UNLABELLED: Oral delivery of poorly soluble and permeable drugs represents a significant challenge in drug development. The oral delivery of drugs remains to be the ultimate route of any drugs. However, in many cases, drugs are not absorbed well in the gastrointestinal tract, or they lose their activity. Polymer micelles were recognized as an effective carrier system for drug encapsulation, and are now studied as a vehicle for oral delivery of insoluble compounds. We characterized the properties of monomethoxy polyethylene glycol-poly lactic acid (mPEG-PLA) micelles, and visualized their internalization in mouse small intestine. Using Caco-2 cells as a cellular model, we studied the kinetics of particle uptake, their transport, and the molecular mechanism of their intestinal absorption. Moreover, by inhibiting specific endocytosis pathways, pharmacologically and genetically, we found that mPEG-PLA nanoparticle endocytosis is mediated by clathrin in an energy-dependent manner, and that the low-density lipoprotein receptor is involved. FROM THE CLINICAL EDITOR: Many current drugs used are non-water soluble and indeed, the ability to deliver these drugs via the gastrointestinal tract remains the holy grail for many researchers. The authors in this paper developed monomethoxy polyethylene glycol-poly lactic acid (mPEG-PLA) micelles as a drug nanocarrier, and studied the mechanism of uptake across intestinal cells. The findings should improve our current understanding and point to the development of more nanocarriers.
OBJECTIVE: Patients suffering from corneal neuropathy may present with photoallodynia; i.e., increased light sensitivity, frequently with a normal slit-lamp examination. This study aimed to evaluate the efficacy of autologous serum tears (AST) for treatment of severe photoallodynia in corneal neuropathy and to correlate clinical findings with corneal subbasal nerve alterations by in vivo confocal microscopy (IVCM). METHODS: Retrospective case control study with 16 patients with neuropathy-induced severe photoallodynia compared to 16 normal controls. Symptom severity, clinical examination and bilateral corneal IVCM scans were recorded. RESULTS: All patients suffered from extreme photoallodynia (8.8±1.1) with no concurrent ocular surface disease. Subbasal nerves were significantly decreased at baseline in patients compared to controls; total nerve length (9208±1264 vs 24714±1056 μm/mm(2); P<.0001) and total nerve number (9.6±1.4 vs 28.6±2.0; P<.0001), respectively. Morphologically, significantly increased reflectivity (2.9±0.2 vs 1.8±0.1; P<.0001), beading (in 93.7%), and neuromas (in 62.5%) were seen. AST (3.6±2.1 months) resulted in significantly decreased symptom severity (1.6±1.7; P=.02). IVCM demonstrated significantly improved nerve parameters (P<.005), total nerve length (15451±1595 μm/mm(2)), number (13.9±2.1), and reflectivity (1.9±0.1). Beading and neuromas were seen in only 56.2% and 7.6% of patients. CONCLUSION: Patients with corneal neuropathy-induced photoallodynia show profound alterations in corneal nerves. AST restores nerve topography through nerve regeneration, and this correlated with improvement in patient-reported photoallodynia. The data support the notion that corneal nerve damage results in alterations in afferent trigeminal pathways to produce photoallodynia.
