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Objective: To clarify which proteases are specifically activated in the lesions of rheumatoid arthritis (RA) and osteoarthritis (OA)., Methods: The activity levels of the serine proteases of the coagulation and fibrinolytic systems, and of elastase and collagenase as controls, in synovial fluid from 27 RA patients and 28 OA patients were measured using fluorogenic synthetic substrates which had methylcoumarylamide (MCA) at their COOH-termini. The thrombin-antithrombin III complex (TAT) content was also measured by ELISA., Results: Among the proteases, thrombin-like activity was the highest in both RA and OA. The profiles of protease activity were similar in RA and OA, but their activities were in general significantly higher in RA than in OA (p < 0.01). The levels of both thrombin-like activity and TAT were about 7.5-fold higher in RA than in OA, while the levels of CRP and fibrinogen were only about 2-fold higher. Biochemical characterization of the thrombin-like activity in the synovial fluid of RA patients showed that this activity was due to thrombin. Thrombin-like activity positively correlated with the TAT concentration in RA (r = 0.750, p < 0.0001), but not in OA., Conclusion: Activation of the coagulation system was more marked in RA than in OA, strongly suggesting that in RA there is an imbalance between thrombin and its inhibitors, and that thrombin is more closely linked to the pathogenesis of RA than to that of OA. Our results also show that analysis of the synovial fluid may be useful to estimate the activation of the coagulation system in RA, but not that of the fibrinolytic system.

We studied the effects of denervation on the energy metabolism and peripheral circulation dynamics of rat hindlimb muscles during and after exercise. The sciatic nerves of male Wistar rats were cut to produce denervation. Energy metabolism was assessed by phosphorus-31 magnetic resonance spectroscopy (MRS), and circulation by fluorine-19 MRS. Exercise of rat hindlimb muscles was induced by electrical stimulation at 40 Hz. The inorganic phosphate (Pi) / ¿Pi + phosphocreatine (PCr)¿ ratio, an indicator of the energy level, was 0.795 immediately after denervation. The ratios 4 and 8 weeks after denervation were 0.870 and 0.853, respectively. The intracellular pH during the 4 min after initiation of stimulation was significantly reduced 4 and 8 weeks after denervation compared with the value immediately after denervation. The signal strength of the research perfluoro-carbon (FC-43; perfluorotributylamine) a measure of circulation dynamics, increased to 167% in controls during exercise, but an increase of only 134% was seen in rats 8 weeks after denervation. These results showed that the energy supply and circulation dynamics in denervated atrophic muscles decreased during exercise compared with findings in control muscles.

The site of lesion, spontaneous healing, onset mechanism, and magnetic resonance imaging findings of 51 knees in 38 patients with osteochondritis dissecans involving the femoral condyle in the growth stage were investigated. tercondylar site, and the remaining 1/4 were in other sites. Compared with those in the other sites, the lesions in a medial intercondylar site had a lower healing rate and required a longer time to heal. T2 weighted images of the lesions showed a progression from low signal areas to the appearance of a high signal line at the fragment to parent to bone interface, to a high signal double line at the interface and parent-bone surface, or to disappearance of the line. Magnetic resonance imaging often revealed discoid menisci or meniscal tears in patients with lesions in the lateral condyle, suggesting that endogenous forces play an important role in the onset of osteochondritis dissecans.

Rationale and Objectives: The authors evaluate the changes in magnetic resonance (MR) relaxation times of rat skeletal muscles in vivo after nerve injury and during neural recovery, and determine the major determinants of relaxation times., Materials: Magnetic resonance relaxation times, blood volume, and water and fat content were examined after nerve injury and during recovery with time course., Results: Nerve injury led to longer T2 values compared with controls, but there were no significant changes in T1 values. After the initial prolongation of T2 after nerve injury, no changes were observed. Neural recovery resulted in a return of T2 values to normal. The time course of changes in blood volume was similar to that of changes in T2, and T2 values were correlated strongly with 19-fluorine-MR spectroscopy estimates of blood volume (r2 = 0.94)., Conclusions: T2 values may be useful to monitor recovery after nerve injury and may be related to the blood volume in skeletal muscle.

