Accurate tissue interface segmentation via adversarial pre-segmentation of anterior segment OCT images

Optical Coherence Tomography (OCT) is an imaging modality that has been widely adopted for visualizing corneal, retinal and limbal tissue structure with micron resolution. It can be used to diagnose pathological conditions of the eye, and for developing pre-operative surgical plans. In contrast to the posterior retina, imaging the anterior tissue structures, such as the limbus and cornea, results in B-scans that exhibit increased speckle noise patterns and imaging artifacts. These artifacts, such as shadowing and specularity, pose a challenge during the analysis of the acquired volumes as they substantially obfuscate the location of tissue interfaces. To deal with the artifacts and speckle noise patterns and accurately segment the shallowest tissue interface, we propose a cascaded neural network framework, which comprises of a conditional Generative Adversarial Network (cGAN) and a Tissue Interface Segmentation Network (TISN). The cGAN pre-segments OCT B-scans by removing undesired specular artifacts and speckle noise patterns just above the shallowest tissue interface, and the TISN combines the original OCT image with the pre-segmentation to segment the shallowest interface. We show the applicability of the cascaded framework to corneal datasets, demonstrate that it precisely segments the shallowest corneal interface, and also show its generalization capacity to limbal datasets. We also propose a hybrid framework, wherein the cGAN pre-segmentation is passed to a traditional image analysis-based segmentation algorithm, and describe the improved segmentation performance. To the best of our knowledge, this is the first approach to remove severe specular artifacts and speckle noise patterns (prior to the shallowest interface) that affects the interpretation of anterior segment OCT datasets, thereby resulting in the accurate segmentation of the shallowest tissue interface. To the best of our knowledge, this is the first work to show the potential of incorporating a cGAN into larger deep learning frameworks for improved corneal and limbal OCT image segmentation. Our cGAN design directly improves the visualization of corneal and limbal OCT images from OCT scanners, and improves the performance of current OCT segmentation algorithms.

Corrigendum to "Improving adherence to endocrine hormonal therapy among breast cancer patients: Study protocol for a randomized controlled trial" [Contemp. Clin. Trials Commun. 12 (2018) 109-115]

[This corrects the article DOI: 10.1016/j.conctc.2018.10.001.].

Improving adherence to endocrine hormonal therapy among breast cancer patients: Study protocol for a randomized controlled trial

Adjuvant endocrine hormonal therapy (EHT) is highly effective and appropriate for nearly all breast cancer patients with hormone receptor-positive tumors, which represent 75% of all breast cancer diagnoses. Long-term use of EHT reduces recurrence rates and nearly halves the risk of death during the second decade after diagnosis. Despite the proven benefits, about 33% of women receiving EHT do not take their medication as prescribed. This causes an increase in the risk for recurrence and death.

To promote adherence to EHT among breast cancer patients, this study will develop and pilot-test an intervention consisting of 1) a bilingual, culturally tailored, personalized, interactive smartphone application (app); and 2) support from a patient navigator. The control group will receive usual care. This 2-group randomized control trial will recruit 120 breast cancer patients receiving EHT at the Mays Cancer Center at UT Health San Antonio. The two-year study will have 3-time assessments (baseline, 3 and 6 months).

This theory-based intervention will empower patients' self-monitoring and management. It will facilitate patient education, identification/reporting of side effects, delivery of self-care advice, and simplify communication between the patient and the oncology team. The ultimate goal of this innovative multi-communication intervention is to improve overall survival and life expectancy, enhance quality of life, reduce recurrence, and decrease healthcare cost. The anticipated outcome is a scalable, evidence-based, and easily disseminated intervention with potentially broad use to patients using EHT and other oral anticancer agents.