IMPORTANCE: Optimization of glycemic control is critical to reduce the number of diabetes mellitus-related complications, but long-term success is challenging. Although vision loss is among the greatest fears of individuals with diabetes, comprehensive personalized diabetes education and risk assessments are not consistently used in ophthalmologic settings. OBJECTIVE: To determine whether the point-of-care measurement of hemoglobin A1c (HbA1c) and personalized diabetes risk assessments performed during retinal ophthalmologic visits improve glycemic control as assessed by HbA1c level. DESIGN, SETTING, AND PARTICIPANTS: Ophthalmologist office-based randomized, multicenter clinical trial in which investigators from 42 sites were randomly assigned to provide either a study-prescribed augmented diabetes assessment and education or the usual care. Adults with type 1 or 2 diabetes enrolled into 2 cohorts: those with a more-frequent-than-annual follow-up (502 control participants and 488 intervention participants) and those with an annual follow-up (368 control participants and 388 intervention participants). Enrollment was from April 2011 through January 2013. INTERVENTIONS: Point-of-care measurements of HbA1c, blood pressure, and retinopathy severity; an individualized estimate of the risk of retinopathy progression derived from the findings from ophthalmologic visits; structured comparison and review of past and current clinical findings; and structured education with immediate assessment and feedback regarding participant's understanding. These interventions were performed at enrollment and at routine ophthalmic follow-up visits scheduled at least 12 weeks apart. MAIN OUTCOMES AND MEASURES: Mean change in HbA1c level from baseline to 1-year follow-up. Secondary outcomes included body mass index, blood pressure, and responses to diabetes self-management practices and attitudes surveys. RESULTS: In the cohort with more-frequent-than-annual follow-ups, the mean (SD) change in HbA1c level at 1 year was -0.1% (1.5%) in the control group and -0.3% (1.4%) in the intervention group (adjusted mean difference, -0.09% [95% CI, -0.29% to 0.12%]; P = .35). In the cohort with annual follow-ups, the mean (SD) change in HbA1c level was 0.0% (1.1%) in the control group and -0.1% (1.6%) in the intervention group (mean difference, -0.05% [95% CI, -0.27% to 0.18%]; P = .63). Results were similar for all secondary outcomes. CONCLUSIONS AND RELEVANCE: Long-term optimization of glycemic control is not achieved by a majority of individuals with diabetes. The addition of personalized education and risk assessment during retinal ophthalmologic visits did not result in a reduction in HbA1c level compared with usual care over 1 year. These data suggest that optimizing glycemic control remains a substantive challenge requiring interventional paradigms other than those examined in our study. TRIAL REGISTRATION: clinicaltrials.gov Identifier:NCT01323348.
We report the whole-genome sequence (WGS) of an in vitro susceptible derivative revertant mutant from a bloodstream isolate involved in a nosocomial outbreak in Brazil. The WGS comprises 2.5 Mb with 2,500 protein-coding sequences, 16rRNA genes, and 60 tRNA genes.
NR2E3 encodes the photoreceptor-specific nuclear hormone receptor that acts as a repressor of cone-specific gene expression in rod photoreceptors, and as an activator of several rod-specific genes. Recessive variants located in the ligand-binding domain (LBD) of NR2E3 cause enhanced short wavelength sensitive- (S-) cone syndrome (ESCS), a retinal degeneration characterized by an excess of S-cones and non-functional rods. We analyzed the dimerization properties of NR2E3 and the effect of disease-causing LBD missense variants by bioluminescence resonance energy transfer (BRET(2) ) protein interaction assays. Homodimerization was not affected in presence of p.A256V, p.R039G, p.R311Q, and p.R334G variants, but abolished in presence of p.L263P, p.L336P, p.L353V, p.R385P, and p.M407K variants. Homology modeling predicted structural changes induced by NR2E3 LBD variants. NR2E3 LBD variants did not affect interaction with CRX, but with NRL and rev-erbα/NR1D1. CRX and NRL heterodimerized more efficiently together, than did either with NR2E3. NR2E3 did not heterodimerize with TLX/NR2E1 and RXRα/NR2C1. The identification of a new compound heterozygous patient with detectable rod function, who expressed solely the p.A256V variant protein, suggests a correlation between LBD variants able to form functional NR2E3 dimers and atypical mild forms of ESCS with residual rod function.
PURPOSE: The aim of this study was to compare patient-reported symptoms of dry eye disease (DED) as assessed by the Ocular Surface Disease Index (OSDI), a 12-item symptom frequency-based questionnaire, and the Symptom Assessment iN Dry Eye (SANDE), a 2-item frequency- and severity-based visual analog scale. DESIGN: Clinic-based evaluation of a diagnostic test. PARTICIPANTS: A total of 114 patients with DED. METHODS: Patients were administered the OSDI and SANDE questionnaires at baseline and follow-up visits to evaluate DED-related symptoms. The correlations between both questionnaires' scores were evaluated using the Spearman coefficient, and their clinical differences were assessed using Bland-Altman analysis. MAIN OUTCOME MEASURES: Baseline and follow-up visit OSDI and SANDE dry eye symptom scores. RESULTS: At the baseline visit, the OSDI and SANDE questionnaire scores were significantly correlated (R = 0.64; P < 0.001). Moreover, a significant correlation was found between changes in the OSDI and SANDE scores from baseline to follow-up visits (R = 0.47; P < 0.001). A Bland-Altman analysis, after score normalization, revealed a difference (bias) of less than 2 centesimal units between the scores of the 2 questionnaires. CONCLUSIONS: Data collected from the SANDE questionnaire showed a significant correlation and negligible score differences with those from the OSDI, suggesting that the SANDE visual analog scale-based questionnaire has the potential to provide clinicians with a short, quick, and reliable measure for DED symptoms.