This study examined the time course of recovery from nerve injury on energy state assessed by phosphorus-31 magnetic resonance spectroscopy and local circulation dynamics by fluorine-19 magnetic resonance spectroscopy in skeletal muscles of rats. The hindlimb muscles that had undergone unilateral sciatic nerve compression for 2 wk (CN) were compared with sham-operated (SO) muscles and with muscles that had the compression removed after 2 wk and were allowed to recover for 4 wk (R4) or for 6 wk (R6). The energy state and local circulation dynamics of CN muscles were less than those of SO muscles (P < 0.01). The energy state of R4 muscles remained at levels similar to CN muscles, whereas the local circulation dynamics improved but not back to SO values. In R6 muscles, both parameters returned to SO values. These results showed that the recovery processes of circulation precede those of energy state in skeletal muscles.

A rare case of well differentiated fibrosarcoma occurring in the left second toe is described in a 12-year-old boy who presented with a destructive lesion that had almost totally destroyed the distal phalanx, except for the epiphysis. Amputated specimens showed microscopic evidence of proliferation of uniform spindle cells arranged in both fascicles and a characteristic herringbone pattern with a small number of mitotic figures. This tumor did not show any specific immunoreactivity except for vimentin and had basic ultrastructural characteristics of fibroblasts and myofibroblasts. The tumor was treated by amputation at the middle phalanx level and had not recurred 3 years later. From the presenting radiographic features, some benign neoplasms and reactive lesions were considered in the differential diagnosis. Only results from the pathologic examination were useful in reaching a correct diagnosis.

Objective: In an attempt to elucidate a possible role for eicosanoids in the pathogenesis of spinal cord injury (SCI), we measured the concentration of leukotriene (LT) C4, thromboxane B2, and 6-keto-prostaglandin F1 alpha in cerebrospinal fluid in both a canine experimental model and 11 patients with SCIs., Methods: The eicosanoid concentration in cerebrospinal fluid was measured by radioimmunoassay. Neurological severity was assessed according to the grading system of Frankel et al.. Control samples were obtained from 20 patients without SCIs., Results: In the canine model, a significant increase in all eicosanoid levels was found on Days 1 to 7, which subsequently returned to the control levels. In the clinical study, the highest mean (+/- standard error of the mean) concentrations of LTC4, thromboxane B2, and 6-keto-prostaglandin F1 alpha in the acute stage of SCI were 95.9 +/- 10.7, 175.2 +/- 38.2, and 167.5 +/- 39.9 pg/ml, respectively. These concentrations were five to nine times higher than control levels. There was a good correlation between cerebrospinal fluid LTC4 levels and the neurological severity. The time-dependent change in LTC4 concentrations in seven patients with SCIs was similar to that observed in the canine model. In addition, the highest mean concentrations of the eicosanoids measured in patients with complete paralysis was also similar to those of the canine model. The eicosanoid concentrations in five patients with SCI were measured more than 6 months after the onset of injury. Although all eicosanoid levels had elevated in the acute stage of injury, they were not elevated and showed the same levels as the controls at the chronic stage., Conclusion: The findings suggest that enhanced arachidonate metabolism occurs in humans and support the evidence from animal experiments that emphasizes the importance of eicosanoids in the secondary processes mediating ischemia and edema.

Study Design: The neurologic outcomes in patients with conservatively managed incomplete closed traumatic cervical spinal cord injuries was evaluated using the motor scoring system and the Frankel classification., Objectives: To show that the motor scoring of recovery system combined with functional Frankel grading will make the documentation of final neurologic outcome more accurate for future comparisons of various methods of treatment., Summary of Background Data: The influence of surgical and pharmacologic methods of treatment on recovery remains debatable., Methods: Sixty-three consecutive patients with incomplete cervical injuries who were admitted to the hospital within 2 days after injury were included. All patients were treated conservatively with 6 weeks of bedrest and 6 weeks of mobilization with neck support., Results: Five patients had neurologic deterioration, and all but one patient recovered without surgery. The evaluation of 44 patients who were observed for more than 12 months showed that the preservation of sharp sensation below the level of injury was an indicator of a good prognosis in patients whose injuries were classified as Frankel B, and the degree of recovery of these patients according to the motor score system was comparable with that of patients who were classified as Frankel C. All patients classified as Frankel C who did not deteriorate recovered in Frankel grade. All but one of the patients in the Frankel D group recovered full motor power. The degrees of motor deficit and recovery did not correlate with the mechanism or the degree of the injury of the spinal axis., Conclusion: Conservative treatment remains a good option for patients with incomplete cervical cord injuries. It is hoped the current study will be a good basis for comparison of the neurologic outcomes of different treatment modalities.

