Optical coherence tomography in gastroenterology: a review and future outlook

NASA Astrophysics Data System (ADS)

Tsai, Tsung-Han; Leggett, Cadman L.; Trindade, Arvind J.; Sethi, Amrita; Swager, Anne-Fré; Joshi, Virendra; Bergman, Jacques J.; Mashimo, Hiroshi; Nishioka, Norman S.; Namati, Eman

2017-12-01

Optical coherence tomography (OCT) is an imaging technique optically analogous to ultrasound that can generate depth-resolved images with micrometer-scale resolution. Advances in fiber optics and miniaturized actuation technologies allow OCT imaging of the human body and further expand OCT utilization in applications including but not limited to cardiology and gastroenterology. This review article provides an overview of current OCT development and its clinical utility in the gastrointestinal tract, including disease detection/differentiation and endoscopic therapy guidance, as well as a discussion of its future applications.

Climate Prediction Center - Seasonal Outlook

Science.gov Websites

maps) Norm Prob of Exceed (Interactive) T P 0.5 Month Outlook for Jun-Jul-Aug 2018 N T P 1.5 Month Outlook for Jul-Aug-Sep 2018 N T P 2.5 Month Outlook for Aug-Sep-Oct 2018 N T P 3.5 Month Outlook for Sep -Oct-Nov 2018 N T P 4.5 Month Outlook for Oct-Nov-Dec 2018 N T P 5.5 Month Outlook for Nov-Dec-Jan 2018

An easy method to differentiate retinal arteries from veins by spectral domain optical coherence tomography: retrospective, observational case series

PubMed Central

2014-01-01

Background Recently it was shown that retinal vessel diameters could be measured using spectral domain optical coherence tomography (OCT). It has also been suggested that retinal vessels manifest different features on spectral domain OCT (SD-OCT) depending on whether they are arteries or veins. Our study was aimed to present a reliable SD-OCT assisted method of differentiating retinal arteries from veins. Methods Patients who underwent circular OCT scans centred at the optic disc using a Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany) were retrospectively reviewed. Individual retinal vessels were identified on infrared reflectance (IR) images and given unique labels for subsequent grading. Vessel types (artery, vein or uncertain) assessed by IR and/or fluorescein angiography (FA) were referenced as ground truth. From OCT, presence/absence of the hyperreflective lower border reflectivity feature was assessed. Presence of this feature was considered indicative for retinal arteries and compared with the ground truth. Results A total of 452 vessels from 26 eyes of 18 patients were labelled and 398 with documented vessel type (302 by IR and 96 by FA only) were included in the study. Using SD-OCT, 338 vessels were assigned a final grade, of which, 86.4% (292 vessels) were classified correctly. Forty three vessels (15 arteries and 28 veins) that IR failed to differentiate were correctly classified by SD-OCT. When using only IR based ground truth for vessel type the SD-OCT based classification approach reached a sensitivity of 0.8758/0.9297, and a specificity of 0.9297/0.8758 for arteries/veins, respectively. Conclusion Our method was able to classify retinal arteries and veins with a commercially available SD-OCT alone, and achieved high classification performance. Paired with OCT based vessel measurements, our study has expanded the potential clinical implication of SD-OCT in evaluation of a variety of retinal and systemic vascular diseases. PMID:24884611

Nanog is an essential factor for induction of pluripotency in somatic cells from endangered felids.

PubMed

Verma, Rajneesh; