Tendon transfer for equinovarus deformed foot caused by cerebrovascular disease

Surgical correction was performed on 125 patients who had equinovarus deformity caused by a cerebrovascular accident and who needed an ankle foot orthosis for walking. The operative procedures involved anterior transfer of the long toe flexors (flexor hallux longus and flexor digitorum longus; long toe flexor group) or lateral transfer of the anterior tibial tendon (anterior tibial tendon group), combined with lengthening of the Achilles tendon. On evaluation more than 2 years after surgery, 83 of 110 patients of the long toe flexor group and eight of 15 patients of the anterior tibial tendon group were able to walk without a brace. Five patients of the anterior tibial tendon group who had shown strong contraction of the anterior tibial muscle during the swing phase before surgery, needed a brace because of a drop foot after surgery. Thus, lateral transfer of the anterior tibial tendon was abandoned in 1984. Recurrence of varus deformity was seen in approximately 15% of the patients in both groups. Anterior transfer of the long toe flexors, using them as dorsiflexor tendons or for tenodesis, seemed to produce better results.

Subtalar instability following lateral ligament injuries of the ankle

A stress radiograph of the subtalar joint was taken using Telos equipment, while the X-ray beam was directed onto the posterior subtalar joint at angles of 30 degrees latero-medially and 40 degrees caudocranially. From this radiograph the subtalar tilt angle was measured as an index of stability of the subtalar joint. Intra-and interobserver evaluations of measurement of this angle were performed on 20 unstable ankles. The errors at a 95 per cent confidence level were 1.9 degrees for intraobserver A, 1.4 degrees for intraobserver B and 2 degrees in interobservation. Stability of the subtalar joint was evaluated on 46 lateral ligament injuries of the ankle (23 acute injuries and 23 chronic injuries) and 80 normal ankles. The subtalar tilt angle was 9.7 degrees +/ 3.2 degrees in acute injuries 10.3 degrees #/ 2.9 degrees in chronic injuries, and 5/2 degrees +/ 2/6 degrees in normal ankles. There were significant differences between the acute or chronic injury and the normal ankles. These results suggested that stability of the subtalar joint was disturbed following acute and chronic lateral ligament injuries of the ankle.

Regression of cervical disc herniation observed on magnetic resonance images

STUDY DESIGN

A retrospective study of cervical disc herniation using results of repeated magnetic resonance imaging examinations.

OBJECTIVES

To clarify the cervical disc herniation morphological changes over time in order to establish a strategy for treatment.

SUMMARY OF BACKGROUND DATA

In the authors' previous magnetic resonance imaging follow-up study of patients with lumbar disc herniation, spontaneous regression was observed in the sequestration-type lesions, and it was found that the tendency toward regression differed based on the anatomic position of extruded disc material.

METHODS

Thirty-eight patients with cervical disc herniation who underwent repeated magnetic resonance imaging examinations were studied. The changes over time in herniated disc size were evaluated using this imaging technique. Evaluation showed the characteristics of those in whom spontaneous regression was found, such as extrusion pattern, and the clinical outcome was evaluated by symptoms.

RESULTS

In 15 patients (40%), the volume of herniated material was decreased. The interval from onset of symptoms to the initial examination was significantly shorter in the regression group than in the group that showed no change in disc herniation. By extrusion pattern, cervical disc herniation, which was divided into migration type on sagittal view and lateral type on axial view, most frequently exhibited spontaneous regression. All of the patients with radicular pain and upper limb amyotrophy were treated successfully with conservative therapy.

CONCLUSION

Although the possibility of the combination of hemorrhage and disc material could not be denied, active resorption of herniated material probably occurred during the acute phase. Extruded material exposed to the epidural space may be resorbed more quickly than that beneath the ligament. Vascular supply probably plays a role in the mechanism of resorption. The phase and position of extrusion were the significant factors affecting cervical disc herniation resorption. It was demonstrated that examination performed during the acute phase using magnetic resonance imaging is necessary for elucidation of the pathogenesis of cervical disc herniation, and that migrating, lateral-type herniations regress so frequently that conservative treatment should be chosen not only for patients with radicular pain, but also for those with upper limb amyotrophy.

