Biomedical subjects

Hiromi Matsuzaki

Publications and source records attributed to Hiromi Matsuzaki.

11 recordsLinked to original sources

PubMed2006

Gene expression changes in an early stage of intervertebral disc degeneration induced by passive cigarette smoking.

STUDY DESIGN: This study attempts to determine the molecular changes in intervertebral disc degeneration of rats induced by passive cigarette smoking. OBJECTIVES: To quantitate and compare the gene expression levels in intervertebral discs from passively cigarette smoking rats and nonsmoking rats. SUMMARY OF BACKGROUND DATA: The molecular mechanism of intervertebral disc degeneration has been investigated mainly in vitro but little in vivo, and gene expression analysis has been performed in a few studies. The cigarette smoking is a risk factor of low back pain. We developed a smoking box to create a rat model of intervertebral disc degeneration induced by passive cigarette smoking. METHODS: Total RNA was extracted from intervertebral discs of rats that were raised in a cigarette-smoking box for 2 to 7 weeks. After synthesis of cDNA, the quantitative analysis of gene expression was performed by the real-time PCR. The remaining spines were subjected to the histologic examination. RESULTS: Histologic changes of the nucleus pulposus and the anulus fibrosus were detected after 2 weeks of smoking and were frequently found after 7 weeks. Collagen genes were downregulated remarkably after 7 weeks of smoking. No significant increase was observed in the expressions of matrix metalloproteinase-3, but the expression of tissue inhibitor of metalloproteinases-1 started to increase at 4 weeks of smoking. Aggrecan also started to be up-regulated at 4 weeks. CONCLUSIONS: Changes in gene expression by passive cigarette smoking precede the histologic changes in the intervertebral discs. Reactions to suppress the destruction of tissue matrix and to regenerate the intervertebral discs are occurring at the same time as the degenerative histologic changes.

Animals↗

PubMed2006

Effectiveness of posterior decompression for patients with ossification of the posterior longitudinal ligament in the thoracic spine: usefulness of the ossification-kyphosis angle on MRI.

STUDY DESIGN: A reliability study was conducted. OBJECTIVE: To report the utility of the ossification- kyphosis angle of a decompression site in the sagittal view of MRI in the preoperative evaluation of the effectiveness of posterior decompression for patients with ossification of the posterior longitudinal ligament in the thoracic spine. SUMMARY OF BACKGROUND DATA: In patients with ossification of the posterior longitudinal ligament, in the thoracic spine, posterior decompression may not always be effective for those with physiologic kyphosis; however, posterior decompression is sometimes useful for patients with multilevel lesions or with ossification of the ligamentum flavum. Therefore, it is necessary to evaluate the indications or limitations of posterior decompression before surgery. METHODS: The indications or limitations of posterior decompression for this disease were reviewed from the findings of intraoperative ultrasonography and various parameters on preoperative imaging in 22 patients with thoracic myelopathy. RESULTS: Thirteen patients had echo-free space and 9 patients had no echo-free space in intraoperative ultrasonography after posterior decompression. In the kyphosis angle of the decompression site and the configuration of the maximal prominent OPLL, there was no significant difference between the group with echo-free space and the group without echo-free space (P = 0.49, P = 0.55). On the other hand, the ossification-kyphosis angle of the decompression site was more than 23 degrees in all patients with no echo-free space (23 degrees -34 degrees , 28.2 degrees +/- 3.6 degrees ), and it was less than 23 degrees in all patients with echo-free space (10 degrees -23 degrees , 17.4 degrees +/- 4.1 degrees ). There was also significant difference between the groups statistically (P < 0.01, P = 1.50789E-06). In addition, in the occupation rate of the greatest prominence of the OPLL, there was statistically significant difference between the groups (P = 0.032). CONCLUSION: The ossification-kyphosis angle in the sagittal view of MRI has potential as an indicator of the effectiveness of posterior decompression in this disease. It is thought that there is a critical point of posterior decompression at nearly 23 degrees of the ossification-kyphosis angle of the decompression site. When the ossification-kyphosis angle is more than 20 degrees , the presence of echo free space should be carefully confirmed in intraoperative ultrasonography.

Adult↗

PubMed2006

Histological changes in intervertebral discs after smoking and cessation: experimental study using a rat passive smoking model.

