Effect of paeoniflorin on distal survival of random flaps.

BACKGROUND: Distal ischemic necrosisis a common complication of orthopedic random skin flaps surgery. Paeoniflorin, a natural compound extracted from Paeonia lactiflora, can enhances angiogenesis and alleviates excessive inflammatory response. We investigated the changes of ischemic extra-long flaps with paeoniflorin and its possible mechanism. METHODS: We raised dorsal McFarlane flaps in 54 Sprague-Dawley rats. We designed three groups of rats: high-paeoniflorin group (HP, 50 mg/kg/d), low-paeoniflorin group (LP, 20 mg/kg/d), and control group. The flap survival rate was calculated, seven days after flap construction.Blood perfusion was detected by laser Doppler flow imaging, and angiogenesis wasdetected by Lead oxide/gelatin angiography.Oxidative stress levels of flaps were determined by detecting superoxide dismutase (SOD) and malondialdehyde (MDA). The histopathological status of flap was evaluated by hematoxylin and eosin (H&E) staining.Immunohistochemistry was used to determine the expression of high mobility group protein B1 (HMGB1), nuclear factor-kappa B (NF-κB), Toll-like receptor 4 (TLR4), tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-1ß, IL-18, vascular endothelial growth factor (VEGF), cysteine protease-1 (caspase-1) and NLPR3. RESULTS: The flap survival rates and SOD activity in the experimental groups were significantly higher, while MDA activity was lower. Experimental groups showed significantly improved microcirculatory blood flow to the flap and increased angiogenesis. Immunohistochemistry revealed that paeoniflorin was associated with significantly increased VEGF expression, and decreased level of HMGB1, TLR4, TNF-α, NF-κB, IL-6, IL-1ß, caspase-1, NLPR3, and IL-18. CONCLUSIONS: Paeoniflorin effectively enhanced the survival of rat random skin flaps by promoting vascular hyperplasia, inhibiting pyroptosis, and down-regulating inflammation.

Exenatide inhibits necrosis by enhancing angiogenesis and ameliorating ischemia/reperfusion injury in a random skin flap rat model.

BACKGROUND: Random skin flaps are often used for plastic repair because they are convenient and flexible. However, necrosis of flaps is a common complication that may lead to disastrous consequences. Exenatide, a glucagon-like peptide 1 receptor agonist, can enhance angiogenesis and ameliorate ischemia/reperfusion injury. Our experiments explored random skin flap outcomes after its use. METHODS: We established modified dorsal McFarlane flaps on 54 Sprague-Dawley rats and divided the rats into three groups (control, Exe-I, and Exe-II). We intraperitoneally injected either 4 or 8 µg/kg/day exenatide into the rats of the Exe-I and Exe-II groups, respectively. On the seventh day after the operation, we measured the levels of superoxide dismutase (SOD) and malondialdehyde (MDA). Tissue sections were obtained for histopathological and immunohistochemical analyses, and we evaluated the expression of vascular endothelial growth factor (VEGF), interleukin (IL) 6, IL-1ß, nuclear factor kappa beta (NF-κB), Toll-like receptor 4 (TLR4), and tumor necrosis factor α (TNF-α). We measured blood flow reconstruction and angiogenesis using laser Doppler blood flowmetry and lead oxide/gelatin angiography, respectively. RESULTS: Exenatide increased the average survival area of the flap and improved microvascular density and blood flow intensity in a dose-dependent manner. Meanwhile, the SOD level was up-regulated and the MDA level down-regulated. Exenatide also enhanced the expression of VEGF and reduced the expression of inflammatory cytokines (IL-6, IL-1ß, NF-κB, TLR4, and TNF-α), thereby promoting angiogenesis and inhibiting inflammation. CONCLUSIONS: Exenatide potentially inhibits necrosis in our rat random skin flap model.

Angiogenic and anti-inflammatory properties of azadirachtin A improve random skin flap survival in rats.

Random skin flaps are widely used to repair tissue defects. However, the distal flap regions are prone to ischemic necrosis, limiting clinical applications. Azadirachtin A, a fruit extract from the neem, improves tissue blood supply and metabolism, reduces cell swelling, promotes tissue healing, and prevents venous thrombosis. We explored whether it enhances random skin flap survival. Fifty-four Sprague-Dawley rats were divided into control, low-dose, and high-dose Azadirachtin A-treated groups using a random number table. We used an improved version of the McFarlane technique to create flaps. On day 2, superoxide dismutase and malondialdehyde levels were measured. Tissue slices prepared on day 7 were stained with hematoxylin and eosin. The expression levels of vascular endothelial growth factor (VEGF), toll-like receptor 4 (TLR4), nuclear factor kappa-B (NF-kB), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were immunohistochemically assayed. Microcirculatory blood flow was measured via laser Doppler blood flowmetry. Flap angiography was performed using the lead-oxide gelatin injection technique. And the azadirachtin A groups exhibited a greater mean flap survival area, an improved mean blood vessel density, a greater blood flow, and higher superoxide dismutase and VEGF levels, especially at the high dose. Azadirachtin A markedly reduced the levels of TNF-α, IL-6, IL-1ß, TLR4, and NF-kB. These findings suggest that azadirachtin A promotes random skin flap survival by improving the blood supply, reducing tissue inflammation, and inhibiting flap ischemia reperfusion injury.

