Union of defects in the pars interarticularis of the lumbar spine in children and adolescents. The radiological outcome after conservative treatment.

Lumbar spondylolysis can heal with conservative treatment, but few attempts have been made to identify factors which may affect union of the defects in the pars. We have evaluated, retrospectively, the effects of prognostic variables on bony union of pars defects in 134 young patients less than 18 years of age with 239 defects of the pars who had been treated conservatively. All patients were evaluated by CT scans when first seen and more than six months later at follow-up.

Development of spondylolytic olisthesis in adolescents.

Background Context: Although it has been well documented that slippage in patients with spondylolysis is most prevalent during the growth period, the exact time when slippage initiates and halts during the growth period is still unknown. Moreover, the contribution of spinal deformities, such as wedging of the vertebral body to the slippage, remains controversial.

Purpose: To clarify when slippage in pediatric spondylolysis initiates and halts.

Effects of active recovery under a decreasing work load following intense muscular exercise on intramuscular energy metabolism.

The effect of active recovery at a decreasing % of MVC following intense muscular exercise on intramuscular pH was investigated in vivo using 31P-MRS. Seven healthy men participated, and their right wrist flexor muscle group was examined. The subjects were asked to flex their right wrist at 60 % of the maximum voluntary contraction (MVC) every 2 s until the intracellular pH in the wrist flexor muscle decreased to 6.

Electrical stimulation prevents deterioration of the oxidative capacity of disuse-atrophied muscles in rats.

Introduction: The purpose of this study was to evaluate the effects of electrical stimulation on disuse-atrophied muscles.

Methods: Sprague-Dawley rats were used and divided into three groups: control (C), hind-limb suspended for 7 d (HS), and HS plus transcutaneous electrical stimulation for 7 d (ES). In the ES group, transcutaneous electrical stimulation was induced at 1 Hz for 1 h every day to condition the gastrocnemius-plantaris-soleus muscles.

Characteristics of velocity-controlled knee movement in patients with cervical compression myelopathy: what is the optimal rehabilitation exercise for spastic gait?

Study Design: The isokinetic strength of knee extensors and flexors was measured at various controlled velocities in patients with spastic paraparesis caused by cervical compression myelopathy.

Objective: To evaluate leg function objectively in patients with myelopathy.

Summary Of Background Data: Cervical compression myelopathy causes varying degrees of spastic paresis in the legs and affects the activities of patients.

Effect of weight bearing on recovery from nerve injury in skeletal muscle.

We examined the effect of weight bearing (WB) on muscle recovery after nerve injury. Rats were housed in individual cages for 2 wk under WB or hindlimb suspension (HS) after being subjected to sciatic nerve compression for 1 wk. Sham operated on rats served as controls (sham group).

Slippage mechanism of pediatric spondylolysis: biomechanical study using immature calf spines.

Study Design: This study analyzed the skeletal-age-dependent strength of the lumbar growth plate to resist anterior shearing forces using the MTS system in the immature calf spine with pars defects.

Objective: To clarify the pathomechanism of the skeletal-age-dependent incidence of slippage in pediatric patients with pars defects by comparing the strength of the lumbar growth plate among three skeletal age groups.

Summary Of Background Data: Isthmic spondylolisthesis occurs and progresses more frequently during the growth period, whereas it is rare afterward.

Evaluation of disuse atrophy of rat skeletal muscle based on muscle energy metabolism assessed by 31P-MRS.

The purpose of this study was to evaluate disuse atrophy of skeletal muscle using a hind-limb suspension model, with special reference to energy metabolism. Twenty-four Sprague-Dawley rats were divided into four groups: control group (C), hind-limb suspended for 3 days (HS-3), for 7 days (HS-7) and for 14 days (HS-14). The gastrocnemius-plantaris-soleus (GPS) muscles in each group were subjected to the following measurements.

Differences in energy metabolism and neuromuscular transmission between 30-Hz and 100-Hz stimulation in rat skeletal muscle.

Objective: To examine differences in energy metabolism and neuromuscular transmission failure in rat hindlimb muscles subjected to electric stimulation at different frequencies.

Design: Experimental animal study.

Setting: Bioenergetic Research Center at Otsuka Pharmaceutical Company, Otsuka, Japan.

Radiographic assessment of scapular rotational tilt in chronic shoulder impingement syndrome.

This study presents an objective evaluation of both scapular upward and axial rotational tilts in shoulder impingement syndrome, using a scapular spine line defined on antero-posterior (AP) radiographs of the shoulder as the referential line. Twenty-seven patients with unilateral shoulder motion pain, who were diagnosed as having chronic shoulder impingement syndrome, were enrolled in the study. Scapular upward and axial rotational tilts were compared between the affected and contralateral shoulders.

Preventive effects of lecithinized superoxide dismutase and methylprednisolone on spinal cord injury in rats: transcriptional regulation of inflammatory and neurotrophic genes.

The effects of lecithinized superoxide dismutase (PC-SOD) and/or methylpredisolone (MP) in preventing secondary pathological changes after spinal cord injury (SCI) were investigated in rats with reference to recovery of hindlimb motor function and expression of mRNA of pro-inflammatory and neurotrophic genes. Hindlimb motor function was assessed as the BBB open field locomotor scores. The BBB scores of three groups treated with either PC-SOD (40,000 units/kg), MP (30 mg/kg), or a combination of PC-SOD and MP (PC-SOD+MP) increased with time until 3 days after SCI, and were significantly higher than that of the control group (p < 0.

