Ultra-fast x-ray tomography for multi-phase flow interface dynamic studies

The present paper describes the concept of a fast scanning Xray tomograph, the hardware development, and measurement results of gas-liquid two-phase flow in a vertical pipe. The device uses 18 pulsed X-ray sources activated in a successive order. In this way, a complete set of 18 independent projections of the object is obtained within 38 ms, i. e. the measuring rate is about 250 frames per second. Finally, to evaluate the measurement capability of the fast X-ray CT, a wire-mesh sensor was installed in the flow loop and both systems were operated for the same two-phase flow simultaneously. Comparison of the time series of the cross section averaged void fraction from both systems showed sufficient agreement for slug flow at large void fractions, while the fast CT underestimated the void fraction of bubbly flow especially in low void fraction range. For the wire-mesh sensor, coerced deformation of slug bubble interface was found. Further hardware improvement is in progress to achieve better resolution with the fast X-ray CT scanner.

Locomotive Syndrome: Operational Definition Based on a Questionnaire, and Exercise Interventions on Mobility Dysfunction in Elderly People

The increasing elderly population has a great impact on public health, and it is important to understand the progression of musculoskeletal disorders seen in this population. To establish useful preventative methods for such locomotive disorders, we must detect early changes in these individuals and identify those at risk in order to implement early interventions. The purpose of this review was: (1) to introduce an operational definition of locomotion dysfunction to prevent a care-need condition, and to verify its validity through a prospective cohort study, and (2) to review the indication of exercise intervention for multiple musculoskeletal involvements from the preceding literature. We developed a measurement scale called the Geriatric Locomotive Function Scale (GLFS)-25, which clearly reflects the degree of functional deterioration. We used it in a prospective cohort study of 314 patients recruited from 5 clinics or nursing care facilities and investigated the relationship of the GLFS-25 with 46 variables covering various clinical manifestations. The results clearly revealed that the change in the GLFS-25 classification reflected a common pattern seen in those with locomotive dysfunction. Recently, several important movements regarding physical activity and its public promotion have been advocated by international health organizations and journal publishers. Though it has not been confirmed yet that complex musculoskeletal diseases can be treated using therapeutic exercise, the promotion of physical activity appears promising. The degree of activity limitation in aged individuals with locomotive disorders can be evaluated using this scale, which may be useful in predicting the effectiveness of future interventions.

Soft-plastic brace for lower limb fractures in patients with spinal cord injury

STUDY DESIGN

Retrospective study at a rehabilitation center.

OBJECTIVES

Patients with spinal cord injury, even if they are wheelchair users, sometimes suffer from fractures of the lower limb bones. As their bones are too weak to have surgery, and because a precise reduction is not required for restoration, such patients are often indicated for conservative treatment. This case series study investigated the use of a hinged, soft-plastic brace as a conservative approach to treating fractures of the lower extremities of patients with spinal cord injury.

SETTING

National Rehabilitation Center, Japan.

METHODS

Fifteen patients (male, n=10; female, n=5; average age, 52.7 years) with 19 fractures of the femur or the tibia who were treated with a newly-developed hinged, soft-plastic brace were studied. All of them used wheelchairs. We analyzed the time taken for fracture union and for wearing orthotics, degree of malalignment, femorotibial angle and side effects.

RESULTS

The fractures in this series were caused by relatively low-energy impact. The average time taken for fracture union was 80.1 (37-189) days, and the average amount of time spent wearing orthotics was 77.9 (42-197) days. On final X-ray imaging, the average femorotibial angle was 176.9° (s.d. ±8.90), and 15° of misalignment in the sagittal plane occurred in one patient.

CONCLUSION

A hinged, soft-plastic brace is a useful option as a conservative approach for treating fractures of the lower extremities in patients with spinal cord injury.

Hes1 functions downstream of growth factors to maintain oligodendrocyte lineage cells in the early progenitor stage

Expansion of the progenitor pool of oligodendrocytes (OLs) is a critical process for obtaining appropriate amounts of mature myelin-forming OLs in the developing and regenerating central nervous system. In vitro, fibroblast growth factor-2 (FGF2), together with platelet-derived growth factor (PDGF), is required to expand oligodendrocyte progenitor cells (OLPs) in an unlimited manner, maintaining them in the early progenitor stage. However, the intracellular mechanisms that prevent OLP maturation remain elusive. In order to investigate these mechanisms, we established a mouse OLP primary culture, which enabled us to undertake biochemical analyses. We found that the suppressive effects on maturation of early OLP to the late O4(+) progenitor by PDGF+FGF2 treatment was abrogated by Mek inhibitor, while transfecting cells with a constitutively active Mek1 construct prevented OLP maturation, suggesting that the Mek-Erk pathway is implicated in the effects of the growth factor treatment. The activation of Mek-Erk pathway promoted proliferation of OLP suggesting that cell cycle progression has suppressive effects to the maturation of OLP. Furthermore, molecular screening using DNA microarrays revealed that Hes1, a negative regulator of bHLH transcription factors, is one of the downstream molecules induced by PDGF+FGF2 treatment. We confirmed that forced activation of Mek-Erk pathway is sufficient to induce Hes1 expression and that Hes1, in turn, exerts suppressive effects on the maturation of OL lineage by itself. Our observations thus indicate that Mek-Erk pathway plays pivotal role in preventing early OLP maturation to late OLPs and the effect is mediated by cell cycle progression as well as Hes1 induction.

