OBJECTIVES:Previous studies have reported that osteoporosis due to estrogen deficiency influences fracture healing. Transforming growth factor (TGF-β) has been found to be involved in fracture healing via the regulation of the differentiation and activation of osteoblasts and osteoclasts. The current study aimed to determine the effects of estrogen on the expression of TGF-β1 during fracture healing in ovariectomized rats.METHODS:Thirty female Sprague-Dawley rats weighing 200–250 g were assigned to: (i) a sham-operated group that was given a normal saline; (ii) an ovariectomized control group that was given a normal saline; or (iii) an ovariectomized + estrogen (100 µg/kg/day) group that was treated with conjugated equine estrogen. The right femur of all rats was fractured, and a Kirschner wire was inserted six weeks post-ovariectomy. Treatment with estrogen was given for another six weeks post-fracture. At the end of the study, blood samples were taken, and the right femur was harvested and subjected to biomechanical strength testing.RESULTS:The percentage change in the plasma TGF-β1 level before treatment was significantly lower in the ovariectomized control and estrogen groups when compared with the sham group (p<0.001). After six weeks of treatment, the percentage change in the plasma TGF-β1 level in the estrogen group was significantly higher compared with the level in the ovariectomized control group (p = 0.001). The mean ultimate force was significantly increased in the ovariectomized rats treated with estrogen when compared with the ovariectomized control group (p = 0.02).CONCLUSION:These data suggest that treatment with conjugated equine estrogen enhanced the strength of the healed bone in estrogen-deficient rats by most likely inducing the expression of TGF-β1.
Calcium phosphate-based bone substitutes have not been used to repair load-bearing bone defects due to their weak mechanical property. In this study, we reevaluated the functional outcomes of combining ceramic block with osteogenic-induced mesenchymal stem cells and platelet-rich plasma (TEB) to repair critical-sized segmental tibial defect. Comparisons were made with fresh marrow-impregnated ceramic block (MIC) and partially demineralized allogeneic bone block (ALLO). Six New Zealand White female rabbits were used in each study group and three rabbits with no implants were used as negative controls. By Day 90, 4/6 rabbits in TEB group and 2/6 in ALLO and MIC groups resumed normal gait pattern. Union was achieved significantly faster in TEB group with a radiological score of 4.50 ± 0.78 versus ALLO (1.06 ± 0.32), MIC (1.28 ± 0.24), and negative controls (0). Histologically, TEB group scored the highest percentage of new bone (82% ± 5.1%) compared to ALLO (5% ± 2.5%) and MIC (26% ± 5.2%). Biomechanically, TEB-treated tibiae achieved the highest compressive strength (43.50 ± 12.72 MPa) compared to those treated with ALLO (15.15 ± 3.57 MPa) and MIC (23.28 ± 6.14 MPa). In conclusion, TEB can repair critical-sized segmental load-bearing bone defects and restore limb function.
Purpose:To report our early experience in image-guided chemoport insertions by interventional radiologists.Materials and Methods:This was a cross-sectional study conducted in a tertiary center with 161 chemoport insertions done from June 2008 to June 2010. The chemoports were inserted either at the angiography suite or at the mobile operation theater unit. Ninety percent of the chemoports had right internal jugular vein (IJV) as the entry site. Other entry sites included the left IJV, subclavian veins and the inferior vena cava. Immediate and early complications were recorded. All insertions were performed under image guidance with the aid of ultrasound and fluoroscopy.Results:The technical success rate was 99.4%. In terms of immediate complications, there were only two cases of arterial puncture that resolved with local compression. No pneumothorax or air embolism was documented. Twenty-six early complications were recorded. The most common early complication was catheter blockage (12/161; 7.4%), followed by catheter-related infection (9/161; 5.6%). Other complications were catheter malposition, venous thrombosis and catheter dislodgement or leak. A total of 11 (6.8%) chemoports had to be removed within 30 days; most of them were due to infections that failed to respond to systemic antibiotic therapy. In terms of place of procedure, there were no significant differences in complication rates between the angiography suite and the mobile operation theater unit.Conclusion:Image-guided chemoport insertion by interventional radiologist gives low periprocedural complication rates. Using right IJV as the entry site, the image guidance gives good success rate with least complication.
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