Although superoxide dismutase (SOD) has been reported to promote functional recovery in ischemic spinal cord injury, it presents many difficulties in practical use primarily due to its short half-life in vivo and low tissue affinity. In this study, we investigated the effects of a new type of SOD, a lecithinized superoxide dismutase (PC-SOD), on motor disturbances, spinal cord edema, levels of myeloperoxidase (MPO), and spinal cord blood flow (SCBF) after spinal cord injury (SCI) in rats. PC-SOD is reported to show a delayed plasma disappearance in vivo in rats and has a higher affinity for vascular endothelium cells, neutrophils, and other cells than unmodified SOD. PC-SOD (4000 units/kg), unmodified SOD (4000 units/kg), or vehicle was injected intravenously 30 min after SCI. Four hours after SCI, SOD activities in spinal cord tissue and plasma were significantly higher in the PC-SOD group than in the unmodified SOD group. In the PC-SOD-treated rats, motor function was significantly better than in the other 2 groups of rats. PC-SOD significantly suppressed MPO activity, an indicator of neutrophils infiltration, in the spinal cord, at 4, 8, and 24 h after SCI, and spinal cord edema at 24 h after SCI. Moreover, the decrease of SCBF after SCI was less marked in the PC-SOD group. The present results suggest that lecithinization can improve the drug delivery of SOD to the spinal cord and PC-SOD may be an alternative pharmacological treatment for SCI.

The mechanism of spinal deformity after surgical removal of a cervical spinal cord tumor or tumorous lesions was studied in 36 patients, based on the spinal functional curve prepared from the intersectional angle. The postoperative spinal deformity depends on the surgical level and the type of operation. In the laminectomy group, kyphosis of the upper cervical spine and compensatory increased lordosis of the lower cervical spine were observed in the C2 laminectomy patients. Localized kyphosis of the spine at the cervicothoracic junction and compensatory increased lordosis of the upper cervical vertebrae were noted in the C7 laminectomy patients. In the laminoplasty group, spinal deformities were less frequently observed, and when present the deformity was limited to a slight increase of lordosis, even in patients who had the facetectomy. These facts demonstrate the preventive effect of the laminoplasty regarding postoperative spinal deformity. Laminoplasty with reconstruction of the erector spinal muscles and the nuchal ligament is recommended for patients with a spinal cord tumor or a tumorous lesion. The spinal functional curve was significant in studying the biomechanics of the vertebral column with the advantage that both alignment and mobility of the spine are simultaneously, respectively and precisely visualized.

The Injury Prevention Committee of the Japan Medical Society of Paraplegia (JMSoP) conducted a nationwide epidemiological survey on spinal cord injury (SCI) using postal questionnaires for 3 years periods from 1990 to 1992, and the annual incidence of the spinal cord injury was estimated as 40.2 per million. From this registry, we investigated SCI related to sports activities. In 3 years, 528 patients were registered and 374 of them had neurological deficits. The incidence was 1.95 per million per annum. Mean age at injury was 28.5 years (10-77), and 88.1% of the patients were males. Diving was the commonest cause of SCI (21.6%), which was followed by skiing (13.4%), football including rugby, American football and soccer (12.7%), sky sports (7.0%), judo (6.8%) and gymnastics (6.6%). Mean age at injury was higher than 30 years in skiing (38.6 years) and sky sports (38.2 years). Cervical injury was predominant in all but sky sports and accounted for 83.5% of SCI. Motor complete paralysis was reported in 35.0% of the patients. Bony injury was observed in 55.9% of the patients; most of the patients who sustained the SCI in diving and sky sports had bony injury, and no bony injury was detected in more than a half of the patients who sustained injuries in skiing, judo or gymnastics. Although the percentage of sports-related SCI was small in the present study as compared to the data from previous reports, it is not difficult to imagine the increase in the number of sports-related SCI. We have launched an injury prevention campaign and are planning to conduct a similar study in future to evaluate the effect of the campaign as well as the changes in the incidence and pattern of SCI.

