Gürsel Soybir

The Effects of Melatonin on Angiogenesis and Wound Healing

PurposeThe pineal gland hormone melatonin is a well-known neoroendocrine hormone. In addition to its immunomodulator effect, it also has a positive effect on monocyte, cytokine, and fibroblast proliferations, which also influence angiogenesis. This study investigated the effects of melatonin hormone on angiogenesis in wound healing on 100 Wistar-Albino rats.MethodsThe rats were divided into two groups. Melatonin dissolved in 0.9% NaCl was administered to the study group in a dose of 0.4u2009mg/kg/rat per day (0.25u2009cc/rat per day), and 0.9% NaCl to the control group in a dose of 0.25u2009cc/rat per day. Incisions 5u2009cm in length were made on the back skin of the rats and the wounds were closed with a skin stapler. Excisional biopsies from healing tissues were taken on the 3rd, 7th, 10th, 14th, and 21st postoperative days. Angiogenesis was evaluated in healing tissues by light and electron microscopy and by hydroxyproline level measurements.ResultsThe commencement of neovascularization and a significant increase (P ≪ 0.05) in the number of vessels were observed at all stages of the study group but not in the control group. The tissue hydroxyproline levels were also higher in the study group than in the control group.ConclusionsMelatonin may have a positive effect on both angiogenesis and wound healing.

Effects of granulocyte colony-stimulating factor on bacterial translocation due to burn wound sepsis

The presence of certain defects in both cellular and humoral immunity after thermal injury has been established. Likewise, the translocation of enteric bacteria to the mesenteric lymph nodes and to distant organs has also been observed following serious thermal injury. The effects of granulocyte colony-stimulating factor (G-CSF) on bacterial translocation, the small bowel mucosa, and cecal bacterial content were investigated in a rat model of burn wound sepsis in which albino Wistar rats were scalded over 30% of their bodies, after which the lesions were infected by 1×108 colony-forming units (cfu)Pseudomonas aeruginosa. The control group was treated with 5% dextrose solution subcutaneously starting 2 days preburn, while the treatment group received 100μg/kg human G-CSF subcutaneously. On the 4th day post burn all animals were killed to examine the bowel and culture of the mesenteric lymph nodes (MLN), livers, and spleens. No significant differences were observed between the groups regarding the cecal bacterial content and small bowel; however, a difference was seen in the ratio of translocation in the MLN liver and spleen and quantitative MLN cultures. Based on these findings, G-CSF was thus found to be significantly effective in reducing bacterial translocation due to burn wound sepsis.

Effects of the ischemic preconditioning on anastomotic healing in laparoscopic colon operations.

Background: Previous experimental studies have repeatedly demonstrated the potential protective effect of remote ischemic preconditioning (IPC) on colon anastomosis. The purpose of this experimental study was to investigate the possible positive effects of IPC by interval insufflations in laparoscopic colon operations. Methods: Thirty Wistar-albino rats were randomized into 3 groups. Colonic transsection and anastomosis were performed in the control group. In the laparoscopic colon operation without IPC group, the intra-abdominal pressure was raised to 14 mm Hg for 60 minutes, and then laparotomy and colonic anastomosis were performed. In the IPC group, the intra-abdominal pressure was raised to 14 mm Hg for 5 minutes, followed by desufflation. Laparotomy and colonic anastomosis were performed exactly as in the non-IPC group. On the seventh postoperative day, all animals were killed, and blood and tissue samples were obtained. Anastomotic healing and inflammatory responses were determined by histopathologic examination and by measuring the anastomotic bursting pressure, tissue hydroxyproline level, and tissue and serum nitric oxide, malondialdehyde (MDA), and catalase activity levels. Differences with P-values of <0.05 were considered to be statistically significant. Results: Although the best anastomotic healing was detected in the control group, anastomotic healing was better in the IPC group than that in the non-IPC group. In terms of anastomotic bursting pressure, plasma MDA, serum catalase activity, and tissue nitric oxide levels, the IPC group was superior to the non-IPC group. No significant differences were found between the control and IPC groups, except in the plasma MDA levels. Conclusions: Use of IPC with colon anastomosis had positive effects on wound healing and may serve as a safe method to reduce the adverse effects of ischemia and wound healing in laparoscopic colon operations.

Chemoprevention of DMBA-induced mammary gland carcinogenesis – preventive effects of free oxygen radical scavengers

This study was carried out to determine the effects of Mangan-Desferrioxamine (Mn-DFX) and Verapamil (VRP) in 7,12-dimethyl-benz-[a]anthracene (DMBA) induced mammary carcinoma. 70 Spraque Dawley rats were divided into four groups; as DMBA alone, DMBA + Mn-DFX, DMBA + VRP, and control. Incidence, multiplicity, and size of tumors were evaluated in addition to analyses of DNA ploidy status and proliferation index by flow cytometric technique. The results revealed that Mn-DFX and VRP caused significant decreases in tumor incidence (p < 0.02 and p < 0.05), multiplicity (p < 0.02 and p < 0.05), size (p < 0.05 and p < 0.02), and proliferation index (p < 0.05 and p < 0.02) without any toxic effect. The appearance of first tumors in Mn-DFX and VRP groups was also later than in the DMBA alone group (10th and 11th week versus 6th week). In conclusion, Mn-DFX and VRP have offered prevention in experimental mammary carcinogenesis. These agents caused slower tumor growth, though they could not achieve a complete prevention.