Statistical modelling of knee valgus during a continuous jump test

Landing with the knee in a valgus position is recognized as a risk factor for anterior cruciate ligament (ACL) injury. Using linear and non-linear regression analyses, the purpose of this study was to examine the correlation between two-dimensional (2D) knee valgus and three-dimensional (3D) knee kinematics measured during a jump landing task. Twenty-eight female collegiate athletes participated. All participants were required to perform a continuous jump test. The average maximum angles of abduction and internal tibial rotation during landing were measured using the Point Cluster Technique. Average peak knee valgus angle was measured using a 2D approach. Linear and non-linear regression analyses between 2D valgus and 3D knee abduction, and between 2D valgus and 3D internal tibial rotation, were performed. The R2 value between 2D valgus and 3D knee abduction was significantly different from zero and had a moderate correlation for all models, whereas the R2 value between 2D valgus and 3D internal tibial rotation was not significantly different from zero. The 2D approach could be used to screen a specific group of individuals for risk of ACL injury; however, using frontal plane 2D analysis of valgus motion to evaluate internal tibial rotation is not advised.

A computer-controlled contracture correction device with low-load and continuous torque: an animal experiment and prototype design for clinical use

The purpose of this study was to clarify the relationship between mechanical stress and tissue response of the contracted knee joint in rats and to propose a new design of contracture correction device for clinical use. Wistar rats were operated on to immobilize their knee joints with a procedure causing periarticular bleeding and were kept in flexed position for 40 days. At day 40, the immobilizing wire was removed, and after day 43, the contracted knee joint had been treated with tunable corrective devices secured by an external fixation method to the rear limb. These devices consisted of four types of motor-driving system which provided several different low-load and continuous stretch torques. Measuring the angle of maximum knee extension, its effectiveness was assessed comparing with a lower load and control group of natural recovery course. The device also had a cyclic joint movement within the acquired range of motion and an oval cam mechanism producing a small distraction force to the joint along its long axis. The results showed that an appropriate range of low-load continuous torque was more effective to correct joint contracture. On the basis of the animal experiment, a new computer-controlled, gas-driven contracture correction device was developed for clinical trial. It was concluded that mechanical application in a condition with low and continuous torque is a useful treatment for fixed joint contracture.

Experimental joint contracture correction with low torque--long duration repeated stretching

Tension is necessary to maintain and restore the mechanical properties of soft connective tissues. Conversely, reduced tension states such as produced by immobilization weaken mechanical properties and facilitate joint contracture. We assessed the effect of low torque-long duration stretching to increase the range of motion (ROM) and to restore the mechanical properties of contracted joints in 66 rat knees immobilized for 40 days. After remobilization, we randomly divided the contracted knees into four treatment groups treated with repeated stretches of diverse torques and duration: stretching with low-torque and long-duration, high-torque and short-duration, high-torque and long-duration, low-torque and short duration. We included control and natural recovery groups. Phase lag in all treatment groups recovered to the same range as in the normal controls. Dynamic stiffness, which was not altered by joint immobilization, increased in all treatment groups. Deformation and load to failure improved substantially only in the low-torque and long-duration stretching group. Low-torque and long-duration repeated stretching leads to a greater restoration of ROM with more normal mechanical properties compared to high-torque and short duration stretching.

Effect of lesion level on the orthotic gait performance in individuals with complete paraplegia

STUDY DESIGN

Cross-sectional, experimental research.

OBJECTIVES

To clarify the effect of lesion level on cardio-respiratory responses and biomechanical characteristics of walking with a reciprocating gait orthosis in complete paraplegia with spinal cord injury (SCI).

SETTING

National Rehabilitation Center for Persons with Disabilities, Japan.

METHODS

Ten SCI individuals (age: 20-34 years, injured level: Th5-12) who experienced orthotic gait training at least for 10 weeks participated in two experiments: (1) measurement of the cardiorespiratory responses during 20 min of orthotic gait exercise; and (2) three-dimensional motion analysis and ground reaction force measurement using the VICON system. We calculated the following parameters: pulmonary ventilation, oxygen consumption (VO(2)), heart rate (HR), gait speed, cadence, stride length, crutch force (CF), hip range of motion (ROM), and hip angular velocity (VEL). Further, energy consumption and energy cost were calculated using the steady-state value of VO(2) and gait speed.

RESULTS

The steady-state value of the VO(2) (18.2 +/- 3.80 ml/kg) and HR (133.0 +/- 21.63 b/min) tended to be larger in higher thoracic SCI subjects. There were strong positive correlations between the lesion level and walking speed (r = 0.74), energy cost (r = 0.85), and hip ROM (r = 0.78). On the other hand, negative correlation between the lesion level and peak CF (r = -0.78) was clarified.

CONCLUSIONS

The physiological intensity of the orthotic gait strongly depended on the level of lesion. It seems likely that a limited hip range of motion and excess upper limb load result in the low energy cost of orthotic gait for the higher thoracic level of paraplegic patients.

Potential impact of orthotic gait exercise on natural killer cell activities in thoracic level of spinal cord-injured patients

STUDY DESIGN

Prospective before-after trial.

OBJECTIVE

To examine the changes of natural killer (NK) cell activity in response to orthotic gait exercise in thoracic level of spinal cord-injured (SCI) patients.

SETTING

National Rehabilitation Center for Persons with Disabilities, Japan.

METHODS

In all, 10 thoracic level of SCI patients (ranging Th5-Th12), who experienced orthotic gait training, participated in this study. NK cell activity at an effector:target (E/T) ratio (20:1) was examined in a sample of peripheral blood taken before and just after orthotic gait exercise for 20 min. On a separate day, to evaluate the physical intensity of the orthotic gait exercise, cardiorespiratory responses at rest and during exercise were measured.

