Biomedical subjects

P See

Publications and source records attributed to P See.

5 recordsLinked to original sources

PubMed2003

Suppression of insulin-like growth factor signalling pathway and collagen expression in keloid-derived fibroblasts by quercetin: its therapeutic potential use in the treatment and/or prevention of keloids.

BACKGROUND: Keloids are characterized by abnormal proliferation of fibroblasts and overproduction of collagen. Insulin-like growth factor (IGF)-I is mitogenic for fibroblasts and a stimulatory factor for collagen synthesis. OBJECTIVES: We have assessed the in vitro effects of quercetin on proliferation, collagen synthesis and the expression of the IGF system in keloid-derived fibroblasts. METHODS: Fibroblasts were isolated from earlobe keloids and exposed to quercetin at different concentrations. The inhibitory effects of quercetin on fibroblast proliferation were assayed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Western and Northern blot analyses. RESULTS: Quercetin inhibited keloid fibroblast (KF) proliferation in a dose-dependent manner. Significant growth inhibition was observed on day 2 of culture. The dose required for 50% growth inhibition was approximately 25 microg mL-1. Collagen 1 expression was significantly decreased while collagen 3 was almost undetectable following quercetin treatment. Basal levels of IGF-I receptor (IGF-IR) beta subunits, p85 subunit of phosphatidylinositol 3-kinase, c-Raf, phospho-Raf-1, phospho-MEK 1/2, phospho-mitogen-activated protein kinase, phospho-Elk-1 and phospho-Akt-1 were significantly reduced when KF cells were exposed to quercetin for 24 h. Blocking IGF-IR activity with IGF-IR antibody or neutralizing endogenous IGF-I activity with IGF-I antibody led to significant growth inhibition suggesting the role of IGF-I in regulation of KF proliferation. CONCLUSIONS: Because the IGF system plays an important part in fibroblast cell proliferation and collagen production, the described activities of quercetin on the IGF system and collagen expression may provide a novel approach for the use of quercetin in treatment and/or prevention of hypertrophic scar and keloid.

Blotting, Northern↗

PubMed2002

[Individually CAD-CAM technique designed, bioresorbable 3-dimensional polycaprolactone framework for experimental reconstruction of craniofacial defects in the pig].

METHODS: Twenty orbital defects (2 x 2 cm) were created in ten adult Yorkshire pigs. Two software products (Velocity and Mimix) were evaluated with regard to image processing, three-dimensional reconstruction, and fabrication of individually shaped polycaprolactone (PCL) scaffolds to reconstruct these defects. Four different techniques were tested for the reconstruction: group 1 = no reconstruction, group 2 = polylactide sheet, group 3 = PCL scaffold, group 4 = bone marrow-coated PCL scaffold. The pigs were sacrificed at 3 months. RESULTS: In group 1 soft tissue scar formation could be found, but without any new bone. Group 2 showed a thick fibrous capsule around the PLLA sheet, whereas at the border zone of the defect signs of new bone formation could be detected. In group 3 the PCL scaffolds were filled with fibrous tissue and some areas that showed new bone formation (6.4% of the area of the defect). In group 4 the new bone formation (17.8% of the area of the defect) was significantly higher in quantity than in group 3. CONCLUSION: The PCL scaffold coated with bone marrow seems to be a material that effectively provides osteoinduction with formation of new bone. Long-term results at 12 months are still pending.

Absorbable Implants↗

PubMed2001

Protective effects of curcumin against oxidative damage on skin cells in vitro: its implication for wound healing.

BACKGROUND: Curcumin, isolated from turmeric, has been known to possess many pharmacologic properties. It has been proven to exhibit remarkable anticarcinogenic, anti-inflammatory, and antioxidant properties. Turmeric curcumin may be a good potential agent for wound healing. METHODS: To further understand its therapeutic mechanisms on wound healing, the antioxidant effects of curcumin on hydrogen peroxide (H2O2) and hypoxanthine-xanthine oxidase induced damage to cultured human keratinocytes and fibroblasts were investigated. Cell viability was assessed by colorimetric assay and quantification of lactate dehydrogenase release. RESULTS: Exposure of human keratinocytes to curcumin at 10 microg/mL showed significant protective effect against hydrogen peroxide. Interestingly, exposure of human dermal fibroblasts to curcumin at 2.5 microg/mL showed significant protective effects against hydrogen peroxide. No protective effects of curcumin on either fibroblasts or keratinocytes against hypoxanthine-xanthine oxidase induced damage were found in our present studies. CONCLUSION: The findings indicate that curcumin indeed possessed powerful inhibition against hydrogen peroxide damage in human keratinocytes and fibroblasts.

Analysis of Variance↗

PubMed2001

Phenolic compounds of Chromolaena odorata protect cultured skin cells from oxidative damage: implication for cutaneous wound healing.

Extracts from the leaves of Chromolaena odorata have been shown to be beneficial for treatment of wounds. The crude ethanol extract of the plant had been demonstrated to be a powerful antioxidant to protect fibroblasts and keratinocytes in vitro. In this study, the most active compounds were fractionated and identified from the crude extract using liquid chromatography coupled with UV spectroscopy and mass spectrometry. The antioxidant effects of purified fractions on cultured fibroblasts and keratinocytes were investigated using colorimetric and lactate hydrogenase release assay. The results showed that the phenolic acids present (protocatechuic, p-hydroxybenzoic, p-coumaric, ferulic and vanillic acids) and complex mixtures of lipophilic flavonoid aglycones (flavanones, flavonols, flavones and chalcones) were major and powerful antioxidants to protect cultured skin cells against oxidative damage. In conclusion, the extract from C odorata contains a mixture of powerful antioxidant compounds that may be one of potential mechanism contributing to enhanced wound healing.

Antioxidants↗

PubMed2000

The role of alternative therapy in the management of partial thickness burns of the face--experience with the use of moist exposed burn ointment (MEBO) compared with silver sulphadiazine.

INTRODUCTION: Conventional management of partial thickness facial burn wounds includes the use of silver sulphadiazine dressings. Silver sulphadiazine forms an overlying slough that makes wound healing assessment difficult. Moist exposed burn ointment (MEBO) has been proposed as the ideal burn wound dressing both for burns of the face and other sites. Proponents of MEBO claim that it accelerates wound healing and results in scarless wound healing and at the same time reduce bacterial colonisation and the need for analgesics. We present here our experience with MEBO in the management of partial thickness burns of the face. MATERIALS AND METHODS: One hundred and fifteen patients with partial thickness burns were randomly assigned to conventional treatment or MEBO. Out of this, 112 were analysed. Thirty-nine patients sustained facial burns; 17 received MEBO and 22 received silver sulphadiazine. Patients were followed up daily until the burn wounds were reduced by 75% of original body surface area (BSA). RESULTS: In patients with facial burns, MEBO was similar to silver sulphadiazine therapy with respect to rate of wound healing. Minimal slough was present over the wounds in MEBO-treated wounds resulting in clearer assessment of healing progression. CONCLUSIONS: Advantages of MEBO as compared to silver sulphadiazine in the management of partial thickness burns of the face include convenient change of dressing and easier assessment of healing progression. This suggests that MEBO is a useful alternative therapy for partial thickness burns of the face.

Anti-Infective Agents, Local↗