Biomedical subjects

E Abe

Publications and source records attributed to E Abe.

At least 19 recordsLinked to original sources

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↗

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↗

PubMed1998

Syndecan-1 is a multifunctional regulator of myeloma pathobiology: control of tumor cell survival, growth, and bone cell differentiation.

Multiple myeloma is characterized by an accumulation of malignant plasma cells in the bone marrow coupled with an altered balance of osteoclasts and osteoblasts, leading to lytic bone disease. Although some of the cytokines driving this process have been characterized, little is known about the negative regulators. We show that syndecan-1 (CD 138), a heparan sulfate proteoglycan, expressed on and actively shed from the surface of most myeloma cells, induces apoptosis and inhibits the growth of myeloma tumor cells and also mediates decreased osteoclast and increased osteoblast differentiation. The addition of intact purified syndecan-1 ectodomain (1 to 6 nmol/L) to myeloma cell lines in culture leads to induction of apoptosis and dose-dependent growth inhibition, with concurrent downregulation of cyclin D1. The addition of purified syndecan-1 in picomolar concentrations to bone marrow cells in culture leads to a dose-dependent decrease in osteoclastogenesis and a smaller increase in osteoblastogenesis. In contrast to the effect on myeloma cells, the effect of syndecan-1 on osteoclastogenesis only requires the syndecan-1 heparan sulfate chains and not the intact ectodomain, suggesting that syndecan's effect on myeloma and bone cells occurs through different mechanisms. When injected in severe combined immune deficient (scid) mice, control-transfected myeloma cells (ARH-77 cells) expressing little syndecan-1 readily form tumors, leading to hind limb paralysis and lytic bone disease. However, after the injection of syndecan-1-transfected ARH-77 cells, the development of disease-related morbidity and lytic bone disease is significantly inhibited. Taken together, our data demonstrate, both in vitro and in vivo, that syndecan-1 has a significant beneficial effect on the behavior of both myeloma and bone cells and therefore may represent one of the central molecules in the regulation of myeloma pathobiology.

Animals↗

PubMed1998

Heterosexual transmission of a murine AIDS virus.

Heterosexual transmission of a murine leukemia virus mixture named LP-BM5 MuLV, which is known as the murine AIDS virus, was investigated. Our results indicated that the heterosexual transmission of LP-BM5 MuLV occurs in both directions with high frequency and that the frequencies of virus transmission in the cervix and penis are higher than those in other genital organs. The results suggested that infection by LP-BM5 MuLV via heterosexual transmission may initially take place at particular retrovirus-sensitive sites (cells) in the genital organs.

Animals↗

PubMed1998

Indications for peripartum aortic pressure monitoring in Takayasu's disease. A patient with past history of intrapartum cerebral hemorrhage.

We describe a successful delivery by prophylactic cesarean section in a patient with Takayasu's disease who had a previous history of intrapartum cerebral hemorrhage during vaginal delivery. Aortography showed occlusion of the common carotid, subclavian and vertebral arteries on the left side, severe narrowing of the right subclavian artery, and moderate narrowing of the entire abdominal aorta. Blood pressure was managed by monitoring central aortic pressure at the thoracic aorta. During the peripartum course, we recommend monitoring the central aortic pressure in patients with Takayasu's disease in whom accurate blood pressure readings can not be obtained in any extremity.

Adult↗

PubMed1998

Changes in transforming growth factor beta1 gene expression and immunoreactivity levels during development of chronic radiation enteropathy.

Chronic intestinal radiation injury is associated with locally increased TGF-beta1 immunoreactivity that correlates with morphological alterations. However, the underlying mechanisms are not known. This study examined changes in intestinal TGF-beta1 immunoreactivity, steady-state TGF-beta1 mRNA levels, and cellular localization of TGF-beta1 mRNA during development of chronic radiation enteropathy in a rat model. A loop of small bowel was fixed inside the scrotum of orchiectomized male rats. The intestine was subsequently exposed locally to 0, 12 or 21 Gy X radiation. Intestine was procured at 24 h and 2, 6 and 26 weeks and subjected to histopathological analysis, quantitative immunohistochemistry with computerized image analysis, assessment of steady-state TGF-beta1 mRNA levels with quantitative reverse transcriptase polymerase chain reaction, and identification of cell types expressing TGF-beta1 mRNA with in situ hybridization. Intestine from the 21-Gy group exhibited more histopathological injury and increased TGF-beta immunoreactivity 2-26 weeks after irradiation compared to the 12-Gy group and sham-irradiated controls. TGF-beta1 mRNA in irradiated intestine increased up to six times relative to controls at 24 h and 2 weeks, was less at 6 weeks, and did not differ from controls at 26 weeks. In situ hybridization detected TGF-beta1 mRNA in epithelial and Paneth cells in control intestine. Irradiated intestine exhibited additional TGF-beta1 mRNA in inflammatory and fibroblast-like cells. We conclude that there is a radiation-induced shift in the cellular sources of TGF-beta1, and that Tgfb1 gene expression is increased mainly during the early phases of radiation enteropathy, preceding the increase in immunoreactivity and histopathological injury. Translational or post-translational mechanisms are likely involved in sustaining increased TGF-beta1 immunoreactivity levels during the chronic phase of radiation enteropathy.