RESULTS

The resting value of the NK cell activity in our SCI patients was remarkably lower than that in normal subjects reported in previous studies. The NK cell activity was significantly increased through a 20 min orthotic gait exercise (pre versus post; 12.7+/-5.28 versus 17.76+/-6.71, P<0.05). The steady-state value of oxygen (VO2) and heart rate (HR) were 18.13+/-3.92 ml/kg and 142.53+/-19.84 b/min, respectively. It was noteworthy that a patient who showed decrement of NK cell activity in response to exercise had the highest level of injury (Th5), and showed the higher energy cost of orthotic gait.

CONCLUSION

These findings suggested that the orthotic gait exercise has the potential to enhance the immune function for SCI persons, although patients with a higher level of SCI may have some difficulties.

SPONSORSHIP

Mitsui Sumitomo Insurance Welfare Foundation

Stretch reflex excitability of the anti-gravity ankle extensor muscle in elderly humans

AIM

To examine whether the stretch reflex excitability of the soleus muscle changes with age, stretch reflexes at rest (REST) and during weak voluntary contractions (ACT) were elicited in 18 older and 14 younger subjects.

METHOD

The amplitude of the stretch reflex responses and gain, defined as the gradient of the regression line for the relation between stretch reflex responses against the angular velocity of the applied perturbation, were evaluated in each short-latency (M1) and two long-latency components (M2 and M3).

RESULTS

It was found that in the older group, both the amplitude and gain of the M1 component did not change from the REST to the ACT conditions, whereas in the younger group both variables significantly increased from the REST to ACT conditions. The latency of the M1 component was significantly shorter under the REST condition (older vs. younger: 51.8 +/- 7.37 vs. 55.1 +/- 8.69 ms), while no group differences were found in those variables under the ACT condition, suggesting that the muscle-tendon complexes of SOL muscles of the older subjects were less elastic and had less slack, probably due to age-related histochemical alterations. Further, the Hoffman reflex (H-reflex), elicited during the REST condition in 10 older and 11 younger subjects showed no significant differences, suggesting that the soleus motoneuron response to the Ia input was comparable between the two subject groups.

CONCLUSION

The histochemical alterations occurring with the ageing process might augment the short-latency stretch reflex in the SOL muscle without enhancement of motoneuronal excitability, and this effect might be masked when the muscle is voluntarily activated.

Energy expenditure during walking with weight-bearing control (WBC) orthosis in thoracic level of paraplegic patients

STUDY DESIGN

Comparative study of the effectiveness of walking exercise with a newly developed gait orthosis, the weight-bearing control (WBC) orthosis, for thoracic level of paraplegic patients.

OBJECTIVES

To test its feasibility as a rehabilitation alternative for paraplegic patients, the energy consumption and cost during walking with WBC were calculated and compared with the values of conventional orthoses given in previous reports.

SETTING

National Rehabilitation Center for the Disabled, Japan.

METHODS

Four paraplegic patients with traumatic spinal cord injuries ranging from T8 to T12 participated. Experiments were conducted after 3 months of the orthotic gait training with WBC. The cardiorespiratory parameters were continuously measured at rest and during walking with a telemetric device. The steady-state value of the oxygen uptake (V(O2)), heart rate (HR), the energy consumption (J/kg/s) and energy cost (J/kg/m) were calculated.

RESULTS

The average walking speed was 19.0 +/- 2.58 m/min. The steady-state value of the V(O2) and HR were 16.08 +/- 1.93 ml/kg and 147.3 +/- 10.94 b/min, respectively. The energy cost during orthotic walking tended to be better than the values of conventional orthoses, whereas the energy consumption was almost similar.

CONCLUSION

WBC enables thoracic level of paraplegic patients to walk at relatively higher speed than conventional orthoses under similar energy expenditure. The special devices equipped with WBC are therefore considered to lead to improvement of the energy cost of walking. The physical intensity presumed by cardiorespiratory responses during walking with WBC is suited to promote their aerobic capacity. Therefore, it is concluded that the WBC orthosis could be an effective alternative in rehabilitation for thoracic level of paraplegic patients.

Somatosensory graviception inhibits the soleus H-reflexin standing man - an underwater experiment-

H-reflexes were elicited in the soleus muscle in subjects standing on a force platform in a water tank, under different loading conditions at the ankle joint. The joint loading was altered by changing the combination of buoys and weights attached to lower limb segments, while the total body mass was kept the same. The results revealed that as the joint load was reduced the H-reflex was significantly enhanced as compared to that under the control condition, while it decreased as the joint load was increased, despite the same background EMG activity level. It was demonstrated that the augmented load information from the lower limb joints has an inhibitory effect on the soleus H-reflex, suggesting that this might be one of underlying neural mechanisms responsible for the suppression of H-reflex during human upright standing.

Fibroma of the vulva

We describe a patient with fibroma of the vulva. The tumor had areas of marked hypointensity consistent with fibrosis on T1 and T2 weighted magnetic resonance (MR) images. The presence of abundant fibrous tissues on MR images enabled us to make a preoperative diagnosis of fibroma.

Effect of low-level laser therapy (LLLT) on viscoelasticity of the contracted knee joint: comparison with whirlpool treatment in rats

BACKGROUND AND OBJECTIVE

The purpose of this study was to compare the effect of Low-Level Laser Therapy (LLLT) with sham and whirlpool treatment on the contracted knee joint in rat.

STUDY DESIGN/MATERIALS AND METHODS

Forty-eight Wistar rats were operated on to immobilize knee joint, and 1 week after operation they were randomly assigned to four treatment groups: laser 40 mW (3.9 W/cm2), laser 60 mW (5.8 W/cm2), whirlpool (42 degrees C), and sham laser. Tunable Ga-Al-As semiconductor (810 nm) laser was used for another 2 weeks of treatment. Removing and preparing bilateral hind legs, degree of knee contracture was assessed by measuring the knee flexion angle, weight of the gastrocnemius muscle, and periarticular connective tissue viscoelasticity measuring phase-lag and stiffness.

