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Intra-arterial chemotherapy from bilateral superficial temporal arteries and radiotherapy were carried out preoperatively on two patients with oral cancer on the midline. Total doses of preoperative chemo- and radio-therapies were 160 mg/m2 of carboplatin, 50 mg of peplomycin and 20 Gy of 60Co-irradiation, respectively. Therapeutic effect of preoperative chemo- and radio-therapies was evaluated on the resected materials from histological point of view. In case 1, the effect was judged as Grade II A in Oboshi's classification, which indicated a mild destruction of architecture of tumor tissue and a few viable tumor cells, but an extreme reduction of the primary lesion was observed on clinical appearance. In case 2, the therapeutic effect was regarded as Grade II B, which indicated a severe destruction of architecture of tumor tissue and few viable tumor cells. Concerning toxicity, mucositis and slight thrombocytopenia (96,000/mm3) in case 1, and mucositis and leukopenia (2,300/mm3) in case 2 appeared. However, they soon recovered after termination of the preoperative therapies. From the above results, it was considered that a combination of bilateral intra-arterial chemotherapy and radiotherapy was quite effective as a preoperative treatment for oral cancers on the midline at the same doses of anti-neoplastic agents and irradiation as for the other unilateral oral cancers.

Electrical stimulation to enhance callus formation has been in use for some time now. This experiment was undertaken to find the relationship between electrical callus formation and the amount of electricity. In this experiment, the long bones of canines were stimulated by direct current and observed microscopically for callus formation. Moreover, distribution patterns of electric potential and current density were calculated theoretically by finite element method. The results are summarized as follows: Electrical callus formation was observed in the medullary canal with 8.7-20 microA direct current. Electrical callus is fibrous ossification and the peak of callus formation is from fourteen to twenty one days. There is no difference in volume and/or speed of callus formation between the simple and the constant direct current. Using platinum electrodes, the amount of callus formed around the cathode and anode is the same. To prevent electrolysis of the tissues, distance between electrodes must be kept at a minimum. On the other hand, the surface area of the electrodes must be widen to keep the electric potential at the minimum level. The area of callus formation is related to 5-10 microA/cm2 of electric current density.

The analgesic effect of calcitonin in osteoporosis has been considered to originate from its actions on bone metabolism. However, the author assumed a possible presence of other mechanism, since the analgesic effect of calcitonin manifests in an extremely early phase in which an increase in bone mass is hardly conceivable. Namely, the author postulated that its analgesic effect is due to its actions on body trunk muscles, and investigated experimentally the effect of calcitonin on skeletal muscles. The following results were obtained. 1) Recovery from decreased twitch contraction of M. triceps surae was shown in vivo in rats treated with calcitonin, with dose-response relationship. 2) Calcitonin exerted no effect on partial blockade by dTc, in neuro-muscular junction. Therefore, the neuro-muscular junction is probably not the site of the actions of calcitonin. 3. In an in vitro study on isolated M. soleus, the decrease contraction was recovered after treatment with calcitonin. A correlation was found between this recovery and the dose of calcitonin. 4) In the calcitonin treated muscle, a pronounced persistence of normal contraction was demonstrated in contrast to the control group. 5) Calcitonin appears to facilitate Ca release through exerting actions on Ca transport system in the sarcoplasmic reticulum. From these results, it was shown that calcitonin appears to possess an activity to elevate contractile ability of skeletal muscles. This activity is considered to be derived from its effect on sarcoplasmic reticulum. This activity of calcitonin on contractile function of skeletal muscles indicates the presence of a mechanism relating to skeletal muscles in the analgesic effect on low back pain in osteoporosis.

Bone remodeling influenced by mechanical stresses was studied using ambulatory chickens. They were divided into four groups with the different mechanical forces applied to the leg. I: running along a circular track, II: walking or standing on one leg, III: control, IV: casting. The animals were sacrificed after 12 weeks and undecalcified cross-sections of femurs and tibias were examined using a tetracycline labeling method. Bone formation was evident at both metaphyses of the femur and at the proximal metaphysis of the tibia. More bone formation was observed at the medial quarter of both femur and tibia than in comparison with the lateral quarter. There was, however, no difference in the membraneous ossification between the medial and lateral quarters in Group II. The lack of significant cortical drift at the medial side of the femur and tibia suggests that no bending moment is generated by standing on one leg.

The processes are as follows: 1) Life-sized photoelastic models molded from a cadaver pelvis are made of Epoxy resin. 2) In order to practice the stress freezing process, the models are set to our original loading apparatus in the electric heater. The forces exerted on the hip models are both body weight and four kinds of muscular forces, those of the abductor, adductor, rectus femoris and gluteus maximus. 3) After the stresses are frozen in the models, they are cut off into slices to observe isochromatic and isoclinic lines. 4) In the stress analysis both the shear difference method and the double slice method are utilized to obtain more accurate stress distributions. And the results have been summarized as follows: 1) In the ring-shaped slices large stresses are observed especially at four areas; namely the central area of the iliac bone, the acetabulum proximal to the ilium, the pubic ramus and the area adjacent to the sacroiliac joint. The specific areas where hydrostatic pressure works are seen at two points in the deep acetabular cavity. 2) The principal stress lines of almost all slices tend to flow smoothly and monotonously along the ilium, the sacrum and the pubic bone, but as they approach the acetabulum they run in complex patterns and make some singular points. 3) Around the acetabulum the principal stress lines of one group run in concentric circles and those of the other group radiate in all directions from the center of the acetabulum at the upper half of the dome which supports the load. The stress here was 5 to 6 times greater than in the lower half of the dome. 4) The acetabulum is stretched vertically and deformed into an oval shape. The horse shoe-shaped articular facet is deformed as both beaks approach each other. 5) As for the slices of the pelvic ring the normal acetabulum tends to be obviously deformed as it holds or embraces the femoral head. As a result of this deformity the stability between the acetabulum and the head increases. On the other hand the dysplastic acetabulum shows none of those phenomena. 6) The iliac bone of the pelvic ring is deformed into the "S" shape and the pubic ramus the "C" shape, the "S" shape, or the "Z" shape depending on the limb position. The pelvic ring tends to be deformed into a heart shape during abduction.

The question concerning reusability of the Hoffmann-Vidal frame has been widely discussed, but no definite recommendation can be made on scientific data. The present study was designed to investigate the change of frame stiffness and fatigue life of the components in a Hoffmann-Vidal quadrilateral fixator. Failures were found at the base of the pin fixation bracket rod. They can be classified into 3 types: complete rod fracture, incomplete rod fracture and loosening of the rod. Only complete fractures of the rod caused a significant reduction of frame stiffness. Strength and loosening torque were proportional to the initial tightening torque for both the universal ball joint and articulation coupling. The mean reduction of screw fixation strength was 16% after 2.5 million cycles. As a result of repeated tightening, two retaining screws from three universal ball joints were severely deformed and the threads flattened. Two fixation screws on the pin bracket and two square-headed screws on the adjustable connecting rods fractured at the 5th to 6th tightening sequence. Significant wear debris were observed during repeated tightening of the articulation coupling. No gross material defects were observed on the fracture surfaces of the failed components. The Hoffmann-Vidal external fixation apparatus may be safely used for four to five sequential applications provided that all critical components be carefully inspected and the fixation screws replaced after each application. The screws should be tightened appropriately using only the T-wrench in order to prevent overloading. These screws should be retightened periodically to maintain incorporated to minimize the screw and rod fractures and to avoid the wear problem after repeated tightening of the screws.