The intercellular adhesion molecule 1 (ICAM-1) plays an important role in immune responses by promoting infiltration of neutrophils into tissues; however, its implication in the secondary destructive pathomechanism after the initial mechanical injury to the spinal cord has not been clarified yet. This study was conducted to examine the role of ICAM-1 in this process after spinal cord injury (SCI) in rats. The expression of ICAM-1 mRNA was investigated by the reverse transcription-PCR method and the effect of monoclonal antibody (mAb) to ICAM-1 on SCI was evaluated by measuring various parameters. ICAM-1 mRNA expression correlated with the severity of injury and reached its maximum level 6 h after SCI. Intravenous injection of ICAM-1 mAb (1 mg/kg) 30 min after SCI reduced motor disturbance and enhanced recovery. Moreover, it significantly suppressed myeloperoxidase activity by 43.0% and spinal cord edema by 1.1% in the injured spinal cord tissue. The posttraumatic drop in spinal cord blood flow was also improved. These results suggest that ICAM-1 is deeply involved in the secondary self-destructive process after mechanical injury of the spinal cord and should be an effective target for developing a pharmacological treatment for SCI.

Study Design: Morphological analysis was performed of the facet joint of the normal and spondylolytic lumbosacral spine in children and adolescents., Objectives: This study was performed to estimate the influence of spondylolysis on growth of the neural arch of the lumbosacral spine., Summary of Background Data: The development of the facet joint and its relation to spondylolysis have not been documented in the literature., Methods: The dimension and orientation of the facet joint at L5/S were measured on radiographs and computed tomography scans from 144 boys without pars defects and 104 boys with pars defects. The latter group was further investigated according to the stage of pars defects. Patients in both groups were between 9 and 18 years of age., Results: Growth of the facet joint in the sagittal and transverse directions and the increase of the transverse angle were remarkable up to approximately 13 years of age. Concavity of the facet joints also progressed in children of the same age. The growth of the facet joint in patients with spondylolysis was significantly retarded as the pars defects advanced from the progressive to the terminal stage. The joint surface was more coronal in orientation and flatter in shape compared with controls., Conclusions: The present results suggest that pars defects occurring in children disturb or retard the growth of the facet joint and that the morphological characteristics of the joint surfaces in patients with spondylolysis are the consequence of these defects.

This study was undertaken to examine the effect of transforming growth factor-beta 1 (TGF-beta 1) administered into the subarachnoid space after spinal cord injury (SCI) on the increased production of inducible-nitric oxide synthase (i-NOS) in the injured spinal cord in rats. The expression of i-NOS mRNA after SCI was remarkably down-regulated by TGF-beta 1 in vivo. Rats treated with TGF-beta 1 showed a better outcome regarding hindlimb motor dysfunction in the first 5 days after injury compared to the saline-treated rats. However, the final outcome was not better and fibrous scar formation in the injured spinal cord was more evident, which was demonstrated as increased immunoreactivity of fibronectin in the later stage after SCI. These results provide evidence of both positive and negative contributions of TGF-beta 1 to the pathology associated with SCI.

Bone mineral density (BMD) of the lumbar spine in patients with ossification of the posterior longitudinal ligaments of the cervical spine (OPLL) was measured to elucidate the relation of spinal ossification with systemic hyperostotic condition. BMD in the lateral projection had a statistically significant correlation with that in the anteroposterior projection, and the former was considered to reflect the condition more accurately than was the latter, which may include the ossified spinal ligaments. BMD of patients with continuous and mixed types of OPLL was higher than that of those with the segmental type. Patients with OPLL and ossification of the other spinal ligaments had higher BMDs than did those without ossification. These results suggest that the BMD of the lumbar spine may reflect the systemic hyperostotic tendency and advancement of the ossification.