Organismal development requires the precise coordination of genetic programs to regulate cell fate and function. MEF2 transcription factors (TFs) play essential roles in this process but how these broadly expressed factors contribute to the generation of specific cell types during development is poorly understood. Here we show that despite being expressed in virtually all mammalian tissues, in the retina MEF2D binds to retina-specific enhancers and controls photoreceptor cell development. MEF2D achieves specificity by cooperating with a retina-specific factor CRX, which recruits MEF2D away from canonical MEF2 binding sites and redirects it to retina-specific enhancers that lack the consensus MEF2-binding sequence. Once bound to retina-specific enhancers, MEF2D and CRX co-activate the expression of photoreceptor-specific genes that are critical for retinal function. These findings demonstrate that broadly expressed TFs acquire specific functions through competitive recruitment to enhancers by tissue-specific TFs and through selective activation of these enhancers to regulate tissue-specific genes.
Pericytes, the mural cells that constitute the capillaries along with endothelial cells, have been associated with the pathobiology of diabetic retinopathy; however, therapeutic implications of this association remain largely unexplored. Pericytes appear to be highly susceptible to the metabolic challenges associated with a diabetic environment, and there is substantial evidence that their loss may contribute to microvascular instability leading to the formation of microaneurysms, microhemorrhages, acellular capillaries, and capillary nonperfusion. Since pericytes are strategically located at the interface between the vascular and neural components of the retina, they offer extraordinary opportunities for therapeutic interventions in diabetic retinopathy. Moreover, the availability of novel imaging methodologies now allows for the in vivo visualization of pericytes, enabling a new generation of clinical trials that use pericyte tracking as clinical endpoints. The recognition of multiple signaling mechanisms involved in pericyte development and survival should allow for a renewed interest in pericytes as a therapeutic target for diabetic retinopathy.
Aung T, Ozaki M, Mizoguchi T, Allingham RR, Li Z, Haripriya A, Nakano S, Uebe S, Harder JM, Chan ASY, Lee MC, Burdon KP, Astakhov YS, Abu-Amero KK, Zenteno JC, Nilgün Y, Zarnowski T, Pakravan M, Safieh LA, Jia L, Wang YX, Williams S, Paoli D, Schlottmann PG, Huang L, Sim KS, Foo JN, Nakano M, Ikeda Y, Kumar RS, Ueno M, Manabe S-I, Hayashi K, Kazama S, Ideta R, Mori Y, Miyata K, Sugiyama K, Higashide T, Chihara E, Inoue K, Ishiko S, Yoshida A, Yanagi M, Kiuchi Y, Aihara M, Ohashi T, Sakurai T, Sugimoto T, Chuman H, Matsuda F, Yamashiro K, Gotoh N, Miyake M, Astakhov SY, Osman EA, Al-Obeidan SA, Owaidhah O, Al-Jasim L, Shahwan SA, Fogarty RA, Leo P, Yetkin Y, Oğuz Ç, Kanavi MR, Beni AN, Yazdani S, Akopov EL, Toh K-Y, Howell GR, Orr AC, Goh Y, Meah WY, Peh SQ, Kosior-Jarecka E, Lukasik U, Krumbiegel M, Vithana EN, Wong TY, Liu Y, Koch AAE, Challa P, Rautenbach RM, Mackey DA, Hewitt AW, Mitchell P, Wang JJ, Ziskind A, Carmichael T, Ramakrishnan R, Narendran K, Venkatesh R, Vijayan S, Zhao P, Chen X, Guadarrama-Vallejo D, Cheng CY, Perera SA, Husain R, Ho S-L, Welge-Luessen U-C, Mardin C, Schloetzer-Schrehardt U, Hillmer AM, Herms S, Moebus S, Nöthen MM, Weisschuh N, Shetty R, Ghosh A, Teo YY, Brown MA, Lischinsky I, Lischinsky I, Lischinsky I, Crowston JG, Coote M, Zhao B, Sang J, Zhang N, You Q, Vysochinskaya V, Founti P, Chatzikyriakidou A, Lambropoulos A, Anastasopoulos E, Coleman AL, Wilson RM, Rhee DJ, Kang JH, May-Bolchakova I, Heegaard S, Mori K, Alward WLM, Jonas JB, Xu L, Liebmann JM, Chowbay B, Schaeffeler E, Schwab M, Lerner F, Wang N, Yang Z, Frezzotti P, Kinoshita S, Fingert JH, Inatani M, Tashiro K, Reis A, Edward DP, Pasquale LR, Kubota T, Wiggs JL, Pasutto F, Topouzis F, Dubina M, Craig JE, Yoshimura N, Sundaresan P, John SWM, Ritch R, Hauser MA, Khor C-C. A common variant mapping to CACNA1A is associated with susceptibility to exfoliation syndrome. Nat Genet 2015;47(4):387-92.Abstract
