. All nine biopsies showed small fragments of necrotic bone associated with viable bone and restoration of hematopoietic bone marrow. Numerous cement lines demarcated the edges of previous cycles of remodeling. The ratio of necrotic to viable bone varied greatly among cases. Small particles of debris were associated with four of the five carbon-fiber cages and one of the four specimens from titanium cages, but there was no visible bone resorption or inflammation. CONCLUSIONS: Autogenous bone graft was incorporated in these radiographically successful human intervertebral body fusion cages. A few debris particles were observed, but there was no histologic evidence of particle-induced bone resorption or inflammation.

Blockade of IL-6 signaling by MR16-1 inhibits reduction of docosahexaenoic acid-containing phosphatidylcholine levels in a mouse model of spinal cord injury.

The interleukin (IL)-6 pathway plays an important role in recovery after spinal cord injury (SCI). The anti-IL-6 receptor antibody MR16-1 has been shown to suppress inflammation after SCI and promote recovery of motor function. The purpose of this study was to analyze the effects of MR16-1 on the expression patterns of phospholipids in the spinal cord in a mouse model of SCI. Eight-week-old C57BL/6JJmsSlc mice were used in this study. Laminectomy was performed at the ninth and tenth thoracic levels (T9-T10), and contusion injury of the spinal cord was induced at level T10. Immediately after SCI, mice were intraperitoneally injected with a single dose of MR16-1 (MR16-1 group) or a single dose of phosphate-buffered saline of the same volume (control group). Imaging mass spectrometry was performed to visualize phosphatidylcholine (PC) expression in the spinal cord 7 days after SCI. We found that MR16-1 treatment suppressed the infiltration of immune cells after SCI, and was able to increase the locomotor function post-injury. Phospholipid imaging revealed that the MR16-1 was able to prevent the reduction of docosahexaenoic acid (DHA)-containing PC in comparison with the control group. We also observed high levels of glial fibrillary acidic protein (GFAP) at the site of DHA-containing PC expression in the MR16-1 group. These results suggest that MR16-1 treatment influences the DHA-containing PC composition of GFAP-positive cells at the injury site as early as 7 days post-SCI.

Functional outcomes of kyphoplasty for the treatment of osteoporotic and osteolytic vertebral compression fractures.

INTRODUCTION: Vertebral body compression fractures secondary to osteoporosis or malignant osteolysis are an increasingly common problem. The primary purpose of our study was to assess functional outcomes of kyphoplasty for the treatment of osteoporotic and osteolytic vertebral compression fractures. Our secondary purpose was to compare such functional outcomes in patients with osteoporosis versus multiple myeloma. METHODS: The 314 consecutive patients prospectively included in our study had progressive and painful compression fractures as a result of osteoporosis or multiple myeloma that were refractory to nonoperative modalities. Of those 314 patients, the 211 (67.2%) patients (155 with osteoporosis and 56 with multiple myeloma) who had complete preoperative and postoperative data formed our final study group. All patients tolerated the kyphoplasty procedure well (that is, there were no adverse events in terms of perioperative patient condition). Follow-up ranged from 1 to 235 weeks (mean 55.0 weeks). Functional outcomes were assessed by the SF-36 and Oswestry Disability Index at baseline and at follow-up examinations. Data were analyzed by Student's t-test and the level of significance was set at P

Simultaneous detection of Staphylococcus aureus and coagulase-negative staphylococci in positive blood cultures by real-time PCR with two fluorescence resonance energy transfer probe sets.

A real-time PCR assay that uses two fluorescence resonance energy transfer probe sets and targets the tuf gene of staphylococci is described here. One probe set detects the Staphylococcus genus, whereas the other probe set is specific for Staphylococcus aureus. One hundred thirty-eight cultured isolates, which contained 41 isolates of staphylococci representing at least nine species, and 100 positive blood cultures that contained gram-positive cocci in clusters were tested. This assay was 100% sensitive and 100% specific for the detection of the Staphylococcus genus and of S. aureus.