RESULTS AND CONCLUSION

Laser irradiation showed no significant changes except the phase-lag of laser 60 mW. Under the conditions of this study, LLLT stimulation did not provide a significant effect for minimizing the degree of experimental joint contracture over whirlpool treatment.

Laser's effect on bone and cartilage change induced by joint immobilization: an experiment with animal model

OBJECTIVE

Influence of low-level (810 nm, Ga-Al-As semiconductor) laser on bone and cartilage during joint immobilization was examined with rats' knee model.

MATERIALS AND METHODS

The hind limbs of 42 young Wistar rats were operated on in order to immobilize the knee joint. One week after operation they were assigned to three groups; irradiance 3.9 W/cm2, 5.8 W/cm2, and sham treatment. After 6 times of treatment for another 2 weeks both hind legs were prepared for 1) indentation of the articular surface of the knee (stiffness and loss tangent), and for 2) dual energy X-ray absorptiometry (bone mineral density) of the focused regions.

RESULTS AND CONCLUSIONS

The indentation test revealed preservation of articular cartilage stiffness with 3.9 and 5.8 W/cm2 therapy. Soft laser treatment has a possibility for prevention of biomechanical changes by immobilization.

Thermostable collagenolytic activity of a novel thermophilic isolate, Bacillus sp. strain NTAP-1

We isolated an acidophilic thermophile belonging to the genus Bacillus, strain NTAP-1, which secreted a thermostable collagenolytic activity into the culture medium. The collagenolytic activity exhibited an optimum pH for Azocoll hydrolysis of pH 3.9 and was not completely inhibited by 10 mM ethylenediaminetetraacetic acid (residual activity, 63%), suggesting that Bacillus NTAP-1 produces a novel acid proteinase with highest activity for collagen. The collagenolytic activity was thermostable; more than 80% of the original activity was retained after incubation of the culture supernatant at pH 4.0 and 60 degrees C for 4 h.

Effect of shoe modifications on center of pressure and in-shoe plantar pressures

This study was conducted to determine the effect of footwear modification on patients with neuromusculoskeletal disorders. Two analyses, the center of pressure and the in-shoe plantar pressures, were studied with the help of healthy volunteers so that the effect of shoe modifications could be assessed. The ground force under the sole of the shoe was measured while the subjects were walking, and the plantar pressure at the foot-insole interface and its distribution were measured while the subjects were in both the standing and walking positions, wearing the trial shoes. The trial shoes had three different types of heels-standard heel, Thomas heel, and reverse Thomas heel-and had three different locations for the rocker bar--just under the metatarsophalangeal joint, 1 cm behind the metatarsophalangeal joint, and 1 cm before the metatarsophalangeal joint. The shift change at the center of pressure showed that the Thomas heel generally pushed the center of pressure more laterally and the reverse Thomas heel shifted it medially more than the standard heel did. While the subjects were in a stable standing position wearing the Thomas heel shoes, the medial forefoot and the lateral heel region's pressure showed significant reduction in the plantar pressure and the lateral forefoot and the medial heel showed a tendency to rise, compared with the standard heel condition. When the trial shoes' heels were changed to the reverse Thomas heel, the above changes tended to reverse. Tests at the foot-insole interface showed that the different types of heels and the location of the bar could change not only the pressure distribution but also the duration of the plantar pressure under the lateral area that shifted to the medial area when the subjects walked. This pressure measurement method was very useful for the design and evaluation of such footwear.

Influence of daily activity on changes in physical fitness for people with post-stroke hemiplegia

To investigate the influence of daily activity on changes in the physical fitness of people with post-stroke (cerebrovascular disorders) hemiplegia, we evaluated the follow-up exercise load test of 30 ambulatory male patients with post-stroke hemiplegia. Between the times of the two tests, patients had no special supervised training. They were advised by their physicians to exercise according to the result of an exercise-loading test. We determined peak oxygen uptake and O2 consumption at the ventilatory threshold point. After 9.4 months, the mean peak oxygen uptake improved significantly from 17.7 to 21.1 ml/min/kg, and ventilatory threshold point also improved significantly from 11.4 to 13.6 ml/min/kg. Among the nine subjects who returned to their jobs, subjects who previously went to their offices by public transportation showed more improvement in ventilatory threshold point level than did subjects who previously walked to their offices. Among the 21 subjects who did not return to work, those who exercised regularly (primarily by walking) showed more improvement of peak oxygen uptake level than did subjects who did not exercise regularly. In conclusion, people with hemiplegia who are living in the community can improve their physical fitness without formal supervised training by simply increasing their daily activities.

[Analysis of intermittent blood flow in experimental tumor using a transparent chamber]

Using a transparent chamber under a microscopic recording system equipped with a CCD camera, we measured real-time fluctuations of microvessel blood flow in an experimental murine tumor. Seven microvessels of the tumor showed 3-4 fluctuations in blood flow (intermittent blood flow) during the observation period (2 hours). Within the 120 min. monitoring period, we obtained approximately a maximum 52.5% of decreased blood flow. The duration of change in blood flow ranged from 15-45 min. Similar temporal fluctuations were seen in experimental animal tumors. Our data clearly demonstrated that fluctuations in blood flow (intermittent blood flow) in tumors are a common feature.

