Biomedical subjects

E Abe

Publications and source records attributed to E Abe.

At least 37 records · Page 2Linked to original sources

PubMed2000

Can insertional torque predict screw loosening and related failures? An in vivo study of pedicle screw fixation augmenting posterior lumbar interbody fusion.

STUDY DESIGN: An investigation of the relation between intraoperative insertional torque of pedicle screws, bone mineral density of the vertebra, and development of screw loosening in vivo. OBJECTIVES: To determine the usefulness of intraoperative measurement of the insertional torque of pedicle screws. SUMMARY OF BACKGROUND DATA: Some biomechanical studies have demonstrated that the insertional torque is highly correlated with bone mineral density and the stability of pedicle screws in vitro. METHODS: Pedicle screw fixation was performed with posterior lumbar interbody fusion in 62 consecutive patients. The mean age of the patients at the time of surgery was 58 years. The insertional torque of pedicle screws was measured intraoperatively in all patients. The mean follow-up period was 2.7 years. RESULTS: The mean insertional torque was 1.28 +/- 0.37 Nm in patients with screw loosening and 1.50 +/- 0. 40 Nm in patients without the problem. The mean insertional torque in patients with compression fractures in the upper vertebra adjacent to the fixed segment was 0.83 +/- 0.23 Nm. There was no significant difference between the mean insertional torque in patients with screw loosening and those without the condition. The mean insertional torque in patients without screw loosening was significantly greater than in patients with compression fractures (P < 0.01). A high correlation was found between insertional torque and bone mineral density (P < 0.01). CONCLUSIONS: Although a high correlation was found between the insertional torque of pedicle screws and bone mineral density in vivo, the insertional torque could not objectively predict screw loosening.

Bone Density↗

PubMed2000

A novel nuclear phosphoprotein, GANP, is up-regulated in centrocytes of the germinal center and associated with MCM3, a protein essential for DNA replication.

Antigen (Ag) immunization induces formation of the germinal center (GC), with large, rapidly proliferating centroblasts in the dark zone, and small, nondividing centrocytes in the light zone. We identified a novel nuclear protein, GANP, that is up-regulated in centrocytes. We found that GANP was up-regulated in GC B cells of Peyer's patches in normal mice and in spleens from Ag-immunized mice. GANP-positive cells appeared in the light zone of the GC, with coexpression of the peanut agglutinin (PNA) (PNA)-positive B220-positive phenotype. The expression of GANP was strikingly correlated with GC formation because Bcl6-deficient mice did not show the up-regulation of GANP. GANP-positive cells were mostly surrounded by follicular dendritic cells. Stimulation with anti-micro and anti-CD40 induced up-regulation of ganp messenger RNA as well as GANP protein in B220-positive B cells in vitro. GANP is a 210-kd protein localized in both the cytoplasm and nuclei, with a homologous region to Map80 that is associated with MCM3, a protein essential for DNA replication. Remarkably, GANP is associated with MCM3 in B cells and MCM3 is also up-regulated in the GC area. These results suggest that the up-regulation of GANP might participate in the development of Ag-driven B cells in GCs through its interaction with MCM3.

Acetyltransferases↗

PubMed2000

Giant cauda equina schwannoma. A case report.

STUDY DESIGN: Case report. OBJECTIVES: To present a rare case of a giant schwannoma of the cauda equina. SUMMARY OF BACKGROUND DATA: Giant spinal schwannoma of the cauda equina, which involves many nerve roots, is rare and there is usually no ossification in the schwannoma. It is unknown whether or not complete excision is preferable if the tumor is located in the lumbar lesion. METHODS: A 57-year-old woman had a 10-year history of low back pain. Scalloping of the posterior surface of the vertebral bodies from L3 to the sacrum was found. Magnetic resonance imaging disclosed a giant cauda equina tumor with multiple cysts. Central ossification revealed by computed tomography and an unusual myelogram made the preoperative diagnosis difficult. RESULTS: The patient underwent incomplete removal of the tumor, decompression of cysts, and spinal reconstruction. The tumor was proved to be a schwannoma. The postoperative course was uneventful and she has been almost free from low back pain for 3 years and 4 months. CONCLUSIONS: Giant schwannoma in the lumbar spine region is usually excised incompletely, because complete removal had the risk of sacrificing many nerve roots. In spite of the incomplete removal of the tumor, the risk of recurrence is low.

