Surgical Treatment for Metastatic Tumors of the Spine

We report herein the results of anterior or posterior neural decompression with spinal stabilization in 16 patients with spinal metastases. Intractable back pain was relieved in 14 patients (87.5%) and 4 had complete pain relief. Neurologic recovery was observed in 8 out of 13 patients (61.5%) who had some neurologic deficits before surgery. The activities of daily living improved in 7 of 9 (77.7%), and 5 out of 8 patients (62.5%) who had been unable to walk before surgery became ambulatory after surgery. The average operation time was 3h 15 min with an average blood loss of 2150 ml. No patient died within 1 month after surgery and the median survival was 19.1 months. The results indicated that, if properly indicated, anterior or posterior neural decompression and spinal stabilization is a safe and effective treatment for patients with spinal metastases to improve the quality of life for the patients' remaining years.</p

Separation Between Silicon and Aluminum Powders Contained Within Pulverized Scraped Silicon-Based Waste Solar Cells by Flotation Method

There are few study examples on the separation of metals by floating method. In this study, separation of silicon and aluminum, which are the main components of silicon-based solar cell module, was carried out by floating method in order to purify silicon from waste solar cell module. The selection of surfactant, control of electric charge, wettability of the solid particles, surface tensions, and bubble surface area are important for separation of solids by floating method. Sodium dodecyl sulfate (SDS) can increase the hydrophobicity of aluminum powder due to the difference of surface potentials between silicon and aluminum. SDS behaves as a collector of aluminum as well as a frothing agent to decrease the bubble size. At a SDS concentration of 2 g/L and sample dipping time of 10 min, 80.1 mass% of aluminum was floated and separated, and the sedimentary silicon reached a purity of 90.7% from a mixture of 50 mass% aluminum and 50 mass% silicon. Finally, at a pH value of 7.0, SDS concentration between 1.0 and 2.5 g/L and air flow rate of 2.5 L/min (STP) were suitable experimental conditions to purify silicon from a mixture of silicon and aluminum by flotation separation method

Prone Position Impairs Oxygen Supply-Demand Balance During Systemic Hypoxia in Rabbits

Ventilation in the prone position improves the prognosis of patients with severe acute respiratory distress syndrome (ARDS). Contraindications to ventilation in this position include unstable systemic circulation. Only a few reports exist on the effects of prone ventilation in respiratory failure on systemic circulation. This animal study compared systemic hemodynamic changes between supine and prone positions in anesthetized rabbits under acute systemic hypoxia (breathing 15% O2). Cardiac output and the systemic O2 extraction ratio increased under the hypoxia, but only in the supine group. Besides, the rate pressure product was higher in the prone group than in the supine group. This study showed that prone ventilation increases myocardial O2 consumption and suppresses compensatory mechanisms to maintain aerobic metabolism during systemic hypoxia. First of all, it will be necessary to examine the effect of prone ventilation on the O2 supply-demand balance in the ARDS model

Marathoners’ Breathing Pattern Protects Against Lung Injury by Mechanical Ventilation: An Ex Vivo Study Using Rabbit Lungs

[Background] Breathing during a marathon is often empirically conducted in a so-called “2:2 breathing rhythm,” which is based on a four-phase cycle, consisting of the 1st and 2nd inspiratory and the 1st and 2nd expiratory phases. We developed a prototype ventilator that can perform intermittent positive pressure ventilation, mimicking the breathing cycle of the 2:2 breathing rhythm. This mode of ventilation was named the marathoners’ breathing rhythm ventilation (MBV). We hypothesized that MBV may have a lung protective effect. [Methods] We examined the effects of the MBV on the pulmonary pre-edema model in isolated perfused rabbit lungs. The pulmonary pre-edema state was induced using bloodless perfusate with low colloid osmotic pressure. The 14 isolated rabbit lung preparations were randomly divided into the conventional mechanical ventilation (CMV) group and MBV group, (both had an inspiratory/expiratory ratio of 1/1). In the CMV group, seven rabbit lungs were ventilated using the Harvard Ventilator 683 with a tidal volume (TV) of 8 mL/kg, a respiratory rate (RR) of 30 cycles/min, and a positive end-expiratory pressure (PEEP) of 2 cmH2O for 60 min. In the MBV group, seven rabbit lungs were ventilated using the prototype ventilator with a TV of 6 mL/kg, an RR of 30 cycles/min, and a PEEP of 4 cmH2O (first step) and 2 cmH2O (second step) for 60 min. The time allocation of the MBV for one cycle was 0.3 s for each of the 1st and 2nd inspiratory and expiratory phases with 0.2 s of intermittent resting between each phase. [Results] Peak airway pressure and lung wet-to-dry ratio after 60 min of ventilation were lower in the MBV group than in the CMV group. [Conclusion] MBV was considered to have a lung-protective effect compared to CMV

Lumbar spinal changes over 20 years after posterior fusion for idiopathic scoliosis

Lumbar X-ray findings and clinical manifestations were investigated in 10 patients who underwent posterior fusion with or without Harrington instrumentation for idiopathic scoliosis between 1965 and 1975. The subjects were 4 men and 6 women, who ranged from 10 to 17 years of age at the time of surgery (mean, 12 years and 9 months). The postoperative follow-up period ranged from 20 to 30 years (mean, 24 years and 7 months). All patients were followed-up at our institution. Three patients received posterior fusion without instrumentation, and Harrington instrumentation was used in 7 from 1967 onwards. The distal end of the fusion was L2 in 4, L3 in 4, and L4 in 2 patients. Pain, evaluated by Moskowitz's criteria, was stage 1 in 5 and stage II in 5 patients (none of them had stage III or IV). In X-ray evaluation, graded according to Lawrence's classification, grade III changes were noted in 2 patients; one with thoracolumbar fusion with Harrington instrumentation to the L4 vertebra and the other patient was assessed at 30 years post-surgery. According to White-Panjabi's criteria, instability was noted in 1 patient with Harrington fixation including the L4 vertebra. Clinical manifestations and X-ray abnormalities were less severe than anticipated at 20 years plus post-surgery, although a tendency for deterioration was observed in patients with fusion including the L4 or patients followed up for more than 30 years post-surgery.</p