Eleven healthy subjects repetitively performed maximal cycling movement for 10 s with 20 s rest intervals. The load of the cycling was respectively set to 30% (high frequency task, lIF' task) and 80% (high power task, TIP task) of the optimal load for exerting maximum anaerobic power. Each task was finished when the exerted maximal power was decreased to 80% of the initial value. While performing each task, transcranial magnetic stimulation (TMS) was delivered to the motor cortex which was effectively able to evoke motor evoked potential (MEP) from the thigh muscles. Elec-tromyographic (EMG) activity of the left rectos femoris (RF), vastus lateralis (VL) and the MEP was analyzed.
The maximal power exerted was decreased to 80.6±1.58 % in the HF task, and 77.3±0.77 % in the HP task. The number of repeated sets in each task was 10.1 ± 1.45 (HF task) and 4.1±0.25 sets (HP task) . The MEP area of the RF and VL was not changed significantly in the HF task, though it was significantly increased in the latter half of the HP task. A two-way ANOVA showed that the time course of the changes in the MEP area was significant in the VL (p<0.01), but not in the RF. In both tasks, the duration of the MEP was progressively prolonged in each 10 sec pedaling, and the prolongation was evident in the latter half of the tasks. However, the magnitude of the prolongation was significantly larger during the HP task. The ratio of the integrated amplitude of the EMG and the exerted power at the initial 5 bouts of cycling (EMG/Power ratio) was significantly increased in both the RF and VL, suggesting that peripheral muscular fatigue was induced during at the latter half of each task. Furthermore, the EMG/Power ratio in the VL was significantly higher during the HP task than the HF task.
These results suggest that central fatigue plays a significant role in decreasing the maximum power output, and that it takes place in a muscle-dependent fashion. It was also suggested that during low load, but relatively higher cadence frequency, central fatigue other than that involving the motor cortex accounts for the decreased power output.

Changes in the motor evoked potential (MEP) evoked by transcranial magnetic motor cortex stimulation (TMS) of rectos femoris (RF) and vastus lateralis (VL) was examined during constant cadence cycling tasks for 60 sec. Subjects were 11 normal male volunteers aged between 19 and 25 years. Pedaling load was set at 100% and 80% of the estimated optimal value for maximum anaerobic power output. For the low load task (LL task), the pedaling rate was set at half the value of the maximum pedaling rate with the load set at 80% of the optimal for maximum anaerobic power output. For the high load task (HL task), the pedaling rate was set such that the power was equivalent to the LL task.
The route mean square of the electromyographic (EMG) activity amplitude tended to steeply increase during the latter half of the task. The magnitude of the increase in the RMS was significantly larger in the HL task than the LL task. The area of the MEP also tended to increase in both tasks, though the degree of the increase was significantly larger in the LL task than the HL task. The EMG silent period (SP) after the MEP tended to steeply increase just after the task initiation and to decrease in the latter half of the task in the HL task. However, in the LL task the facilitation of MEP was not found, but it showed a gradual decrease while performing the task. The duration of the MEP tended to increase in both tasks, though the degree of the increase in the VL was significantly larger in the LL task than the HL task. The linear regression analysis between the size of the MEP and the background EMG shows a significant positive correlation coefficient during isometric contraction, but not during the two types of cycling tasks.
These results suggest that the neural circuit responsible for the MEP was controlled differentially during isometric contraction and constant cadence pedaling. Also it is likely that the mechanism of central fatigue differed depending on the cadence and or load in a task-dependent fashion irrespective of the same power output.