BACKGROUND: Passive smoking has been reported to induce intervertebral disc degeneration in rats, and the objective of the present study was to histologically investigate changes in smoking-induced intervertebral disc degeneration after cessation of smoking. METHODS: Four-week-old rats were subjected to passive smoking for 8 weeks in a smoking box [20 cigarettes a day: one cigarette an hour (inhaled over 3 minutes and followed by ventilation with room air for 5 minutes)] to induce intervertebral disc degeneration. Smoke-free periods of different lengths were then established, and intervertebral discs were histologically analyzed. RESULTS: Immediately after 8 weeks of passive smoking, intervertebral discs exhibited cracks, tears, and misalignment of the annulus fibrosus, and increased fibrous tissue was seen in the nucleus pulposus. In addition, the level of interleukin-1beta in intervertebral discs was higher in the smoking group than in the non-smoking group. After cessation, progression of degeneration ceased, and the matrix of the nucleus pulposus and annulus fibrosus exhibited increased fibrous connective tissue and proteoglycan. However, there were no changes in annulus fibrosus misalignment. Interleukin-1beta levels also remained significantly elevated after 8 weeks of cessation. CONCLUSIONS: While the annulus fibrosus degeneration caused by smoking was partially irreversible after cessation of smoking, the amount of mucin (proteoglycan) in the nucleus pulposus and annulus fibrosus tended to increase after cessation, thus suggesting the possibility that smoking-induced intervertebral disc degeneration can be repaired to some degree by cessation of smoking.

Animals↗

PubMed2005

A revised scoring system for preoperative evaluation of metastatic spine tumor prognosis.

STUDY DESIGN: A semi-prospective clinical study was conducted. OBJECTIVES: To evaluate the accuracy of a revised scoring system predicting metastatic spinal tumor prognosis and the suitability of the subsequent treatment strategy. SUMMARY OF THE BACKGROUND DATA: We used a scoring system for the preoperative evaluation of the prognosis of metastatic spinal tumors and selected treatment methods for the predicted prognosis. In the previous version of our scoring system, the reliability of the predicting prognosis was 63.3% in 128 patients with metastatic spinal tumors. METHODS: The study participants were 164 patients who died after surgery and 82 who died after conservative treatment. Six parameters were used in the revised scoring system. Each parameter ranged from 0 to 5 points, and the total score was 15 points. In principle, conservative treatment or palliative procedures were indicated in patients with a total score of 8 or less (predicted survival period, less than 6 months) or those with multiple vertebral metastases, while excisional procedures were performed in patients with a total score of 12 or more (predicted survival period, 1 year or more) or those with a total score of 9 to 11 (predicted survival period, 6 months or more) and with metastasis in a single vertebra. The selection of treatment modality was followed faithfully according to the criteria of the revised scoring system after 1998. The prognosis predicted by the revised scoring system and the actual survival period after treatment were compared, and the reliability of the prognostic criteria was analyzed for the group subjected to it prospectively after 1998 (n = 118) and for all 246 patients it was applied to retrospectively. RESULTS: The total score for each patient could be correlated with the survival period. This correlation was also observed in each treatment group. The consistency rate between the predicted prognosis from the criteria of the total scores and the actual survival period was high in patients within each score range (0-8, 9-11, or 12-15), 86.4% in the 118 patients evaluated prospectively after 1998, and 82.5% in the 246 patients evaluated retrospectively. Furthermore, a similar result was also observed in both the surgical procedure group and conservative treatment group. The rate of consistency between the predicted prognosis and the actual survival period in each local extension of the lesion was 75% or more in all types, excluding Type 6 in the surgical classification of Tomita et al. CONCLUSION: The prognostic criteria using the total scores from our revised scoring system were useful for the pretreatment evaluation of metastatic spinal tumor prognosis irrespective of treatment modality or local extension of the lesion.

Adolescent↗

PubMed2005

Trapeziometacarpal joint instability after Bennett's fracture-dislocation.