Relationship between brain atrophy estimated by a longitudinal computed tomography study and blood pressure control in patients with essential hypertension

To evaluate the relationship between blood pressure control and the progression of brain atrophy in the elderly, patients with essential hypertension and brain atrophy were longitudinally evaluated using computerized tomography (CT). The study evaluated 48 patients with essential hypertension aged 46-78 years, and 30 sex- and age-matched normotensive control subjects. The extent of brain atrophy as determined by caudate head index (CHI), the inverse cella media index (iCMI), and Evans' ratio (ER) was estimated twice at an interval of 5-9 years (mean, 6.9 years). The mean annual increases in CHI (deltaCHI), iCMI (delta iCMI), and ER (deltaER) were evaluated. Mean blood volume in the common carotid artery (BF) and the decrease in BF per year (deltaBF) were also determined. The deltaCHI, delta iCMI, and deltaER increased with age in the hypertensive subjects as well as the control group across all age groups evaluated. The deltaCHI, delta iCMI, and deltaER were significantly greater in the patients with essential hypertension in their 50 s as compared with the controls. In patients with essential hypertension aged 65 years or older, the deltaCHI, delta iCMI, and deltaER were significantly lower in the group in whom the blood pressure was controlled within the range of borderline hypertension than the groups in which it was controlled in the range of normal or mild hypertension. In the younger patients under the age of 65 with essential hypertension, blood pressure control did not affect the deltaCHI, delta iCMI, and deltaER. The deltaCHI, delta iCMI, and deltaER were significantly correlated with deltaBF in both groups. These findings indicate that control of systolic blood pressure within the range of borderline hypertension may delay the progression of brain atrophy in elderly patients with essential hypertension.

[Lung abscess resulting from esophageal carcinoma successfully treated with intraesophageal covered self-expandable metallic stent]

An 82-year-old man was admitted to our hospital with high fever and back pain. He already suffered from esophageal carcinoma and expandable metallic stent had been inserted because of esophageal stenosis. A chest x-ray film obtained on admission showed infiltrative shadows in the right lower lung filled. The diagnosis of lung abscess was made on the basis of aspirate findings. Despite closed drainage, antibiotic treatment, and fasting therapy, progressive pulmonary infiltrates developed. Esophagography and esophagoscopy revealed that an esophageal fistula due to an advanced esophageal carcinoma had caused the lung abscess. An additional covered self-expandable metallic stent (EMS) was placed on the surface of the esophageal carcinoma, close to the esophageal fistula. This promptly resolved the lung abscess. Our conclusion was that the covered-EMS can be effective for the palliation of esophagorespiratory fistulas.

Effects of right hemithoracic irradiation on ceftazidime penetration into the alveolar space in rats

The effect of thoracic irradiation on antibiotic penetration into the alveolar space was determined in a hemithoracic irradiation rat model to evaluate radiation-induced acute alveolar injury at various time intervals. The results of this investigation may be summarized as follows: (1) The transfer of ceftazidime (CAZ: Modacin) from blood to lung tissue, that is, the permeability of pulmonary capillary epithelium, and the transfer of ceftazidime from lung tissue to bronchoalveolar lavage fluid, that is, the permeability of the alveolar epithelium, peaked at 4 to 5 weeks after thoracic irradiation; (2) the time course of change in the absolute concentration of ceftazidime in lung tissue showed a significant increase not only in the irradiated lung but also in the contralateral non-irradiated lung 3 days or more after irradiation. The finding that the administration of antibiotics may cause a significant increase in drug concentration in lung tissue even in the contralateral lung at 3 days after irradiation suggests that the change induced at the alveolar level immediately after irradiation affects the non-irradiated lung field through an as yet unknown mechanism.

Leukotoxin (9, 10-epoxy-12-octadecenoate) impairs energy and redox state of isolated perfused rat lung

We investigated the perturbation of energy balance and redox state in leukotoxin (9, 10-epoxy-12octadecenoate) (Lx)- and endothelin-1 (ET-1)-induced lung injury, using isolated perfused rat lungs. To examine any relationship between these parameters, intracellular levels of adenine nucleotides, pyridine coenzymes and glutathione were determined by reversed-phase high-performance liquid chromatography (HPLC) in the freeze-dried tissues of isolated rat lungs. The tissue samples were perfused with a physiological salt solution containing either Lx only, Lx plus NG-monomethyl-L-arginine (L-NMMA), Lx plus NG-monomethyl-D-arginine (D-NMMA), Lx plus superoxide dismutase (SOD) or ET-1 only. In isolated perfused lung tissue, 10 mol of Lx caused permeability-increased lung injury, and 10 nM of ET-1, which caused a comparable increase in wet lung weight, evoked pulmonary capillary hypertensive lung injury. Lx-injured lungs showed decreases in the contents of ATP, NADPH, NADH, reduced glutathione (GSH), (2ATP + ADP)/2(ATP + ADP + AMP) ratio (energy charge) and NADH/NAD+ ratio, and increased the contents of ADP and AMP compared with the vehicle control and ET-1-injured lungs. Such effects of Lx were significantly attenuated by pretreatment with 0.4 mM L-NMMA or 500 units/ml of SOD, but not with 0.4 mM D-NMMA. On the other hand, the ET-1-injured lung evidenced decreased tissue GSH. These findings indicate that Lx shifted the lung redox state toward oxidation and that Lx-induced lung injury was involved in the imbalance of the energy and redox state via production of nitric oxide and/or superoxide anion.