Exfoliation syndrome (XFS) is the most common recognizable cause of open-angle glaucoma worldwide. To better understand the etiology of XFS, we conducted a genome-wide association study (GWAS) of 1,484 cases and 1,188 controls from Japan and followed up the most significant findings in a further 6,901 cases and 20,727 controls from 17 countries across 6 continents. We discovered a genome-wide significant association between a new locus (CACNA1A rs4926244) and increased susceptibility to XFS (odds ratio (OR) = 1.16, P = 3.36 × 10(-11)). Although we also confirmed overwhelming association at the LOXL1 locus, the key SNP marker (LOXL1 rs4886776) demonstrated allelic reversal depending on the ancestry group (Japanese: ORA allele = 9.87, P = 2.13 × 10(-217); non-Japanese: ORA allele = 0.49, P = 2.35 × 10(-31)). Our findings represent the first genetic locus outside of LOXL1 surpassing genome-wide significance for XFS and provide insight into the biology and pathogenesis of the disease.
CONTEXT: A heterozygous de novo c.1228G>A mutation (E410K) in the TUBB3 gene encoding the neuronal-specific β-tubulin isotype 3 (TUBB3) causes the TUBB3 E410K syndrome characterized by congenital fibrosis of the extraocular muscles (CFEOM), facial weakness, intellectual and social disabilities, and Kallmann syndrome (anosmia with hypogonadotropic hypogonadism). All TUBB3 E410K subjects reported to date are sporadic cases. OBJECTIVE: This study aimed to report the clinical, genetic, and molecular features of a familial presentation of the TUBB3 E410K syndrome. DESIGN: Case report of a mother and three affected children with clinical features of the TUBB3 E410K syndrome. SETTING: Academic Medical Center. MAIN OUTCOME MEASURES: Genetic analysis of the TUBB3 gene and clinical evaluation of endocrine and nonendocrine phenotypes. RESULTS: A de novo TUBB3 c.1228G>A mutation arose in a female proband who displayed CFEOM, facial weakness, intellectual and social disabilities, and anosmia. However, she underwent normal sexual development at puberty and had three spontaneous pregnancies with subsequent autosomal-dominant inheritance of the mutation by her three boys. All sons displayed nonendocrine features of the TUBB3 E410K syndrome similar to their mother but, in addition, had variable features suggestive of additional endocrine abnormalities. CONCLUSIONS: This first report of an autosomal-dominant inheritance of the TUBB3 c.1228G>A mutation in a family provides new insights into the spectrum and variability of endocrine phenotypes associated with the TUBB3 E410K syndrome. These observations emphasize the need for appropriate clinical evaluation and complicate genetic counseling of patients and families with this syndrome.
In the study presented by D. S. Kohane and co-workers on page 1159, fluorescein molecules are initially bound to collagen fibers through UV-sensitive bonds. Collagen fibers are exposed to NIR light, which is upconverted to UV light through second harmonic generation. The UV-sensitive bonds absorb the upconverted UV light and undergo an irreversible cleavage releasing the fluorescein molecules.
