Nihon Seikeigeka Gakkai zasshi最新文献

Both the cancellous and the cortical envelopes of the vertebral bone of osteopenic rats were histomorphometrically evaluated to elucidate the effect of an intermittent administration of h-PTH (1-34) on bone remodeling. Seven-eight-month-old female Wistar rats were used, and osteopenia was produced by ovariectomy, by prednisolone administration, or by streptozotocin-induced diabetes mellitus. The rats were divided into 10 groups; as base line control rats, vehicle administered rats, and h-PTH administered rats for each of the three kinds of osteopenia, and sham operated rats. Vehicle or h-PTH was administered subcutaneously six times a week from the 9th to the 12th week of the experiment. The dosage of h-PTH was 6.0 micrograms/kg. Ovariectomy developed a high turn-over osteopenia, and prednisolone administration and diabetes mellitus caused a low turn-over osteopenia. All 3 kinds of osteopenia showed similar changes in histomorphometric parameters after h-PTH treatment. In the cancellous envelope, the bone volume increased significantly in all groups. The trabecular thickness, osteoid surface, mineralizing surface, mineral apposition rate, and the bone formation rate increased in all groups after the treatment with h-PTH. The eroded surface significantly decreased except in the diabetes mellitus rats. In the endocortical envelope, the osteoid surface, mineralizing surface and the mineral apposition rate increased in all groups. The eroded surface significantly decreased in all groups after the treatment with h-PTH. The cortical thickness significantly increased except in the ovariectomized rats. The results of the present study suggested that an intermittent administration of h-PTH stimulated bone formation without increasing bone resorption in all three kinds of osteopenia induced by ovariectomy, corticosteroid, or diabetes mellitus.

Serum and urine chemical analyses were combined with a bone histomorphometrical study of rat metaphyses to evaluate the osteogenetic effect of intermittent administration of human parathyroid hormone (h-PTH) on steroid-induced osteopenia. Seven-month-old female Wistar rats were divided into the following 4 groups: (1) a control group: age-matched and untreated; (2) a baseline control group (BL group): given 2.5 mg/kg prednisolone subcutaneously 6 times/week for 8 weeks, at the end of which the animals were sacrificed; (3) a PTH group: in the 9th week of continuous steroid administration, 6.0 micrograms/kg h-PTH was added to the regimen; and the animals were sacrificed in the 12th week; (4) a vehicle group, as a control for the h-PTH group: only the vehicle was administered instead of PTH. At the necropsy at the end of the experiment, both tibias were collected. The undecalcified sections were stained by Villanueva bone stain and labelled with tetracycline, and the decalcified sections were stained by TRAP, and examined histomorphometrically. Serum Ca and P were not changed by any treatment. Serum 1,25 (OH)2D3 values were significantly increased in rats treated with h-PTH. There was no significant change in urinary Ca, P, or hydroxyproline excretion in any group. Histomorphometrically, the parameters related to bone formation--osteoid surface, mineralized surface and bone formation rate--were all reduced in the BL group and in the vehicle group. The bone volume was significantly lower in these group than in controls. The PTH group, on the other hand, showed increases in the osteoid surface, mineral apposition rate, and bone formation rate and the bone volume was significantly higher than in controls. The PTH group showed no increases in the osteoclast number or in the osteoclast surface. These results suggested that intermittent administration of h-PTH activated bone formation only, and increased bone volume.

A large variation in the shape of the medial epicondyle is encountered. This study was performed to investigate any role of the shape of medial humeral epicondyle in the etiology of osteoarthritis in the elbow, which can lead to cubital tunnel syndrome. A total of 71 humerus from 36 cadaveric specimens (mean age 75, ranging from 52 to 93) were used to study the morphological characterization of the medial humeral epicondyle. The specimens were divided into four types according to the index of medial epicondylar breadth and medial epicondylar length. A correlation was found between the angle of inclination of the sulcus nervi ulnaris and osteophyte formation in the medial epicondyle. This finding suggested that Type 2 (wider type) and 3 (longer type) might each contribute to the onset of osteoarthritis, resulting in cubital tunnel syndrome. However, we found some cases of Type 1 (wider and longer type) with a large angle and only minor osteophyte formation, suggesting that a large inclination angle of the sulcus nervi ulnaris alone was not an independent factor in osteophyte formation. Moreover from our results of measuring the distance between the tip of the medial epicondyle and the medial edge of the anterior medial collateral ligament origin, we concluded that medial epicondylectomy (King's method) without damaging this ligament should be performed at a point approximately 20% of the overall width of the medial epicondyle from the tip of the medial epicondyle.