Cauda Equina↗

PubMed2000

Dumb-bell-type teratoma in the lumbar spine.

We report a case of a lumbar teratoma in a 50-year-old woman. The teratoma showed a dumb-bell-type expansion at the level of the left L3/4 foramen with massive erosion of the L3 vertebral body. MRI revealed inhomogeneous signal changes in the tumor, which were histologically compatible with a mixture of bone, muscle, fat, and cyst containing sebaceous material. Complete resection of the tumor and spinal arthrodesis with pedicle screw fixation was necessary to obtain stability of the affected spinal segment.

Bone Screws↗

PubMed2000

An electronmicroscopic study of hexagonal phases related to quasicrystals in Zn-Mg-RE alloys

A number of hexagonal phases with inflated/deflated a lattice parameters but equal c parameters are found to exist with compositions close to that of the icosahedral phase. Surprisingly, no cubic or orthorhombic approximants are found. The closeness of the hexagonal phases to the icosahedral phase is shown through the electron diffraction features. Through stereographic analysis of the hexagonal phases it is shown that they consist of three icosahedral units rotated by 120 degrees about a common twofold axis, forming the sixfold axis. It is suggested that this phase falls into a class of crystals closely related to both the icosahedral and decagonal quasicrystals, but are not approximants to them. These phases can instead be considered to be approximant to the hexagonal quasicrystal.

Journal Article↗

PubMed2000

Total spondylectomy for primary tumor of the thoracolumbar spine.

STUDY DESIGN: Six patients with primary malignant tumor of the thoracolumbar spine who underwent total spondylectomy (TS) by en bloc resection were reviewed retrospectively. OBJECTIVES: To report surgical technique and preliminary results of TS and to evaluate its oncological curability. SETTING: Japan. METHODS: Six patients were treated by TS by en bloc resection of the vertebral tumor. TS through a posterior approach was performed in three cases (T1 osteosarcoma, L1 osteosarcoma and L1 chordoma) and in the others through a single stage anterior and posterior combined approach (T6-8 recurrent giant cell tumor. L4 chordoma and L5 giant cell tumor). Surgical margins of the specimens were evaluated histologically. All patients were followed, and their status was evaluated by clinical and imaging studies. RESULTS: There were no complications related to surgery. Programmed sacrifice of nerve roots were performed in three cases for oncologic excision. A wide surgical margin was achieved in one case, a marginal one in four, and an intralesional margin in one. Five patients were alive without evidence of tumor and one was alive with disease at follow-up evaluation after 2.0-4.8 years. Local recurrence was found in one case of T1 osteosarcoma with an intralesional margin. CONCLUSIONS: These preliminary results suggested that TS is an effective procedure in control of local recurrence with acceptable complications.

Adolescent↗

PubMed2000

Total en-bloc spondylectomy for correcting congenital kyphosis.

STUDY DESIGN: A case report of congenital kyphosis corrected using a total en-bloc spondylectomy. OBJECTIVES: To report a new surgical technique for the treatment of congenital kyphosis with myelopathy. SETTING: Department of Orthopedic Surgery, Akita University School of Medicine, Akita, Japan. METHODS: A 16-year-old boy who showed a 61 degrees angular kyphosis and a 32 degrees scoliosis from T6 to T9 due to the failure of the vertebral bodies formation in T7 and T8 was treated with a total en-bloc spondylectomy. RESULTS: The kyphosis was corrected to 26 degrees (57.3%) and the scoliosis was corrected to 5 degrees (84.4%) postoperatively. Three years postoperatively, no loss of correction has occurred and the patient has no complaints. CONCLUSIONS: Total en-bloc spondylectomy is one of the useful surgical procedures for correction of congenital kyphosis Type I, with a high correction rate. Spinal Cord (2000) 38, 382 - 385.

Adolescent↗

PubMed2000

Pyogenic vertebral osteomyelitis presenting as single spinal compression fracture: a case report and review of the literature.