The influence of minor trauma to the neck on the neurological outcome in patients with ossification of the posterior longitudinal ligament (OPLL) of the cervical spine was evaluated retrospectively. Out of 118 patients treated in our clinic for cervical OPLL between 1976 and 1992, 27 had sustained minor trauma to the cervical spine. Of these 27 patients, 13 developed myelopathy, seven showed deterioration of preexisting myelopathy, and no neurological change was observed in seven patients. Regarding the relationship between the diameter of the residual spinal canal and the neurological outcome in these 27 patients, 18 out of the 19 patients with a narrow residual spinal canal (< 10 mm) developed neurological deterioration, whereas that occurred in only two of the eight patients with a wider spinal canal (> or = 10 mm). Although the severity of myelopathy and the transverse area of the spinal cord measured from T1-weighted magnetic resonance images, in patients who had sustained minor trauma was not statistically different from patients without trauma, neurological recovery after surgical treatment was poorer in the former group than in the latter. These results indicate that even indirect minor trauma to the neck can cause irreversible changes in the spinal cord if there is marked stenosis of the cervical spinal canal; such patients who are at risk, must be educated, and should be told to avoid even minor injuries at any cost.

This survey of traumatic spinal cord injuries in Japan from January 1990 to December 1992 was carried out by a statistical method of the nationwide epidemiological study. The number of the registered patients during these 3 years was 9752 and the mean response rate of every of the 47 prefectures was 51.4%. The registered patients with neurological deficits (Frankel A-D) were 7471 and the annual spinal cord injury incidence was 40.2 per million. The ratio of cervical cord injuries to more caudal SCI was 3:1. The age distribution and the causes of spinal cord injuries are presented in detail. From the results of this study, the prevention campaign should be focused mainly on the following topics: sports and motorcycle accidents involving young people; traffic accidents involving adults; falling accidents involving aged people.

Arachidonate metabolites have many kinds of bioactivities. Thromboxane A2 (TXA2) stimulates platelet aggregation and vasoconstriction, whereas prostaglandin I2 (PGI2) antagonises its activities. Thromboxane B2 (TXB2) and 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) are determined in biological materials. Production of TXB2, 6-keto-PGF1 alpha and leukotriene C4 (LTC4), which have potent vascular permeability, was measured by radioimmunoassay in experimental spinal cord injured animals. TXB2 level in the rat spinal cord reached a peak concentration of 133.6 +/- 3.8 pmol/g cord, and 6-keto-PGF1 alpha increased to 26.2 +/- 11.7 pmol/g cord 5 minutes after the injury. There was good correlation between TXB2 production and vascular damage as monitored by fluorescein uptake. When OKY-046 ((E)-3-[4-(1-imidazolylmethyl) phenyl]-2-propenoic acid), which selectively inhibits TXA2 synthetase activity, was administered 10 minutes before injury, the increase in TXB2 production was inhibited by more than 80%, but the degree of vascular damage was reduced by only 40%. In the guinea pig spinal cord, LTC4 levels reached a peak concentration of 2.2 +/- 0.4 pmol/g cord 10 minutes after compression, while that of TXB2 reached 146.8 +/- 6.2 pmol/g cord. The increased production of TXB2 was correlated with the degree of compression injury while that of LTC4 production did not. These findings suggest that vasoactive eicosanoids, TXA2, PGI2 and LTC4, play important roles in secondary damage following spinal cord injury, although their roles may be different among species of animals.

We studied the effects of stimulation frequency on the energy metabolism of rat skeletal muscles during electrical low-frequency stimulation, using in vivo phosphorus-31 magnetic resonance spectroscopy. The sciatic nerve of Wistar-Kyoto rats (n = 16) was stimulated electrically using low frequency stimulation (LFS) at 30 Hz and high frequency stimulation (HFS) at 100 Hz as tetanizing frequencies. The initial tension during LFS was significantly different from that during HFS, 200.49 +/- 19.47 vs. 516.67 +/- 5.38 dynes (mean +/- S.E.; n = 8) (p < 0.01). In the first 2 min of stimulation, the ratio of phosphocreatine (PCr) to inorganic phosphate (Pi) + sugar phosphate (SP) during LFS and HFS were 0.28 +/- 0.04 and 0.53 +/- 0.06 (mean +/- S.E.; n = 8), respectively. Subsequently, the ratio during LFS remained lower than that during HFS. The intracellular pH during LFS and HFS in the first 2 min of stimulation was 6.27 +/- 0.02 and 6.75 +/- 0.03 (mean +/- S.E.; n = 8), respectively. From 2 min to 12 min of stimulation, the intracellular pH during LFS remained lower than that during HFS. The results showed that lower levels of both energy and intracellular pH of skeletal muscles were maintained during LFS than during HFS, facilitating aerobic glycolysis to produce ATP during stimulation.

