A case of melanoma-associated retinopathy with autoantibodies against TRPM1.

PURPOSE: To report a case of melanoma-associated retinopathy (MAR) with autoantibodies against the transient receptor potential cation channel, subfamily M, member 1 (TRPM1) with asymmetric severe vision loss. METHODS: We evaluated a patient with heel skin melanoma showing progressive vision loss in both eyes confirmed with a baseline ophthalmic examination, fluorescein angiography, spectral domain optical coherence tomography (OCT), visual field test, and full-field electroretinogram (ERG). Immunofluorescence assays and western blot analysis revealed autoantibodies in the patient's serum. RESULTS: The patient's best-corrected visual acuities were 20/50 in the right eye and hand motion in the left eye. Visual field test showed severely depressed visual fields especially in the left eye. Fluorescein angiography and OCT revealed extrafoveal choroidal neovascularization in the left eye. The patient had an electronegative ERG, suggesting MAR, and autoantibodies against TRPM1 and aldolase C were detected in the patient's blood sample. CONCLUSIONS: The clinical features of MAR patients with positive anti-TRPM1 autoantibodies can be manifested as severe vision loss, and the identification of autoantibodies can be helpful for confirming the diagnosis.

Enhancement of tendon-bone healing with the use of bone morphogenetic protein-2 inserted into the suture anchor hole in a rabbit patellar tendon model.

BACKGROUND AIMS: Suture anchor fixation failure has been reported as a result of anchor loosening and migration during the tendon-bone repair. The aim of this study was to evaluate the effects of bone morphogenetic protein-2 (BMP-2) inserted into the suture anchor hole on bone formation and the tendon-bone healing. METHODS: Both back legs of 24 New Zealand White rabbits (n = 48) were used in this study. A metal suture anchor was then placed 5 mm below the cortex. In the control group, the space over the eyelet of the anchor (suture anchor hole) was not filled. In the experimental group, the suture anchor hole was filled with 0.1 mL of fibrin glue (group 2) or collagen gel (group 3) with 1 µg BMP-2. Histologic analysis, real-time-polymerase chain reaction, bone density and failure load measurement were performed, and differences were analyzed at 4 and 8 weeks. RESULTS: Histologic analysis revealed more abundant new bone, mature bone and organized fibrocartilage at the tendon-bone interface at 4 and 8 weeks in groups in which BMP-2 was applied. At 8 weeks, the failure load of groups 1, 2 and 3 was significantly different among the three groups (P = 0.01). After post hoc Tukey test, the failure load of group 2 was significantly higher than that of group 1 (P = 0.01). CONCLUSIONS: BMP-2, administrated as described in this study, improved tendon-bone healing and bone formation, resulting in improved biomechanical strength of the tendon-bone junction.

Optimal condition of heparin-conjugated fibrin with bone morphogenetic protein-2 for spinal fusion in a rabbit model.

BACKGROUND AIMS: Heparin-conjugated fibrin (HCF) is a carrier for long-term release of bone morphogenetic protein-2 (BMP-2) and has been shown to promote bone formation in animal models. We performed an experimental study to determine the optimal dose of BMP-2 with an HCF carrier that promotes bone formation comparable to that of autograft while minimizing complications in spinal fusion. METHODS: Twenty-four rabbits underwent posterolateral fusion of the L5-6 spinal segments. Different concentrations of HCF BMP-2 (1/10, 1/20, 1/30 or 1/40) were implanted in the spines of experimental rabbits, and autograft or INFUSE was implanted in the spines of control animals. Eight weeks after treatment, spinal fusion efficacy was evaluated by plain radiography, micro-computed tomography (micro-CT), mechanical testing and histomorphometry. RESULTS: Similar to autograft, the 1/40 HCF BMP-2 showed significant bone formation on micro-CT and histomorphometry with mechanical stability. However, the other HCF BMP-2 concentrations did not show significant bone formation compared with autograft. Although conventional BMP-2 (INFUSE) led to higher bone formation and stability, it also led to excessive ectopic bone and fibrous tissue formation. CONCLUSIONS: This study suggests the optimal concentration of BMP-2 using HCF for spinal fusion, which may decrease the complications of high-dose conventional BMP-2.

Combination therapy with BMP-2 and BMSCs enhances bone healing efficacy of PCL scaffold fabricated using the 3D plotting system in a large segmental defect model.