Effects of batroxobin treatment on the survival of random skin flaps in rats.

OBJECTIVE: Batroxobin is a medicinal preparation extracted from the venom of the Fer-de-Lance snake, and is used to lower blood viscosity, promote blood fibrinogen decomposition, and inhibit thrombosis. This research is to investigate whether batroxobin can improve the survival of random skin flaps in a rat model. MATERIALS AND METHODS: Dorsal McFarlane flaps were harvested from 36 rats divided into two groups. Experimental group: Batroxobin was administered via the tail vein once daily. CONTROL GROUP: The same amount of normal saline was injected instead. On day 2, superoxide dismutase (SOD) and malondialdehyde (MDA) levels were measured. On day 7, tissue slices were stained with haematoxylin and eosin. Expression of vascular endothelial growth factor (VEGF) was immunohistochemically evaluated. Microcirculatory flow was measured by laser Doppler flowmetry. Flap angiography, using the lead oxide-gelatin injection technique, was performed with the aid of a soft X-ray machine. RESULTS: The batroxobin group exhibited a greater mean flap survival area, a better microcirculatory flow, and higher-level expression of SOD and VEGF compared with the control group. However, the MDA level was significantly reduced. CONCLUSION: Batroxobin effectively improved the survival of random skin flaps.

Effect of oxytocin on the survival of random skin flaps.

Random flap transplantation is widely used to repair and rebuild skin soft tissue. However, such flaps exhibit poor survival. Plastic surgeons seek to improve flap survival. We explored whether oxytocin improved skin flap survival. Overlength random skin flaps (9 × 3 cm) were established on backs of 80 healthy male SD rats randomly divided into two groups. One group was injected daily with oxytocin (1 mg/kg; test group) and the other with normal saline (control group). On postoperative day 2, malondialdehyde (MDA) and superoxide dismutase (SOD) levels were measured. On postoperative day 7, the flap survival area was measured using transparent graph paper. Microvessel numbers were evaluated histologically by hematoxylin and eosin staining. VEGF expression was assessed immunohistochemically. Angiogenesis was evaluated via lead oxide-gelatin angiography and blood flow via laser Doppler flowmetry. In the test group compared with the control group, the flap survival rate and SOD activity were increased markedly, the MDA level was decreased, and according to hematoxylin and eosin staining, inflammation was significantly attenuated. In addition, the test group exhibited higher levels of VEGF and skin flap angiogenesis. Oxytocin improved flap survival rate by increasing microcirculation and angiogenesis and attenuating ischemia-reperfusion injury.

Effect of Electroacupuncture at The Zusanli Point (Stomach-36) on Dorsal Random Pattern Skin Flap Survival in a Rat Model.

BACKGROUND: Random skin flaps are commonly used for wound repair and reconstruction. Electroacupuncture at The Zusanli point could enhance microcirculation and blood perfusion in random skin flaps. OBJECTIVE: To determine whether electroacupuncture at The Zusanli point can improve the survival of random skin flaps in a rat model. MATERIALS AND METHODS: Thirty-six male Sprague Dawley rats were randomly divided into 3 groups: control group (no electroacupuncture), Group A (electroacupuncture at a nonacupoint near The Zusanli point), and Group B (electroacupuncture at The Zusanli point). McFarlane flaps were established. On postoperative Day 2, malondialdehyde (MDA) and superoxide dismutase were detected. The flap survival rate was evaluated, inflammation was examined in hematoxylin and eosin-stained slices, and the expression of vascular endothelial growth factor (VEGF) was measured immunohistochemically on Day 7. RESULTS: The mean survival area of the flaps in Group B was significantly larger than that in the control group and Group A. Superoxide dismutase activity and VEGF expression level were significantly higher in Group B than those in the control group and Group A, whereas MDA and inflammation levels in Group B were significantly lower than those in the other 2 groups. CONCLUSION: Electroacupuncture at The Zusanli point can effectively improve the random flap survival.

Effects of diammonium glycyrrhizinate on random skin flap survival in rats: An experimental study.