Animals↗

PubMed1997

Regulation of the gp80 and gp130 subunits of the IL-6 receptor by sex steroids in the murine bone marrow.

Both estrogen and androgen exert their antiosteoporotic effects, at least in part, by inhibiting IL-6 production, thereby suppressing osteoclastogenesis. Several observations, however, suggest that besides increased IL-6 production, sensitivity of the osteoclastogenic process to this cytokine is altered after ovariectomy. Based on this and evidence that the ligand-binding subunit of the IL-6 receptor (gp80) is a limiting factor for the actions of IL-6 on bone, we hypothesized that sex steroids regulate expression of the IL-6 receptor as well. We report that 17beta-estradiol or dihydrotestosterone in vitro decreased the abundance of the gp80 mRNA as well as the mRNA of the signal-transducing subunit of the IL-6 receptor (gp130) in cells of the bone marrow stromal/osteoblastic lineage, and also decreased gp130 protein levels. These effects did not require new protein synthesis. In contrast to sex steroids, parathyroid hormone stimulated gp130 expression; this effect was opposed by sex steroids. Consistent with these findings, ovariectomy in mice caused an increase in expression of gp80, gp130, and IL-6 mRNAs in ex vivo bone marrow cell cultures as determined by quantitative reverse transcription (RT)-PCR, and confirmed on an individual cell basis using in situ RT-PCR. The demonstration of increased expression of the IL-6 receptor after loss of sex steroids provides an explanation for why IL-6 is important for skeletal homeostasis in the sex steroid-deficient, but not replete, state.

Animals↗

PubMed1997

Anterior decompression of foraminal stenosis below a lumbosacral transitional vertebra. A case report.

STUDY DESIGN: A case of unilateral far-out foraminal entrapment of the L5 spinal nerve below a transitional vertebra is presented with a review of the literature. OBJECTIVES: To describe management of a rare far-out foraminal stenosis below a transitional vertebra and to evaluate the surgical procedure and results. SUMMARY OF BACKGROUND DATA: Far-out foraminal stenosis with radiculopathy caused by bony spur formation secondary to anomalous articulation between the transverse process and the sacral ala is rarely reported. Decompression at this point traditionally has been performed through a posterior approach, similar to that performed for the far-out syndrome. There are no previous reports describing anterior decompression through an extraperitoneal approach. METHODS: The diagnosis was confirmed by computed tomography, magnetic resonance imaging, and selective radiculography. Anterior decompression was performed by resecting the bony spur using a wide muscle-splitting extraperitoneal approach. RESULTS: Anterior decompression was performed with minimal intervention to the spine and the trunk muscles. Good relief of low back pain and sciatica was obtained. CONCLUSIONS: Selective radiculography was the method of examination with the optimal diagnostic value for far-out foraminal stenosis. An anterior approach to the decompression of far-out foraminal stenosis below a lumbosacral transitional vertebra is a relatively simple and effective method.

Adult↗

PubMed1997

Inhibition of intracellular multiplication of human strains of Chlamydia trachomatis by nitric oxide.