Abstract P1-02-02: FASN inhibition by TVB-3166 associates with breast cancer subtype

Fatty acid synthase (FASN) is overexpressed in numerous tumor types, including breast carcinomas, and promotes changes in the genetic program controlling lipid biosynthesis. While inhibiting FASN appears to be an attractive therapeutic approach under development, the success of this approach may depend on the identification of tumor subtypes with specific metabolic requirements. Applying a comprehensive profile of circulating tumor cells (CTC) using canonical pathway gene sets, we identified a correlation of metabolic subtypes with breast tumor subtype. A lipogenic subtype is strongly associated with Luminal A subtype, whereas the glycolytic subtype associated with Luminal B tumors. The triple negative subtype was more heterogeneous and had the expression of both sets of gene. Such a difference in the metabolic profile may dictate differential sensitivity to inhibitors targeting de novo lipid synthesis, including FASN. This was supported by in vitro studies using selective FASN inhibitor, TVB-3166. Exposure to TVB-3166 over 14 days incubation in Advanced MEM with 1% charcoal-stripped FBS selectively inhibited growth and viability of Luminal A breast cancer cells, but had no effect on Luminal B subtype. This was further confirmed in short-term patient derived cultures. Mechanistic studies suggest that TVB-3166 quickly disrupts FA synthesis leading to the disruption of the lipid raft architecture and tumor cell death through an apoptotic mechanism. In conclusion, our findings highlight that success of targeting cancer metabolism directly may depend on identification of tumor subtypes with specific metabolic requirements.

Citation Format: Gruslova AB, Chen C-L, Wang C-M, Elledge RM, Kaklamani VG, Lathrop K, Huang TH, Brenner A. FASN inhibition by TVB-3166 associates with breast cancer subtype [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-02-02.

Subterranean mammals show convergent regression in ocular genes and enhancers, along with adaptation to tunneling

The underground environment imposes unique demands on life that have led subterranean species to evolve specialized traits, many of which evolved convergently. We studied convergence in evolutionary rate in subterranean mammals in order to associate phenotypic evolution with specific genetic regions. We identified a strong excess of vision- and skin-related genes that changed at accelerated rates in the subterranean environment due to relaxed constraint and adaptive evolution. We also demonstrate that ocular-specific transcriptional enhancers were convergently accelerated, whereas enhancers active outside the eye were not. Furthermore, several uncharacterized genes and regulatory sequences demonstrated convergence and thus constitute novel candidate sequences for congenital ocular disorders. The strong evidence of convergence in these species indicates that evolution in this environment is recurrent and predictable and can be used to gain insights into phenotype-genotype relationships.

Collagen Architecture of the Posterior Pole: High-Resolution Wide Field of View Visualization and Analysis Using Polarized Light Microscopy

Purpose

The purpose of this study was to leverage polarized light microscopy (PLM) to visualize the collagen fiber architecture of posterior pole and optic nerve head with micrometer-scale resolution and to identify and quantify major organizational components.

Methods

Eight sheep posterior poles were cryosectioned and imaged using PLM. Collagen fiber orientation was determined by using custom scripts, and the resulting orientation maps were inspected and quantified to identify major structural elements and tested for differences in mean fiber orientation and anisotropy, using linear mixed effect models.

Results

Images revealed an intricate organization of collagen fibers in the posterior pole. In the lamina cribrosa, interweaving fibers formed large knots and wrapped around nerve fiber pores, with beam insertions into the scleral canal wall that were either narrow and straight or wide. In the peripapillary sclera, three significantly different (P < 0.0001) components were identified: fibers oriented circumferentially proximal to the canal, radially in the innermost sclera, and unaligned with interweaving fibers. The radial fibers were between 60 and 180 μm thick, extending at least 3 mm from the canal.

Conclusions

PLM revealed structural aspects of the lamina cribrosa and sclera that may have important biomechanical roles but that were previously unreported or not characterized quantitatively. In the lamina cribrosa, these roles included wide and narrow beam insertions and details of collagen fibers interweaving and wrapping around the pores. In the sclera, we described regions of circumferential, radial, and unaligned “random” fibers. Although there is consensus that circumferential fibers protect neural tissues by resisting canal expansion, the role of the radial fibers remains unclear.