The three-dimensional (3D) plotting system is a rapidly-developing scaffold fabrication method for bone tissue engineering. It yields a highly porous and inter-connective structure without the use of cytotoxic solvents. However, the therapeutic effects of a scaffold fabricated using the 3D plotting system in a large segmental defect model have not yet been demonstrated. We have tested two hypotheses: whether the bone healing efficacy of scaffold fabricated using the 3D plotting system would be enhanced by bone marrow-derived mesenchymal stem cell (BMSC) transplantation; and whether the combination of bone morphogenetic protein-2 (BMP-2) administration and BMSC transplantation onto the scaffold would act synergistically to enhance bone regeneration in a large segmental defect model. The use of the combined therapy did increase bone regeneration further as compared to that with monotherapy in large segmental bone defects.

Preclinical Efficacy and Safety of VEGF-Grab, a Novel Anti-VEGF Drug, and Its Comparison to Aflibercept.

Purpose: VEGF-Grab is a novel anti-vascular endothelial growth factor (VEGF) candidate drug with higher affinity to both VEGF and placental growth factor (PlGF) compared to aflibercept. We investigated the preclinical efficacy of VEGF-Grab for ophthalmic therapy and compared it to that of aflibercept. Methods: The in vitro anti-VEGF efficacy of VEGF-Grab was determined using VEGF-induced cell proliferation/migration and tube formation assays. The in vivo antiangiogenic efficacy of intravitreal injection of either VEGF-Grab or aflibercept was evaluated using murine models of ocular angiogenesis: mouse oxygen-induced retinopathy (OIR) and rat laser-induced choroidal neovascularization (CNV). The in vivo retinal toxicity in the mouse eye resulting from the injection of either drug was evaluated with light and electron microscopy. Results: VEGF-Grab showed greater inhibition of VEGF-induced cell proliferation/migration than aflibercept, but it showed comparable inhibition of tube formation in vitro. In the in vivo OIR model, VEGF-Grab showed a comparable suppression of retinal neovascularization compared to aflibercept. Additionally, VEGF-Grab showed an efficacy similar to that of aflibercept in terms of CNV inhibition in the laser-induced CNV model. Histology and transmission electron microscopy showed no significant signs of toxicity in the mouse retina at 7 and 30 days following the intravitreal injection of VEGF-Grab or aflibercept. Conclusions: Compared to aflibercept, VEGF-Grab presented comparable in vivo antiangiogenic efficacy and superior in vitro anti-VEGF activity. The retinal safety profiles were comparable for the two drugs. Considering its known higher binding affinity to VEGF and PlGF compared to aflibercept, VEGF-Grab could be a potential candidate drug for neovascular retinal diseases and an alternative to aflibercept.

Effect of Leukocyte-Rich and Platelet-Rich Plasma on Healing of a Horizontal Medial Meniscus Tear in a Rabbit Model.

There are limited reports on the effect of platelet-rich plasma (PRP) on meniscus healing. The purpose of this study was to investigate the effect of leukocyte-rich PRP (L-PRP) on potential healing of the horizontal medial meniscus tears in a rabbit model. A horizontal medial meniscus tear was created in both knees of nine skeletally mature adult rabbits. Left or right knees were randomly assigned to a L-PRP group, or a control group. 0.5 mL of L-PRP from 10 mL of each rabbit's whole blood was prepared and injected into the horizontal tears in a L-PRP group. None was applied to the horizontal tears in a control group. The histological assessment of meniscus healing was performed at two, four, and six weeks after surgery. We found that there were no significant differences of quantitative histologic scoring between two groups at 2, 4, and 6 weeks after surgery (p > 0.05). This study failed to show the positive effect of single injection of L-PRP on enhancing healing of the horizontal medial meniscus tears in a rabbit model. Single injection of L-PRP into horizontal meniscus tears may not effectively enhance healing of horizontal medial meniscus tears.

Immobilization of fibronectin onto a large area nanoimprinted polystyrene patterns.

A well known fibrous protein, fibronectin was successfully immobilized onto well-fabricated nanopatterns of polystyrene (PS) substrates. The nanopatterns with finely-defined physical dimensions were obtained by nanoimprinting lithography (NIL) using anodized aluminum oxide (AAO) molds of which the pore sizes were controlled in nanometer scale; 45 nm, 250 nm and 410 nm for the widths and 110 nm and 500 nm for the pitches. Discrete changes of the surface images before and after the protein-adsorption on the patterns were demonstrated by scanning electron microscope (SEM), and the effect of the patterned features on the immobilization has been investigated and discussed.