An Intelligent Optical Coherence Tomography-based System for Pathological Retinal Cases Identification and Urgent Referrals.

Purpose: This study aimed to develop an automated system with artificial intelligence algorithms to comprehensively identify pathologic retinal cases and make urgent referrals. Methods: To build and test the intelligent system, this study obtained 28,664 optical coherence tomography (OCT) images from 2254 patients in the Eye and ENT Hospital of Fudan University (EENT Hospital) and Shanghai Tenth People's Hospital (TENTH Hospital). We applied a deep learning model with an adapted feature pyramid network to detect 15 categories of retinal pathologies from OCT images as common signs of various retinal diseases. Subsequently, the pathologies detected in the OCT images and thickness features extracted from retinal thickness measurements were combined for urgent referral using the random forest tool. Results: The retinal pathologies detection model had a sensitivity of 96.39% and specificity of 98.91% from the EENT Hospital test dataset, whereas those from the TENTH Hospital test dataset were 94.89% and 98.76%, respectively. The urgent referral model achieved accuracies of 98.12% and 98.01% from the EENT Hospital and TENTH Hospital test datasets, respectively. Conclusions: An intelligent system capable of automatically identifying pathologic retinal cases and offering urgent referrals was developed and demonstrated reliable performance with high sensitivity, specificity, and accuracy. Translational Relevance: This intelligent system has great value and practicability in communities where exist increasing cases of retinal disease and a lack of ophthalmologists.

A novel model of persistent retinal neovascularization for the development of sustained anti-VEGF therapies.

Anti-vascular endothelial growth factor (VEGF) therapies lead to a major breakthrough in treatment of neovascular retinal diseases such as age-related macular degeneration or diabetic retinopathy. Current management of these conditions require regular and frequent intravitreal injections to prevent disease recurrence once the effect of the injected drug wears off. This has led to a pressing clinical need of developing sustained release formulations or therapies with longer duration. A major drawback in developing such therapies is that the currently available animal models show spontaneous regression of vascular leakage. They therefore not only fail to recapitulate retinal vascular disease in humans, but also prevent to discern if regression is due to prolonged therapeutic effect or simply reflects spontaneous healing. Here, we described the development of a novel rabbit model of persistent retinal neovascularization (PRNV). Retinal Müller glial are essential for maintaining the integrity of the blood-retinal barrier. Intravitreal injection of DL-alpha-aminoadipic acid (DL-AAA), a selective retinal glial (Müller) cell toxin, results in persistent vascular leakage for up to 48 weeks. We demonstrated that VEGF concentrations were significantly increased in vitreous suggesting VEGF plays a significant role in mediating the leakage observed. Intravitreal administration of anti-VEGF drugs (e.g. bevacizumab, ranibizumab and aflibercept) suppresses vascular leakage for 8-10 weeks, before recurrence of leakage to pre-treatment levels. All three anti-VEGF drugs are very effective in re-ducing angiographic leakage in PRNV model, and aflibercept demonstrated a longer duration of action compared with the others, reminiscent of what is observed with these drugs in human in the clinical setting. Therefore, this model provides a unique tool to evaluate novel anti-VEGF formulations and therapies with respect to their duration of action in comparison to the currently used drugs.

GSK3ß regulates Bcl2L12 and Bcl2L12A anti-apoptosis signaling in glioblastoma and is inhibited by LiCl.

BCL2L12 has been reported to be involved in post-mitochondrial apoptotic events in glioblastoma, but the role of BCL2L12A, a splicing variant of BCL2L12, remains unknown. In this study, we showed that BCL2L12 and BCL2L12A were overexpressed in glioblastoma multiforme (GBM). Large-scale yeast two-hybrid screening showed that BCL2L12 was a GSK3b binding partner in a testis cDNA library. Our data demonstrated that GSK3b interacts with BCL2L12 but not BCL2L12A, whose C terminus lacks a binding region. We found that a BCL2L12(153-191) fragment located outside of the C-terminal BH2 motif is responsible for GSK3b binding. In contrast, no interaction was detected between BCL2L12A and GSK3b. In vitro kinase and l-phosphatase assays showed that GSK3b phosphorylates BCL2L12 at S156, while this site is absent on BCL2L12A. Moreover, our data also showed that the BCL2L12(153-191) fragment directly interrupted GSK3bmediated Tau phosphorylation in a dose-dependent manner. Ectopic expression of GFP-fused BCL2L12 or BCL2L12A in U87MG cells leads to repression of apoptotic markers and protects against staurosporine (STS) insults, indicating an antiapoptotic role for both BCL2L12 and BCL2L12A. In contrast, no anti-apoptotic ability was seen in BCL2L12(S156A). When BCL2L12-expressing U87MG cells were co-administrated with STS and LiCl, cells underwent apoptosis. This effect could be reversed by LiCl. In short, we established a model to demonstrate that GSK3b interacts with and phosphorylates BCL2L12 and might also affect BCL2L12A to modulate the apoptosis signaling pathway in glioblastoma. These findings suggest that LiCl may be a prospective therapeutic agent against GBM.

