Facilitated tissue expansion with topical estriol.

Tissue expansion is a helpful technique in reconstructive plastic surgery. Unfortunately, tissue expansion still needs to be improved. Twenty-four male Wistar rats were used to evaluate the effect of estriol on tissue expansion. The agents hyaluronidase, estriol, and base cream (as a control) were applied topically to separate animal groups for 5 weeks, and their effects were studied on tissue expansion. Both hyaluronidase (p < 0.05) and estriol (p < 0.001) enhanced the rate of expansion when compared with control animals. Estriol was more effective than hyaluronidase (p < 0.05). Breaking strengths were measured in the estriol and the control groups. Breaking strength was not evaluated in the hyaluronidase group because of the necrotic changes seen at the end of the fifth week. The breaking strength was higher in the control group than in the estriol group (p < 0.05). The authors suggest that topical estriol be used as an adjunctive agent to facilitate tissue expansion.

Comparative study of the effect of ultrasound and electrostimulation on bone healing in rats.

This study was performed to compare the effects of direct current with ultrasound on fracture healing. Thirty-two rats were subjected to the experiment. Each rat's right legs were used as the experimental sample, and their left legs were used as the control. Four groups were formed, each consisting of 16 ultrasound, 16 electrostimulation, 16 ultrasound control, and 16 electrostimulation control animals. Fibular osteotome was applied to the rats under anesthesia. In the electrostimulation and electrostimulation control groups, a stainless steel cathode electrode was installed in the fractured side. In the electrostimulation group, 10 microA of direct current for 30 min, using a semi-invasive method, was given one day after fracture, for 15 days. On the control side, the aforementioned protocol was followed but sham treated. The ultrasound group was treated with 0.1 W/cm2 ultrasound for 2 min every second day for 6 days after fracture (4 times). Rats were killed on the 7th and 14th days to investigate the macroscopic, radiologic, and histopathologic parameters of fracture healing. There was a difference (P < 0.05) between the electrostimulation and the electrostimulation control groups on the 7th day. There was a difference (P < 0.05) between the ultrasound and ultrasound control groups on the 14th day. After statistical evaluation of the experimental results, it was found that in both the ultrasound and the electrostimulation groups, the fracture healing had been accelerated more so than in the control groups. There was no observed statistical difference between ultrasound and electrostimulation effects.

The effect of Gingko biloba extract (Egb 761) as a free radical scavenger on the survival of skin flaps in rats. A comparative study.

Free radicals may have a role in pedicle flap necrosis. We undertook this study to compare the effect of various antioxidants and scavengers of free radicals such as vitamin E, vitamin C, deferoxamine, and Gingko biloba extract (Egb 761) on McFarlane caudal-based dorsal rat flaps. Fifty rats were divided into five groups of 10 animals each. One group served as a control (saline) group. The remaining four groups were given vitamin C 340 mg/kg, deferoxamine 150 mg/kg, Egb 761 100 mg/kg, and vitamin E 20 mg/kg. The necrosed area of flap was significantly reduced in the deferoxamine (p < 0.001), Egb 761 (p < 0.001), and vitamin C (p < 0.05) groups compared with the control group. Vitamin E had no effect on distal flap necrosis (p = 0.20).

A comparative study of the effect of ultrasound and electrostimulation on wound healing in rats.

A comparative study has been carried out to investigate the effects of electrical stimulation and ultrasound on wound healing. Eighty-four female rats were divided into four groups depending on the treatment received. The first group was given electrical stimulation of 300 microA direct current, 30 minutes daily, starting with negative polarity and then changed after 3 days of treatment. Group 2 received sham electrostimulation treatment. The third group received 0.1 W/cm2 pulsed ultrasound using the moving applicator technique for 5 minutes a day. Group 4 received sham ultrasound treatment. A total of 7 days of treatment was given to all groups. Histopathologic and biochemical analyses on the fourth and seventh days and wound breaking strength on the twenty-fifth day were performed for all groups. By accelerating the inflammatory phase, electrical stimulation had progressed the proliferative phase of wound healing earlier than ultrasound had done. Both electrical stimulation and ultrasound have positive effects on proliferative phases, but electrical stimulation was superior to ultrasound at the maturation phase. There was no difference between the two experimental groups on the mast cell reduction effect. Although ultrasound treatment may seem to be efficient in terms of time, when the effects of electrical stimulation and ultrasound on wound healing with the methods employed in our study are considered, it is concluded that electrical stimulation is a means of treatment superior to ultrasound in wound healing.