STUDY DESIGN: A case report of pyogenic vertebral osteomyelitis (PVO) presenting as single collapsed vertebral body without narrowing of the intervertebral disc space, and review of the literature. OBJECTIVE: To describe an unusual case of PVO showing atypical radiological change and call attention to this condition so that others may avoid this diagnostic pitfall. SETTING: Japan. METHODS: A 62-year-old diabetic woman with suspected T12 pathological fracture of malignant spinal tumor and neurological involvement received urgent anterior decompression and spinal reconstruction without biopsy. RESULTS: Anterior decompression and spinal reconstruction was performed, but histological examination of the specimen after surgery unexpectedly revealed PVO. The surgery was followed by therapy with antibiotics for 7 months. A follow-up radiograph at 5 years after surgery revealed that solid consolidation has been achieved. CONCLUSIONS: Diagnosis of PVO presenting with single spinal compression fracture is very difficult. Although the finding of the high signal intensity in the lesion equal to or higher than that of the cerebrospinal fluid on T2-weighted MR image seemed to be the most reliable diagnostic modality retrospectively, diagnosis of this type of PVO is impossible without histology. A needle biopsy before surgery is strongly recommended.

Anti-Bacterial Agents↗

PubMed2000

Essential requirement of BMPs-2/4 for both osteoblast and osteoclast formation in murine bone marrow cultures from adult mice: antagonism by noggin.

Bone morphogenetic proteins (BMPs) have been heretofore implicated in the induction of osteoblast differentiation from uncommitted progenitors during embryonic skeletogenesis and fracture healing. We have tested the hypothesis that BMPs are also involved in the osteoblastogenesis that takes place in the bone marrow in postnatal life. To do this, we took advantage of the properties of noggin, a recently discovered protein that binds BMP-2 and -4 and blocks their action. Addition of human recombinant noggin to bone marrow cell cultures from normal adult mice inhibited both osteoblast and osteoclast formation; these effects were reversed by exogenous BMP-2. Consistent with these findings, BMP-2 and -4 and BMP-2/4 receptor transcripts and proteins were detected in these primary cultures, in a bone marrow-derived stromal/osteoblastic cell line, as well as in murine adult whole bone; noggin expression was also documented in all these preparations. Moreover, addition of antinoggin antibody caused an increase in osteoblast progenitor formation. These findings suggest that BMP-2 and -4 are expressed in the bone marrow in postnatal life and serve to maintain the continuous supply of osteoblasts and osteoclasts; and that, in fact, BMP-2/4-induced commitment to the osteoblastic lineage is a prerequisite for osteoclast development. Hence, BMPs, perhaps in balance with noggin and possibly other antagonists, may provide the tonic baseline control of the rate of bone remodeling on which other inputs (e.g., hormonal, biomechanical, etc.) operate.

Animals↗

PubMed2000

Total spondylectomy for solitary spinal metastasis of the thoracolumbar spine: a preliminary report.

Eight cases of solitary spinal metastasis with neurological deficit in thoracolumbar spine in which total en bloc spondylectomy (TS) was performed by bisecting the affected vertebra through both pedicles using fine thread wire saws were reviewed. Patient age ranged from 40 to 78 (mean, 62) years. Primary lesions were in the lung (2), kidney (2), thyroid (3) and prostate (1). TS was performed through a posterior approach in 5 cases (T6-7, T12, L2, L2 and L2-3) and through a one-stage anterior and posterior combined approach in the others (L2, L3 and L4). The spine was reconstructed with a ceramic vertebral prosthesis and a pedicle screw fixation system in 5 cases, and with augmented anterior spinal instruments in 3 cases. There were neither surgical complications nor surgical mortality. All patients became ambulatory and pain-free after surgery. Histologically, a marginal surgical margin was achieved in only one case. The other 7 cases had intralesional margin at the osteotomized pedicles. Four patients died from causes unrelated to local recurrence 4 to 44 (mean, 19) months after surgery. Effectiveness of surgery was maintained until death in all 4 of these patients. Asymptomatic local recurrence occurred in 2 patients with renal cancer at 10 and 33 months after surgery. These preliminary results suggest that TS for solitary spinal metastasis can achieve good control of local recurrence without major complications and is clinically acceptable surgery.

Adult↗

PubMed2000

Matrix metalloproteinases in multiple myeloma.

