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Biomedical subjects

O O Oni

Publications and source records attributed to O O Oni.

At least 19 recordsLinked to original sources
PubMed2000

Proto-oncogene expression during fracture repair.

The possibility that proto-oncogenes play a role in fracture repair has been investigated in this study. Closed fractures were created in the tibiae of NZW rabbits and treated with a plaster cast. At intervals of 1 and 2 weeks, sections of the fracture callus were obtained and stained using an immunocytochemical technique which localised c-myc and c-jun. Osteogenic cells of the periosteum, endosteum, Haversian canal and new bone trabeculae expressed proto-oncogenes while hypertrophic chondrocytes were generally immunoreactive negative. The results suggest that proto-oncogene expression may be involved in post-fracture osteogenesis but not in the chondrogenic processes which precede endochondral bone formation. This could be used as a tool for diagnosing slow healing in the early stages of fracture repair.

Animals↗
PubMed1999

The microvascular anatomy of the physis as revealed by osteomedullography and correlated histology.

The microvascular anatomy of the physis has been demonstrated by perfusing the epiphysis with an aqueous suspension of barium sulfate. Plain radiographs taken immediately after perfusion reveal escape of dye into the metaphysis and into the system veins. Microradiographs reveal a labyrinthine network of channels on either side of the physis. The density of these channels is much greater than the density of vessels observed in histologic sections.

Adolescent↗
PubMed1998

The mechanical 'quality' of osteophytes.

Intrinsic mechanical properties of osteophytes have been compared with those of normal articular cartilage by obtaining force-indentation curves. The cartilage of the osteophyte was found to be thinner than articular cartilage. The mean stiffness of osteophytes was 272.8 (+/- 78.8) N/mm and the mean stiffness of articular cartilage was 1412 (+/- 917.3) N/mm.

Aged↗
PubMed1998

The biomechanical properties of fascia lata grafts: a preliminary study.

The mechanical properties of fascia lata in the form of a sheet and as a tubulised structure have been determined. The stiffness of the sheet was 3.3 +/- 0.58 N/mm and the stiffness of the tube was 6.2 +/- 1.06 N/mm. The ultimate tensile strength of the tube was 35.7 +/- 14.1 N.

Biomechanical Phenomena↗
PubMed1998

The effect of knee flexion angle on knee stiffness values obtained using the Leicester arthrometer.

Knee stiffness was measured in 20 patients with a unilateral ACL-deficiency at 0 degree, 20 degrees and 65 degrees of knee flexion, respectively. The reduction in stiffness when the ACL deficient knee was compared with the normal contralateral knee was 46, 39 and 39%. The differences between these values were not statistically significant. The data raise the possibility that the angle at which instrumented measurement is made may not be critical provided the deficient knee is compared with the normal knee at the same angle.

Adult↗
PubMed1997

Osteocalcin expression in the groove of Ranvier of the rabbit growth plate.

The biology of the growth plates of rabbits of different ages was studied using an immunocytochemical technique which localized osteocalcin. Immunoreactivity was observed in the cells of the groove of Ranvier. Other findings suggest that the groove is a separate structure from the cartilaginous physis and is the terminal end of the diaphysis/periosteum complex.

Animals↗
PubMed1997

The development of the growth plate after birth: a study by osteocalcin immunocytochemistry.

The post natal development of the growth plate was studied in the rabbit lower limb using an immunocytochemical technique which localized osteocalcin in situ. At birth, there is poor columnar organization of the physis and bone is not produced. Instead the predominant activity is cartilage remodelling. The columnar architecture develops later when endochondral ossification is also observed.

Aging↗
PubMed1997

MRI findings in simultaneous bilateral meniscal lesions.

This study investigates concurrent lesions of the knee that may be associated with bilateral simultaneous meniscal lesions. The MRI images of the knees of 22 patients with this condition were examined in detail. The results suggest a degenerative cause.

Adult↗
PubMed1997

The early stages of the repair of adult human diaphyseal fractures.

Periosteum was obtained within 10 days of injury from the site of 17 adult tibial diaphyseal fractures during internal fixation. Osteogenic cells, non-osteogenic cells and vascular elements were identified in situ using a variety of techniques. In all cases, the periosteum was thickened with randomly distributed plaques of cartilage and bone. Cells covering newly formed bone trabeculae expressed osteocalcin. Lectin-binding revealed high vascularity. Few mast cells were observed. Macrophages and acid phosphatase positive cells, some multinucleate, were observed in abundance. These findings suggest that the repair of the adult human diaphyseal fracture is similar to that of experimental fractures in rapidity of onset, high vascularity and in bone and cartilage formation. They differ in the fact that chondrogenesis and osteogenesis appear to be simultaneous in human fractures but sequential in experimental fractures. The paucity of mast cells suggests that they probably play no significant role in the repair of the human fractures.

Acid Phosphatase↗
PubMed1996

A comparison of isokinetics and muscle strength ratios following intra-articular and extra-articular reconstructions of the anterior cruciate ligament.

A prospective, randomized clinical trial was conducted to compare an intra-articular with an extra-articular reconstruction of the anterior cruciate ligament. Isokinetic muscle testing was carried out 6 months to 2 years following operation using the Biodex isokinetic dynamometer. The extra-articular procedure resulted in a lower deficit for the peak quadriceps and hamstring torques and the range of motion.

Adult↗
PubMed1995

A non-union model of the rabbit tibial diaphysis.

A consistently reproducible non-union model has been created in the adult rabbit tibial diaphysis. After making an osteotomy, the marrow was removed, the periosteum was excised and a silastic sheath was wrapped around the shaft. The fracture cleft was invaded by a non osteogenic fibrous tissue following the removal of the sheath after an interval of 4 weeks.

Animals↗
PubMed1995

Monitoring fracture healing with strain gauges: the effect on strain values of strain gauge location on the pin circumference.

In an attempt to establish some principles for the use of strain gauges in monitoring fracture healing, four strain gauges were fastened onto the most proximal pin of a Shearer external fixator applied to a hardwood fracture model. Compression and bending loads were applied and the strain data were obtained. The results show that the location of the strain gauge on the circumference of the pin has a significant effect on strain values.

Bone Nails↗