Second harmonic generation is a process through which nonlinear materials such as collagen can absorb two photons and scatter one with twice the energy. Collagen upconverts 730 nm (near-IR) to 365 nm (UV) through second harmonic generation, which cleaves a molecule bound to collagen via a UV-sensitive linker.
Symmetry is an organizational principle that is ubiquitous throughout the visual world. However, this property can also be detected through non-visual modalities such as touch. The role of prior visual experience on detecting tactile patterns containing symmetry remains unclear. We compared the behavioral performance of early blind and sighted (blindfolded) controls on a tactile symmetry detection task. The tactile patterns used were similar in design and complexity as in previous visual perceptual studies. The neural correlates associated with this behavioral task were identified with functional magnetic resonance imaging (fMRI). In line with growing evidence demonstrating enhanced tactile processing abilities in the blind, we found that early blind individuals showed significantly superior performance in detecting tactile symmetric patterns compared to sighted controls. Furthermore, comparing patterns of activation between these two groups identified common areas of activation (e.g. superior parietal cortex) but key differences also emerged. In particular, tactile symmetry detection in the early blind was also associated with activation that included peri-calcarine cortex, lateral occipital (LO), and middle temporal (MT) cortex, as well as inferior temporal and fusiform cortex. These results contribute to the growing evidence supporting superior behavioral abilities in the blind, and the neural correlates associated with crossmodal neuroplasticity following visual deprivation.
Dry eye is a common disorder caused by inadequate hydration of the ocular surface that results in disruption of barrier function. The homeostatic protein clusterin (CLU) is prominent at fluid-tissue interfaces throughout the body. CLU levels are reduced at the ocular surface in human inflammatory disorders that manifest as severe dry eye, as well as in a preclinical mouse model for desiccating stress that mimics dry eye. Using this mouse model, we show here that CLU prevents and ameliorates ocular surface barrier disruption by a remarkable sealing mechanism dependent on attainment of a critical all-or-none concentration. When the CLU level drops below the critical all-or-none threshold, the barrier becomes vulnerable to desiccating stress. CLU binds selectively to the ocular surface subjected to desiccating stress in vivo, and in vitro to the galectin LGALS3, a key barrier component. Positioned in this way, CLU not only physically seals the ocular surface barrier, but it also protects the barrier cells and prevents further damage to barrier structure. These findings define a fundamentally new mechanism for ocular surface protection and suggest CLU as a biotherapeutic for dry eye.
It has been hypothesized that synaptic pruning precedes retinal ganglion cell degeneration in glaucoma, causing early dysfunction to retinal ganglion cells. To begin to assess this, we studied the excitatory synaptic inputs to individual ganglion cells in normal mouse retinas and in retinas with ganglion cell degeneration from glaucoma (DBA/2J), or following an optic nerve crush. Excitatory synapses were labeled by AAV2-mediated transfection of ganglion cells with PSD-95-GFP. After both insults the linear density of synaptic inputs to ganglion cells decreased. In parallel, the dendritic arbors lost complexity. We did not observe any cells that had lost dendritic synaptic input while preserving a normal or near-normal morphology. Within the temporal limits of these observations, dendritic remodeling and synapse pruning thus appear to occur near-simultaneously.
The ability to form biofilms in a variety of environments is a common trait of bacteria, and may represent one of the earliest defenses against predation. Biofilms are multicellular communities usually held together by a polymeric matrix, ranging from capsular material to cell lysate. In a structure that imposes diffusion limits, environmental microgradients arise to which individual bacteria adapt their physiologies, resulting in the gamut of physiological diversity. Additionally, the proximity of cells within the biofilm creates the opportunity for coordinated behaviors through cell-cell communication using diffusible signals, the most well documented being quorum sensing. Biofilms form on abiotic or biotic surfaces, and because of that are associated with a large proportion of human infections. Biofilm formation imposes a limitation on the uses and design of ocular devices, such as intraocular lenses, posterior contact lenses, scleral buckles, conjunctival plugs, lacrimal intubation devices and orbital implants. In the absence of abiotic materials, biofilms have been observed on the capsule, and in the corneal stroma. As the evidence for the involvement of microbial biofilms in many ocular infections has become compelling, developing new strategies to prevent their formation or to eradicate them at the site of infection, has become a priority.
