Microwave ablation of the canine prostate: an experimental study / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the effect of transrectal ultrasound-guided microwave ablation of canine prostate tissue.</p><p><b>METHODS</b>Guided by transrectal ultrasound, we conducted microwave ablation on each side of the prostate in 12 male dogs, 6 at 40 W/ 120 s (group A) and the other 6 at 40 W/160 s (group B), and observed the changes in the thermal lesions using grayscale ultrasound. After thermal ablation, we measured the volume of the thermal lesions by contrast-enhanced ultrasound (CEUS). Then we harvested the whole prostate from the animals and determined the lesion volumes in the fresh tissue specimens.</p><p><b>RESULTS</b>Grayscale ultrasound revealed an echogenic area at the initiation of the microwave ablation procedure, which was enlarged with the increase of ablation time. At the end of the procedure, the lesions appeared as an irregular heterogeneous echogenic area. CEUS showed oval non-perfused areas, which appeared as well-defined non-echoic areas in sharp contrast with the surrounding normal prostate parenchyma with bolus injection of contrast material (Sonovue, 2.4 ml), and that the thermal lesion volumes of groups A and B were (1.18 +/- 0.23) cm3 and (1.52 +/- 0.23) cm3, respectively. The thermal lesions of the gross specimen exhibited an elliptical shape, pale color and clear margin, and their volumes were (1.13 +/- 0.20) cm3 and (1.48 +/- 0.20) cm3, respectively, in groups A and B.</p><p><b>CONCLUSION</b>Different combinations of time and power can produce coagulative necrotic lesions of different volumes in the local prostatic tissue. CEUS can accurately manifest the lesion area and thus avoid excessive or inadequate ablation treatment.</p>

Effect of vascular endothelial growth factor on bone marrow-derived mesenchymal stem cell proliferation and the signaling mechanism / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effect of vascular endothelial growth factor (VEGF) on bone marrow-derived mesenchymal stem cell (MSC) proliferation and explore the signaling mechanism involved.</p><p><b>METHODS</b>MSC culture was performed following the classical whole bone marrow adhering method. The characteristics of MSC were identified by induction of multi-lineage differentiation and flow cytometry for surface marker analysis (CD34, CD45, CD29, and CD90). Following the addition of 50 nmol/L wortmannin, 50 µmol/L PD98059, 30 µmol/L SB203580, 10 µmol/L H89, 20 µmol/L Y27632, 1 µmol/L rapamycin, 10 µmol/L straurosporine, 6 nmol/L Go6976, or 50 µmol/L Pseudo Z inhibitors in the cell culture, the MSC were treated with 20 ng/ml VEGF and the changes of the cell proliferation rate was measured with MTT assay.</p><p><b>RESULTS</b>Cultured MSC were capable of multi-linage differentiation and did not express VEGF-R, CD29 or CD90. Treatment with 20 ng/ml VEGF obviously promoted MSC proliferation, and this effect was inhibited partially by p38 mitogen-activated protein kinase (MAPK) inhibitor rapamycin, PD98059, SB203580, Go6976, and straurosporine.</p><p><b>CONCLUSIONS</b>VEGF promotes MSC proliferation in close relation to the AKT-PKC pathway, in which PKC signal pathway may play the central role.</p>

Ultrasound-guided transrectal microwave ablation of the prostate in dogs / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the feasibility and safety of ultrasound-guided transrectal microwave ablation in reducing the prostate volume.</p><p><b>METHODS</b>Ultrasound-guided transrectal microwave ablation of both sides of the prostate was conducted on experimental dogs with the output volume of 30W for 120 seconds. The dogs were sacrificed on the very day of the ablation, and the prostate and its surrounding tissues were excised for observation of the thermal lesions and pathological examination.</p><p><b>RESULTS</b>A total of 12 thermal lesions were achieved on the two sides of the prostate. The ultrasonogram manifested dense echo and increasing extent in the ablated area, and then an irregular heterogeneous echogenic area and clearly differentiated margin. Pathological examination of the gross specimen showed a little stagnant blood under the rectal mucous, the urethra and bladder not injured, and the thermal lesions elliptical, clearly margined and with the mean size of (0.94 +/- 0.30) cm3.</p><p><b>CONCLUSION</b>Ultrasound-guided transrectal microwave ablation of the prostate can effectively cause coagulative necrosis of the local tissue without inflicting thermal injury upon the surrounding tissues. Conventional grayscale ultrasound can give a real-time'display of the extent of thermal lesion and the whole process of the ablation.</p>