We have investigated the utility of transcranial magnetic stimulation for spinal cord monitoring, experimentally in dog. Experiment 1. Spinal cord potentials evoked by transcranial magnetic stimulation (TCMS) were recorded in the epidural space, using a bipolar mapping spinal electrode, and compared with potentials by transcranial electrical stimulation (TCES). Experiment 2. The effect of lateral compression on the spinal cord was observed, recording from 3 bipolar electrodes attached to the bilateral and dorsal midline epidural space. Experiment 3. The potentials evoked by TCMS were compared with the afferent potentials evoked by spinal electrical stimulation after lateral compression of the spinal cord. Efferent spinal cord potentials evoked by TCMS consisted of a 1 st component of high amplitude and short latency and a later polyphasic component with prolonged latency. The 1 st component was stable, and not affected by intravenous anesthesia. The potentials evoked by TCMS were similar to the potentials evoked by mild TCES, and the mean latency of the 1 st component by TCMS was very similar to that by mild TCES. After releasing the lateral compression, the amplitude recorded from the contralateral side of the spinal cord showed better recovery than that from the compression side. In experiment 3, for both potentials after good recovery, the latency was almost completely normalized, but the amplitude gradually decreased after two days. When there was relatively good recovery in the potentials by magnetic stimulation, the hind limbs resumed normal function. However when there was poor recovery in the potentials, the hind limbs showed a poor functional recovery. From these findings, we concluded that the potentials evoked by TCMS seem to reflect the function of the posterolateral portion of the spinal cord. These potentials were therefore a good indicator for monitoring the motor function of the spinal cord.

The anatomy of the interosseous membrane (IOM) was studied in 117 forearms from sixty cadavers (average age; 73 years old) for the purpose of optimizing the osteotomy portion in forearm lengthening, or in osteotomy for an old Monteggia fracture. The morphological anatomy of the interosseous membrane, and its relation anatomically to the surrounding structures were investigated. A total of 68.4% of the IOM was classified as Type 1a or 1 b, in which one cord-like portion was observed. The accessory cord-like portion was found in 57.8% of the forearms. The cord-like portion was attached at a position of 39.6-54.8% from the distal end of the radial bone and at 21.9-42.1% from the distal end of the ulnar bone (average rate per forearm length). The accessory cord-like portion was attached at a position of 48.9-53.3% from the distal end of the radial bone and at 56.9-61.8% from the distal end of the ulnar bone. From there results, the optimal portion for osteotomy in forearm lengthening and in old Monteggia fracture was determined to minimize the anatomical and functional damage to the forearm.

Unlabelled: The present study was designed to investigate the possible clinical application of hypertonic saline (HS), phenol in glycerin (PHG) and osmic acid (OSA) for intradiscal therapy.

Materials & methods: HS in several concentrations, 10% PHG and 4% OSA were separately injected into the lumbar intervertebral discs of 60 Japanese white rabbits. Additionally, these substances were placed directly on the dura of the spinal cord of 48 guinea pigs. The animals were sacrificed periodically and were submitted to histological examination using light microscopy.

Results: HS caused localized necrosis of the nucleus pulposus cells in a concentration-related fashion. Some discs decreased their height. With time, all the discs generally regained their normal histology. Following administration of 10% PHG, the area of necrosis of the nucleus pulposus cells was more extensive than that by HS, but the regenerative or reparative reaction was not so brisk. Examination of the discs treated with 4% OSA demonstrated severe changes in the nucleus pulposus and the inner annulus fibrosus with resultant disc-space narrowing. The reparative tissue seen after injection of OSA was fibrocartilage in nature. No histological change was seen in the surrounding tissue including the neural tissue following administration of any of the substances.

Discussion: Chymopapain is the substance most frequently used for clinical chemonucleolysis. The major clinical complication with chymopapain has been anaphylaxis. The present substances have been used in other clinical applications without reports of anaphylaxis. In this report, HS was shown to hold the potential for reducing intradiscal pressure without induction of scar tissue or significant loss of disc function. PHG and OSA caused considerable but circumscribed histological damage to the disc tissue, but had no such effect on the neural tissues. These data suggested that HS, PHG and OSA may have clinical applications as agents in intradiscal therapy.

We have evaluated changes in bone volume, bone marrow tissue, and the density of osteoclasts caused by intermittent administration of human parathyroid hormone (h-PTH) to experimental osteopenia induced in rat by ovariectomy (OVX) or by diabetes mellitus (use of streptozotocin: STZ). A bone and marrow histomorphometric study was performed on HE-stained and tartrate-resistant acid phosphatase-stained (TRAP-stain) tibial bone sections. Retired Wistar rats, 7-8 months old, were used. They were separated into the following nine groups; sham operated, base line control, vehicle administered, low or high dosage h-PTH administered OVX and STZ groups. 6.0 micrograms/kg/day of h-PTH (1-34) as a low dosage, and 60.0 micrograms/kg/day as a high dosage, was injected subcutaneously six times a week for 4 weeks from 9 weeks after ovariectomy or injection of streptozotocin. The bone volume decreased in both the OVX and STZ groups, while the fat tissue volume increased in the bone marrow in the OVX groups to compensate for this decrease, and the foamy marrow tissue volume increased in the STZ groups. The bone volume and the mean trabecular thickness in both the OVX and STZ groups increased by the intermittent administration of h-PTH, while the TRAP positive trabecular surface and the number of osteoclasts decreased. There was no significantly different bone changes between the low and high dosage groups. It is thought that the TRAP positive trabecular surface represented not only the active bone resorption surface but also the related contiguous uneroded surface.