Anterior cruciate ligament deficiency accompanied by patellar subluxation treated by reconstruction with lateral retinacular release

Five patients with an anterior cruciate ligament (ACL) deficiency accompanied by patellar subluxation who were treated by ACL reconstruction with lateral retinacular release (LRR) are reported. In two patients, the LRR was performed at the same time as the ACL reconstruction, and in three patients, the LRR was performed secondarily. The three patients requiring the secondary LRR needed the procedure to recover knee stability to return to sporting activities. In all patients, the apprehension sign of the patella was subsequently improved. When managing ACL deficiencies in a young athletic population, patellar subluxation should be suspected. In our patients with patellar subluxation accompanying an ACL deficiency, ACL reconstruction with LRR was effective in relieving their instability.

Contrast-enhanced magnetic resonance imaging in conservative management of lumbar disc herniation

STUDY DESIGN

This study was designed to investigate the morphologic changes in contrast-enhanced magnetic resonance imaging that occur during conservative treatment of patients with unilateral leg pain resulting from herniated nucleus pulposus without significant lumbar canal stenosis.

OBJECTIVES

To compare the morphologic results with clinical outcomes to ascertain whether enhanced magnetic resonance imaging contributes to the management of lumbar disc herniation.

SUMMARY OF BACKGROUND DATA

Contrast-enhanced magnetic resonance imaging has already been reported to be useful in the postoperative examination of the lumbar spine and in visualization of symptomatic nerve roots. However, there have been few reports about its usefulness in the conservative management of herniated nucleus pulposus or about the correlation between herniated nucleus pulposus regression and enhanced effect. The study population consisted of 48 patients with radiculopathy. All patients primarily reported unilateral leg pain, and 94% had positive tension signs. Additionally, 38% exhibited muscle weakness corresponding to the symptomatic nerve root.

METHODS

All patients were studied twice or more using gadolinium-magnetic resonance imaging during conservative therapy, at a mean interval of 191 days. Changes in the size of the herniated nucleus pulposus on precontrast images fell into four categories, with changes in enhancement on postcontrast images classified into two categories: "enlargement" and "no change."

RESULTS

In all cases of migrating type herniated nucleus pulposus, circular enhancement was seen on postcontrast images. In 17 of 22 cases, the enhanced area gradually thickened and intruded into the migrated disc materials as the size of the herniated nucleus pulposus decreased; the herniated nucleus pulposus disappeared in nine cases and showed a marked decrease in seven cases. These cases showed good clinical courses of sciatica. In the other five patients, in whom there were no changes in the enhanced area, there was less of a tendency for the herniated nucleus pulposus to decrease in size, and there were poorer clinical results. In six cases of extruding-type herniated nucleus pulposus, no enhanced effects were observed throughout the follow-up period. The other 20 cases showed enhancement that was relatively weaker than that of migrating disc herniation. Extension or expansion of the enhanced area was observed in the follow-up images of 15 cases, though only four showed obvious changes in the size of the herniated nucleus pulposus. These 15 cases had better clinical results than the other cases, in which enhanced effects did not change or were not observed.

CONCLUSION

Contrast-enhanced magnetic resonance imaging is a useful prognostic parameter, and multiple use contributes to the proper management of lumbar disc herniation.

[Reproductive and developmental toxicity studies of landiolol hydrochloride (ONO-1101) (1). Fertility study in rats]

A fertility study of landiolol hydrochloride (ONO-1101), a novel ultra short acting beta-blocker, was conducted in Sprague-Dawley (SD) rats. ONO-1101 was administered intravenously to males from the 64th day before mating until necropsy, and to females from 15th day before mating until day 7 of gestation, at a dose level of 0 (control), 25, 50 or 100 mg/kg/day. On day 20 of gestation, all dams were sacrificed and their fetuses were examined. In the 100 mg/kg/day group, hypoactivity, clonic convulsion, bradypnea/apnea and redish lacrimation were observed after administration in both sexes, and 3 males and 2 females died. Reddish lacrimation was occasionally seen in males at late stage of the treatment period in 50 mg/kg/day group. In the 100 mg/kg/day group, body weight gain suppressed in females from the premating through the gestation period, and food consumption decreased in females during the premating period, and mean thymus weight decreased in males. ONO-1101 did not affect estrous cycle, copulatory or fertility in both sexes or external, skeletal or visceral features of the fetuses. From the above results, it is estimated that the no-toxic dose level of ONO-1101 under these experimental conditions is 50 mg/kg/day for general toxicity in parents, and 100 mg/kg/day for the reproductive performance in parents and for the development of fetuses.