To survey the situation of traumatic spinal cord injuries (SCI) in Japan, the SCI Prevention Committee of the Japanese Medical Society of Paraplegia sent out by mail study charts in the form of questionnaires to institutions nationwide. Using the statistical method of the nationwide epidemiological survey described by Hashimoto et al,1 the annual estimated incidence was obtained from the number of patients registered, and from the questionnaire reply rate at each prefecture. The number of registered patients in 1990 was 3465 and the mean reply rate was 56.6%. There were 2665 registered patients with a neurological deficit (Frankel A-D) and the annual SCI incidence was 39.4 per million. The male:female ratio was 4.3:1 and the ratio of cervical cord injures to those caudal to the cervical cord was 2.9:1. The mean age at the time of injury was 48.5 years. The cause most frequently seen was traffic accidents, the second most frequent being falls from a height. Besides those two, sports injuries and falls on level ground were the third most frequent causes of SCI in the young generation and in elderly people respectively.

The morphologic changes and signal intensity of the spinal cord on preoperative magnetic resonance images were correlated with postoperative outcomes in 74 patients undergoing decompressive cervical surgery for compressive myelopathy. The transverse area of the spinal cord on T1-weighted images at the level of maximum compression was closely correlated with the severity of myelopathy, duration of disease, and recovery rate as determined by the Japanese Orthopaedic Association score. In patients with ossification of the posterior longitudinal ligament or cervical spondylotic myelopathy, the increased intramedullary T2-weighted magnetic resonance imaging signal at the site of maximal cord compression and duration of disease significantly influenced the rate of recovery. A multiple regression equation was then developed with these three variables to predict surgical outcomes.

The effect of active recovery after intense muscular exercise was examined by 31P-MRS. Seven healthy males participated in this study, and their right wrist flexor muscles were examined. Each subject flexed the right wrist at 60% of the maximum voluntary contraction (MVC) until the intracellular pH in the wrist flexor muscle decreased to approximately 6.4. This was followed either by active recovery (AR) which consisted of 5, 10, 20, 30 or 40% MVC exercise, and by passive recovery (PR) during a 10-min-recovery period. The intracellular pH (pHi) recovered faster during AR at each condition than during PR. Besides, from the 2nd to the 5th min of the recovery period, the pHi was significantly higher during AR than during PR. The quadratic regression curve of pHi recovery during the 10-min-recovery-period against the % MVC was obtained. The optimal contraction intensity determined from this curve was 8.7% MVC for a 10-min-recovery-period. The optimal levels were determined for another recovery duration within 10 min, and the level decreased with the prolonged recovery duration. These data suggest that mild exercise is an effective maneuver to promote the recovery from intracellular metabolic acidosis, and that the intensity of the recovery exercise should be determined according to the cooling down duration or the resting interval before the subsequent exercise performance.

When human synovial fluid as such was subjected to radioimmunoassays of prostaglandin E2 (PGE2) and leukotriene C4 (LTC4), there was no linear increase in PGE2 and LTC4 as the amount of synovial fluid was raised. For removal of substances thus disturbing the assay we developed a method of immunoaffinity purification of PGE2 and LTC4. A monoclonal antibody against PGE2 or LTC4 was coupled to BrCN-activated Sepharose 4B. When synovial fluid mixed with radiolabelled PGE2 or LTC4 was applied to the column of immobilized antibody, the ligand was adsorbed to the column and eluted with a mixture of methanol/water in a recovery of about 80%. The purified material showed a linearity between the amount of the sample and the value of radioimmunoassay. The one-step method was applied to synovial fluid from patients with rheumatoid arthritis, osteoarthritis and other joint diseases.