The present study investigated how resistance training affects behaviors related to central and peripheral fatigue during a sustained maximal voluntary contraction (MVC) . The subjects were well-trained (TR, n=8) and sedentary untrained (UT, n=6) males. The subjects were asked to repetitively perform 3 sets of MVC (elbow flexion) for 1 min with a rest interval of 1 min. Transcranial magnetic stimulation (TMS) was delivered to the contralateral motor cortex to evoke the motor evoked potential (MEP) and electromyographic (EMG) silent period (SP) after the MEP. Ratio of root mean square (RMS) of the EMG and elbow flexion force (RMS/F) was also calculated.
The time course of the decrease in elbow flexion force that was standardized with respect to the maximal value obtained at the beginning of the first MVC was almost identical in both TR and UT. At the end of the task, the elbow flexion force decreased to around 30 % of the initial value in both groups. Decrease in voluntary activation (VA) estimated by the increment of the force after TMS was significantly larger in UT (77.3%) than in TR (88.2%) at the end of the task. Although the increase in MEP during the first set was significantly greater in UT than in TR, elongation of SP was significantly larger in UT than in TR. Increase in RMS/F, which is a manifestation of peripheral fatigue, was significantly larger in TR than in UT.
These results suggest that decrease in MVC in UT and in TR is respectively more attributable to central and peripheral fatigue, and that inhibitory inputs to motor cortex were larger in UT than in TR. It is concluded that expression of central and peripheral fatigue is affected by resistance training.

A 4-year-old boy was born with cyanosis and was given a diagnosis of tetralogy of Fallot and pulmonary atresia. Echocardiography showed membranous atresia of the pulmonary trunk that was connected to the left side of the ascending aorta via an aortopulmonary window 3 mm in diameter. Four major aortopulmonary collateral arteries (MAPCAs) were detected by cardiac catheterization and computed tomography angiography prior to undergoing surgery at 4 years of age. We performed one-stage complete unifocalization and definitive repair via a median sternotomy. The MAPCA supplying the left lower lobe was anastomosed to the true left pulmonary artery and the pulmonary artery trunk was augmented with an autologous pericardium patch. We then reconstructed the right ventricular outflow tract using a transannular patch and simultaneously patch-closed the VSD. The right/left ventricle pressure ratio after weaning from cardiopulmonary bypass was 0.8. The postoperative course was uneventful and the patient was discharged 26 days later. Seven months after the procedure, the right/left ventricle pressure ratio was decreased to 0.56 on cardiac catheterization.

A baby girl delivered at 41 weeks of gestation with persistent truncus arteriosus (PTA) and interrupted aortic arch (IAA) type A was referred to our institute for surgical intervention. Bilateral pulmonary artery banding (BPAB) proceeded through a median sternotomy at the age of 11 days to control excessive pulmonary blood flow. Thereafter, she gained weight under continuous prostaglandin E1 (PGE 1) infusion. Definitive repair proceeded at the age of 2 months. Cardiopulmonary bypass was established through a redo-median sternotomy, with two arterial cannulae (brachiocephalic artery and descending aorta). The aortic arch was reconstructed with direct anastomosis. The orifice of the pulmonary artery was removed from the arterial trunk and the defect in the aortic wall was directly closed. A ventricular septal defect was closed under cardioplegic arrest via a right ventriculotomy. The continuity from the right ventricle to the pulmonary artery was made using a hand-made, extended polytetrafluoroethylene (ePTFE) conduit with a bicusp. The sternum was left open at the end of the procedure and the chest was closed on post-operative day (POD) 3. She was weaned from mechanical ventilation on POD 4 and the postoperative course was uneventful. She was discharged on POD 49.

We report a rare case of double outlet right ventricle (DORV) with sub-pulmonary type ventricular septal defect (VSD). The great arteries were almost side-by-side, and the ascending aorta was located slightly posterior to the right of the pulmonary artery. We performed complete repair at the age of 25 days. Intra-cardiac rerouting (VSD closure) was carried out through the tricuspid valve. Arterial switch procedure was performed without the Lecompte maneuver. His postoperative course was uneventful and he was discharged 19 days after the operation without any complications.

We performed bilateral pulmonary artery banding (BPAB) through a median sternotomy on a four-day-old male infant with a double-outlet right ventricle (DORV) and interrupted aortic arch (IAA) who was delivered at 40 weeks of gestation. After urinary output improved, definitive repair was carried out 5 days later. Intra-ventricular rerouting was followed by arterial switch with the Lecompte maneuver. The aortic arch was reconstructed with direct anastomosis and the right ventricular outflow tract was augmented with a patch. The sternum was left open at the end of the procedure and the chest was closed on post-operative day (POD) 4. The patient was discharged from hospital on POD 78 after receiving treatment for pneumonia and chylothorax.