[Toxicity studies of landiolol hydrochloride (ONO-1101) (1). Single intravenous toxicity study in rats and dogs]

Single dose toxicity studies of landiolol hydrochloride (ONO-1101), a novel ultra short acting beta-blocker, were conducted in Sprague-Dawley (SD) rats and beagle dogs. ONO-1101 was administered intravenously at a dose level of 37.5, 75, 150 or 300 mg/kg to rats of both sexes and 25, 50 or 100 mg/kg to male dogs. In the rat study, 5/6 males in the 150 mg/kg group and all animals in the 300 mg/kg group died during or right after administration. Survivors in the 150 mg/kg group showed temporal hypoactivity, bradypnea, dyspnea, tremor, loss of righting reflex and reddish lacrimation up to 5 min after injection. One male in the 150 mg/kg group had a tendency of suppression on body weight gain. No effects on clinical signs and body weight gain were seen in the 75 mg/kg group or lower. Necropsy findings showed only red tear in the majority of the decedents. In the dog study, all animals died within 6 min after administration in the 100 mg/kg group, showed ataxic gait, rolling and tachypnea followed by bradypnea and gasping/apnea. Incontinence of urine, defecation and vocalization were also seen in each one of two animals before death. Temporal hypoactivity was seen 1 min after administration in the 50 mg/kg group. No clinical signs were seen in the 25 mg/kg group. ONO-1101 did not affect bodyweight or food consumption. Necropsy findings of the decedents showed no abnormalities. It is indicated that the minimum lethal doses are 150 mg/kg in rats and 100 mg/kg in dogs.

[Toxicity studies of landiolol hydrochloride (ONO-1101) (2). 4-week repeated dose intravenous toxicity study in rats with 4-week recovery test]

4-week repeated dose toxicity study with 4-week recovery test of landiolol hydrochloride (ONO-1101), a novel ultra short acting beta-blocker, was conducted in Sprague-Dawley (SD) rats. ONO-1101 was administered intravenously to rats of both sexes at a dose level of 0 (control), 12.5, 25, 50 or 100 mg/kg/day. In the 100 mg/kg/day group, bradypnea or dyspnea was seen in all animals, pale in ear, eye and foot, tremor, reddish lacrimation and loss of righting reflex were also observed in some animals right after administration, and then those signs disappeared within 1 min after administration. During the treatment period, 3/20 animals of each sex in the 100 mg/kg/day showed clonic convulsion and died within 2 min after administration. No clinical changes were seen in the 50 mg/kg/day group or lower. Histopathological findings showed atrophy of the submaxillary gland in females and vessel-wall thickening and perivascular fibrosis of the injection site (tail) in both sexes at 100 mg/kg/day, however those changes were reversible. ONO-1101 did not effect on body weight, food consumption, ophthalmology, urinalysis, hematology, blood chemistry, organ weights or necropsy at any doses. These results indicate that the no-adverse-effect level of ONO-1101 in rats is 50 mg/kg/day for both sexes in this study.

Sequential dynamics of monocyte chemotactic protein-1 expression in herniated nucleus pulposus resorption

We previously demonstrated that the granulation tissues of herniated nucleus pulposus are composed of a marked infiltration of macrophages that strongly express monocyte chemotactic protein-1. Monocyte chemotactic protein-1 is a chemotactic cytokine that contributes to the activation and recruitment of macrophages. Relatively little is known about its role in the resorption process of herniated nucleus pulposus. To clarify the sequential dynamics of expression of monocyte chemotactic protein-1 in the granulation tissues of herniated nucleus pulposus, we introduced a rat autologous transplantation model of nuclear materials onto its lumbar dura mater and performed immunohistological analysis and competitive polymerase chain reaction assay using the grafted samples. Immunohistological analysis demonstrated that the majority of infiltrating mononuclear cells expressed monocyte chemotactic protein-1. Monocyte chemotactic protein-1 mRNA was expressed in the first 3 weeks after the procedure and was significantly and maximally upregulated at 1 week. To determine whether human recombinant monocyte chemotactic protein-1 facilitates the resorption process of herniated nucleus pulposus, we introduced another model of autologous transplantation, wherein the nuclear materials were grafted to the abdominal subcutaneous tissues and recombinant monocyte chemotactic protein-1 was subsequently applied to these materials. When monocyte chemotactic protein-1 was injected into the murine nucleus pulposus tissues, they reduced in size more rapidly than in the control group. These findings suggest that monocyte chemotactic protein-1 plays an important role in the recruitment of macrophages in the early phase of the resorption process of herniated nucleus pulposus and that its application may physiologically facilitate the resorption process of the nucleus pulposus.