Differential expression of hedgehog signaling components and Snail/E-cadherin in human brain tumors.

The hedgehog (Hh) transcription factor Gli induces transformation of epithelial cells via induction of Snail, a repressor of E-cadherin. Epithelial-mesenchymal transition is also a determinant of the progression of tumorigenesis, following down-regulation of E-cadherin. However, the role of Hh signaling components and Snail/E-cadherin in brain tumors is not yet fully understood. We analyzed the expression of Hh signaling components and Snail/E-cadherin in 69 brain tumors by reverse transcription-polymerase chain reaction (RT-PCR). The data showed that overexpression of Smo (35/69), Ptch (50/69), Gli1 (56/69), Gli2 (29/69) and N-myc (39/69) might contribute to brain tumorigenesis. Our results also indicated that Snail and E-cadherin showed opposing expression in malignant tumors (high grade astrocytoma and metastasis). Snail and E-cadherin showed less correlation in benign brain tumors. We further investigated mutations of Gli2 and Snail by RT-PCR and direct sequencing. No mutation was observed on Gli2 but several sporadic mutations on Snail were found, including S96G, S111L, S111L/S119Y and one nonsense mutation at codon 158 (Y158*). An in vitro E-cadherin promoter assay showed that S96G, S111L, S111L/S119Y Snail mutants were decreased by 15, 25 and 50%, respectively, whereas Y158* was increased by 40% compared to wild-type. Furthermore, our data showed that wild-type Snail and S96G, S111L, S111L/S119Y translocated to the nucleus, while the Y158* mutant failed to translocate to the nucleus. Taken together, our results demonstrate that Hh signaling components, the expression and mutations of Snail and the expression of E-cadherin may play an important role in human brain tumorigenesis.

Molecular orientation and film structure of gramicidin on highly oriented pyrolitic graphite.

Gramicidin molecules were deposited on HOPG surfaces to characterize molecular orientation and film structure as a function of surface coverage and temperature. At low coverage (0.35 ML), the molecules adopted a flat-lying orientation and formed dendritic islands. At higher coverage (0.86 ML), molecules adopted an upright orientation and circular holes formed in the films. The upright film exhibited higher adhesion in force spectroscopy measurements, supporting our molecular orientation assignments. At elevated deposition temperatures (50 °C) on the higher coverage films, the holes were still present, but partially filled in. At 60 °C the film structure was quite different, forming tall irregular islands without the circular holes observed at lower temperatures. These results demonstrate that gramicidin molecular orientation and film structure on HOPG can be controlled by tuning the surface coverage and deposition temperature.

Improved performance of aminopropylsilatrane over aminopropyltriethoxysilane as an adhesive film for anchoring gold nanoparticles on silicon surfaces.

Aminopropylsilatrane (AP-silatrane) was investigated as an adhesive layer for anchoring Au nanoparticles on silicon substrates. We compared the preparation procedure and film quality of the AP-silatrane films to those of 3-aminopropyltriethoxysilane (APTES), which is commonly used for nanoparticle attachment on silicon. The films were characterized by Fourier Transform infrared (FTIR) spectroscopy, contact angle measurements, and atomic force microscopy (AFM). The process for preparing the AP-silatrane films was much easier and resulted in more reproducibly high quality films due to its insensitivity to water. In surface roughness measurements, we observed a 39% increase (99 pm RMS) for the AP-silatrane film over that of a plasma-cleaned silicon sample (71 pm RMS). In contrast, we observed a 218% increase (226 pm RMS) for the APTES film. The much higher roughness observed for the APTES film was due to its sensitivity to water, which results in molecular aggregate formation and polymerization. Gold nanoparticles (7.5 nm) were deposited and firmly anchored to both types of film surfaces. The measured height of the particles on the films was less than the actual size of the particles, and plasma treatment was used to remove the organic layer, resulting in a corrected measurement of the particle size. AP-silatrane offers an easy preparation procedure that creates a smooth, aggregate-free adhesive layer for anchoring Au nanoparticles strongly to silicon substrates.

Seroprevalence of chronic hepatitis B virus infection among taiwanese human immunodeficiency virus type 1-positive persons in the era of nationwide hepatitis B vaccination.