Thirty-four patients with congenital cardiac disease were studied to evaluated the role of ultrafiltration after cardiopulmonary bypass without homologous blood transfusion. We used either polypropylene microporous hollow fiber hemoconcentrator (HC-30M or 100M) or polyacrylonitrile microporous hollow fiber hemoconcentrator (PHC-500). Ultrafiltration was useful in the reduction of fluid overloading after cardiopulmonary bypass with extreme hemodilution. Thirty-two patients tolerated the procedure uneventfully without donor blood transfusion and were discharged from the hospital. The values of hematocrit, serum protein and free hemoglobin increased significantly after ultrafiltration with either type of hemoconcentrator. However the degree of concentration of blood components was significantly higher with polyacrylonitrile hemoconcentrator than those with polypropylene hemoconcentrator. These results indicated that ultrafiltration was useful for maintaining water balance after cardiopulmonary bypass without homologous blood transfusion in pediatric cardiac surgery and that polyacrylonitrile microporous hollow fiber hemoconcentrator should be employed in patients with shorter bypass time and less hemolysis.

Transcatheter embolization of 25 aortopulmonary collateral arteries (7 bronchial arteries and 18 intercostal arteries) was attempted prior to intracardiac repair in 7 patients. The underlying disease was tetralogy of Fallot in 3 patients, pulmonary atresia with ventricular septal defect in 2, double-outlet right ventricle with ventricular septal defect and pulmonary stenosis in 1 and tricuspid stenosis with pulmonary atresia in 1. The intervals between embolization and intracardiac repair ranged from 0 to 17 days (mean 4.5 days). Embolization resulted in total occlusion in 7 bronchial arteries and 17 intercostal arteries, with an overall success rate of 96%. Complications included a coil dislodgement from a collateral artery into the aorta in one patient, necessitating surgical removal of the dislodged coil from the femoral artery, an exacerbation of cyanosis and dyspnea on exercise in 5, and slight fever in 2. In one patient with tetralogy of Fallot, who had 5 collateral vessels, transcatheter embolization caused hypoxemia, bradycardia and hypotension and therefore intracardiac repair was performed immediately after embolization. Aortopulmonary collateral arteries in patients with congenital heart disease can be effectively treated by transcatheter embolization. Embolization should be performed just before intracardiac repair because an excessive decrease in arterial oxygen saturation after embolization may require an emergency operation.

OBJECTIVE: We wanted to clarify the relationship between the visibility of air cysts on CT images, the CT slice thickness and the size of the air cysts, with contact radiographs as the gold standard, for the accurate evaluation of honeycomb cysts. MATERIALS AND METHODS: An inflated and fixed autopsied lung having idiopathic interstitial pneumonia was evaluated. The corresponding air cysts were identified on the contact radiographs of a 0.5 mm-thick-section specimen and also on the CT images of three different kinds of section thickness: 0.5, 1.0 and 2.5 mm. The maximal diameters of the air cysts were measured under a stereomicroscope. RESULTS: A total of 341 air cysts were identified on the contact radiograph, and they were then evaluated. Sixty-six percent of air cysts 1 to 2 mm in diameter were detected by 0.5 mm slice thickness CT, while only 34% and 8% were detected by 1.0 and 2.5 mm slice thickness CT, respectively. Only 28% and 22% of air cysts less than 1 mm in diameter were detected by 0.5 and 1.0 mm slice thickness CT, respectively. CT with a 2.5 mm slice thickness could not demonstrate air cysts less than 1 mm in diameter. CONCLUSION: The CT detection rate of honeycombing is significantly influenced both by the slice thickness and the size of the air cysts.
Aged ; Aged, 80 and over ; Cadaver ; Cysts/*radiography ; Female ; Humans ; Lung Diseases/pathology/*radiography ; Tissue Fixation/methods ; *Tomography, X-Ray Computed