Evaluation of motor function during thoracic and thoracolumbar spinal surgery based on motor-evoked potentials using train spinal stimulation

STUDY DESIGN

Using compound muscle action potentials after train spinal stimulation, intraoperative motor functional monitoring was performed during thoracic and thoracolumbar spinal surgery.

OBJECTIVES

This study was designed to clarify the clinical usefulness of train spinal stimulation and to determine the critical point of compound muscle action potential change at which neurologic injury during surgery occurs.

SUMMARY OF BACKGROUND DATA

In 1995 the authors reported that train spinal stimulation allows for the recording of compound muscle action potentials, even in animals and humans under general anesthesia. The facilitative effect of train stimulation overcomes the suppressive effects of anesthetics and allows potentials to pass through synapses, thereby enabling a reliable recording of lower extremity compound muscle action potential.

METHODS

Multisegmental recording of compound muscle action potentials after train spinal stimulation was conducted on 34 patients Undergoing surgical treatment for thoracic or thoracolumbar lesions. During surgery, train stimuli (5 pulse, Interstimular Interval: 1 ms) were administered using an epidural electrode introduced transcutaneously. Compound muscle action potentials were recorded from a total of 128 muscles. Anesthesia was maintained using fentanyl and propofol or nitrous oxide with or without isoflurane. Muscle relaxation was attained mainly by controlled infusion of vecuronium bromide. The percent occurrence of recordable compound muscle action potentials was determined, and the potential changes were correlated with changes in muscle strength.

RESULTS

Compound muscle action potentials could be recorded from at least one muscle in 94% of the patients, even in most patients with severe motor dysfunction. The compound muscle action potential changes before and after surgical maneuver were divided into four grades. All compound muscle action potential changes in deteriorated muscles belonged to Grade 2 (a 10% latency delay) or Grade 3 (disappearance).

CONCLUSIONS

The success rate in obtaining muscle potentials was greatly enhanced when all of the following methods were used: train spinal stimulation, anesthetic with weak suppressive effect, multiple muscle recording, and percutaneous introduction of epidural electrode. The critical point of compound muscle action potential change should be defined as a 10% latency delay or disappearance. Multisegmental muscle potential after train spinal stimulation is the most appropriate method for thoracic and thoracolumbar spinal surgery.

Chemonucleolysis with human stromelysin-1

STUDY DESIGN

Immunohistologic analysis was performed on surgically removed samples of herniated nucleus pulposus to examine the expression of stromelysin-1. We performed in vitro and in vivo experiments to determine whether recombinant human (rh) stromelysin-1 is capable of degrading nucleus pulposus.

OBJECTIVE

To analyze the production of stromelysin-1 in various types of herniated nucleus pulposus, and to examine the effects of this recombinant protein on nucleus pulposus tissues.

SUMMARY OF BACKGROUND DATA

The authors previously demonstrated a progressive decrease in herniated nucleus pulposus size in some of the transligamentous and sequestration types of herniated nucleus pulposus using magnetic resonance imaging. An increased production of stromelysin-1, a cartilage proteoglycan degrading enzyme, in herniated nucleus pulposus was reported recently. The authors speculated that if stromelysin-1 is involved in the degradation of herniated nucleus pulposus, stromelysin-1 itself may be used as a chemonucleolytic agent.

METHODS

Immunohistologic analysis using streptoavidin-biotin method was performed on 20 herniated nucleus pulposus samples to investigate the expression of stromelysin-1. Five herniated nucleus pulposus samples were incubated in a tissue culture medium in the presence or absence of rh stromelysin-1. After 24 hours of incubation, their weight changes were measured, and the loss of proteoglycan was assessed by Safranin O staining. Rat nucleus pulposus tissues were obtained from coccygeal intervertebral discs, and autologous subcutaneous transplantation was performed. Rh stromelysin-1 was injected into the grafted materials, and the reduction in size was followed by two-dimensional measurements from the skin surface, using engineer's calipers.