It was previously shown that murine T cell clones could inhibit the intracellular growth of the mouse strain of Chlamydia trachomatis by cytokine-mediated induction of the inducible nitric oxide synthase (iNOS) system in epithelial cells, an effect enhanced by direct epithelial-T cell interaction via specific adhesion molecules. These findings and other recent reports showing that human mucosal epithelial cells secrete nitric oxide (NO) via iNOS expression would suggest that mucosal epithelial-derived NO may be involved in mucosal defense against Chlamydia and other pathogens that infect epithelial cells. As an initial approach to investigating whether NO contributes to chlamydial control in humans, the present studies evaluated the susceptibility of human isolates of C. trachomatis to NO delivered by chemical donors or via induction of the epithelial iNOS system by a cytokine-secreting T cell clone. It was found that a chlamydial-specific, cytokine-secreting, murine T lymphocyte clone (clone 2.14-0) could inhibit the intraepithelial growth of human strains of Chlamydia trachomatis (serovar E and H, and Lymphogranuloma venerum type L2) via the iNOS pathway when the clone was co-cultured with chlamydial-infected epithelial cells. Furthermore, treatment of infected epithelial cells with 50 microM of the NO donor, S-nitroso-L-glutathione, resulted in significant inhibition (approximately 70%) of chlamydial multiplication, while the NO scavenger, myoglobin plus ascorbate, could reverse the effect, demonstrating that NO could directly inhibit human strains of Chlamydia. The results are consistent with the hypothesis that the IFN-gamma-inducible iNOS pathway can contribute to chlamydial control in humans.

Animals↗

PubMed1997

Thoracolumbar burst fracture with horizontal fracture of the posterior column.

STUDY DESIGN: Nine patients with thoracolumbar burst fractures associated with horizontal fractures in the posterior column were studied retrospectively. OBJECTIVES: To clarify the clinical and radiographic findings and evaluate the postoperative results for this type of fracture. SUMMARY OF BACKGROUND DATA: It is not well recognized that burst fractures occasionally are accompanied by horizontal fractures of the posterior column such as those that result from seatbelt-type injuries. This type of burst fracture differs from flexion-distraction injuries combined with burst fracture, which are accompanied by horizontal fractures not only in the posterior but also in the middle column. Radiographic features of these two different types of injuries are very similar to each other, and their differentiation in diagnosis and treatment has not been recognized clearly. METHODS: Patients were reviewed using a combination of clinical records, follow-up examination, and radiographic data (computed tomography [CT], plain radiographs, and tomographs). Anterior spinal fusion was performed in eight patients using the Kaneda device (Mizuhoika Tokyo, Japan), and one was treated by posterior fusion with pedicle screw fixation. The average follow-up period was 4 years. RESULTS: Patients with fractures of this type represented 21% of the 48 patients with thoracolumbar burst fractures. The injury was sustained by falling in all nine patients. All of the burst fractures were Denis' type B. The horizontal fracture was located at the lamina and spinous process in the posterior column of the upper vertebra adjacent to the involved vertebra in all nine patients. The integrity of the ligamentous structures of the middle column, such as the posterior longitudinal ligament, the periosteum, and the outermost anulus, was confirmed at surgery in eight patients, although not in the patient who underwent posterior fusion. One patient required surgery because of progression of kyphotic deformity during conservative treatment. Solid fusion with no complications was noted in all patients. CONCLUSION: This type of burst fracture is not accompanied by ligamentous injuries because of distraction force in the middle column, which is not present in flexion-distraction injuries, but it seems to be more unstable than burst fractures with no horizontal splitting of the posterior column and requires surgical stabilization.

Adult↗

PubMed1997

Nitric oxide production by superficial and deep articular chondrocytes.

OBJECTIVE: Chondrocytes have been shown to produce large amounts of nitric oxide (NO) when appropriately stimulated with proinflammatory cytokines or bacterial lipopolysaccharide (LPS). In view of recent observations underscoring profound phenotypic differences between superficial and deep articular chondrocytes, these studies investigated NO production, inducible NO synthase (iNOS) activity, and messenger RNA (mRNA) expression of superficial and deep cartilage explants and cells. METHODS: Superficial and deep bovine and human articular cartilage explants and isolated bovine chondrocytes were cultured in the presence of stimulating cytokines or LPS. NO was measured by the Griess reagent. Inducible NOS activity was quantitated by conversion of L-14 C-arginine to L-14C-citrulline. Inducible NOS mRNA expression was quantitated by reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization. RESULTS: Superficial bovine cartilage explants stimulated with interleukin-1 alpha, LPS, or tumor necrosis factor alpha for 24 and 48 hours produced significantly more NO than did deep explants with all stimulants and at both times. Similar results were obtained with stimulated isolated superficial and deep cells. NO synthase activity, measured by the conversion of L-14C-arginine to L-14C-citrulline, paralleled NO production. Comparable results were obtained using explants from a normal human donor. Semiquantitation of iNOS mRNA by RT-PCR showed significantly larger amounts of PCR products in superficial cells and superficial explants. These results were confirmed by in situ hybridization of explants and isolated cells. CONCLUSION: Increased NO production at the cartilage surface-synovial fluid interface may play an important role in the modulation of cartilage damage in inflammatory arthritis.