BACKGROUND: Investigation of trapeziometacarpal joint instability was undertaken following Bennett's fracture-dislocation. METHODS: We treated six patients who were experiencing trapeziometacarpal joint instability following Bennett's fracture-dislocation. The average age of the patients at the initial visit was 22.2 years. There were four men and two women. All six patients complained of trapeziometacarpal joint pain and instability preoperatively. Fluoroscopy confirmed that the beak fragment moved with the shaft fragment. The length of time from injury to surgery ranged from 1 to 29 months (average 10.7 months). Ligament reconstruction based on Eaton's method was performed on five patients, and in one patient the fracture site was osteotomized and reduced and the dorsoradial ligament repaired. RESULTS: Over an average follow-up observation period of 20 months, none of the patients complained of severe joint pain or instability. CONCLUSIONS: When treating Bennett's fracture-dislocation, it is necessary to pay careful attention not only to accurate anatomic reduction of the joint surface but also to joint instability.

Adolescent↗

PubMed2005

Alteration of gene expression in intervertebral disc degeneration of passive cigarette- smoking rats: separate quantitation in separated nucleus pulposus and annulus fibrosus.

OBJECTIVE: We constructed a passive cigarette-smoking model with rats to investigate the molecular mechanism of intervertebral disc degeneration, and found by gene expression analysis that passive cigarette smoking stimulated the stress-responsive signal pathway and inhibited the apoptotic pathway. In this study, to clarify that these changes were derived from either nucleus pulposus (NP) or annulus fibrosus (AF), we separately collected NP and AF and quantitatively analyzed gene expression. METHODS: Total RNA was extracted from NP and AF of the lumbar intervertebral discs from rats which were kept in a smoking box for 4 and 8 weeks. Gene expression was measured by real-time PCR of cDNA synthesized from the total RNA. RESULTS: Stress-responsive protein, heat shock protein 70, was expressed similarly in NP and AF, and was upregulated to the same degree after 8 weeks of passive cigarette smoking. The protein tyrosine phosphatase gene was expressed more strongly in AF than in NP, and was upregulated after 8 weeks of smoking in both tissue parts. The type II collagen and aggrecan genes were predominantly expressed in AF and NP, respectively. CONCLUSION: These results indicate that passive cigarette smoking stimulates both NP and AF, and induces the stress-responsible genes such as heat shock protein 70 and protein tyrosine phosphatase in both.

Aggrecans↗

PubMed2005

Ultrasonography in tarsal tunnel syndrome.

OBJECTIVE: The purpose of this study was to clarify the diagnostic value of ultrasonography in tarsal tunnel syndrome. METHODS: Seventeen patients (17 feet) with tarsal tunnel syndrome were treated between 1988 and 2003. Preoperative ultrasonography was performed, and the cause of the syndrome was confirmed intraoperatively in all cases. Long and short axes of the tarsal tunnel were scanned to ascertain the presence of any space-occupying lesion. RESULTS: The causes of tarsal tunnel syndrome, as confirmed by surgery, were ganglia (n = 10), talocalcaneal coalition (n = 1), talocalcaneal coalition associated with ganglia (n = 3), and varicose veins (n = 3). Among the cases involving ganglia, hypoechoic or anechoic regions were observed. The mean sizes +/- SD of these regions were 19.4 +/- 8.8 mm in the long axis, 15.2 +/- 6.3 mm in the short axis, and 10.4 +/- 3.8 mm in depth. Of these, 3 ganglia were not clearly palpable before surgery and were small: 10 x 10 x 7, 13 x 11 x 9, and 9 x 8 x 7 mm. Among the cases involving talocalcaneal coalition, ultrasonography indicated a beak-shaped bony process on the short axis images. Although these 3 cases were associated with ganglia, this could not be determined by preoperative palpation. CONCLUSIONS: As a diagnostic imaging technique for tarsal tunnel syndrome, ultrasonography is extremely useful for identifying space-occupying lesions. Ultrasonography should be performed routinely in patients with suspected tarsal tunnel syndrome.

Adolescent↗

PubMed2004

Degeneration of intervertebral discs due to smoking: experimental assessment in a rat-smoking model.

We have investigated the intervertebral discs of rat-smoking models to demonstrate that smoking is a cause of degenerative intervertebral disc disease. A smoking box was developed for this study. We exposed 8-week-old rats to indirect tobacco smoke inhalation. Each rat was forced to inhale the smoke from one cigarette per hour. The mean blood nicotine level of rodents exposed to cigarette smoke corresponds to about twice that of ordinary human smokers. Histological and immunological studies were then performed to assess the effects of smoking for varying periods of time. After 8 weeks, the chondrocytes in the disordered annulus fibrosus layer tended to grow larger and attain a rounder form than normal chondrocytes. The interleukin-1beta level in the 8-week smoking group was significantly higher than that of the control group. Tobacco smoke inhalation increased local production and release of inflammatory cytokines and resultant decomposition of chondrocyte activity.