RESULTS

Immunohistologic analysis demonstrated the production of stromelysin-1 in the granulation tissues of herniated nucleus pulposus. When stromelysin-1 was injected into the murine nucleus pulposus tissues, they reduced in size more rapidly than the control group. In addition, human herniated nucleus pulposus materials obtained at surgery showed significant weight loss when treated with stromelysin-1 in an organ culture system. Safranin O staining revealed extensive depletion of proteoglycan in these herniated nucleus pulposus samples.

CONCLUSIONS

Stromelysin-1 is a possible key enzyme in herniated nucleus pulposus resorption, and stromelysin-1 may be a good candidate for use in chemonucleolysis. Administration of human stromelysin-1 may physiologically facilitate the resorption process of herniated nucleus pulposus, increase the healing rate and decrease complications after chemonucleolysis.

Lumbar nerve root compression caused by lumbar intraspinal gas. Report of three cases

STUDY DESIGN

Three cases of lumbar nerve root compression associated with intradiscal gas formation and its migration are reported.

OBJECTIVES

To establish the pathogenic mechanism by which gas is formed in the spinal canal.

SUMMARY OF BACKGROUND DATA

Few such cases have been reported of patients with clinical symptoms of lumbar radiculopathy resulting from gas in the spinal canal.

METHODS

Surgery with needle aspiration of the gas was performed in all cases.

RESULTS

The presence of the gas was detected in the extradural space in one patient and within the nerve sheath in two patients. After surgery, all patients recovered well, and there were no obvious remnant neurologic abnormalities. One year later, all patients were completely free of symptoms.

CONCLUSIONS

Surgery with needle aspiration of the gas resulted in clinical improvement in all cases, confirming that intraspinal gas is an important cause of lumbar radiculopathy. The composition of the gas in one patient was analyzed by gas chromatography, which revealed an overwhelming preponderance of nitrogen. A relationship between a gas-containing pseudocyst in the spinal canal and a degenerated intervertebral disc was identified, a key finding for understanding the precise nature of this disorder. Intradiscal gas formation and its outward migration as a sequel of intervertebral disc degeneration also has been addressed in this report.

Isolation and mapping of karyopherin alpha 3 (KPNA3), a human gene that is highly homologous to genes encoding Xenopus importin, yeast SRP1 and human RCH1

From a human fetal-brain cDNA library, we isolated and characterized a novel gene (KPNA3) encoding a protein highly homologous to certain nuclear transport proteins of Xenopus and human. The complete cDNA clone, designated karyopherin alpha 3, contained an open reading frame of 1,563 nucleotides encoding 521 amino acids. The predicted amino acid sequence showed 48%, 45% and 48% identity with Xenopus importin, yeast SRP1 and human RCH1, respectively. The similarities among these proteins suggest that karyopherin alpha 3 may be involved in the nuclear transport system. Eight repeats of the arm motif were well conserved among these proteins. The N-terminal region of the predicted karyopherin alpha 3 product was highly basic and the C-terminal region was strongly acidic. A 4.3-kb transcript was expressed in all adult human tissues examined by Northern blotting. The cDNA clone was assigned to chromosome band 13q14.3 by fluorescence in situ hybridization.

Messenger RNA expression of the genes encoding receptors for bone morphogenetic protein (BMP) and transforming growth factor-β (TGF-β) in the cells from the posterior longitudinal ligament in cervical spine