Multiple myeloma is a deadly malignancy characterized by plasma cell infiltration of bones. The resulting effect is painful "punched-out" lesions where bone is eroded and filled with myeloma cells that suppress and replace the normal marrow components. Recently it has been shown that myeloma cells produce matrix-metalloproteinase-9 (MMP-9) and MMP-2 and that accumulation of MMP-9 protein is suppressed upon expression of the heparan sulfate proteoglycan, syndecan-1. In this review, we briefly consider the potential roles for MMPs in the pathogenesis of multiple myeloma. MMPs likely have major roles in: 1) the infiltration of bone and other tissues by the myeloma cells; 2) the osteolytic bone destruction caused by overly active osteoclasts, 3) extracellular matrix remodeling by bone marrow stromal cells; 4) promoting the invasion of the endothelial cells that form neoangiogenic blood vessels necessary to sustain tumor foci; and 5) promoting the growth of myeloma cells. Effective and safe synthetic inhibitors of MMPs are available and these may prove useful in limiting the growth and spread of myeloma cells. In addition, recent insights into the suppression of MMP-9 by syndecan-1 may suggest new strategies for treatment of myeloma.

Animals↗

PubMed1999

Surface strain distribution on thoracic and lumbar vertebrae under axial compression. The role in burst fractures.

STUDY DESIGN: The surface strain distribution on the thoracic and lumbar vertebrae during axial compressive loading was examined. OBJECTIVES: To examine the general mechanical behavior of the thoracic and lumbar vertebrae to evaluate their role in burst fractures. SUMMARY OF BACKGROUND DATA: Burst fractures are generally characterized by injury to the middle column and fracturing of the superior endplate. However, results in previous biomechanical investigations have not shown how these fractures are initiated during compression. METHODS: Twenty-one thoracic and lumbar vertebrae (5 T10, 10 L1, and 6 L4) with upper and lower vertebrae were studied. Three-axis rosette strain gauges were cemented to 11 sites on the vertebral surface. An axial compressive load was applied, and the strain was measured in each specimen. The strain recorded by each rosette gauge was converted into a tensile, compressive, and shear component. RESULTS: The highest tensile and compressive strain was recorded at the base of the pedicle. Shear strain in the vertebral body was significantly higher than that in the lamina at all three spinal levels. At L1 and L4, the tensile strain at the superior vertebral rim was higher than that at the inferior rim. CONCLUSIONS: The high tensile and compressive strains found at the base of the pedicle of T10, L1, and L4 indicate that the base of the pedicle is the site of fracture initiation. The higher tensile strain at the superior vertebral rim of L1 and L4 supports the clinical observation of the thoracolumbar burst fractures.

Aged↗

PubMed1999

Anterior decompression with single segmental spinal interbody fusion for lumbar burst fracture.

STUDY DESIGN: The clinical and radiologic records for seven patients with lumbar burst fracture who underwent anterior decompression with single segmental interbody fusion were reviewed. OBJECTIVE: To determine the clinical results obtained with this method and its influence on the intervertebral disc degeneration inferior to the fusion. SUMMARY OF BACKGROUND DATA: Some patients with Denis' type B fracture can tolerate one-segment anterior fusion. However, there is no reliable information in the literature regarding the juxtafusional disc degeneration after one-segment fusion. METHODS: Seven patients with type B lumbar burst fractures, including four with cleavage fracture of the lower endplate, underwent anterior single segmental fusion; three patients underwent surgery with no instrumentation, and four underwent surgery with Kaneda instrumentation. The mean follow-up period lasted 85 months. The kyphosis angle and inferior intervertebral disc height adjacent to the fusion were measured before and after surgery. Pain and working status were evaluated using the scales proposed by Denis et al. RESULTS: Significant correction loss was obtained 1 year after surgery in the patients in whom no instrumentation was used (7.3 +/- 0.6 degrees), compared with the correction loss in patients whose surgery included the use of instrumentation (0.3 +/- 0.5 degree; P = 0.00001). No further correction losses were seen in either group at the final follow-up examination. No marked reduction in disc height was observed in any patient, including the four patients with cleavage fracture of the lower endplate. All patients returned to their previous occupation; five patients were rated as P1 (no pain) and W1 (returned to heavy labor), and two patients were rated as P2 (minimal pain) and W2 (return to heavy labor with lifting restrictions) at the final follow-up examination. CONCLUSIONS: There was slight correction loss within 1 year when no instrumentation was used, but this deformity did not affect the clinical results. The results provided no evidence that cleavage fracture of the lower endplate accelerates degeneration of the adjacent intervertebral disc.

