Biomedical subjects
Otto Chan
Publications and source records attributed to Otto Chan.
Helical computed tomographic scanning for the evaluation of the cervical spine in the unconscious, intubated trauma patient.
BACKGROUND: Assessment of the spine in the unconscious trauma patient is limited by an inadequate clinical examination. The potential of a missed unstable disc or ligamentous injury results in many patients remaining immobilized in critical care units for prolonged periods. METHODS: This study evaluates helical computed tomographic (CT) scanning of the whole cervical spine as part of a spinal assessment and clearance protocol. RESULTS: Four hundred thirty-seven unconscious, intubated, blunt trauma patients underwent CT scanning of the cervical spine. Sixty-one patients had a cervical spine injury and 31 (7.0%) were unstable. CT scanning had a sensitivity of 98.1%, a specificity of 98.8%, and a negative predictive value of 99.7%. There were no missed unstable injuries. In contrast, an adequate lateral cervical spine film detected only 24 injuries (14 unstable), with a sensitivity of 53.3%. CONCLUSION: Helical CT scanning of the cervical spine allows rapid and safe evaluation of the cervical spine in the unconscious, intubated trauma patient.
Disease modifying and anti-nociceptive effects of the bisphosphonate, zoledronic acid in a model of bone cancer pain.
Inoculation of syngeneic MRMT-1 mammary tumour cells into one tibia of female rats produced tumour growth within the bone associated with a reduction in bone mineral density (BMD) and bone mineral content (BMC), severe radiological signs of bone destruction, together with the development of behavioural mechanical allodynia and hyperalgesia. Histological and radiological examination showed that chronic treatment with the bisphosphonate, zoledronic acid (30 microg/kg, s.c.), for 19 days significantly inhibited tumour proliferation and preserved the cortical and trabecular bone structure. In addition, BMD and BMC were preserved and a dramatic reduction of tartrate resistant acid phosphatase-positive polykaryocytes (osteoclasts) was observed. In behavioural tests, chronic treatment with zoledronic acid but not the significantly less effective bisphosphonate, pamidronate, or the selective COX-2 inhibitor, celebrex, attenuated mechanical allodynia and hyperalgesia in the affected hind paw. Zoledronic acid also attenuated mechanical hyperalgesia associated with chronic peripheral neuropathy and inflammation in the rat. In contrast, pamidronate or clodronate did not have any anti-hyperalgesic effect on mechanical hyperalgesia in the neuropathic and inflammatory pain models. We conclude that zoledronic acid, in addition to, or independent from, its anti-metastatic and bone preserving therapeutic effects, is an anti-nociceptive agent in a rat model of metastatic cancer pain. This unique property of zoledronic acid amongst the bisphosphonate class of compounds could make this drug a preferred choice for the treatment of painful bone metastases in the clinic.