Posterior longitudinal ligament (PLL) in cervical spine is one of the sites of ossification in idiopathic hyperostotic diseases. Although the mechanism of the pathological triggering of the disease has not yet been clarified, the cells in PLL have been reported to express osteotropic cytokines such as BMP-2 and TGF-β. However, it has not been known whether the cells in PLL express receptors for these cytokines. We examined the expression of the messenger RNAs of the genes encoding receptors for BMP-2/4 and TGF-β in the PLL cells. Tissues from three OPLL (ossification of the posterior longitudinal ligament) patients who underwent anterior decompression surgery with removal of the ossified PLL were dissected microscopically and were subjected to explant cultures; the cells outgrown from the explants were examined. Type I BMP receptor (BMPR) mRNA was expressed at moderate levels in the cells derived from both ossifying PLL tissues as well as nonossifying adjacent fibrous tissues. Type II TGF-β receptor (TβR) mRNA and α1(I) collagen mRNA were also constitutively expressed in these PLL cells from either regions. Treatment with BMP-2 enhanced the expression of BMPR mRNA in five out of ten of the cell cultures, suggesting that functional BMP receptors were expressed in at least a part of the PLL cells. The BMP-2 effect on BMPR was specific since no such enhancement was observed with regard to the levels of TβR mRNA in all of the ten cultures. These results indicated for the first time that mRNAs of the genes encoding receptors for BMP-2/4 and TGF-β were expressed in the cells derived from human PLL cells.

A cadaveric study on the stability of lumbar segment after partial laminotomy and facetectomy with intact posterior ligaments

This study aimed to biomechanically investigate a change in the stability of decompressed segments in the degenerative lumbar spine. Cyclic loading tests to the cadaveric spinal unit were conducted in compressive and bending directions with a stepwise resection of the posterior elements such as wide fenestration (partial laminotomy), unilateral and bilateral facetectomy with the intact supra- and interspinous ligaments and spinous process. Flexion stability did not decrease significantly, and may reflect the fact that the aforementioned ligamentous structures were preserved throughout the resection process. After wide fenestration, the loss of compression stiffness amounted to only half that of bilateral facetectomy, and extension stiffness dropped to this same level. Lateral bending stiffness was maintained until unilateral facetectomy was performed. We recommend restricted decompression surgeries for a single-level central stenosis in the degenerative lumbar spine.

An analysis of the posterior epidural ligament role on the cervical spinal cord

STUDY DESIGN

Laminectomy was performed on cats to destroy the posterior epidural ligament. Evoked potentials and spinal cord blood flows quantified the spinal cord function before and after cervical flexion.

OBJECTIVES

This work describes a relationship between the loss of the posterior epidural ligaments and cervical spinal cord injury.

SUMMARY OF BACKGROUND DATA

The posterior epidural ligaments of the human cervical spine have been recently described. These ligaments theoretically prevent injury to the spinal cord by resisting collapse of the dura during cervical flexion.

METHODS

The animals were divided into three experimental groups: 1) control: no laminectomy and standard position, 2) flexion control: no laminectomy and known imposed flexion, 3) laminectomy (C3-C7) and flexion. Motor-evoked potentials and evoked spinal cord potentials were recorded to quantify the spinal cord functions. Radioactive microspheres were used to quantify ischemia in the spinal cord.

RESULTS

Control subjects showed blood flows of 36 mL/100 g/min (C3-C4) to 46 mL/100 g/min (C7-C8). Flexion control subjects did not experience significant reductions in blood flows or substantial change in evoked potentials. The laminectomy plus flexion group experienced reduced blood flows and substantial motor-evoked potentials and slight evoked spinal cord potential changes with 50 degrees, 60 degrees, and 70 degrees flexion. Blood flow reduction was greater in the anterior half of the C7-C8 segments compared with the posterior half at 60 degrees flexion. Evoked spinal cord potentials were less vulnerable than motor-evoked potentials.

CONCLUSIONS

The role of the posterior cervical epidural ligaments is to anchor the posterior dura mater to the ligamentum flavum. Loss of the ligaments allows anterior displacement of the posterior dura mater in flexion. Abnormal distribution of or lack of the cervical posterior epidural ligaments may lead to flexion myelopathy.

Upregulated expression of chemokines in herniated nucleus pulposus resorption

STUDY DESIGN

Immunohistologic examination was performed on surgically removed samples of herniated nucleus pulposus.

OBJECTIVES

To determine what cell types predominate in the granulation tissues of herniated nucleus pulposus, and to elucidate whether chemokines are involved in the resorption process of herniated nucleus pulposus. SUMMARY OF BACKGROUND DATA. The study population consisted of 30 patients suffering from herniated nucleus pulposus. Five macroscopically normal discs were obtained from spinal cord tumor and spinal cord injury managed with anterior discectomy (age range, 27-63 years) as a healthy control group.

METHODS

Immunohistochemical analysis was used to analyze the expression of chemokines.