Leukotriene C4 (LTC4) production in the guinea pig spinal cord following compression injury was determined by radioimmunoassay, in the same way thromboxane B2 (TXB2), a stable metabolite of thromboxane A2 (TXA2), was also measured. When the spinal cords were compressed under a 20 gram weight for 10 minutes, LTC4 levels reached peak values (2.2 +/- 0.4 pmol/g cord) 10 minutes after release, then gradually decreased until being undetectable 60 minutes later. TXB2 levels reached peak values (146.8 +/- 6.2 pmol/g cord) 5 minutes after the release from compression, the TXB2 level then gradually decreased, but remained at about 1/2 of the peak level even 60 minutes after the release. When the spinal cords were compressed with various weights, TXB2 production depended on the degree of compression, while LTC4 production was not affected by the compression injury. The LTC4 production confirmed in the injured spinal cords is suggestive of its relation to secondary disorders after spinal cord injury, spinal edema, in particular.

Spinal cord plasticity in 55 patients with cervical compression myelopathy was assessed with magnetic resonance imaging, by which the transverse area of the spinal cord was measured at the site of maximum compression before and after surgery and compared with the conventional modalities of computed tomographic myelography. A high correlation (r = 0.901, P less than 0.01) was observed between the preoperative measurements of magnetic resonance imaging and computed tomographic myelography. The preoperative transverse area was in good correlation with the preoperative Japanese Orthopaedic Association score (r = 0.466, P less than 0.01). In most patients with a spinal cord area of less than 0.45 cm2, the clinical results were poor despite considerable morphologic restoration of the spinal canal obtained after decompression surgery, reflecting an irreversible pathology developed in the spinal cord.

The influences of vitamin E deficiency on compression injury of the rat spinal cord associated with ischemia were investigated. Growing rats were divided into two groups and given a diet containing either 2 IU/100 g or less than 0.1 IU/100 g of alpha-tocopherol acetate, respectively, for 6-8 weeks before experiments. Motor disturbances induced by spinal cord injury were found to be enhanced by vitamin E deficiency. The spinal cord blood flow (SCBF) was reduced by compression and subsequently increased transiently and then decreased gradually in both groups, but the level was lower in the vitamin E-deficient group than in the control group. After injury, the vitamin E-deficient group showed lower recoveries than the control group in the amplitude and latency of spinal cord evoked potentials and greater pathological changes of the spinal cord, such as bleeding and edema. The increase in the level of TBA-reactive substances in the spinal cord after injury increased with decrease in the dietary level of vitamin E. These results suggest that vitamin E may have a protective effects against ischemic spinal cord injury by its antioxidant effect.

Thromboxane A2 (TXA2) is an eicosanoid with potent platelet aggregation and vasoconstricting activity, while prostaglandin I2 (PGI2) antagonizes its activity. But these eicosanoids are so labile that the stable degradation products, thromboxane B2 (TXB2) and 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha), are determined in biological materials. In a rat spinal cord compression injury model, a production of TXB2 reached a peak (133.6 +/- 13.8 pmol/g cord) 5 minutes after compression injury, while that of 6-keto-PGF1 alpha slightly increased (26.2 +/- 11.7 pmol/g cord). And the magnitude of the increase in TXB2 and the extent of post-traumatic vascular damage as determined by fluorescein uptake were both dependent on the degree of spinal cord compression injury. We also studied the effect of a selective TXA2 synthetase inhibitor, OKY-046 [E)-3-[4-(1-imidazolylmethyl)phenyl]-2-propenoic acid), both on TXB2 production in the injured spinal cord and post-traumatic vascular damage. When OKY-046 was administered intravenously 10 minutes prior to compression injury at a dose of 500 micrograms/kg body weight, the increased production of TXB2 was inhibited by about 80% and uptake of sodium fluorescein was reduced by a maximum of 40%. When the compression injury was induced before OKY-046 was administered, the inhibitory effect of OKY-046 on TXB2 production decreased depending on the duration before administration. In contrast, the 6-keto-PGF1 alpha level was not affected in the presence of OKY-046.

