Effects of electrical noise to a knee joint on quiet bipedal stance and treadmill walking.

The present study assessed whether an unperceivable, noise-like electrical stimulation of a knee joint enhances the stability of quiet bipedal stance and treadmill walking in young subjects. The results showed that the slow postural sway measures in quiet bipedal stance were significantly reduced by the electrical noise (P<0.05). In the treadmill walking, low frequency component (below 1 Hz) of mediolateral acceleration, measured at the third lumbar vertebra, significantly decreased with the electrical noise (P<0.05), while there were no changes in the anteroposterior and vertical directions. These results indicate that the electrical noise to a knee joint can be applied to enhance postural control in quiet bipedal stance and treadmill walking.

Development of a Portable Acceleration Monitor Device and its clinical application for the Quantitative Gait Assessment of the Elderly.

In this study, a handy gait assessment system with a tri-axial accelerometer has been developed and its application for a quantitative assessment of gait in the elderly was examined. This assessment system consists of a portable acceleration monitor device and PC analysis software. This portable device was fixed to the lower front of the subject, and the subject was asked to walk around a test course at a voluntary speed. The activities performed on the test course include standing up, normal walking, fast walking, and walking over a barrier. Gaits in 402 elderly people were measured three times every three months. These subjects were under nursing health services, such as expert place nursing, walking training, power rehabilitation, fall prevention training, and pool training. The measured acceleration was converted into relative velocity and relative displacement of the center of gravity of the subject. Four evaluation indices, i.e., physical activity, stability, symmetry, and average speed were calculated. The results reveal that both the physical activity and average speed decreased after six months under nursing services.

Virtual walkway system and prediction of gait mode transition for the control of the gait simulator.

A virtual walkway system is proposed in This work. This system consists of a new developed gait simulator and a HMD system to present virtual space to the user. The gait simulator is designed to permit the user to walk straight, change direction, go up and down stairs, etc. Main part of this gait simulator is two foot plates driven by three arms and actuators. Each foot plate follows the foot during swing phase and pulls it back during the stance phase while the user is walking straight However this gait simulator has one weak point, that is, this simulator cannot follow the change of gait mode sufficiently, like the start of walking or the end of walking. To solve this problem it is necessary to predict the change of gait mode to follow the transition perfectly. In this paper we chose the start and the end of straight walking and have tried to measure this transition of gait mode. To do this we paid attention on the anterior bending of the upper trunk. It is expected that the trunk bends forward before the start of walking and bends back before the stop of walking. In the experiment the distance between the upper trunk and the center of gravity (COG) was measured and it was proven that the measurement of this distance showed to be useful to know the transition of straight walking. This result was examined again on the gait simulator. Implanted control algorithm of gait simulator is as follows; two foot plates pull back the feet when the start of walking was predicted and stop when the stop of walking was predicted. Results show that the gait simulator was able to reproduce the start and the end of walking by this prediction algorithm.

Clinicopathological features of multiple primary gastric carcinoma.

The clinicopathological features of multiple primary gastric carcinoma in 107 patients who had undergone gastrectomy between 1972 and 1992 were studied and compared with those of single gastric carcinoma in 1,456 patients. The incidence of occurrence of multiple primary gastric carcinoma was 6.8% of patients who had gastrectomy for gastric cancer. Such carcinoma was detected less often in patients <49 years of age. Dominant findings involved an elevated gross appearance, papillary or well-differentiated adenocarcinoma in the histology, and invasion to the depth of mucosa. When multiple primary gastric carcinoma was classified by main and concomitant lesions based on the stage of the disease, concomitant lesions were detected more often in the lower third of the stomach and at the distal site of main lesions located in the upper or middle third of the stomach. These results indicate that the lower third of the stomach and the distal site of the main lesion must be investigated carefully to ensure that incidental concomitant lesions are not overlooked, especially when a patient has the clincopathological features described above.

Recurrent death among early gastric cancer patients: 20-years' experience.

Six hundred and ninety-six patients, from among a total of 1,868 cases, were diagnosed as having gastric cancer, and underwent surgical treatment at this Medical Institution, between 1972 and 1992. Eighteen patients (2.6%) died of recurrent disease, four (0.6%) tumors being mucosal, and fourteen (2.0%) submucosal, in accordance with depth of invasion. The clinico-pathological findings were analysed to clarify the risk factors of recurrence in patients with early gastric cancer, as follows: (a) submucosal invasion, (b) mixed type IIa+IIc in gross appearance, (c) tumor size more than 40 mm in diameter. In mucosal cancers, recurrence occurred in patients with lymph-vessel invasion and lymph-node metastasis. In terms of the site of the recurrent lesion, the patients had predominantly hepatic recurrence. We conclude that there are specific factors related to the increased risk of recurrence, that can be evaluated pre-operatively. By identifying the risk factors of recurrence, we can optimize the therapeutic approach to these patients.

Three-dimensional study of the cytoskeleton in macrophages and multinucleate giant cells by quick-freezing and deep-etching method.

The three-dimensional ultrastructure of multinucleate giant cells in subcutaneous granulomas was compared with those of peritoneal macrophages using a quick-freezing and deep-etching method. Subcutaneous granulomas were induced by implanting plastic coverslips in the dorsal subcutaneous tissue of rats. The quick-freezing and deep-etching replicas were prepared from the cells attached to the coverslips. Dense networks of actin filaments were distributed along all peripheral aspects (beneath the plasma membrane, and on free and coverslip-attached surfaces) of the multinucleate giant cells. On the coverslip-attached surface, numerous clathrin-coated pits and vesicles occurred between the actin filaments. In these cells, intermediate filaments, but not actin filaments, were the predominant cytoskeletal components in perinuclear regions and were attached to the cell nucleus, mitochondria and other vesicular cell organelles. A similar distribution of cytoskeletal components was observed in the mononuclear macrophages of the granulomas and the peritoneal macrophages. These results show that the cytoskeletal organization varies in different regions of the cytoplasm of multinucleate giant cells, while the characteristic cytoskeletal arrangement, resembling that of mononuclear macrophages, is maintained.