RESULTS

A marked infiltration of macrophage and vascular proliferation was identified with a T lymphocyte infiltration of mild degree in the granulation tissues. This tendency was more prominent in the exposed group compared with the nonexposed group. Infiltrating macrophages, fibroblasts, and endothelial cells in the granulation tissues strongly expressed monocyte chemotactic protein-1 and macrophage inflammatory protein-1 alpha. Statistical analysis demonstrated that the exposed group was more abundant in Factor VIII, monocyte chemotactic protein-1, and macrophage inflammatory protein-1 alpha positive cells than the unexposed group.

CONCLUSIONS

Inflammatory cells and their positivity for chemokines, such as monocyte chemotactic protein-1 and macrophage inflammatory protein-1 alpha, are associated with blood vessels. Chemokines, such as monocyte chemotactic protein-1 and macrophage inflammatory protein-1 alpha, were overexpressed in macrophages, fibroblasts, and endothelial cells, suggesting that these chemokines contribute to activation and recruitment of macrophages in a paracrine or autocrine fashion.

Morphological observations of megakaryocytic emperipolesis in the bone marrow of rats treated with lipopolysaccharide

A morphological examination was performed on megakaryocytic emperipolesis containing neutrophils in the rat bone marrow induced by intravenous administration of lipopolysaccharide (LPS). Ultrastructurally, the engulfed neutrophils appeared to lie in the demarcation membrane system (DMS) of megakaryocytes. Intact neutrophils generally migrated from DMS into the lumen of vascular sinus across the endothelium of sinus wall. However, some neutrophils showed characteristics of apoptosis, and DNA fragmentation was detected in these cells by the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling method. Thus, the cell death of neutrophils engulfed by megakaryocytes was thought to be apoptosis. The present results suggest that megakaryocytes contribute to random selection of an excess of neutrophils in the bone marrow of rats treated with LPS.

Selecting a surgical method for thoracic myelopathy caused by ossification of the posterior longitudinal ligament

STUDY DESIGN

The authors classified typical distributional patterns of ossification of the posterior longitudinal ligament of the thoracic spine in 1) central part of S-curve, 2) just above apical vertebra, and 3) combined with ossification of ligamentum flavum below apical vertebra. The results of the surgical methods selected according to the authors' classification were compared with those of previous reports.

OBJECTIVES

To establish the criteria for selecting an appropriate surgical method for ossification of the posterior longitudinal ligament of the thoracic spine.

SUMMARY OF BACKGROUND DATA

Poor surgical results for ossification of the posterior longitudinal ligament of "middle or lower thoracic spine" have been reported, but the unsuccessful location and curve has not been strictly defined.

METHODS

The authors studied postsurgical results in 26 cases of thoracic myelopathy caused by ossification of the posterior longitudinal ligament. They also investigated radiographs of 111 cases, including 85 patients under observation, and examined the relationships between thoracic spine alignment and ossification of the posterior longitudinal ligament distribution.

RESULTS

Twenty-three patients treated with methods conforming to the authors' criteria achieved satisfactory recovery in walking ability except for one patient. The results of the other three patients who underwent surgery with nonconforming methods were uneven.

CONCLUSION

Posterior decompression, as well as anterior decompression, is effective in the first pattern in the cervicothoracic region. In case of the second pattern, the responsible ossification of the posterior longitudinal ligament always lies one or two levels above the apical vertebra and should be removed by anterior approach, regardless of the extent of kyphosis. Transthoracic anterior decompression surgery is considered the best method for most patients under the second and third patterns.

Monitoring of anterior cervical spinal cord function

Anterior surgery is frequently chosen for treatment of cervical myelopathy. However, intraoperative spinal cord recording has rarely been used to monitor the function of the ventral columns. We report a method of monitoring evoked spinal cord potentials useful for detection of minor injury of the anterior spinal cord. Evoked spinal cord potentials elicited in cats by thoracic spinal cord and labyrinth stimulation were studied. Evoked intraspinal field potentials recorded after labyrinth stimulation were confirmed to originate from the vestibulospinal tract in the ventral columns. Low-amplitude potentials were recorded from the posterior epidural space. However, this method has not been used clinically because of difficulty in obtaining selective stimulation in humans. Spinal cord potentials evoked by thoracic stimulation were recorded from the anterior and posterior epidural spaces. The amplitude of the potentials was large enough to permit quantitation of neural function. We confirmed that anterior recording was more sensitive in detecting ventral column injury than posterior recording was. Based on these findings, we used anterior recording from the disc clinically for anterior spinal cord monitoring during anterior cervical surgery.

