Micro-Computed Tomography Detection of Gold Nanoparticle-Labelled Mesenchymal Stem Cells in the Rat Subretinal Layer.

Mesenchymal stem cells are widely used in many pre-clinical and clinical settings. Despite advances in molecular technology; the migration and homing activities of these cells in in vivo systems are not well understood. Labelling mesenchymal stem cells with gold nanoparticles has no cytotoxic effect and may offer suitable indications for stem cell tracking. Here, we report a simple protocol to label mesenchymal stem cells using 80 nm gold nanoparticles. Once the cells and particles were incubated together for 24 h, the labelled products were injected into the rat subretinal layer. Micro-computed tomography was then conducted on the 15th and 30th day post-injection to track the movement of these cells, as visualized by an area of hyperdensity from the coronal section images of the rat head. In addition, we confirmed the cellular uptake of the gold nanoparticles by the mesenchymal stem cells using transmission electron microscopy. As opposed to other methods, the current protocol provides a simple, less labour-intensive and more efficient labelling mechanism for real-time cell tracking. Finally, we discuss the potential manipulations of gold nanoparticles in stem cells for cell replacement and cancer therapy in ocular disorders or diseases.

Guidelines from an expert panel for the management of diabetic macular edema in the Malaysian population.

AIM: To derive a Malaysia guideline and consensus as part of the Malaysia Retina Group's efforts for diagnosis, treatment, and best practices of diabetic macular edema (DME). The experts' panel suggests that the treatment algorithm to be divided into groups according to involvement the central macula. The purpose of DME therapy is to improve edema and achieve the best visual results with the least amount of treatment load. METHODS: On two different occasions, a panel of 14 retinal specialists from Malaysia, together with an external expert, responded to a questionnaire on management of DME. A consensus was sought by voting after compiling, analyzing and discussion on first-phase replies on the round table discussion. A recommendation was deemed to have attained consensus when 12 out of the 14 panellists (85%) agreed with it. RESULTS: The terms target response, adequate response, nonresponse, and inadequate response were developed when the DME patients' treatment responses were first characterized. The panelists reached agreement on a number of DME treatment-related issues, including the need to classify patients prior to treatment, first-line treatment options, the right time to switch between treatment modalities, and side effects associated with steroids. From this agreement, recommendations were derived and a treatment algorithm was created. CONCLUSION: A detail and comprehensive treatment algorithm by Malaysia Retina Group for the Malaysian population provides guidance for treatment allocation of patients with DME.

Sturge-Weber-Syndrome with extreme ocular manifestation and rare association of upper airway angioma with anticipated difficult airway.

We report a rare case of an 18 year old girl with Sturge-Weber syndrome, she had extensive facial port wine stains, right bupthalmos and advanced glaucoma involving both eyes. She underwent right eye glaucoma drainage device surgery under general anaesthesia, and had a difficult intubation due to extensive angiomatous like soft tissue swelling at her upper airway. This report highlights the importance of being aware of the need for continuous follow-up in Sturge-Weber syndrome patients as this syndrome can lead to blindness due to advance glaucoma and the awareness of possible difficult intubation for this group of patients.

Photodynamic therapy for polypoidal choroidal vasculopathy secondary to choroidal nevus.

We report a case of a Caucasian female who developed active polypoidal choroidal vasculopathy (PCV) at the edge of a stable choroidal nevus and was successfully treated with verteporfin photodynamic therapy. No active polyp was detectable on indocyanine green angiography 2 years after treatment, and good vision was maintained. Indocyanine green angiography is a useful investigation to diagnose PCV and may be underutilized. Unlike treatment of choroidal neovascularization secondary to choroidal nevus, management of PCV secondary to nevus may not require intravitreal anti-vascular endothelial growth factor therapy. Photodynamic monotherapy may be an effective treatment of secondary PCV.

POLYPOIDAL CHOROIDAL VASCULOPATHY SECONDARY TO A STABLE CHOROIDAL NEVUS.

PURPOSE: Choroidal nevus is the most common ocular fundus tumor in adults. Previous studies have widely discussed the features of choroidal neovascularization secondary to nevus and its treatment options. Polypoidal choroidal vasculopathy (PCV) is an exudative chorioretinopathy that is often underdiagnosed. Clinical features, natural history, and treatment response of PCV are distinct from occult choroidal neovascularization. Polypoidal choroidal vasculopathy secondary to choroidal nevus has not been previously documented. We report a patient with a history of stable choroidal nevus who developed a polypoidal lesion at the edge of the nevus lesion. METHODS: A white woman who presented with a choroidal nevus and clinical features of PCV was examined using fundoscopy, optical coherence tomography, fluorescein angiography, and indocyanine green angiography. RESULTS: A polypoidal lesion with an associated branching vascular network adjacent to the nevus was demonstrated by optical coherence tomography, fluorescein angiography, and indocyanine green angiography. The patient was asymptomatic and was managed conservatively. CONCLUSION: Our case showed that PCV developing in association with a stable choroidal nevus. Pathogenic mechanisms of this condition may include chronic degenerative or inflammatory changes at the level of the retinal pigment epithelium resulting in vascular changes. Unlike treatment of occult choroidal neovascularization secondary to nevus, optimal management of PCV secondary to nevus may vary. Indocyanine green angiography is the gold standard for the diagnosis of PCV and is a useful investigation in atypical choroidal neovascularization.

Mapping the excited states of single hexa-peri-benzocoronene oligomers.

Electronic states of a molecule are usually analyzed via their decomposition in linear superposition of multielectronic Slater determinants built up from monoelectronics molecular orbitals. It is generally believed that a scanning tunneling microscope (STM) is able to map those molecular orbitals. Using a low-temperature ultrahigh vacuum (LT-UHV) STM, the dI/dV conductance maps of large single hexabenzocoronene (HBC) monomer, dimer, trimer, and tetramer molecules were recorded. We demonstrate that the attribution of a tunnel electronic resonance to a peculiar π molecular orbital of the molecule (or σ intermonomer chemical bond) in the STM junction is inappropriate. With an STM weak-measurement-like procedure, a dI/dV resonance results from the conductance contribution of many molecular states whose superposition makes it difficult to reconstruct an apparent molecular orbital electron probability density map.