Partial necrosis of skin flaps continues to restrict the survival of local skin flaps following plastic and reconstructive surgeries. The aim of the present study was to investigate the effects of diammonium glycyrrhizinate (DG), a salt of glycyrrhetinic acid that has been widely used in the therapy of chronic hepatitis and human immunodeficiency virus infection, on random skin flap survival in rats. McFarlane flaps were established in 60 male Sprague-Dawley rats randomly divided into three groups. Group I served as the control group and was injected with saline (10 mg/kg) once per day. Group II and group III were the experimental groups, and were injected with 10 mg/kg DG once and twice per day, respectively. On day 7, the survival area of the flap was measured. Tissue samples were stained with hematoxylin and eosin and immunohistochemically evaluated. Tissue edema, neutrophil density, superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels were evaluated. The mean survival areas of the flaps of group II were significantly larger when compared with those of group I (P<0.05), and the rats of group III exhibited significantly higher survival areas than group II (P<0.05). Histologic and immunohistochemical evaluation showed that microvessel development and the expression level of vascular endothelial growth factor were higher in the two experimental groups than in the control group. Furthermore, SOD activity was significantly increased (P<0.05), while the neutrophil density and MDA level were significantly reduced (P<0.05) in group II when compared with group I. Significant differences between group II and group III with regard to SOD activity and MDA level were also observed (P<0.05). Thus, DG may have a dose-dependent effect on promoting the survival of random skin flaps.

Effects of calcitriol on random skin flap survival in rats.

Calcitriol, a metabolite of vitamin D, is often used in osteoporosis clinics. However, the material has other bioactivities; for example, it accelerates angiogenesis, has anti-inflammatory properties, and inhibits oxidative stress. We investigated the effects of calcitriol in a random skin flap rat model. "McFarlane flap" models were established in 84 male Sprague Dawley rats, divided into two groups. One group received intraperitoneal injections of calcitriol (2 µg/kg/day) whereas control rats received intraperitoneal injections of saline. The percentage flap survival area and tissue water content were measured 7 days later, which showed that calcitriol improved flap survival area and reduced tissue edema. It also increased the mean vessel density and upregulated levels of VEGF mRNA/protein, both of which promote flap angiogenesis. Moreover, it decreased leukocyte and macrophage infiltration, reduced the inflammatory proteins IL1ß and IL6, increased SOD activity, decreased MDA content, and upregulated the level of autophagy. Overall, our results suggest that calcitriol promotes skin flap survival by accelerating angiogenesis, having anti-inflammatory effects, reducing oxidative stress, and promoting autophagy.

Correlation between E-cadherin-regulated cell adhesion and human osteosarcoma MG-63 cell anoikis.

PURPOSE: The aim of this study was to investigate the relationship between cell adhesion and anoikis evasion among human osteosarcoma cells (MG-63), and to further study the molecular mechanisms. MATERIALS AND METHODS: Human osteosarcoma cells (MG-63) were assessed for apoptosis, and caspase-3, E-cadherin and ß-catenin expression in EDTA and control non-EDTA groups. RESULTS: MG-63 cells were predominantly aggregated when in suspension, and the suspended cells were more dispersed in the EDTA group. Following culture in suspension for 24 h, 48 h, or 72 h, the rates of apoptosis were 34.88%±3.64%, 59.3%±7.22% and 78.5%±5.21% in the experimental group and 7.34%±2.13%, 14.7%±3.69%, and 21.4%±3.60% in the control group, respectively. Caspase-3 expression progressively increased and E-cadherin and ß-catenin were decreased in the experimental group, whereas there was no change in the control group. CONCLUSIONS: MG-63 cells could avoid anoikis through cell adhesion, and E-cadherin might play a role in this process.

Hyperoside, a flavonoid compound, inhibits proliferation and stimulates osteogenic differentiation of human osteosarcoma cells.

Osteosarcoma, one of the most common malignant bone tumours, is generally considered a differentiation disease caused by genetic and epigenetic disruptions in the terminal differentiation of osteoblasts. Novel therapies based on the non-cytotoxic induction of cell differentiation-responsive pathways could represent a significant advance in treating osteosarcoma; however, effective pharmaceuticals to induce differentiation are lacking. In the present study, we investigated the effect of hyperoside, a flavonoid compound, on the osteoblastic differentiation of U2OS and MG63 osteosarcoma cells in vitro. Our results demonstrated that hyperoside inhibits the proliferation of osteosarcoma cells by inducing G0/G1 arrest in the cell cycle, without causing obvious cell death. Cell migration assay further suggested that hyperoside could inhibit the invasion potential of osteosarcoma cells. Additionally, osteopontin and runt-related transcription factor 2 protein levels and osteocalcin activation were upregulated dramatically in hyperoside-treated osteosarcoma cells, suggesting that hyperoside may stimulates osteoblastic differentiation in osteosarcoma cells. This differentiation was accompanied by the activation of transforming growth factor (TGF)-ß and bone morphogenetic protein-2, suggesting that the hyperoside-induced differentiation involves the TGF-ß signalling pathway. To our knowledge, this study is the first to evaluate the differentiation effect of hyperoside in osteosarcoma cells and assess the possible potential for hyperoside treatment as a future therapeutic approach for osteosarcoma differentiation therapy.

