A 4-Axis Technique for Three-Dimensional Printing of an Artificial Trachea

BACKGROUND: Several types of three-dimensional (3D)-printed tracheal scaffolds have been reported. Nonetheless, most of these studies concentrated only on application of the final product to an in vivo animal study and could not show the effects of various 3D printing methods, materials, or parameters for creation of an optimal 3D-printed tracheal scaffold. The purpose of this study was to characterize polycaprolactone (PCL) tracheal scaffolds 3D-printed by the 4-axis fused deposition modeling (FDM) method and determine the differences in the scaffold depending on the additive manufacturing method. METHODS: The standard 3D trachea model for FDM was applied to a 4-axis FDM scaffold and conventional FDM scaffold. The scaffold morphology, mechanical properties, porosity, and cytotoxicity were evaluated. Scaffolds were implanted into a 7 × 10-mm artificial tracheal defect in rabbits. Four and 8 weeks after the operation, the reconstructed sites were evaluated by bronchoscopic, radiological, and histological analyses. RESULTS: The 4-axis FDM provided greater dimensional accuracy and was significantly closer to CAD software-based designs with a predefined pore size and pore interconnectivity as compared to the conventional scaffold. The 4-axis tracheal scaffold showed superior mechanical properties. CONCLUSION: We suggest that the 4-axis FDM process is more suitable for the development of an accurate and mechanically superior trachea scaffold.

Antidepressant-like Effects of p-Coumaric Acid on LPS-induced Depressive and Inflammatory Changes in Rats

Depression causes mental and physical changes which affect quality of life. It is estimated to become the second most prevalent disease, but despite its commonness, the pathophysiology of depression remains unclear and medicine is not sufficiently protective. p-Coumaric acid (p-CA) is a dietary phenolic acid which has been proven to have antifungal, anti-HIV, anti-melanogenic, antioxidant and anti-inflammatory effects. Considering these effects, we investigated whether p-CA can prevent depressive symptoms by reducing inflammatory cytokines in animals injected with lipopolysaccharide (LPS). Changes in despair-related behaviors, inflammatory cytokines, neurotrophic factors and synaptic activity were measured. In these animals, p-CA improved despair-related behavioral symptoms induced by LPS in the forced swim test (FST), tail suspension test (TST) and sucrose splash test (SST). p-CA also prevented the increase of inflammatory cytokines in the hippocampus such as cycloxigenase-2 and tumor necrosis factor-α due to LPS. Similarly, it prevented the reduction of brain-derived neurotrophic factor (BDNF) by LPS. Electrophysiologically, p-CA blocked the reduction of long-term depression in LPS-treated organotypic tissue slices. In conclusion, p-CA prevented LPS-induced depressive symptoms in animals, as determined by behavioral, biochemical and electrophysiological measures. These findings suggest the potential use of p-CA as a preventive and therapeutic medicine for depression.

Comparison study on results of LAVH according to prior abdominal surgery / 대한산부인과학회지

OBJECTIVE: To evaluate the result of laparoscopically assisted vaginal hysterectomy (LAVH) according to history of prior abdominal surgery. METHODS: From January, 2003 to June, 2005, a total of 504 patients were performed LAVH at our Hospital. The patients were divided into 2 groups: Group of non prior abdominal surgery (Op. Hx(-) group) included 262 cases and group of prior abdominal surgery (Op. Hx(+) group) had 242 cases. We reviewed medical records and analyzed these cases regarding age, parity, weight, height, operation indication, operation outcome, duration of hospitalization and complication. RESULTS: There were no differences in terms of patients' mean age, parity, weight and height, and indications for surgery between the two groups. Mean operation time of Op. Hx(+) group (86.9+/-28.2 min) was longer than Op. Hx(-) group (80.7+/-20.0 min). There was no statistical difference on mean postoperative hemoglobin drop and mean uterine weight between the 2 groups. Mean hospital stay of Op. Hx(+) group (4.6+/-1.7 days) was longer than Op. Hx(-) group (4.3+/-0.9 days). The incidence of major surgical complications was higher in Op. Hx(+) group (10 cases - 4.1%) than Op. Hx(-) group (3 cases - 1.2%). In case of blader injury, Op. Hx(+) group (5 cases) was higher than Op. Hx(-) group (0 case). Op. Hx(+) group had 2 ureteral injuries and 1 rectal injury but there were no statistical differences. In case of trocar site bleeding, both group had 2 cases trocar site bleeding respectively. Op. Hx(-) group had 1 inferior vena cava injury but there was no statistical difference. CONCLUSION: At the time of LAVH, the incidence of bladder injury was higher in group of patients with history of prior abdominal surgery. So special attention should be paid to prevent bladder injury.

Comparison study on results of LAVH according to prior abdominal surgery / 대한산부인과학회지

OBJECTIVE: To evaluate the result of laparoscopically assisted vaginal hysterectomy (LAVH) according to history of prior abdominal surgery. METHODS: From January, 2003 to June, 2005, a total of 504 patients were performed LAVH at our Hospital. The patients were divided into 2 groups: Group of non prior abdominal surgery (Op. Hx(-) group) included 262 cases and group of prior abdominal surgery (Op. Hx(+) group) had 242 cases. We reviewed medical records and analyzed these cases regarding age, parity, weight, height, operation indication, operation outcome, duration of hospitalization and complication. RESULTS: There were no differences in terms of patients' mean age, parity, weight and height, and indications for surgery between the two groups. Mean operation time of Op. Hx(+) group (86.9+/-28.2 min) was longer than Op. Hx(-) group (80.7+/-20.0 min). There was no statistical difference on mean postoperative hemoglobin drop and mean uterine weight between the 2 groups. Mean hospital stay of Op. Hx(+) group (4.6+/-1.7 days) was longer than Op. Hx(-) group (4.3+/-0.9 days). The incidence of major surgical complications was higher in Op. Hx(+) group (10 cases - 4.1%) than Op. Hx(-) group (3 cases - 1.2%). In case of blader injury, Op. Hx(+) group (5 cases) was higher than Op. Hx(-) group (0 case). Op. Hx(+) group had 2 ureteral injuries and 1 rectal injury but there were no statistical differences. In case of trocar site bleeding, both group had 2 cases trocar site bleeding respectively. Op. Hx(-) group had 1 inferior vena cava injury but there was no statistical difference. CONCLUSION: At the time of LAVH, the incidence of bladder injury was higher in group of patients with history of prior abdominal surgery. So special attention should be paid to prevent bladder injury.