Effects of repeated ether stress on the hypothalamic-pituitary-testes axis in adult rats with special reference to inhibin secretion

Effects of ether stress on the hypothalamo-hypophysial-gonadal axis in adult male rats were examined. To clarify the role of adrenal glucocorticoids in gonadal function, the effects of adrenalectomy and Dexamethasone treatment were also investigated. Ether stress increased the plasma concentrations of ACTH and corticosterone, but decreased the plasma concentrations of LH, FSH, inhibin and testosterone. The pituitary responsiveness to LH-RH for LH release and testicular responsiveness to the endogenous LH for testosterone release were maintained in stressed rats. Adrenalectomy caused an increase in the plasma concentrations of ACTH, but decreased the plasma concentrations of LH, FSH and testosterone. Dexamethasone treatment in adrenalectomized rats recovered the levels of plasma gonadotropins to control levels. The concentration of plasma inhibin did not change in adrenalectomized rats, but it was decreased compared to control rats by Dexamethasone treatment. Treatments of Dexamethasone in intact male rats resulted in a decline in plasma levels of testosterone and inhibin without a decrease in the levels of LH and FSH, indicating the direct effect of Dexamethasone on the testes. These results indicate that increased ACTH secretion in stressed rats is probably due to hypersecretion of CRH from the hypothalamus, which suppresses gonadotropin secretion via the inhibition of LH-RH. The decreased levels of testosterone may be caused by a stress-induced decrease in plasma LH concentrations and increased secretion of corticosterone in the ether stressed rats. The low levels of plasma inhibin in stressed rats was also probably due to the direct effect of corticosterone on the Sertoli cells.

[Effects of atherogenic risk factors on asymptomatic brain infarct]

This study was done to clarify the relationship between asymptomatic brain infarcts and risk factors for atherogenis. A total of 312 patients (151 men and 161 women) who had no neurologic deficits were enrolled. Their ages ranged from 41 to 83 years (mean age 63 years). The patients were divided into two groups: 158 patients without asymptomatic brain infarct and 154 patients with at least one asymptomatic brain infarct of at least 5 mm as diagnosed by magnetic resonance imaging. The patients with asymptomatic brain infarct were more likely than those without asymptomatic brain infarct to be 65 years old or older, and to have essential hypertension, diabetes mellitus, or atrial fibrillation. Among patients with hypertension the frequency of left ventricular hypertrophy or hypertensive ocular findings (Scheie's class H2) was significantly higher in those with asymptomatic brain infarct than in those without asymptomatic brain infarct. These results indicate that aging, essential hypertension (especially with left ventricular hypertrophy or hypertensive ocular findings), diabetes mellitus, and atrial fibrillation are associated with asymptomatic brain infarct.

Electrical stimulation on joint contracture: an experiment in rat model with direct current

OBJECTIVE

To examine whether electrical stimulation could decrease the degree of joint stiffness in a rat lower extremity model.

DESIGN

Rat knee joints were surgically immobilized in a flexed position for 3 weeks. Two groups of rats were stimulated with 20 microA and 50 microA constant direct current. Another group had surgical intervention and sham electrodes without electricity. The hind leg was extirpated and prepared for a sample with the femur-knee joint-tibia unit. Recording the knee flexion angle with extension torque, the degree of joint contracture was assessed biomechanically by measuring the bone-joint-bone sample as a cantilever. Measurement was performed with (1) spectral analysis of transfer function measurement using random mechanical noise with frequency range from 1 to 50Hz, and (2) dynamic stiffness and loss tangent with steady-state sinusoidal excitation (11 and 35Hz).

RESULTS

The results showed that no significant difference or trend was found in vibration analysis among three groups. However, spectral analysis of transfer function measurement revealed more deformation against load, and more viscous nature in the stimulation groups, especially in low frequency band, than in the sham group.

CONCLUSION

Electrical stimulation with constant direct current has a possibility of reducing the degree of joint contracture.

Localized osteoarticular change due to joint immobilization; biomechanical test and bone densitometry in rat's hind limb model

Bone change induced by knee immobilization was assessed on dissected femurs and tibias to clarify the influences upon the mechanical properties and their demands. Fifty-eight Wistar-Imamichi male rats (11-12 weeks old, body weight 350-450 g) were subjected to knee joint immobilization (150 degrees flexed position) on one side while the opposite side served as a control. Animals were killed in seven groups at time intervals of 1, 2, 3, 4, 5, 7, and 10 weeks. The hind leg was extirpated and prepared for (1) biomechanical analysis by the indentation method at the articular surfaces of the femoral condyle and head and at the subchondral bone of the proximal tibia, and for (2) dual-energy X-ray absorptiometry of the distal metaphysis of the femur. The biomechanical parameters measured induced dynamic stiffness and phase lag derived from forced oscillation (preload 3 N, cyclic load 2 N and 11 Hz, 35 Hz), and bone mineral density was analyzed. These were compared between the immobilized side and control side, and among the seven time groups. The biomechanical results showed an early change of osteocartilaginous properties at the femoral condyle, a late response at the tibial subchondral bone, and no change at the femoral head. The measurement of bone mineral density revealed that a very sensitive reaction started within 1-2 weeks. This study provides objective data demonstrating that disuse or lack of mechanical stress greatly affects the remodeling activity for homeostasis of joints, and dramatically impairs normal bone mineral density next to the immobilized joint in young animals.

Adrenal and gonadal function in hypothyroid adult male rats

The functional relationship between thyroid, adrenal and gonadal hormones was investigated using adult male rats. Hypothyroidism was produced by the administration of 4-methyl-2-thiouracil (thiouracil) in the drinking water for 2 weeks. Plasma concentrations of TSH dramatically increased, whereas plasma concentrations of tri-iodothyronine and thyroxine decreased in thiouraciltreated rats as compared with euthyroid rats. Hypothyroidism increased basal levels of plasma ACTH and pituitary content of ACTH. The pituitary responsiveness to CRH for ACTH release markedly increased, whereas the adrenal responsiveness to ACTH for corticosterone release decreased. These results indicated that hypothyroidism causes adrenal dysfunction in adult male rats. Pituitary contents of LH and prolactin decreased in hypothyroid rats as compared with euthyroid rats. In addition, hypothyroidism lowered pituitary LH responsiveness to LHRH. Testicular responsiveness to human chorionic gonadotrophin for testosterone release, however, was not different between euthyroid and hypothyroid animals. These results indicated that hypothyroidism causes adrenal dysfunction and results in hypersecretion of ACTH from the pituitary gland. Adrenal dysfunction may contribute to the inhibition of LHRH secretion from the hypothalamus, possibly mediated by excess CRH.