[Effect of hirudin on random skin flap survival in rats].

OBJECTIVE: To investigate the effect of Hirudin on random skin flap survival in rats. METHODS: 24 SD rats were randomly divided into control group and experimental group. The "McFarlane flap (3 cm x 9 cm)" rat models were established on the rat dorsum. 3 ml Hirudin (30 ATU) was injected into the flap in the experimental group, while 3 ml saline in the control group. The injection was performed for 7 days. The flap survival area in the two groups was measured. The tissue samples were taken from proximal (I), middle (II) and distal (III) portions of flaps for histologic study. The VEGF and bFGF expression was also detected with immunohistochemistry method. RESULTS: 7 days after operation, the flap survival rate was (69.52 +/- 3.23)% in the experimental group, while (50.36 +/- 2.37)% in control group, showing a significant difference between the two groups (P < 0. 01). In the middle portion, tissue edema and infiltration of neutrophils in experimental group was markedly slighter than that in control group. The VEGF and bFGF expression and neovascularization was enhanced markedly in experimental group. CONCLUSIONS: Hirudin can increase the survival of random pattern skin flaps. It may increase the VEGF, bFGF expression through a series of complex regulatory pathway. Then flap neovascularization is promoted and the flap blood supply is increased.

[Analysis on recurrence factors associate with giant cell tumor of tendon sheath in upper extremity].

OBJECTIVE: To study the relation of the sex, age, location and chemotherapy with recurrence of the tumor. METHODS: From January 2000 to August 2010, 47 patients with giant cell tumor of tendon sheath in upper extremity were retrospectively analyzed. Statistical analysis of sex, age at presentation, lesion location, chemical inactivation, surgical complications, tumor recurrence and pathological findings were explored. There were 28 females and 19 males, ranging in age from 17 to 78 years, with an average of 38.15 years. All the patients underwent surgical excision. Fourteen patients received intraoperative chemically inactive treatment. All the patients had routine follow-up to observe the wound healing, pathological findings,tumor recurrence, and received necessary imaging examinations. RESULTS: All the patients were followed up, and the duration ranged from 22 to 129 months, with a mean time of 53.89 months. Four patients who received intraoperative alcohol inactivation appeared wound complications such as wound swelling, discharge of necrotic tissue, delayed wound healing. Fifteen patients had active growth of tumor tissue, 1 patient had low-grade malignant giant cell tumor of tendon sheath. The recurrence rate was significantly higher in the group which preoperative X-ray was found to have bone destruction (P = 0.003); patients receiving chemically inactivation had lower risk of recurrence after surgery than patients not receiving chemically inactivation (P = 0.042). CONCLUSION: The recurrence rate of giant cell tumor of tendon sheath in upper limb was closely related to tumor growth site, bone destruction and chemical inactivation. Local excision of giant cell tumor of tendon sheath was the effective treatment. How to identify the patients at high risk of recurrence, how to reduce the recurrence rate and the functional restoration after wide resection are the priorities and difficulties of future researches.

Angiotensin II activates connective tissue growth factor and induces extracellular matrix changes involving Smad/activation and p38 mitogen-activated protein kinase signalling pathways in human dermal fibroblasts.

Angiotensin II (Ang II) stimulation has been shown to regulate proliferation of skin fibroblasts and the production of extracellular matrix, which are very important processes in skin wound healing and fibrosis; however, there is little knowledge about the mechanisms involved in this process. We investigated the molecular aspects of this system with regards to Ang II in human dermal fibroblasts (HDF) and its potential role in fibrosis. Fibroblasts derived from human skin were subjected to examine differential relative gene and protein expression after transfection with specific reporter expression vectors and Ang II in vitro. In growth-arrested HDFs, Ang II treatment for 20 min caused acute activation of Smad2 phosphorylation, Smad overexpression and Smad-dependent gene transcription. The angiotensin type 1 (AT1) antagonist losartan diminished Ang II-induced Smad activation. The blockade of endogenous transforming growth factor-beta1 did modify the activation of Smad caused by Ang II. The p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580 diminished Ang II-induced Smad2 phosphorylation. Transient transfection with Smad7, which interferes with receptor-mediated activation of Smad2, diminished Ang II-induced connective tissue growth factor promoter activation, gene and protein expression and fibronectin, type I procollagen and type III procollagen overexpression, showing that Smad activation is involved in Ang II-induced dermal fibrosis. Our results show that Ang II activation of Smad2 occurs via the AT1 receptor, but not the AT2 receptor. Activation of Smad2 required p38 MAPK but not p42/p44 MAPK or the epidermal growth factor receptor.