Ki-Tae Lee

Recombinant IGFBP-3 inhibits allergic lung inflammation, VEGF production, and vascular leak in a mouse model of asthma

Vascular endothelial growth factor (VEGF) plays a pro‐inflammatory mediator as well as a vascular permeability factor in bronchial asthma. Insulin‐like growth factor (IGF)‐I is also involved in the inflammatory process associated with bronchial asthma and stimulates VEGF expression. The IGF‐binding proteins (IGFBPs), especially IGFBP‐3, display distinctive properties and can interfere with various biological processes.

Anterior fusion alone compared with combined anterior and posterior fusion for the treatment of degenerative cervical kyphosis

We evaluated the efficacy of anterior fusion alone compared with combined anterior and posterior fusion for the treatment of degenerative cervical kyphosis. Anterior fusion alone was undertaken in 15 patients (group A) and combined anterior and posterior fusion was carried out in a further 15 (group B). The degree and maintenance of the angle of correction, the incidence of graft subsidence, degeneration at adjacent levels and the rate of fusion were assessed radiologically and clinically and the rate of complications recorded. The mean angle of correction in group B was significantly higher than in group A (p = 0.0009). The mean visual analogue scale and the neck disability index in group B was better than in group A (p = 0.043, 0.0006). The mean operation time and the blood loss in B were greater than in group A (p < 0.0001, 0.037). Pseudarthrosis, subsidence of the cage, and problems related to the hardware were more prevalent in group A than in group B (p = 0.034, 0.025, 0.013). Although the combined procedure resulted in a longer operating time and greater blood loss than with anterior fusion alone, our results suggest that for the treatment of degenerative cervical kyphosis the combined approach leads to better maintenance of sagittal alignment, a higher rate of fusion, a lower incidence of complications and a better clinical outcome.

Effects of strontium gallate addition on sintering behavior and electrical conductivity of yttria-doped ceria

The densification behavior and electrical conductivity of Ce0.8Y0.2O1.9 ceramics with strontium gallate concentrations ranging from 0 to 5 mol. % were investigated. The sintered density was found to increase rapidly for concentrations up to 0.5 mol. % Sr2Ga2O5 and then to decrease upon further Sr2Ga2O5 addition. It was possible to obtain dense Ce0.8Y0.2O1.9 ceramics with 95% of the theoretical density using a 0.5 mol. % Sr2Ga2O5-added specimen sintered at 1250°C for 5 h, whereas pure Ce0.8Y0.2O1.9 ceramics needed to be sintered at 1550°C in order to obtain an equivalent theoretical density. The electrical conductivity was measured as a function of the dopant content over the temperature range of 450°C–700°C in air. The conductivity of the 0.5 mol. % Sr2Ga2O5-added specimen showed a maximum value of 4.43 × 10−3Ω−1·cm−1 at 700°C. The addition of Sr2Ga2O5 was found to promote the sintering properties and electrical conductivities of Y2O3-doped CeO2.

Effects of gallia addition on sintering behavior and electrical conductivity of yttria-doped ceria

The densification behavior and electrical conductivity of Ce0.8Y0.2O1.9 ceramics with gallia concentrations ranging from 0 to 5 mol. % were investigated. The sintered density was found to increase with increasing Ga2O3 content up to 1 mol. % and then to decrease upon further Ga2O3 addition. Dense Ce0.8Y0.2O1.9 ceramics with 94% of the theoretical density could be obtained by sintering the milled mixture with 1 mol. % Ga2O3 addition at 1400°C for 5 h. The conductivity of the 1 mol. % Ga2O3-added specimen showed a maximum value of 1.37 × 10−2 Ω−1· cm−1 at 700°C. Pure Ce0.8Y0.2O1.9 ceramics needed to be sintered at 1550°C in order to obtain an equivalent theoretical density and conductivity. The introduction of Ga2O3 doping had a good effect on the sintering properties and electrical conductivities of Y2O3-doped CeO2.

Rectus femoris muscle atrophy and recovery caused by preoperative pretibial traction in femoral shaft fractures-comparison between traction period ☆

BACKGROUND Skeletal traction is performed to temporarily stabilize fracture sites before surgery in patients with femoral fracture. To date, however, there is no study evaluating the difference in the degree of the recovery, of the muscle strength, as well as muscle atrophy following skeletal traction. The purpose of this study was to compare the degree of recovery of rectus femoris muscle strength after surgery in association with muscle atrophy by analyzing the duration of preoperative tibial traction, age and sex in patients with femoral fracture. HYPOTHESIS Rectus femoris muscle atrophy will progress depending on the duration of preoperative tibial traction, age and sex in patients with femoral fracture. PATIENTS AND METHOD Thirty-one patients who underwent preoperative pretibial skeletal traction and intramedullary nailing were divided into two groups according to the traction period: group A (n=12) with a duration of traction of <7 days (mean: 4.08±1.78 days) and group B (n=19) ≥7 days (mean: 13.63±7.17 days). The degree of muscle atrophy and recovery were compared between the two groups, according to age and gender. The degree of muscle atrophy was measured by the difference in thickness of the rectus femoris between pre- and post-traction using ultrasound. The degree of muscle recovery was evaluated by the Q-setting and heel off time. Clinical outcome was evaluated by the non-union rate and Lysholm score. RESULTS The degree of muscle atrophy was 0.99±0.14mm in group A and 2.22±0.11mm in group B (P<0.001). The Q-setting time was 4.83±0.94 days in group A and 6.56±1.38 days in group B (P=0.001). Heel off time was also shorter in group A at 2.58±0.90 days, taking 3.72±1.27 days in group B (P=0.012). The recovery rate in the rectus femoris was significantly higher in group A than in group B (P<0.001). There was no significant difference in non-union rate between group A and B (P=0.672) but the mean Lysholm score at the last follow-up was significantly higher in group A than in group B (P=0.006). However, no significant differences were detected in the mean thickness of the rectus femoris, Q-setting, and heel off time between the different age and gender groups (P<0.05). CONCLUSIONS The prolonged duration of preoperative skeletal traction indicates not only that the resulting disuse atrophy would progress further but also that the muscle atrophy would be accelerated more rapidly for shorter periods of time, based on a cut-off value of 7 days. In addition, the rate of rectus femoris muscle recovery and clinical outcomes were lower in patients undergoing traction for longer periods of time. This indicates that it would be effective for increasing the rate of the recovery and minimizing the occurrence of post surgical complications if surgeons could perform surgery at the earliest possible opportunity following traction, within seven days after the onset of trauma. LEVEL OF EVIDENCE IV, retrospective cohort study.