Animals↗

PubMed1997

A polypeptide encoded within the murine AIDS defective virus stimulates primary proliferation of CD8+ T-cells.

The murine AIDS (MAIDS) is a retrovirus-induced disease that shows severe immunodeficiency with abnormal lymphoproliferation in susceptible strains of mice. To clarify the antigenicity of gag gene products of the LP-BM5 defective virus, which is known as the causative virus of MAIDS, we expressed and purified the gag p12 gene product (P12) by using a baculovirus expression vector system. The P12 protein strongly stimulated the proliferation of normal C57BL/6 (B6) lymph node T-cells in vitro. Furthermore, a 25-mer synthetic polypeptide within the P12 sequence gave rise to the similar or even higher activation of T-cells. The phenotype of responding T-cells was found to be CD8+ CD44low, indicating that naive CD8+ T-cells respond against a peptide encoded within a MAIDS defective virus gag p12 gene. Finally, the expression of T-cell receptor (TcR) V beta on the responding CD8+ T-cells was analyzed. Although CD8+ T-cells with the particular V beta chains were expanded in response to the 25-mer peptide, this polypeptide does not seem to be a superantigen, since this response is MHC class I-restricted and the V beta preference is not striking. The presentation pathway of this highly antigenic polypeptide will be discussed.

Amino Acid Sequence↗

PubMed1997

Osteopontin expression by osteoclast and osteoblast progenitors in the murine bone marrow: demonstration of its requirement for osteoclastogenesis and its increase after ovariectomy.

Osteoclast development requires cell-to-cell contact between hematopoietic osteoclast progenitors and bone marrow stromal/osteoblastic support cells. Based on this, we hypothesized that osteopontin, an adhesion protein produced by osteoclasts and osteoblasts, plays a role in osteoclastogenesis. Using in situ hybridization, we demonstrate that cells expressing the osteopontin messenger RNA (mRNA) appear after 3 days of culturing murine bone marrow cells. The number of these cells increases thereafter, reaching a peak on day 5. In the same cultures, cells expressing alkaline phosphatase (AP) or tartrate resistant acid phosphatase (TRAP), phenotypic markers for osteoblastic and osteoclast-like cells, respectively, appeared subsequent to the appearance of the osteopontin-positive cells. By means of a combination of in situ hybridization and histostaining, it was shown that the osteopontin mRNA was localized in 30-50% of the AP-positive or the TRAP-positive, as well as in nonspecific esterase (NSE)-positive, cells. The number of cells expressing both the osteopontin mRNA and either one of the three phenotypic markers was significantly increased in bone marrow cultures from estrogen-deficient mice, as compared with controls. Conversely, the number of all three populations of double positive cells was decreased in cultures treated with a specific antimouse rabbit osteopontin antibody or an RGD peptide. These findings indicate that osteopontin is expressed during the early stages of the differentiation of osteoclast and osteoblast progenitors in the bone marrow and that its cell adhesion properties are required for osteoclastogenesis.

Animals↗

PubMed1997

New multi zinc finger protein: biosynthetic design and characteristics of DNA recognition.

New six zinc finger protein DSp1 was created by connecting two Sp1 DNA binding domains. The DNA recognition characteristics of DSp1 demonstrate that (1) this multi finger protein binds eighteen contiguous base pairs of DNA sequence, (2) each zinc finger wraps around DNA major groove, and (3) two Sp1 domains have nonequivalent contribution to the DNA binding of DSp1.

Amino Acid Sequence↗

PubMed1996

Myelopathy resulting from the atlantodental hypertrophic osteoarthritis accompanying the dens hypertrophy. Two case reports.