BACKGROUND: Endoscopic orbital surgery represents the next frontier in endonasal surgery. The current literature is largely composed of small, heterogeneous, case series with little consensus regarding optimal techniques. The purpose of this study was to combine the experience of multiple international centers to create a composite of the global experience on the endoscopic management of a single type of tumor, the orbital cavernous hemangioma (OCH). METHODS: This was a retrospective study of techniques for endoscopic OCH resection from 6 centers on 3 continents. Only primary data from strictly endoscopic resection of OCHs were included. Responses were analyzed to qualitatively identify points of both consensus and variability among the different groups. RESULTS: Data for a total of 23 patients, 10 (43.5%) male and 13 (56.5%) female were collected. The majority of lesions were intraconal (60.9%). The mean ± standard deviation (SD) surgical time was 150.7 ± 75.0 minutes with a mean blood loss of 82.7 ± 49.6 mL. Binarial approaches (26.1%) were used exclusively in the setting of intraconal lesions, which were associated with a higher rate of incomplete resection (31.3%), postoperative diplopia (25.0%), and the need for reconstruction (37.5%) than extraconal lesions. Orthotropia and symmetric orbital appearance were achieved in 60.9% and 78.3% of cases, respectively. CONCLUSION: Extraconal lesions were managed similarly; however, greater variability was evident for intraconal lesions. These included the laterality and number of hands in the approach, methods of medial rectus retraction, and the need for reconstruction. The increased technical complexity and disparity of techniques in addressing intraconal OCHs suggests that continued research into the optimal management of this subclass of lesions is of significant priority.
PURPOSE: To evaluate the effectiveness of a therapeutic trial of valganciclovir in patients with uveitis with positive Epstein-Barr virus early antigen D immunoglobulin G titers (EBV EA-D). METHODS: We performed a retrospective chart review of 14 patients at the Massachusetts Eye Research and Surgery Institution who had uveitis with positive EBV EA-D but negative studies for all other causes of uveitis and were treated with valganciclovir 450 mg twice a day or valganciclovir 900 mg twice a day between January 2010 and August 2014. RESULTS: Nine of 14 patients, who had presumed EBV reactivation with associated intraocular inflammation, were successfully treated with valganciclovir: 3 of these were treated with valganciclovir 450 mg twice a day and 6 were treated with valganciclovir 900 mg twice a day. Five of 14 patients failed to respond to valganciclovir with persistent inflammation after at least 2 weeks of valganciclovir therapy, and were subsequently treated with immunomodulatory therapy to control inflammation. CONCLUSIONS: Uveitis can be caused by EBV infection/reactivation. A therapeutic trial with valganciclovir 450 mg twice a day for 1 month in patients with uveitis with positive EBV EA antibody may be beneficial.
PURPOSE: To evaluate the safety and efficacy of topical loteprednol etabonate (LE) 0.5% compared with cyclosporine A (CsA) 0.05% for the prophylaxis and treatment of dry eye syndrome (DES) after hematopoietic stem cell transplantation (HSCT). METHODS: Seventy-five patients were randomized to LE (n = 76 eyes of 38 patients) or CsA (n = 74 eyes of 37 patients) pre-HSCT. Lissamine green and fluorescein staining, tear break-up time, tear osmolarity (Osm), Schirmer score (Sch), intraocular pressure, visual acuity, and Ocular Surface Disease Index were assessed pre-HSCT, 3, 6, 9, and 12 months post-HSCT. RESULTS: There were no differences in DES incidence (P = 0.22; log-rank test) or progression (P = 0.41; log-rank test) between the 2 treatment arms during the course of the study. Among eyes with no DES at enrollment, the Kaplan-Meier analysis yielded a 90% rate of DES development in cyclosporine-treated eyes and a 79% rate of DES development in LE-treated eyes by 12 months post-HSCT. The Kaplan-Meier analysis of eyes with DES at enrollment demonstrated a 38% rate of disease progression among cyclosporine-treated eyes and a 26% rate of disease progression among loteprednol-treated eyes by 12 months. No patient in either group had an elevation of 10 mm Hg or greater from baseline at any study visit, and no patients had their treatment discontinued for elevation in intraocular pressure. CONCLUSIONS: Pre-HSCT initiation of LE 0.5% appears to be safe and may be as effective as CsA 0.5% for the treatment and prophylaxis of DES following HSCT.