Clinical experiences with a convertible thermoplastic knee-ankle-foot orthosis for post-stroke hemiplegic patients

As rehabilitation for post-stroke hemiplegic patients has become widely accepted practice, there has been an increase in patients who are more difficult to treat. In the prescription rationale of orthoses for hemiplegics, the knee-ankle-foot orthosis (KAFO) for the lower limb has generally been underestimated because of its inhibitory effect on the normal walking pattern and also its interference with gait training. The authors had an experience of 28 hemiplegics with severe physical impairments who were fitted with a convertible plastic KAFO. Among these patients, there were 11 cases in which the KAFO was replaced by an ankle-foot orthosis (AFO) within 1.5 to 8 months (average 4 months) following initial prescription when they were able to control their knee actively. Ambulatory capability in these patients was superior to that of the remaining KAFO group. The Barthel index of the AFO group patients was higher than the KAFO group (p < 0.01). However neither age, sex, severity of hemiplegia, starting time of rehabilitation following onset of stroke, time of fitting with the orthosis, nor the functional recovery stage were critical factors between the two groups, only the incidence of major complications affected ambulatory capability.

[Immunodeficiency with thymoma (Good's syndrome) similar to sino-bronchial syndrome]

A 58-year-old man was admitted to our hospital because of recurrent pulmonary infections that began three years previously. Laboratory data showed hypogammaglobulinemia and a chest computed tomogram showed diffuse bilateral micronodular shadows and an anterior mediastinal tumor. Immunodeficiency with thymoma (Good's syndrome) was diagnosed. After undergoing a thymectomy, he received intravenous gamma-globulin injections once a month for prophylaxis. Good's syndrome occurs rarely in Japan. A solid tumor-like shadow is not necessarily observed in routine chest X-ray studies, and hypogammaglobulinemia is one sign of this syndrome. The hypogammaglobulinemia of Good's syndrome should be carefully differentiated from that of other immunodeficiency diseases such as common variable immunodeficiency, the acquired immunodeficiency syndrome, chronic lymphocytic leukemia, non-Hodgkin's lymphoma, and multiple myeloma (non-secretory type).

[Lung injury and pulmonary vascular endothelial cell injury]

Pulmonary vascular endothelial cells are an important barrier that helps keep lung tissue intact. These cells are exposed to potentially injurious cells and to harmful mediators that are produced in or released into the blood. The endothelial cells may then be stimulated and injured. Stimulated and injured pulmonary vascular endothelial cells can themselves produce and release injury-promoting mediators. Using isolated perfused rat lungs and cultured human pulmonary endothelial cells, we assessed the effect of neutrophil-derived injurious mediators, leukotoxin, and neutrophil elastase on the pulmonary endothelium. Both mediators caused high-permeability pulmonary edema in the isolated lungs and caused dose-dependent and time-dependent damage in the cell cultures. Injury due to leukotoxin was suppressed in the presence of LNMMA or superoxide dismutase and injury due to neutrophil elastase was suppressed by neutrophil elastase inhibitors. These data indicate that these mediators cause lung injury via different mechanisms and that they may synergistically evoke clinical lung injury.

Effect of direct current stimulation on triradiate physeal cartilage. In vivo study in young rabbits

Electrical stimulation with 8 microA direct current was applied to the triradiate physeal cartilage of young rabbits for periods of 3, 4, and 5 weeks. The effect was evaluated by morphometric measurement and histological observation. We tried to improve some previously described technical problems (e.g., movement of electrode during experiment) in this model of the growing acetabulum. Statistically significant differences in acetabular depth were found between the experimental and the control side in the 3-week group, but no obvious differences were found among the other measurements. Characteristic thickening of the growing physeal cartilage, especially proliferating cells, was found in the stimulated sides. Electricity affects the cell behavior in the triradiate physeal cartilage as well as the growth plate of long bone, but further study is still necessary to find more appropriate conditions to gain actual growth.

Changes of cytochemical properties in the Golgi apparatus during in vivo differentiation of the ameloblast in developing rat molar tooth germs

The cytochemical changes of the Golgi stacks occurring concomitantly with cell differentiation were examined in ameloblasts of developing rat molar tooth germs using osmium impregnation and cytochemistry with nicotinamide adenine dinucleotide phosphatase (NADPase), thiamine pyrophosphatase (TPPase), and acid phosphatase (Acpase). NADPase, TPPase, and Acpase activities were already present in the Golgi stacks of the inner enamel epithelial cells, the undifferentiated form of the ameloblast: NADPase activity existed in the medial Golgi cisternae, TPPase activity in the trans Golgi cisternae, and Acpase activity in almost all cisternae and strongly in the trans-most cisterna of the Golgi stack. At this stage, however, osmium deposits after impregnation were not observed in the cisterna of Golgi stacks but were present in some small vesicles. These vesicles were located throughout the cytoplasm. Osmiophilic cisternae in the Golgi stacks were apparent for the first time at the stage when the Golgi apparatus developed and migrated to the region distal to the nucleus with the progression of cell differentiation. These findings indicate that the cis subcompartment of the Golgi apparatus was incomplete in the inner enamel epithelial cells with regard to appearance of its cytochemical property, as compared with the medial and trans subcompartments. It is suggested that the cis compartment of the Golgi stack may be completed only in the last stage of the compartmentalized Golgi organization during differentiation of the ameloblast.