Inhibitory effect of the NMDA receptor antagonist, dizocilpine (MK-801), on the development of morphine dependence

We investigated the effect of a noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist, (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imin ehydrogen maleate (dizocilpine, MK-801), on hippocampal norepinephrine release in morphine-treated rats in order to clarify the relationship between NMDA receptors and the development of morphine dependence. Naloxone hydrochloride injected subcutaneously (s.c.) into morphine-dependent rats, induced an immediate increase in hippocampal norepinephrine release, which was associated with a typical morphine withdrawal syndrome. The increased norepinephrine levels persisted for at least 2 hr, even after the disappearance of the behavioral withdrawal syndrome. This striking effect of naloxone on hippocampal norepinephrine release was dependent on the duration of the intracerebroventricular (i.c.v.) morphine infusion. Pretreatment with dizocilpine (s.c.) before naloxone challenge reduce the rate of the rise in hippocampal norepinephrine release induced by naloxone in morphine-treated rats. Concurrent infusion (i.c.v.) of dizocilpine and morphine decreased the level of hippocampal norepinephrine release after a naloxone challenge. Both pretreatment with dizocilpine (s.c.) before naxolone injection and infusion (i.c.v.) of dizocilpine suppressed rearing and teeth-chattering signs, but not wet-dog shakes in morphine-treated rats. These results suggest that dizocilpine attenuates the development of morphine dependence through NMDA receptors, and thus that interaction between opioid receptors and NMDA receptors may be involved in the development of morphine dependence.

Urodynamic and electrophysiologic study of the urinary disturbances caused by cervical myelopathy

Urinary disturbance is one of the significant symptoms of cervical myelopathy. To make the diagnosis of urinary disturbance, preoperative urodynamic studies and evoked spinal cord potentials (ESCPs) recording were performed on 60 surgical patients with cervical myelopathy. Half (30) of this group complained of urinary disturbance, and 22 (37%) were diagnosed as having neurogenic bladder. The presence of neurogenic bladder was closely correlated with severe limb symptoms and relatively slow ESCP velocity. It was confirmed that neurogenic bladder was caused by severe spinal cord damage. However, for 47% of the patients with urinary complaints, findings of urodynamic examinations were negative; these patients probably had pathologic or psychosomatic factors other than neurogenic bladder due to cervical myelopathy. The prognosis of the neurogenic bladder appears to be influenced by irreversibility of the spinal cord lesions.

Countercurrent chromatographic analysis of ovalbumin obtained from various sources using the cross-axis coil planet centrifuge

The present studies have been conducted to investigate the cause of an unusually broad peak of ovalbumin obtained by countercurrent chromatography (CCC) reported earlier [K. Shinomija et al., J. Chromatogr., 644 (1993) 215]. A series of CCC experiments using our prototyte of the cross-axis coil planet centrifuge revealed that commercial ovalbumin products were classified into two groups: group A formed two peaks of ovalbumin at pH 7.0 and 5.8, while group B showed a relatively sharp single peak in a broad range of pH. Electrophoresis indicated that the group A ovalbumin consisted of both natural and denatured products: the natural ovalbumin is a monomer (Mr 45 000) whereas the denatured products form dimers (Mr 90 000). The abnormally broad peak obtained from the group A ovalbumin at pH 9 is apparently caused by the heterogeneity of the sample protein.

Inverse relation between vertebral body deformity and intervertebral disk narrowing in lumbar spine of elderly women

To investigate the relation between vertebral body deformity and disk narrowing in the lumbar spine of elderly patients, a longitudinal radiographic study of 56 aged women was retrospectively performed. We measured disk areas and body heights on two lateral lumbar radiograph sets obtained with an average interval between examinations of 10 years. The absolute values of disk areas on first examination and the rates of change of area of disks adjacent to nondeformed bodies were smaller than the corresponding values for the deformed bodies. Conversely, deformed bodies tended to have normal or expanded disks regardless of the mode of deformity. Despite the small number of subjects studied, our findings suggested that an inverse relation may exist between vertebral body deformity and disk narrowing.