Proliferation of the mesenchymal stem cells in a delayed fat flap: an experimental study in rabbits / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the possibility to enhance the proliferation of adipose-derived stem cells (ASCs) in a delayed fat flap in rabbits.</p><p><b>METHODS</b>A delayed fat flap was formed in one side of inguinal region of a rabbit. 21 days after operation, the fat tissues at the delayed flaps and at the unoperated side were harvested and digested with 0.25% collagenase and sieved. The cell suspensions were centrifuged. The cells were obtained from tissue precipitate after centrifugation. The expression rates of the surface marker (CD29, CD44, CD14 and CD45) were measured by FCM and compared between the experimental and control groups.</p><p><b>RESULTS</b>Expression rates of CD29 and CD44 were higher in the delayed fat flap (74.06% and 90.74%) than in the contralateral fat tissue (62.88% and 77.54%, P < 0.05), while those of CD14 and CD45 were lower in the delayed fat flap (57.66% and 4.84%) than in the contralateral fat tissue (72.10% and 75.82%, P < 0.05 and P < 0.01).</p><p><b>CONCLUSIONS</b>Tissue hypoxic ischemia such as fat tissue in a delayed fat flap can promote proliferation of ASCs. It indicates that tissue in the delayed flap may be transplanted with better survival rate. The ischemia pretreatment of fat tissue may become a new method for fat transplantation.</p>

Experimental study of increasing effect of the fat flap tissue after delay operation on its free graft survival volume and duration / 中华整形外科杂志

<p><b>OBJECTIVE</b>To observe the effects of the fat flap tissues after delay operation on free fat-graft survival rate and duration.</p><p><b>METHODS</b>The delay operation of fat flaps was performed in the inguinal region of a rabbit. Expression of VEGF was assayed using Elisa method after 12 hours of flap delay. The fat flaps were harvested and cut into pieces after 21 days. A subdermal pocket was created in each side of the dorsal midline of a rabbit, the fat pieces were grafted randomly into a pocket and the normal fat pieces into the other pocket as control. After 1, 3, 6, 9 and 12 months of implantation, the grafted fats were harvested, gross observation, weight measurement and histology were carried out. Number of the vessels stained with anti-CD34 antibody was counted out.</p><p><b>RESULTS</b>VEGF concentrations in flaps were significantly higher (P < 0.05). The density of vessels in experimental groups increased significantly compared with that in control groups at 1 and 3 months, respectively (P < 0.01), and no significant differences in the survival rate of fat tissues between experimental and control groups were observed at 1 and 3 months (P > 0.05). The fat cells from the flaps survived after 12 months of fat plantation, while those in control groups disappeared after 6 months.</p><p><b>CONCLUSIONS</b>The survival rate and duration of grafted fat could be increased implanting the fat tissues from delayed fat flap, which may provide researchers with a new method for fat graft.</p>

Effect of lanthanum chloride on expressions of collagen protein in a wound tissue / 中华整形外科杂志

<p><b>OBJECTIVE</b>To evaluate the effect of lanthanum chloride on expressions of collagen protein and find a way to prevent and treat scar.</p><p><b>METHODS</b>Four linear incisions were made on the dorsal skin of an adult, female Sprague-Dawley rat as an animal model. One was non-manipulated as a control; the second was injected with distilled water as a sham-control; the third was injected with 50 mmol/L of lanthanum chloride, and the fourth was injected with 50 micrograms neutralizing antibody of TGF-beta 1 as a positive control. All of the wound tissues were harvested and assayed with ABC method in 14 days and 28 days after the surgery.</p><p><b>RESULTS</b>The expressions of type I, III and IV of collagen protein in the third group significantly reduced in 14 and 28 days after the operation, compared with the control or sham-control group. Its values wen as similar as the fourth group.</p><p><b>CONCLUSION</b>Lanthanum chloride could inhibit the expressions of collagen protein, and it may be used to prevent and treat scars.</p>

Effects of lanthanum chloride on the apoptosis of fibroblasts in trauma tissue / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the effects of lanthanum chloride on the apoptosis of fibroblasts in trauma tissue.</p><p><b>METHODS</b>Fifty adult female SD rats were used and linear incisions were made on the back near the joints of extremities of the rats. One of the cuts receiving no treatment was designated as blank control (C). 0.25 ml of distilled water, lanthanum chloride (50 mmol/L) and the antibody of (TGFbeta(1)) transforming growth factor beta(1) (0.2 mg/ml) were respectively injected into the both sides of the other three wounds subcutaneously and the wounds were divided into simulating control (SC), lanthanum chloride (LC) and antibody (A) groups. The fibroblast apoptosis in the wound tissue samples and the change in intracellular calcium concentration (Ca(2+)) were determined by flow cytometry (FCM) and TUNEL methods on the 14th and 28th day after the injection.</p><p><b>RESULTS</b>Apoptosis of fibroblasts was enhanced significantly after 14 days of injection in LC and A groups compared with that in C and SC groups (P < 0.05 approximately 0.01). Furthermore, intracellular Ca(2+) was increased evidently in LC group (P < 0.01).</p><p><b>CONCLUSION</b>It is indicated that lanthanum chloride might be effective in preventing scar development.</p>