Koushin Nakamura

Effect of coenzyme Q10 on superoxide production in rats with reperfusion injuries.

We examined the effect of coenzyme Q10 (Co Q10) on superoxide radical (O2-) production in a model of rat reperfusion injury. The chemiluminescence method using a derivative of luciferin was used to quantify O2- production by erythrocytes in the reperfused limb after a period of ischaemia. A total of 20 limbs from Lewis rats were preserved at 4 degrees C in Euro-Collins solution for 72 hours, and were grafted orthotopically to syngeneic rats by a microsurgical technique. In the treated group (n = 10), Co Q10 (10 mg/kg) was injected intraperitoneally into the recipients one hour before reperfusion. In the control group (n = 10), the same dose of solvent was given. To measure the extent of oxidative stress, heparinised blood from the treated and control recipients was collected before, and at 15, 30, and 60 minutes after reperfusion for the measurement of chemiluminescence. O2- production in the Co Q10-treated group was significantly lower than in the control group (p < 0.05). Although these findings suggest that Co Q10 scavenged O2- that was produced in the replanted limbs as a result of ischaemia-reperfusion injury, we should consider other possible mechanisms by which this agent may protect against ischaemia-induced reperfusion injury.

Tibial fractures associated with crush injuries to the soft tissues of the dorsal foot in children

We retrospectively studied 15 children with tibial fractures associated with crush injuries to the soft tissues of the dorsal foot. The fractures, including six open fractures, were united with no complications within an average of 11.1 weeks. Wound closure to treat crush injuries of the dorsal foot was achieved using split- or full-thickness skin grafts in most patients. The outcomes of these grafts were acceptable, and all skin coverage was successful and remained viable with no breakdown. Extensor tendon injuries of the foot sustained by eight patients could not be sutured or repaired due to the nature of the injuries. However, the functional abilities of those injured tendons that could be sutured to surrounding tissues in a neutral position were acceptable, even though two patients had contracture of the toes that was problematic when wearing shoes. To manage crush skin injuries of the dorsal foot, split- or full-thickness skin grafts appear to provide a simple and convenient treatment strategy. In cases associated with extensor tendon injuries, suturing damaged extensor tendons to surrounding tissues represents another useful strategy with acceptable outcomes.

Evaluated of the γ-Ray Radiosterilized Cross-Linked PLLA and PLLA/HA In Vivo

There are still some existing problems that are common to all absorbable materials; 1) It cannot be subjected to radiosterilization, 2) Sufficient strength cannot be maintained until the complete bone union is obtained. To solve these problems, PLLA and PLLA/HA were mixed with cross-bridge supplementary agent, Triallyl Isocyanurate (TAIC). Using these materials in vivo, we created and tested γ-ray radiosterilized absorbable bone fixation materials.