Topical application of Sadat-Habdan mesenchymal stimulating peptide (SHMSP) accelerates wound healing in diabetic rabbits.

OBJECTIVE: Diminished wound healing is a common problem in diabetic patients due to diminished angiogenesis. SHMSP was found to promote angiogenesis. The present study was carried out to examine the effect of this peptide in healing of wounds in diabetic rabbits. MATERIALS AND METHODS: Twenty male New Zealand rabbits were used in this study. Diabetes mellitus was induced and the rabbits were randomly divided into two equal groups: control group and peptide group. A-full thickness punch biopsy was made to create a wound of about 10 mm on the right ears of all rabbits. Every day, the wound was cleaned with saline in control groups. In the peptide group, 15 mg of SHMSP was applied after cleaning. On day 15th, all animals were sacrificed, and the wounds were excised with a rim of 5 mm of normal surrounding tissue. Histo-pathological assessment of wound healing, inflammatory cell infiltration, blood vessel proliferation, and collagen deposition was performed. RESULTS: There were no deaths among the groups. There was significant increase in wound healing, blood vessel proliferation and collagen deposition, and significant decrease in inflammatory cell infiltration in the peptide group compared to the control group. CONCLUSION: Topical application of SHMSP improves wound healing in diabetic rabbits.

Human CD34+ stem cells promote healing of diabetic foot ulcers in rats.

OBJECTIVE: Diabetic patients with foot ulcers usually manifest with high amputation and mortality rates. Preliminary evidence supports the effectiveness of stem cell (St) therapy on diabetic foot ulcers. The objective of this study was to evaluate the efficacy of stem cells in the healing of wounds among streptozotocin-induced diabetic albino rats. METHODS: Thirty male albino rats were divided into three groups each of 10 rats: control group, diabetic control (DC) group and St group. Diabetes was induced by intra-peritoneal injection of streptozotocin. A full thickness circular wound of ∼10 mm in diameter was performed on the front of right legs of all rats. In the diabetic St group, the wounds were treated by injection of umbilical cord blood-derived CD34+ stem cells into the wound bed. Half of each group rats were sacrificed after 1 week and the rest after 2 weeks. The wound areas were used for histopathology, immunohistochemistry and transmission electron microscope studies. Assessment of wound surface area, epidermal thickness, blood vessel proliferation and collagen deposition were performed. RESULTS: There was a significant decrease in mean wound surface area, increase in mean epidermal thickness, blood vessel proliferation and collagen deposition in the St group compared with the DC group. CONCLUSION: Treatment with CD34+-enriched cells decreased wound size, accelerated epidermal healing and dramatically accelerated revascularization of the wounds compared with the DC group.

Effect of anastomotic length on the development of intimal hyperplasia in the distal anastomosis of bypass graft.

Many hemodynamic factors have been shown to be associated with increased intimal hyperplasia at the distal anastomosis of arterial bypass graft. However, the relationship between the length of anastomosis and the development of such a complication has not been studied before. The aim of this study was to assess this relationship at the distal anastomosis with a Dacron graft. Iliofemoral bypass using 6 mm Dacron grafts was performed in 10 German shepherd dogs. In accordance with preoperative randomization to individual animal legs, distal anastomoses were reconstructed using four different groups (A, B, C, and D), depending on the length of the arteriotomy: 3.0, 3.5, 4.0, and 4.5 times the internal diameter of the artery, respectively. The vessels were harvested 6 months after the operation, and specimens were processed for histologic and transmission electron microscopic (TEM) studies. Quantitative analysis was performed to assess the extent of intimal hyperplasia at three zones (heel, toe, and midzone of the arterial bed) of the distal anastomosis. Sixteen arterial bypasses were included in this study. Both light and TEM studies revealed evidence of intimal hyperplasia in the four groups. Quantitative analysis showed a significant decrease in intimal hyperplasia with increasing the length of the anastomosis at the heel, toe, or midzone of the arterial bed. Mean (mum +/- SD) intimal hyperplasia of the three zones together was significantly higher in group A than group B (585 +/- 106 vs 423 +/- 8.6, p < .001) and in group B than group C (423 +/- 8.6 vs 202 +/- 15, p < .001). However, the difference between group C and group D (202 +/- 15 vs 162 +/- 8.6; p = .13) was statistically insignificant. The present study showed that the length of the anastomosis is one of the hemodynamic factors involved in the development of intimal hyperplasia. Anastomotic techniques that resulted in the least intimal hyperplasia were end to side, with length 4 or 4.5 times the internal diameter of the artery.

Role of saphenous vein wall in the pathogenesis of primary varicose veins.

UNLABELLED: Varicose veins may be due to weakness of the vein wall as a result of structural problems. There are conflicting findings in the literature about these problems especially concerning collagen, elastin and smooth muscle cells content. The aim of this study was to look at the structural abnormalities of varicose veins (with and without valvular incompetence). MATERIALS AND METHODS: We studied 70 specimens of long saphenous veins from 35 patients (24 with varicose and 11 with normal veins). Two specimens were taken from each vein approximately 3-4 cm from the saphenofemoral junction. Vein specimens were processed for histological and electron microscopic studies. Both qualitative and quantitative analyses were performed to assess the degree of wall changes. Using the image analyzer, contents of collagen, elastin and smooth muscle cells, in addition to intimal and medial thickness, were measured. RESULTS: Light microscopy revealed significant increase in intimal and medial thickness and collagen content of media and significant decrease in elastin content in varicose veins compared with normal veins. There was no statistical significant difference between varicose veins with and without saphenofemoral valve incompetence. Electron microscopy showed marked degenerative changes in intima and media of varicose veins. CONCLUSION: The findings in our study supported the theory of primary weakness of the vein wall as a cause of varicosity. This weakness is due to intimal changes, disturbance in the connective tissue components and smooth muscle cells.