Expression Patterns of HIF-1α Under Hypoxia in Vascular Smooth Muscle Cells of Venous Malformations.

PURPOSE: The molecular pathophysiology of venous malformations (VMs), which are a type of vascular malformation, is poorly understood. Until now, it is known that VM lesions are related to the process of angiogenesis. Because angiogenesis is induced under hypoxic conditions, hypoxia is thought to be important in VM lesion formation. Therefore, we examined the implications of hypoxia on the biological behavior of VM vascular smooth muscle cells (VSMCs). In doing so, we investigated the expression patterns of hypoxia-inducible factor-1α (HIF-1α), which plays a key role in hypoxia-induced angiogenesis, to provide a further understanding of the molecular mechanisms involved in VM. METHODS: Vascular smooth muscle cells from 5 normal veins and 5 VM lesions were cultured under moderate hypoxic conditions (3% O2, 5% CO2). The effects of hypoxia on HIF-1α expression were measured by immunocytochemical staining, reverse transcription-polymerase chain reaction, and real-time reverse transcription-polymerase chain reaction. RESULTS: Overall, the expression of HIF-1α in cells was high after exposure to hypoxia for 6 or 12 hours, but decreased after 24 hours of hypoxia. HIF-1α expression in VM VSMCs was 2 times higher than that in normal VSMCs. Immunocytochemically, HIF-1α was mainly located in the nucleus and the intensity in VM VSMCs was stronger after 6 and 12 hours of hypoxia when compared to the expression pattern of HIF-1α in VSMCs from normal tissue. This suggested that VM tissue is more susceptible to the effects of hypoxia than normal tissue. CONCLUSIONS: These results indicate that the high expression of HIF-1α in VM VSMCs under hypoxic conditions could be an important factor for stimulating downstream angiogenesis in VM. Furthermore, the results of this investigation could provide the basis for future studies of VM pathophysiology, and ultimately lead to the development of new therapeutic approaches.

Our Experiences in Nipple Reconstruction Using the Hammond flap.

BACKGROUND: Nipple reconstruction following breast mound reconstruction is the final step in breast reconstruction. Although nipple reconstruction is a simple surgery, the psychological aspects of nipple reconstruction are thought to be important. Nipple projection is a key factor in determining patient satisfaction with the surgery. In the present study, the Hammond flap technique was introduced for nipple reconstruction. METHODS: Twenty-six patients who had undergone breast reconstruction from February 2008 to March 2012 were enrolled in this prospective study. All patients were evaluated based on preoperative photos, and their nipple diameters and heights were measured. Postoperative evaluation was conducted 3, 6, 9, and 12 months following nipple reconstruction. A questionnaire on patient satisfaction with the nipple reconstruction was administered 12 months after nipple reconstruction. Moreover, the same plastic surgeon scored nipple projection and overall cosmetic result of the new nipple. RESULTS: The mean projection was 4.4 mm (range, 3-6 mm), and it well matched the contralateral nipple. Twelve months following nipple reconstruction, the mean reduction rate in the nipple projection was 43.6%. Patients were satisfied or very satisfied with the nipple projection and the overall cosmetic result in 80.7% cases. CONCLUSIONS: In the present study, compared with other techniques, the use of the Hammond flap technique in nipple reconstruction showed competitive results with regard to nipple projection and patient satisfaction.

Platelet-rich plasma: quantitative assessment of growth factor levels and comparative analysis of activated and inactivated groups.

BACKGROUND: Platelet-rich plasma (PRP) has more concentrated platelets than normal plasma (approximately 150-400×10(3) cell/dL). Platelets excrete several growth factors and cytokines that are associated with the healing and regeneration process. However, even though PRP is widely used, the mechanism or actual effect is presently unclear. Therefore, this study was performed to investigate the levels of growth factors and platelet concentration rate. METHODS: Autologous blood for preparing PRP was obtained from healthy subjects aged 25 to 35 years. The samples were divided into 4 experimental groups (inactivated whole blood, inactivated PRP, activated whole blood with thrombin and calcium chloride, and activated PRP). The platelet counts in the blood were analyzed and the growth factors were quantitatively measured. A statistical analysis was performed by using Dunn's multiple comparison test. RESULTS: In the blood cell analysis, the platelet count of the PRP group was approximately 4.25 times higher than that of the whole blood group. In the quantitative analysis of growth factors, the platelet-derived growth factor (PDGF)-AB, PDGF-BB, and transforming growth factor-ß of the inactivated and activated PRP groups were higher than those of the inactivated and activated whole blood groups (P<0.05). CONCLUSIONS: In this study, the platelet count and the levels of PDGF-AB and PDGF-BB in the PRP were determined. Further, more research is required on the bioactivity level of the growth factors secreted during the process of PRP preparation and the potency of growth factors that can be exerted physiologically in vivo.