An experimental study was performed using the canine sciatic nerve in order to compare the efficacies of a vascularized trunk graft (VTG), a free trunk graft (FTG), a vascularized cable graft (VCG), a free cable graft (FCG) and a two stage procedure (TSP) for the repair of a peripheral nerve defect. Both a 4 cm, and a 5 cm nerve defect was repaired using each method, and also a 6 cm defect, using VCG and FCG. After 24 weeks, the intraneural blood flow (IBF) was measured in the 4 cm defect group, and the recovery of nerve regeneration and muscle reinnervation were evaluated by motor nerve conduction velocity, wet muscle weight, and histological examinations of the nerve and the muscles. VTG and VCG both demonstrated superior IBF. The IBF after TSP was less than after VTG and VCG but greater than after FTG and FCG. In the 4 cm defect group, VTG showed the most favorable recovery in both the axonal regeneration and muscle reinnervation and was followed by VCG. Although the recovery after FTG, FCG and TSP appeared to be worse than after VTG and VCG, there was no significant difference. In the 5 cm defect group, VTG showed the most favorable recovery followed by VCG and FCG. For axonal regeneration, FTG was significantly worse than VTG, VCG and FCG. TSP was worst within the 5 cm defect group for muscular reinnervation, although it showed somewhat better axonal regeneration than FTG. In the 6 cm defect group, no significant difference was found between VCG and FCG for the axonal regeneration. Clinically, TSP is used for repairing a short nerve defect just beyond the critical distance that cannot be overcome by a primary end-to-end suture. Nerve grafting, other than FTG, appeared to be the most reliable method of bridging a long nerve defect, and FCG might be the most practical method.

An experimental model was prepared to investigate the process of inflammation in pyogenic spondylitis. Forty-seven mongrel dogs were used, involving 24 mature and 23 immature dogs. Under intravenous pentobarbital anaesthesia, the lumbar vertebral bodies were approached posterolaterally and inoculated using a small piece of gauze soaked in a staphylococcus aureus suspension. Roentgenographic and histological examinations were regularly performed for 24 weeks after the inoculation. Histologically, acute inflammation started within 1 or 2 weeks, and subsided by 5 or 6 weeks in both the mature and immature dogs. In 55% of the dogs, the inflammation was confined within the vertebral body, in 10% it invaded into the intervertebral disc, and in 35% inflammation invaded into the anterior longitudinal ligament. In the immature dogs, thickening of the trabeculae and the anterior cortex was observed around the inflammatory focus more often than in the mature dogs. The epiphyseal line acted as a barrier against invasion by the inflammation in the immature dogs. However, direct invasion of the inflammatory process into the disc could have occurred through the vascular buds which were the terminal branches of the metaphyseal artery close to the disc in both the mature and immature dogs. In contrast to the results reported by Ohno who inoculated the lumbar discs of mongrel dogs with staphylococcus aureus, in the present study, the disc space remained intact and was replaced by fibrous tissue. Consequently, it was concluded that pyogenic spondylitis should be defined as a different clinical entity from discitis.

We investigated the co-relationships of the granule size of hydroxyapatite with the amount of new bone formation and with mechanical properties at the bone defect site filled with hydroxyapatite granules. In this experimental study, cylindrical bone defects 6.4 mm in diameter and about 1 cm in depth were prepared in the bilateral femoral condyles and in the tibial condyles of large albino rabbits (body weight 5.1-7.3 kg), filled with three types of hydroxyapatite granules 0.3-0.6 mm, 0.6-1.0 mm, and 1.0-2.0 mm in diameter, and examined after 2, 4, and 8 weeks after sacrificing the animals. Two animals (4 limbs) each were examined for the same granule size and the same period after filling. Undecalcified sections of the tibia at the defect site were examined histologically, and the volume and surface of hydroxyapatite, the volume of new bone, the surface of the new bone in contact with hydroxyapatite, and the percent of this surface relative to the entire surface of hydroxyapatite were determined. Columnar specimens 6.0 mm in diameter and 5.0 mm in length were prepared from the defect sites of the femur, compressed at a deformation rate of 2.4 mm/min, and the failure stress, stiffness, and energy absorption were calculated from the load-deformation curve. The normal cancellous bone from 2 unoperated animals (4 limbs) and bone defect sites not filled with hydroxyapatite granules of 2 animals (4 limbs) were examined as controls. A greater amount of new bone was formed as the granule size was smaller. After 8 weeks, the failure stress and energy absorption were higher as the granule size was smaller, and the mechanical properties of the bone defect sites filled with 0.3-0.6 mm granules were similar to those of normal cancellous bone.