Effects of specific warm-up at various intensities on energy metabolism during subsequent exercise.

Background: To investigate the effects of specific warm-up at various intensities on energy metabolism during subsequent intense exercise.

Experimental Design: specific warm-up was consisted of 3 sets of wrist flexions for 5 min, with each set followed by a 3-min rest. The intensity of specific warm-up was set at 20%, 30% or 40% of maximal voluntary contraction (MVC).

Characteristics of regional bone mineral density and soft tissue composition in patients with atraumatic vertebral fractures.

To clarify the characteristics of total body and regional bone mineral density (BMD) and soft tissue composition in patients with atraumatic vertebral fractures (AVF), we measured total body and regional BMD, lean mass, and fat mass using dual-energy X-ray absorptiometry. Sixty-four women, aged 55-75 years, were divided into two groups: women with AVF (fracture group, n = 30) and women without AVF (nonfracture group, n = 34). Mean BMD of the second to fourth lumbar vertebrae (L2-4BMD), regional BMD, and soft tissue mass were measured.

Characteristics of bone mineral density and soft tissue composition of obese Japanese women: application of dual-energy X-ray absorptiometry.

We studied the characteristics of bone mineral density (BMD) and soft tissue composition in obese Japanese women using dual-energy X-ray absorptiometry. Eighty-nine women, aged 45-85 years, were divided into three groups according to their body mass index (BMI): a thin group (n = 38: BMI < 21), a standard weight group (n = 31; BMI, 21-25), and an obese group (n = 20; BMI > or = 25). The mean BMD of the second to fourth lumbar vertebrae and BMD of the lumbar spine, thoracic spine, pelvis, legs, and ribs of the thin group were significantly lower than those of the standard weight group or the obese group (P < 0.

Cathepsins B and L in synovial fluids from patients with rheumatoid arthritis and the effect of cathepsin B on the activation of pro-urokinase.

To clarify the pathophysiological role of cathepsins in rheumatoid arthritis (RA), we investigated whether cathepsin B or cathepsin L was increased in synovial fluid (SF) of RA joints, and whether the cathepsin isolated from SF of RA patients activated pro-urokinase or not. Thus, we estimated the content of cathepsins in SF of RA patients by measuring their activities by fluorospectrometry, using Z-Phe-Arg-MCA as the substrate. Cathepsin activity was approximately 4-fold higher in the SF of RA patients than in those of patients with osteoarthritis.

Spectral analysis of erector spinae muscle surface electromyography as an index of exercise performance in maximal treadmill running.

Thirteen male athletes (mean 20.7 years) participated in the present study which investigated the relationship between mean power frequency (MPF) and exercise intensity determined from gas analysis during maximal treadmill running. All subjects performed two consecutive ramp exercise tests on the treadmill.

Effects of sciatic neurectomy on the femur in growing rats: application of peripheral quantitative computed tomography and Fourier transform infrared spectroscopy.

The effects of unilateral sciatic neurectomy (USN) on the development of the femur were studied in 15 growing Wistar-derived rats (age, 5 weeks). The rats were divided into four groups: USN-operated group (right femur), USN-nonoperated group (left femur), sham-operated group (right femur), and sham-nonoperated group (left femur). Bone mineral density (BMD), bone mineral content (BMC), bone area, periosteal circumference, and endosteal circumference were measured by peripheral quantitative computed tomography (pQCT) and the mineral/matrix ratio was evaluated by Fourier transform infrared spectroscopy (FTIR).

Effects of denervation on energy metabolism of rat hindlimb muscles: application of (31)P-MRS and (19)F-MRS.

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.

Characteristics of the protease activity in synovial fluid from patients with rheumatoid arthritis and osteoarthritis.

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.

Whole body hyperthermia selectively induces heat shock protein 72 in neurons of the rat spinal cord.

The aims of this study were to examine whether the heat shock response is operative in the spinal cord, and to identify the type of responsible cell. Immunoblot analysis using an antibody specific for a highly stress-inducible heat shock protein with a molecular mass of 72 kDa (HSP72) showed that exposing rats to whole body hyperthermia remarkably induced HSP72 protein in the spinal cord within 2 h. Northern blot analysis with a cDNA probe for human HSP72 demonstrated that whole body hyperthermia induced the expression of HSP72 mRNA within 30 min in the spinal cord.

The pathomechanism of isthmic lumbar spondylolisthesis. A biomechanical study in immature calf spines.

Study Design: Anterior shearing force was applied to immature calf lumbar functional spinal units until failure.

Objectives: To clarify the mechanism of slippage in immature calf lumbar spines with pars defects as a first step to understand the mechanism of spondylolisthesis in pediatric human lumbar spines.

Summary Of Background Data: Progression from lysis to olisthesis occurs during the adolescent growth spurt.

MRI high-signal intensity in the menisci of asymptomatic children.

We reviewed retrospectively the MRI examinations of 108 knees of 80 children to identify the prevalence of a high signal in the menisci of those without symptoms. There were 51 boys and 29 girls with a mean age of 12.2 years (8 to 15).

Osteochondritis dissecans of the femoral condyle in the growth stage.

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.