STUDY DESIGN: This is a report of two patients who sustained cervical myelopathy that seemed to be associated with hypertrophic atlantodental osteoarthritis accompanying dens hypertrophy. OBJECTIVES: Pathogenesis of hypertrophic osteoarthritis in the atlantodental articulation was elucidated, and these two patients were treated by C1 decompressive laminectomy with or without posterior fusion. SUMMARY OF BACKGROUND DATA: One case of myelopathy resulting from the hypertrophic nonunion of the dens has been reported, but to the authors' knowledge, there have been no reports describing a case similar to those presented in this report. METHODS: History, physical findings, and image examination findings common to the two cases were analyzed to elucidate pathogenesis of hypertrophic osteoarthritis in the atlantodental articulation. C1 decompressive laminectomy alone was performed in one patient and additional atlantoaxial transarticular fixation in the other patient. RESULTS: Myelopathy in two patients was caused by the cervical cord compressed between the hypertrophic and sclerotic dens and the anteriorly displaced posterior arch of the atlas in the developmentally small atlas ring. Postoperative neurologic recovery was satisfactory with the atlantoaxial solid fusion. CONCLUSION: The atlantodental hypertrophic osteoarthritis accompanying the dens hypertrophy seemed to have developed because of post-traumatic atlantoaxial instability. Their developmentally small atlas ring may be a predisposing factor toward the development of myelopathy.

Aged↗

PubMed1996

Outcome of anterior decompression and stabilization for thoracolumbar unstable burst fractures in the absence of neurologic deficits.

STUDY DESIGN: This study investigated the outcome of anterior decompression and stabilization for "unstable" burst fractures without initial neurologic deficits in the thoracolumbar spine. OBJECTIVE: To determine the pain and work status of the patients, who underwent the anterior decompression and stabilization, to evaluate the relationship between residual back pain and the degree of kyphosis, and to analyze the advantages and disadvantages of surgery for burst fractures without initial neurologic deficits in the thoracolumbar spine. SUMMARY OF BACKGROUND DATA: A retrospective review was conducted on 45 patients with unstable burst fractures in the thoracolumbar spine treated by anterior decompression and stabilization in our institutions from 1982 to 1993. Nineteen patients were available for this study. Ten patients were men and 9 were women. Their age at surgery ranged from 15 to 76 years (average, 46 years). The duration of follow-up ranged from 24 to 84 months (average follow-up, 54 months). METHODS: All clinical charts and radiologic data of these patients were reviewed by the first author. Their pain, work, and employment statuses were assessed by the scales proposed by Denis in 1984. RESULTS: Nine patients were rated P1, 7 were rated P2, 2 were rated P3, 1 was rated P5, 11 were rated W1, 3 were W2, 1 was W3, and 4 were rated W5. Even the physical laborers' return to work averaged 5 months after surgery (range, 3-12 months). The postoperative kyphotic angle ranged from -6 degrees to 45 degrees (average, 11 degrees), and it remained -5 degrees to 45 degrees (average, 12 degrees) at final follow-up. There was no statistical correlation between the kyphotic angle and the pain scale. CONCLUSIONS: Anterior decompression and stabilization for unstable burst fracture without initial neurologic deficits in the thoracolumbar spine has some advantages in the view of anatomical reduction and rigid stability that allows patients an early rehabilitation, return to work, and gainful employment.

Adolescent↗

PubMed1996

Fibronectin synthesis in superficial and deep layers of normal articular cartilage.

OBJECTIVE: To study the distribution and synthesis of fibronectin (FN) in superficial and deep layers of normal articular cartilage. METHODS: Superficial and deep bovine and human articular cartilage slices were used to extract and quantitate FN by radioimmunoassay. Chondrocytes were also isolated by collagenase digestion for FN extraction and culture. Superficial and deep cartilage explants were cultured with and without stimulation by cytokines. Quantitation of newly synthesized FN was carried out by incubation with 35S-methionine. FN was purified on gelatin-agarose columns and further characterized by polyacrylamide gel electrophoresis. FN messenger RNA (mRNA) was quantitated by Northern blot analysis. RESULTS: Freshly isolated bovine chondrocytes from deep cartilage contained 2.3 +/- 0.2 times more FN than was found in superficial cells (P < 0.025). Deep cartilage explants contained 1.2 times more FN than was found in superficial tissue. Explants obtained from deep cartilage synthesized 2.4 times more FN per cell than did superficial tissues (P < 0.01). FN synthesis as a fraction of total protein synthesis was significantly greater in deep explants (P < 0.01) compared with superficial tissues. Isolated deep chondrocytes in culture synthesized 1.89 +/- 0.33-fold more FN than did superficial cells (P < 0.05). Cytokine-stimulated superficial cartilage explants failed to respond in terms of FN synthesis. FN mRNA quantitation showed no significant differences between superficial and deep populations. CONCLUSION: Since FN plays a major role in cell adhesion to damaged cartilage surfaces, our results suggest that modulation of FN synthesis near the articular surface of cartilage may be one of the factors that impede pannus invasion following an inflammatory insult to the joint.

Animals↗