OBJECTIVES: We aimed to assess the impact of nationwide hepatitis B virus (HBV) vaccination program on the seroprevalence of HBV infection among human immunodeficiency virus (HIV)-positive persons in a country where most HBV exposure occurs during the perinatal period or in early childhood. METHODS: Data on HBV surface antigen (HBsAg), anti-HBV surface (anti-HBs), anti-HBV core (anti-HBc), and anti-hepatitis C virus (anti-HCV) antibody were retrospectively collected from 3,164 HIV-positive and 2,594 HIV-negative persons between 2004 and 2007. Comparisons of serological markers of HBV and HCV were made between HIV-positive and -negative adults born before and after the implementation of the HBV vaccination program in Taiwan in July 1984. RESULTS: Compared with HIV-negative persons, the adjusted odds ratio for HBsAg seropositivity was 1.100 (95% confidence interval, 0.921-1.315) among HIV-positive persons. Although the seroprevalence of anti-HCV antibody remained similar between HIV-positive persons born before and those born after 1984, the seroprevalence of HBsAg declined from 20.3 to 3.3% in HIV-positive persons (P<0.001) and from 15.5 to 8.5% in HIV-negative persons (P<0.001). Despite the high seroprevalence of anti-HCV antibody (97.1%) in HIV-positive injecting drug users (IDUs), there was no statistically significant difference in the seroprevalence of HBsAg (5.6% vs. 8.5%, P=0.75) or anti-HBc antibody (40.7% vs. 27.9%, P=0.14) between HIV-positive IDUs and HIV-negative persons who were born after 1984. CONCLUSIONS: Our study showed a significant decline of seroprevalence of HBV infection among both HIV-negative and -positive persons who were born in the era of the nationwide HBV vaccination in Taiwan.

Assessment of capsular block syndrome with anterior segment optical coherence tomography.

A 59-year-old woman developed progressive, moderate myopia 1 year after routine phacoemulsification and insertion of a soft posterior chamber intraocular lens (IOL). After biomicroscopy, late capsular block was diagnosed and treated with a neodymium:YAG laser posterior capsulotomy. The myopia disappeared immediately. This case was illustrated using optical coherence tomography developed for the anterior segment. After capsulotomy, the IOL moved backward by 448 microm, corresponding to -0.75 diopter of induced myopia.

Static and dynamic analysis of the anterior segment with optical coherence tomography.

PURPOSE: To study biometric modifications of the anterior segment with accommodation and age and determine possible applications in areas of anterior segment surgery, particularly implantation of refractive lenses. SETTING: Clinique Monticelli, Marseille, France. METHOD: The study comprised subjects between 7 years of age and 82 years of age in whom anterior chamber biometry was evaluated using 1,310 nm wavelength optical coherence tomography (OCT). The equipment has a fixation target that can be focused and defocused with negative lenses to stimulate natural accommodation. All measurements were performed by the same operator. The horizontal diameter of the AC, the anterior chamber depth (ACD), the horizontal pupil diameter, and the horizontal radius of curvature of the crystalline lens' anterior pole were measured in the unaccommodated state and after stimulating accommodation. RESULTS: Fifty-six subjects (104 eyes) were included; the refractions ranged from +5.0 diopters (D) to -5.0 D. The static and dynamic measurements were compared with ametropia, age, and accommodation. At rest, the mean AC diameter was 12.334 mm, the mean ACD was 3.106 mm, and the mean pupil diameter was 4.258 mm. With 1.0 D of accommodation, the anterior pole moved forward by a mean of 30 microm, the radius of curvature decreased 0.3 mm, and the pupil diameter decreased 0.15 mm. CONCLUSIONS: The AC OCT is a user-friendly instrument for evaluating the anterior segment and examining the AC (cornea, iris, crystalline lens, and iridocorneal angle). The 1,310 nm light wavelength is blocked by pigments, preventing examination behind the iris. However, the AC OCT is capable of good image quality and visualization of the anatomical relationships in the anterior segment, even behind an opaque cornea.

Contact between 3 phakic intraocular lens models and the crystalline lens: an anterior chamber optical coherence tomography study.

Three phakic intraocular lens (IOL) models were implanted in 3 different patients. With the usual slitlamp examination, it was not possible to determine whether there was contact between the IOLs and the natural crystalline lens. Using the anterior chamber optical coherence tomography (AC OCT) scanner, direct contact between the natural crystalline lens and the 3 phakic IOLs was revealed. A dynamic study of the contact was performed during accommodation. These observations show that examination of the anterior segment with the AC OCT scanner provides new data about the status of the anterior segment after implantation of phakic IOLs.

Anterior chamber optical coherence tomography study of human natural accommodation in a 19-year-old albino.

Anterior segment optical coherence tomography is a new method to explore the anterior chamber. The target can be focused and defocused with positive or negative lenses to reproduce the conditions of natural accommodation. We studied accommodation in an albino patient because the absence of pigment allows the infrared beam to penetrate the iris and explore the modifications of the ciliary body and the crystalline lens during natural accommodation in a human subject.