Abstract OT1-02-10: A phase 2 study of poziotinib in patients with HER2-positive metastatic breast cancer (MBC) who have received prior HER2 regimens for MBC

Background: Poziotinib is a novel, oral, quinazoline-based pan-HER inhibitor that irreversibly blocks signaling through the epidermal growth factor receptor (EGFR) family of tyrosine-kinase receptors, including EGFR (HER1/ErbB1/EGFR), HER2 (ErbB2), and HER4 (ErbB4), as well as HER receptor mutations. This, in turn, leads to inhibition of the proliferation of tumor cells that overexpress these receptors. It is well established that breast cancers are associated with a mutation in, or overexpression of, members of the EGFR receptor family. The primary objective of this Phase 2 study is to evaluate the Objective Response Rate (ORR) of poziotinib in patients with human epidermal growth factor receptor 2 (HER2)-positive MBC. The secondary efficacy variables are Progression-Free Survival (PFS), Disease Control Rate (DCR), Overall Survival (OS), and Time to Progression (TTP).

Trial Design: This is a Phase 2, open-label, multicenter study to evaluate the efficacy, safety and tolerability of poziotinib in patients with HER2-positive MBC who have received at least 2 prior HER2- directed treatment regimens. Each treatment cycle is 21 days in duration. During each cycle, eligible patients receive 24 mg of poziotinib orally (as three 8-mg tablets) once daily for 14 days, followed by a 7 day treatment-free period.

Eligibility Criteria: Eligible patients are at least 18 years of age, have confirmed HER2 overexpression, adequate hematologic, renal and hepatic function, and have received at least 2 prior HER2-directed therapy regimens, including trastuzumab and trastuzumab emtansine (TDM-1). Patients are excluded if they have prior exposure to poziotinib, a history of congestive heart failure, left ventricular ejection fraction &lt;50%, unable to take oral medications, or have conditions that cause malabsorption. A 30 day wash out period from previous chemotherapeutic or radiation therapies is required.

Statistical Methods: The purpose of this study is to evaluate the efficacy of poziotinib compared to the efficacy of other standard HER2-positive breast cancer treatments as reported in the literature. The ORR will be analyzed descriptively along with the 95% CI. The secondary efficacy variables will be analyzed descriptively.

Target Accrual: Approximately 70 patients. Enrollment began February 2016.

Contact Information: For more information or to refer a patient,

email: spi-poz-201@sppirx.com or fax: 1-949-398-9711.

Citation Format: Lathrop K, Lucas J, Vacirca JL, Bhat G, Choi MR, Naughton M. A phase 2 study of poziotinib in patients with HER2-positive metastatic breast cancer (MBC) who have received prior HER2 regimens for MBC [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT1-02-10.

Reversible nerve damage regulates pathology in murine herpes simplex stromal keratitis. (VIR7P.1056)

Herpes simplex type 1 (HSV-1) keratitis (HSK) is characterized by recurrent bouts of immunopathology consisting of corneal opacity, vascularization, and progressive scarring that is triggered by viral reactivation from a latent state and release from sensory nerves in the cornea. Nerve damage and loss of corneal blink reflex (BR) accompanies HSK recurrences, but testing BR is usually not part of the clinical HSK workup in humans or mouse models. Although loss of BR can lead to desiccation of the corneal surface, especially in mice that lack consensual blink reflex, a possible contribution of nerve damage to HSK immunopathology has not been explored. Here we show that chronic HSK in mice is associated with loss of corneal BR, and that preventing corneal desiccation through tarsorrhaphy (eyelid stitching) dramatically reduces HSK severity and resolves existing severe HSK. Tarsorrhaphy dramatically reduced the neutrophilic infiltrate and expression of the neutrophil chemotactic factor CXCL1 in infected corneas. Mice that were depleted of CD4+ T cells exhibited transient severe HSK, with concurrent resolution of HSK, recovery of corneal BR, and regeneration of corneal nerves. Thus, CD4-mediated chronic, but reversible nerve damage and the accompanying corneal desiccation accounts for much of the inflammation associated with HSK in mice.