Animals↗

PubMed2004

Endoscopic release for carpal tunnel syndrome accompanied by thenar muscle atrophy.

PURPOSE: The objective of this study was to ascertain whether endoscopic carpal tunnel release (ECTR) is indicated for treatment of carpal tunnel syndrome accompanied by thenar muscle atrophy. TYPE OF STUDY: Prospective cohort study. METHODS: Two-portal ECTR was performed on 67 hands in 52 patients with carpal tunnel syndrome accompanied by thenar muscle atrophy. RESULTS: Preoperative severity of thenar muscle atrophy was severe in 24 hands, moderate in 23 hands, and mild in 20 hands. Postoperative severity of thenar muscle atrophy was severe in 6 hands, moderate in 2 hands, mild in 23 hands, and none in 36 hands. CONCLUSIONS: Improvements with thenar muscle function in most cases of carpal tunnel syndrome can be expected with 2-portal ECTR. LEVEL OF EVIDENCE: Level IV.

Adult↗

PubMed2002

Mechanism of intervertebral disc degeneration caused by nicotine in rabbits to explicate intervertebral disc disorders caused by smoking.

STUDY DESIGN: The effects of nicotine on intervertebral discs in rabbits were studied experimentally. OBJECTIVES: To investigate the effects of nicotine on the vascular buds in rabbits for elucidating the mechanism of nicotine-induced vertebral disc degeneration. BACKGROUND DATA: Several groups have suggested that cigarette smoking is associated with low back pain, but the exact mechanism is not yet fully understood. METHODS: The pump was filled with a diluted nicotine solution, then implanted under the skin of rabbits for 8 weeks. This model was designed to maintain blood nicotine concentration at approximately 110 ng/mL. Rabbits receiving physiologic saline were used as control animals. RESULTS: Nicotine treatment resulted in necrosis and hyalinization of the nucleus pulposus in all rabbits. The anulus fibrosus showed a disturbance of the pattern of overlapping laminae with and without clefts and separation. These resulted in changes indicative of stenosis of vascular buds and perivascular calcification. Nicotine treatment resulted in hypertrophy of vascular walls, necrotic changes in endothelial cells, and narrowing of the vascular lumen. Nicotine treatment resulted in delineation of vascular buds in the vicinity of the vertebral endplate and a reduction of their numbers. However, the control animals showed a dense vascular network. The number of vascular buds decreased in nicotine treatment. CONCLUSION: The authors believe that both reduction in the density of vascular buds and narrowing of the vascular lumen result in decreased oxygen tension, leading to decreased synthesis of proteoglycan and collagen, thus facilitating degeneration of the disc.

Animals↗

PubMedDate not supplied

Extensor retinaculum graft for chronic boxer's knuckle.

PURPOSE: Boxer's knuckle is a tear of the metacarpophalangeal (MCP) joint capsule that occurs while punching. Because of the nature of boxing, boxer's knuckle tends to be a chronic condition and often is associated with sagittal band rupture. Chronic cases often feature excessive scarring in the damaged area where the sagittal band and the MCP joint capsule become indistinguishable. The purpose of this study was to ascertain whether extensor retinaculum grafting to the defect is useful in treating chronic boxer's knuckle when direct repair of a capsular tear is not possible. METHODS: In 5 professional boxers with chronic boxer's knuckle in whom capsular repair could have impaired MCP joint flexion, scar tissue of the damaged capsule and the sagittal band-if ruptured-were removed and an oval extensor retinaculum graft was sutured in the capsule/sagittal band defect. The mean age of the patients was 22 years. In all patients, surgery was performed on the middle finger. The capsule was damaged on the ulnar side in 3 patients and on the radial side in 2 patients. RESULTS: All boxers reported alleviation of pain when punching. The range of motion for the MCP joint was not restricted after surgery in any patient. Tendon dislocation did not occur after surgery in any patient. All 5 patients were able to return to professional competition. CONCLUSIONS: Extensor retinaculum grafting is useful in treating chronic boxer's knuckle if the damaged capsule cannot be repaired directly. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, Level IV.

Adult↗