Adolescent↗

PubMed1999

Meltrin-alpha, a fusion protein involved in multinucleated giant cell and osteoclast formation.

The formation of multinucleated cells such as myotubes, macrophage-derived giant cells (MGC), and osteoclasts is the result of cell-cell fusion of mononuclear precursors. Meltrin-alpha, -beta, and -gamma are members of a recently discovered family of proteins that contain disintegrin and metalloprotease domains and are related to fertilin, a protein involved in egg-sperm fusion. Based on this and evidence implicating meltrin-alpha in myoblast formation, we have investigated the possibility that meltrins may also play a role in the formation of MGC and osteoclasts. Using in situ RT-PCR, we have determined that murine mononuclear alveolar macrophages cultured under basal conditions express the transcript for meltrin-beta, but not for meltrin-alpha. However, meltrin-alpha mRNA appeared in mononuclear cells before cell fusion after treatment with 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], a potent inducer of giant cell and osteoclast formation. Moreover, addition of meltrin-alpha antisense oligonucleotides to the cultures caused a 50% inhibition of giant cell formation. Similarly, meltrin-alpha antisense oligonucleotides inhibited by 70% the formation of multinucleated osteoclast-like cells expressing tartrate-resistant acid phosphatase (TRAP) in co-cultures of bone marrow cells and osteoblastic cells (2107) in the presence of 1,25(OH)2D3. Mononucleated TRAP-positive cells, induced by 1,25(OH)2D3 in the co-cultures, also expressed meltrin-alpha mRNA, but their number was not changed in the presence of meltrin-alpha antisense oligonucleotide. In contrast to mononuclear macrophages and osteoclast-like cells, murine bone marrow stroma and calvaria derived-cell lines (+/+ LDA.11 and 2107), primary cultures of calvaria cells, and primary cultures of bone marrow cells expressed both meltrin-alpha and -beta mRNA under basal conditions; whereas embryonic fibroblasts (NIH3T3) expressed only the meltrin-beta transcript. Upregulation of meltrin-alpha protein expression during cell fusion in alveolar macrophages and expression in osteoblastic cell lines were confirmed by Western blot analysis. These observations demonstrate that meltrins play a role in MGC and osteoclast formation from mononuclear precursors, as in the case with myotubes.

ADAM Proteins↗

PubMed1999

The effect of spinal instrumentation on lumbar intradiscal pressure.

The purpose of this study was to investigate the effect of spinal instrumentation on the intradiscal pressure (IDP) within the fixed motion segment. In vitro biomechanical testing was performed in six single functional spinal units of fresh calf lumbar spines using a pressure needle transducer. Various loads were applied by a materials testing system device. In addition to intact spine (control), anterior spinal instrumentation (ASI) and pedicle screw fixation (PS) constructs, as well as destabilized spine were tested. Relative to the control, the destabilized spine tended to have an increased IDP; by 15% in axial compression and by 9-36% in flexion-extension. Compared to the control, PS decreased the IDP by 23% in axial loading and 51% in extension loading and increased it by 60% in flexion for each loading. ASI decreased the IDP by 32% in flexion and 1% in extension. Lateral bending produced symmetrical changes of IDP in the control and destabilized spine, but no change in the PS construct. The IDP of the ASI construct was decreased by 77% in ipsilateral bending and increased by 22% in contralateral bending. These results demonstrated that eccentric loading from the spinal instruments increased IDP and significant disc pressure may still exist despite an increase in motion segment stiffness after lumbar stabilization.

Animals↗

PubMed1999

Posterior lumbar interbody fusion: a retrospective study of complications after facet joint excision and pedicle screw fixation in 148 cases.