A robust procedure for distinctively visualizing zebrafish retinal cell nuclei under bright field light microscopy

To simultaneously visualize individual cell nuclei and tissue morphologies of the zebrafish retina under bright field light microscopy, it is necessary to establish a procedure that specifically and sensitively stains the cell nuclei in thin tissue sections. This necessity arises from the high nuclear density of the retina and the highly decondensed chromatin of the cone photoreceptors, which significantly reduces their nuclear signals and makes nuclei difficult to distinguish from possible high cytoplasmic background staining. Here we optimized a procedure that integrates JB4 plastic embedding and Feulgen reaction for visualizing zebrafish retinal cell nuclei under bright field light microscopy. This method produced highly specific nuclear staining with minimal cytoplasmic background, allowing us to distinguish individual retinal nuclei despite their tight packaging. The nuclear staining is also sensitive enough to distinguish the euchromatin from heterochromatin in the zebrafish cone nuclei. In addition, this method could be combined with in situ hybridization to simultaneously visualize the cell nuclei and mRNA expression patterns. With its superb specificity and sensitivity, this method may be extended to quantify cell density and analyze global chromatin organization throughout the retina or other tissues.

Rho/ROCK signaling in regulation of corneal epithelial cell cycle progression

PURPOSE

The authors' previous study showed that the expression of a Rho-associated serine/threonine kinase (ROCK) is regulated during cell cycle progression in corneal epithelial cells. The present study was conducted to determine whether and how Rho/ROCK signaling regulates cell cycle progression.

METHODS

Rabbit corneal epithelial cells (RCECs) in culture were arrested in the G(0) phase of the cell cycle by serum deprivation and then allowed to re-enter the cell cycle in the presence or absence of the ROCK inhibitor (Y27632) in serum-supplemented medium. The number of cells in the S phase, the relative levels of specific cyclins and CDKs and their intracellular distribution, and the relative levels of mRNAs were determined by BrdU labeling, Western blot and immunocytochemical analyses, and real-time RT-PCR, respectively.

RESULTS

ROCK inhibition delayed the progression of G(1) to S phase and led to a decrease in the number of RCECs entering the S phase between 12 and 24 hours from 31.5% +/- 4.5% to 8.1% +/- 2.6%. During the cell cycle progression, protein and mRNA levels of cyclin-D1 and -D3 and cyclin-dependent kinases CDK4 and CDK6 were significantly lower, whereas the protein levels of the CDK inhibitor p27(Kip1) were higher in ROCK-inhibited cells. Intracellular mRNA or protein levels of cyclin-E and protein levels of CDK2 were not significantly affected, but their nuclear translocation was delayed by ROCK inhibition.

CONCLUSIONS

ROCK signaling is involved in cell cycle progression in RCECs, possibly by upregulation of cyclin-D1 and -D3 and CDK4, -6, and -2; nuclear translocation of CDK2 and cyclin-E; and downregulation of p27(Kip1).

RETRACTED: Sensory Neurons Regulate the Effector Functions of CD8+ T Cells in Controlling HSV-1 Latency Ex Vivo

We provide evidence that sensory neurons regulate the effector functions and phenotype of CD8+ T cells during active immunosurveillance of HSV-1 latency. Low-level viral gene expression in latently infected sensory ganglia gives rise to a unique, functionally active CD8+ T cell population. Surprisingly, distinct neuronal subsets require different CD8 effector mechanisms to maintain viral latency, with some requiring IFN-gamma and others requiring lytic granules (LG). This nonredundant efficacy of CD8+ T cell effector mechanisms in maintaining viral latency is explained as follows: (1) a subset of neurons that expresses IFN-gamma receptors (IFN-gamma R+) and Qa 1 responds to IFN-gamma, but Qa 1 engagement of CD94/NKG2a blocks LG exocytosis by CD8+ T cells; (2) another neuronal subset is responsive to LG because it lacks Qa 1 and is refractory to IFN-gamma because it also lacks IFN-gamma R. In the latter subset, LG appear to provide a nonlethal block of viral reactivation.