Biomedical subjects

C Hamanishi

Publications and source records attributed to C Hamanishi.

At least 37 records · Page 2Linked to original sources

PubMed1996

A self-setting TTCP-DCPD apatite cement for release of vancomycin.

Vancomycin (VCM), a methiciline-cefem resistant Staphylococcus aureus (MRSA)-specific antibiotic, was incorporated in a self-setting tetracalcium phosphate (TTCP)-dicalcium phosphate dihydrate (DCPD) apatite cement that hardened isothermally into a hydroxyapatite (HAP) phase with crystallinity similar to that of host bone. Effective release of VCM into PBS lasted for 2 weeks from cements containing 1% VCM and for longer than 9 weeks from cements containing 5% VCM. The rate of release of VCM differed between cements with different crystallinities as well as between the two dissolution media, PBS and simulated body fluid. Mean concentration of VCM in the bone marrow tissue released from cements containing 5% VCM was 20 times the minimum inhibitory concentration 3 weeks after implantation in bone. Direct contact with new bone was observed with the cements containing 1% VCM. Slow delivery of VCM from a self-setting TTCP-DCPD apatite cement with low crystallinity could be used to treat MRSA osteomyelitis.

Animals↗

PubMed1996

Alpha and epsilon isozymes of protein kinase C in the chondrocytes in normal and early osteoarthritic articular cartilage.

Protein kinase C (PKC) isozymes (alpha, beta I, beta II, gamma and, epsilon-PKC) were examined immunocytochemically in control and mechanically induced osteoarthritic knee joints in rats. beta I, beta II, and gamma PKC-positive cells were not observed in sham-operated or osteoarthritic knee joints. alpha-PKC, which was observed only in the cells in the subchondral bony layer in the controls, appeared in the chondrocytes in the superficial and columnar layers of the osteoarthritic knees. epsilon-PKC was observed in the control chondrocytes in the superficial portion of the columnar layers. In early osteoarthritic joints, however, epsilon-PKC-positive chondrocytes disappeared from the superficial portion of columnar layer and increased in number in the middle columnar layers. The appearance and changes in distribution of these PKC-positive chondrocytes, either under normal or osteoarthritic conditions, have not been reported previously. The role of the redistribution of PKC isozymes is still unclear as to whether they are involved in initiating destructive processes, reflect attempted cell repair mechanisms, or are simply a consequence of the cellular changes.

Animals↗

PubMed1996

Protein kinase C activator inhibits progression of osteoarthritis induced in rabbit knee joints.

To study the role of protein kinase C (PKC) in cartilage tissue in osteoarthritis, experimental osteoarthritis was induced in the knee joints of rabbits by resection of the anterior cruciate ligament (ACL). At 4 weeks after the operation, osteoarthritic changes varying from surface irregularities and cleft formation to loss of the tangential layer were observed, and cloning or hypocellularity of the chondrocytes was observed mainly in the transitional and radial layers. The PKC activator 12-O-tetradecanoyl-phorbol-13-acetate (TPA) or non-PKC-activating phorbol ester 4 alpha-phorbol-12,13-didecanate (PDD) was administered intraarticularly once a week from the day of the operation for 3 weeks. Histologic evaluation with a rating scale was carried out. In the TPA-administered group, cartilage structures were preserved almost completely, and score of the cartilage lesion was significantly less than that in animals administered PDD or in nonadministered controls. A chondroprotective role of PKC under mechanical stress was suggested.

Animals↗

PubMed1996

Bilateral multilevel laminectomy with or without posterolateral fusion for cervical spondylotic myelopathy: relationship to type of onset and time until operation.

The authors retrospectively evaluated the relationship of several preoperative factors in 69 patients who had myelopathy due to multilevel cervical spondylosis without ossification of the posterior longitudinal ligament treated with Kirita's bilateral wide laminectomy. In 34 patients with focal instability or malalignments, posterolateral fusion was also combined. The clinical results at an average follow-up period of 3.5 years (range 1-10 years) after operation in the groups that had and had not undergone fusion were equally satisfactory, and preoperative focal instability was believed to be the sole useful indication for adding posterolateral fusion. The patients were classified in three groups according to the acuteness of the onset. The type of onset and time until operation were found to be the factors most strongly related to prognosis, and clinical outcome was correlated with the duration after onset when plotted as days in the acute, months in the subacute, and years in the insidious onset groups. Wide laminectomy with or without posterolateral fusion is a simple operation that is recommended, provided that it is performed early enough according to the type of onset.

Aged↗

PubMed1995

Ossification of the posterior longitudinal ligament. Autosomal recessive trait.