Distribution of calcitonin gene-related peptide and substance P-immunoreactive nerve fibers and their correlation in the periodontal ligament of the mouse incisor

The distribution of calcitonin gene-related peptide (CGRP)- and substance P (SP)-immunoreactive (IR) nerve fibers and their correlation in the periodontal ligament of mouse incisors were examined by indirect immunofluorescence. Both CGRP-IR and SP-IR thin nerve fibers were abundant in the apical and middle third of the periodontal ligament. In the lingual portion of the incisal periodontal ligament, these nerve fibers were localized in the alveolar half of the periodontal ligament and were observed as free nerve endings. No CGRP-IR and SP-IR specialized nerve endings, such as Ruffini-like corpuscles, were observed. In the labial periodontal ligament, CGRP-IR and SP-IR nerve fibers ran along the incisal axis. The distribution of CGRP-IR nerve fibers was very similar to that of SP-IR nerve fibers.

[Effect of a direct electric current on modification of bone and ligament repair processes--experimental investigation of a rabbit model]

Investigations of the effect of direct current on 1) fracture healing, and 2) ligament healing was conducted by applying 10 microA to 1) the defect of the fibula, and 2) that of the patellar ligament of adult rabbits. After time periods for stimulation all specimens were tested with combinations of roentgenological, histological, biomechanical and biochemical methods. The results were analyzed and compared with the non-stimulated, opposite side and with the normal tissue. The electricity produced 1) a more massive callus with normal histological features in an early stages at the fracture site, and 2) higher tensile stiffness and earlier change of the collagen types in the newly-formed tissue, though no significant differences were observed as to 1) the mechanical parameters of callus and bone material, and 2) histological findings of repairing tissue. Electrical stimulation was indicated not only on bone tissue but also on non-osseous tissues and their components.

Neuropeptide Y- and substance P-like immunoreactivities in the guinea pig parotid gland

These immunoreactivities were examined by double immunofluorescence, which demonstrated that many nerve fibres around the glandular acini and blood vessels contain neuropeptide Y and substance P. It appears that these substances may coexist in nerve fibres around acini, but that there may be two populations of fibres containing these peptides around the blood vessels.

Ontogeny of cholinergic ganglionic cells which take up L-3,4-dihydroxyphenylalanine and contain vasoactive intestinal polypeptide in the mouse tongue

During the prenatal development of the mouse tongue, the intralingual ganglion was investigated histochemically and immunohistochemically for acetylcholinesterase (AChE) activity, the capacity to take up L-3,4-dihydroxyphenylalanine (L-DOPA) and vasoactive intestinal polypeptide (VIP)-like immunoreactivity. AChE-positive cells were first observed at gestational day 12, and AChE-positive neurons which take up L-DOPA were found at gestational day 14, while VIP-like immunoreactive neurons were not seen until gestational day 16. The present results suggested that the cholinergic neurons within the mouse tongue can take up L-DOPA from gestational day 14 and synthesize VIP from gestational day 16.

Case report 685: Ossifying fibromyxoid tumor of the soft parts of the upper arm

We report an unusual case of an ossifying tumor arising in the deep soft tissue adjacent to the humerus of a 72-year-old woman. The tumor exhibited sarcoma-like features histologically, although its clinical course unexpectedly differed from that of a malignant tumor. We diagnosed this particular case as an ossifying fibromyxoid tumor of soft parts, which has been recently described by Enzinger et al.. This is another example of an ossifying soft-tissue tumor which simulates a malignant sarcoma.

Aversive taste stimuli increase CGRP levels in the gustatory insular cortex of the rat

Calcitonin gene-related peptide-like immunoreactivity (CGRP-IR) was surveyed immunohistochemically in the insular cortex of the rat, and the levels of insular cortical CGRP-IR were measured with the radioimmunoassay method following intraoral stimulation with various taste stimuli. CGRP-IR was localized in nerve fibers within the agranular and dysgranular insular cortices. The CGRP-IR levels in the rostral (gustatory) part of the insular cortex were increased significantly by strongly aversive taste stimuli such as quinine hydrochloride and conditioned taste stimuli (NaCl and sucrose) which animals had been taught to avoid. The results suggest that CGRP in the gustatory insular cortex is concerned with rejection or avoidance behaviors to aversive taste stimuli.

Influence of colchicine on the addition of a sugar to the enamel protein in secretory ameloblasts of cultured germs of rat molar tooth by 3H-galactose radioautography

The influence of colchicine on the addition of 3H-galactose to the enamel protein in secretory ameloblasts of cultured germs of rat molar tooth was investigated by light- and electron-microscopic radioautography. In tooth germs cultured without colchicine, the reaction products of 3H-galactose were observed over Golgi cisternae at early chase times and then localized over the enamel with time. In tooth germs cultured with colchicine, the silver grains were seen over the Golgi cisternae, condensing granules and accumulated secretory granules. Some grains also appeared with time over the pale granular material precipitated in the intercellular space with colchicine treatment. In quantitative analysis with light microscopic radioautography, values of silver grain counts over the unit area (100 microns2) on ameloblasts and enamel of colchicine-treated tooth germs were significantly lower at both 0 min and 30 min chase after 30 min pulse than those of control tooth germs, respectively. This finding indicates that colchicine diminished the incorporation of 3H-galactose into the secretory ameloblast of cultured tooth germs. It is suggested that colchicine decreases the activity of the Golgi apparatus with regard to the addition of sugar to the synthesizing glycoprotein in the secretory ameloblast.