We retrospectively evaluated neurological and other complications related to posterior lumbar interbody fusion (PLIF) performed by facet joint excision and pedicle screw fixation, in 148 consecutive patients with degenerative disorders. Their mean age at surgery was 59 (19-80) years. The mean follow-up period was 3 (2-6.5) years. Overall, 91 complications in 75 cases were observed. Although no permanent neural damage was detected, transient neural palsy occurred in 8% of the cases. Dural tear, partial misplacement, loosening, breakage of the pedicle screw and loss of correction were seen in 6, 6, 4, 1 and 1 of the cases, respectively. Deep infection of the fused segment developed in 2 cases. We conclude that PLIF, performed by facet joint excision and pedicle screw fixation, demonstrated a very low incidence of osteosynthesis failure, such as screw loosening, breakage and loss of correction. However, the high incidence of other complications, particularly neurological impairment, is still a disadvantage of this technically-demanding procedure.

Adult↗

PubMed1998

Artificial nine zinc-finger peptide with 30 base pair binding sites.

It is well-known that DNA binding of native nine zinc-finger protein TEIIIA is dominated by interaction of select few fingers. Newly designed zinc-finger peptide Sp1ZF9 containing nine Cys2-His2 type motifs has been manipulated. The DNA-binding property of Sp1ZF9 was compared with those of native three zinc-finger Sp1(530-623) and artificial six zinc-finger Sp1ZF6 peptides. Although the equilibrium time was less than 0.5 h for Sp1(530-623)-DNA complex, Sp1ZF6 and Sp1ZF9 required approximately 48 and 72 h, respectively, for full complex formation. Evidently, the footprinting analysis demonstrated that Sp1ZF9 and Sp1ZF6 bind at least 27 and 18 contiguous base pairs of DNA sequence, respectively. Sp1ZF9 showed two step bindings to DNA, namely first the recognition of GC (5'-GGG-GCG-GGGCC-3') sequence by the N-terminal Sp1 domain and next the recognition of the corresponding target sequences by the middle and C-terminal Sp1 domains. In contrast with unimolecular binding of Sp1ZF9 and Sp1ZF6, two Sp1(530-623) molecules bind to one GCIII (5'-GGG-GCG-GGG-GGG-GCG-GGG-GGG++ +-GCG-GGGCC-3') site region. Semispecific complex formed at the beginning of Sp1ZF9-DNA interaction has also been characterized by kinetic analysis using surface plasmon resonance. Interestingly, the association rate constants for GC and GCIII complexes of Sp1ZF9 are smaller than those of the corresponding Sp1(530-623) complexes. Of special interest is the fact that new nine zinc-finger peptide Sp1ZF9 can bind to DNA sequence of approximately 30 base pairs. Such multi zinc-finger peptides may be useful as genome-specific transcriptional switches in future.

Base Pairing↗

PubMed1998

Mode of action of interleukin-6 on mature osteoclasts. Novel interactions with extracellular Ca2+ sensing in the regulation of osteoclastic bone resorption.

We describe a physiologically significant mechanism through which interleukin-6 (IL-6) and a rising ambient Ca2+ interact to regulate osteoclastic bone resorption. VOXEL-based confocal microscopy of nonpermeabilized osteoclasts incubated with anti- IL-6 receptor antibodies revealed intense, strictly peripheral plasma membrane fluorescence. IL-6 receptor expression in single osteoclasts was confirmed by in situ reverse transcriptase PCR histochemistry. IL-6 (5 ng/l to 10 microg/l), but not IL-11 (10 and 100 microg/l), reversed the inhibition of osteoclastic bone resorption induced by high extracellular Ca2+ (15 mM). The IL-6 effect was abrogated by excess soluble IL-6 receptor (500 microg/l). Additionally, IL-6 (5 pg/l to 10 microg/l) inhibited cytosolic Ca2+ signals triggered by high Ca2+ or Ni2+. In separate experiments, osteoclasts incubated in 10 mM Ca2+ or on bone released more IL-6 than those in 1.25 mM Ca2+. Furthermore, IL-6 mRNA histostaining was more intense in osteoclasts in 10 or 20 mM Ca2+ than cells in 1.25 mM Ca2+. Similarly, IL-6 receptor mRNA histostaining was increased in osteoclasts incubated in 5 or 10 mM Ca2+. Thus, while high Ca2+ enhances IL-6 secretion, the released IL-6 attenuates Ca2+ sensing and reverses inhibition of resorption by Ca2+. Such an autocrine-paracrine loop may sustain osteoclastic activity in the face of an inhibitory Ca2+ level generated locally during resorption.

Animals↗