We report a malignant peripheral nerve sheath tumor (MPNST) showing the unusual immunohistochemical feature of epithelial membrane antigen (EMA) immunoreactivity in a 52-year-old man. The tumor, located in the left paravertebral muscles, was composed of both cellular and myxoid areas. Spindle-shaped tumor cells were arranged in longitudinal cell cords, in a storiform pattern, and in whorled structures. Ultrastructurally, the tumor cells had many interdigitating cell processes, primitive cell junctions, and discontinuous external laminae. These histological and ultrastructural features were most consistent with those of an MPNST; but on immunohistochemistry, the tumor cells reacted for epithelial membrane antigen rather than for S-100 protein or Leu-7. Because EMA-immunoreactivity was recently demonstrated in perineurial cells, we concluded that the tumor was an MPNST mainly composed of tumor cells showing perineurial cell differentiation.

The effects of vitamin E on compression injury of the spinal cord associated with ischemia were studied in rats. Growing rats were divided into two groups and given diet containing 2 IU/100 g (group C) or 50 IU/100 g (group E) of alpha-tocopherol acetate from 8-10 weeks before experiments. The motor disturbance induced by spinal cord injury was greatly reduced by vitamin E-supplementation. After injury, the value of TBA-reactive substances (TBARS) was immediately increased and the level of alpha-tocopherol was correspondingly decreased in the spinal cord. A higher level of TBARS was observed in the proximal region than in the injured region of the spinal cord. The high level persisted for 24 hrs in group C, but decreased within 1 hr in group E. Pathological examination of the spinal cord revealed less damage, such as bleeding and edema, in group E than in group C.

Studies were made on the influence of vitamin E on the effects of compression injury of the spinal cord associated with ischemia in rats. The motor disturbance induced by spinal cord injury was greatly reduced by vitamin E supplementation. After injury, the spinal cord evoked potentials showed greater recovery of both amplitude and latency in the vitamin E-supplemented group than in the control group. Spinal cord blood flow was promptly restored and remained normal after injury in the vitamin E-supplemented group, but was significantly decreased from 3 h after injury in the control group. Thiobarbituric acid (TBA)--reactive substances in the spinal cord was immediately increased by compression injury in both groups, and after injury it persisted at a high value for 24 h in the control group, but decreased within 1 h in the vitamin E-supplemented group. Pathological examination of the spinal cord showed less damage, such as bleeding and edema, in the vitamin E-supplemented group than in the control group. Vitamin E may have protective effects on the spinal cord by inhibiting damage induced by lipid peroxidation and/or by sustaining the blood flow by maintaining the normal metabolism of arachidonic acid.

For investigation of the intramedullary penetration of metrizamide, the intramedullary movements of fluorescein, Evans Blue, Horseradish peroxidase (HRP) and ionic lanthanum in the normal cord and experimental syringomyelia of rats were studied. Syringomyelia was induced by injection of kaolin suspension into the cisterna magna. Subsequently HRP or ionic lanthanum was perfused into the subarachnoid space and its distribution was examined by electron microscopy. In normal rats, HRP mainly became localised in the basement membrane between the pia mater and glial cells and only a few vesicles migrated into the extracellular spaces (ECS) between glial cells. Ionic lanthanum, however, migrated deep into the ECS. In rats with experimental syringomyelia many vesicles of HRP migrated deep into the ECS of glial cells and the white matter. These findings indicated that the ECS of the marginal glia and the neuropil constitute part of a pathway through which metrizamide migrates into the intramedullary cavity.

A total of 118 patients with cervical spinal cord injury were studied to determine the neurologic improvement achieved by either conservative or surgical treatment. Useful recovery was observed in 55% of the patients with incomplete cord injuries, but in none of those with complete cord injuries. There was no significant difference between the treatment groups regarding neurologic improvement. In experimental studies on rats, the increased levels of lipid peroxides and thromboxane after spinal cord injury were found to be proportional to the magnitude of injury. These evidences suggest that spinal cord injury is directly related with the magnitude of injury, and the prognosis is determined entirely at the time of injury.