STUDY DESIGN: This study analyzed the mode of inheritance of ossification of the posterior longitudinal ligament (OPLL) from the pedigree of a family. OBJECTIVES: The results were correlated to provide a new mode of inheritance of OPLL. SUMMARY OF BACKGROUND DATA: Although a nation-wide multicenter survey of OPLL has been carried out in 347 subjects and 1030 relatives in Japan since 1981, no parental consanguinity has been reported. METHODS: In the family, three siblings and one other member of a family underwent operations for OPLL in our department, and the clinical information regarding other family members was obtained from interviews with these four patients or relatives. RESULTS: The parents of three affected siblings and another unaffected sister were first cousins, and the father was suspected to be affected as well. CONCLUSION: Transmission of OPLL as an autosomal recessive trait in this family, which has not been reported, is suspected; although, the possibility that it is a dominant trait can not be excluded.

Aged↗

PubMed1995

Bone mineral density changes in distracted callus stimulated by pulsed direct electrical current.

To evaluate the effect of application of pulsed direct current electrical stimulation to callus tissue, a 1-cm bone-lengthening model using an external lengthener was applied to rabbit tibia. Twenty-microampere pulsed direct current was applied 12 hours daily from the day of osteotomy until 40 days after the completion of lengthening. The area, bone mineral content, and bone mineral density of the distracted callus and of the proximal and distal segments of the tibia were evaluated using dual-energy xray absorptiometry. The absolute and relative values of bone mineral density of the electrically stimulated callus were significantly increased as compared with those in the control group. Pulsed direct current electrical stimulation may be indicated in bone lengthening to stimulate the poorly mineralized callus, and may shorten the overall time course of leg lengthening.

Absorptiometry, Photon↗

PubMed1994

Schmorl's nodes on magnetic resonance imaging. Their incidence and clinical relevance.

Schmorl's nodes were observed in 76 (19%) of 400 patients with lumbar symptoms, and in 10 (9.4%) of 106 control patients. In the lumbar group, the highest incidence was 57%, in the second decade of life, and the lowest was 5%, in the sixth decade of life. Using MRI, among both groups, a total number of 218 Schmorl's nodes were observed at 170 disc levels; however, plain x-ray revealed only 73 (33%) of them. There were associated posterior disc herniations at 39 disc levels in 30 cases (39%), most of which were at the L4/5 level. The ratio of the cases showing only Schmorl's nodes to those with associated disc herniations at the same level increased markedly with age. Three of the four teenaged patients with multiple Schmorl's nodes at four or more disc levels had a history of hard sports. Schmorl's nodes, therefore, appear to be a type of vertical disc herniation, and to be an important pathognomonic condition, especially for young people.

Adolescent↗

PubMed1994

Turned head--adducted hip--truncal curvature syndrome.

One hundred and eight neonates and infants who showed the clinical triad of a head turned to one side, adduction contracture of the hip joint on the occipital side of the turned head, and truncal curvature, which we named TAC syndrome, were studied. These cases included seven with congenital and five with late infantile dislocations of the hip joint and 14 who developed muscular torticollis. Forty one were among 7103 neonates examined by one of the authors. An epidemiological analysis confirmed the aetiology of the syndrome to be environmental. The side to which the head was turned and that of the adducted hip contracture showed a high correlation with the side of the maternal spine on which the fetus had been lying. TAC syndrome is an important asymmetrical deformity that should be kept in mind during neonatal examination, and may be aetiologically related to the unilateral dislocation of the hip joint, torticollis, and infantile scoliosis which develop after a vertex presentation.

Female↗

PubMed1994

Maturation of the distracted callus. Sonographic observations in rabbits applied to patients.

We measured the corticalization of lengthened callus in rabbits and humans with ultrasonography. In rabbits, the echo reflection value was correlated with the strength of the callus; when this value exceeded 70 percent of that of the normal cortex, the callus strength was equal to that of the normal tibia. Clinically, the lengtheners in 8 patients were removed when the echo value exceeded 70 percent, regardless of attained lengthening. Neither fracture nor collapse of the callus ensued. The time required from the end of the lengthening process until the echo reflection value reached 70 percent was correlated with the patients' age.

Adolescent↗

PubMed1994

Cross-sectional area of the stenotic lumbar dural tube measured from the transverse views of magnetic resonance imaging.

The cross-sectional area of the lumbar dural tube was calculated from transverse-slice lumbosacral magnetic resonance images (MRI) using the simple geometric formulas and computerized digitizer in 51 patients with low-back pain only, 79 with mainly radicular symptoms, and 53 with intermittent claudication, and in 39 controls with confirmed symptomatic lesions at a nonlumbar level or of a nonspinal organ. Findings suggesting developmental narrowing of the spinal canal were found not only in the intermittent claudication group, but also in the radicular pain group. Cross-sectional area of < 100 mm2 at more than two of three (L2/3, L3/4, and L4/5) intervertebral levels was highly associated with the presence of intermittent claudication. The cross-sectional area value obtained with the simplified geometric formulas was highly correlated with that calculated with the digitizer, indicating that this simple method can be used with MRI in outpatient clinics for the rapid determination of the most stenotic portion of the dural tube.

Adolescent↗

PubMed1994

Lengthened callus activated by axial shortening. Histological and cytomorphometrical analysis.

The tibiae of rabbits were lengthened by 10 mm in 2 weeks, then approximately one half of the limbs were shortened by 2 mm in 3 days, and left for 3 days. Histological and cytomorphometrical findings of the calluses in both groups were compared. In the shortened callus, marked histologic changes were observed in the central mesenchymal cell layer where the number of the osteoblasts increased 4 fold, and massive primitive fiber bone formation took place. Cartilaginous tissue did not seem to respond to the axial shortening stress.

Animals↗

PubMed1994

Bone mineral density of lengthened rabbit tibia is enhanced by transplantation of fresh autologous bone marrow cells. An experimental study using dual X-ray absorptiometry.

Autologous bone marrow cells were transplanted into the primitive callus in the lengthened tibia in young and adult rabbits. Bone mineral density (BMD) in the lengthened callus was evaluated using dual-energy x-ray absorptiometry. Basal BMD in the lengthened callus in the young rabbits was higher than that in the adult rabbits (p < 0.001). Transplantation of fresh suspended bone marrow cells increased the BMD in the young (p < 0.01) and adult (p < 0.001) groups. In the young rabbits, lysate of the bone marrow cells decreased the BMD (p < 0.005). Transplantation of cultured colony-forming cells or of separated multinucleated marrow cells did not increase the BMD. The authors' study indicates that the osteogenesis of the lengthened rabbit tibia is enhanced by transplantation of fresh autologous bone marrow cells.

Absorptiometry, Photon↗

PubMed1993

Dorsal root ganglia in the lumbosacral region observed from the axial views of MRI.

A total number of 442 dorsal root ganglia (DRG) in the lumbosacral region of 104 patients were depicted from the axial views of MRI and their localities were classified as intraspinal, intraforaminal, or extraforaminal types. The DRG of the more distal nerve root were located more medially. Asymmetrical locations were observed in 25 pairs of DRG among 221, of which the symptomatic side tended to locate either medially or proximally compared with those on the asymptomatic side.

Adult↗

PubMed1993

Acrodysostosis associated with spinal canal stenosis.

An adult case of acrodysostosis with striking lumbar spinal canal stenosis is reported. She complained of numbness on the right arm, intermittent claudication with numbness on both legs and pain and weakness on the left leg. Although the reduced lumbar interpedicular distance has been reported, no adult case with neurologic symptoms has been reported.

Adult↗

PubMed1993

Progressive scoliosis associated with lateral gaze palsy.

Two cases with progressive scoliosis and lateral gaze palsy were reported. The preoculomotor centers, which are connected by the fasciculus longitudinalis medialis in the brain stem, are deemed to be the common focus for progressive scoliosis and associated visual dysfunction.

Adolescent↗

PubMed1992

Classification of the callus in limb lengthening. Radiographic study of 35 limbs.

35 calluses formed during limb lengthening were classified radiographically into 6 types: external, straight, attenuated, opposite, pillar, and agenetic. The healing indexes correlated well to the intrinsic periosteal and endosteal conditions of each type. This classification enabled us to estimate the intrinsic conditions, predict the healing index, control the daily lengthening speed, and decide to apply early augmentation of the callus.

Adolescent↗

PubMed1992

The Spitzy shelf operation for the dysplastic hip. Retrospective 10 (5-25) year study of 124 cases.

Since 1961 we have used the Spitzy shelf operation combined with a vertical flap osteotomy of the outer cortex of the ilium for early arthrosis secondary to acetabular dysplasia, subluxation, and dislocation. In 124 hips, followed for 10 (5-25) years, clinical improvement was maintained in 67/85 of patients who were operated on under the age of 30 and in 22/39 of patients treated after 30. However, less than half of the hips in the younger group and only one out of ten in the older group were symptom-free.

Acetabulum↗

PubMed1992

Early physeal closure after femoral chondrodiatasis. Loss of length gain in 5 cases.

Chondrodiatasis (symmetric physeal distraction) was carried out in 5 patients with short femora because of congenital dislocations of the hip joint (4 patients) and congenital shortening (1 patient). In all but 1 case the physis closed shortly after lengthening, and loss of gained length or further shortening ensued in all of them. Chondrodiatasis should be avoided in the subjects under 13 years of age with mild leg-length discrepancies.

Adolescent↗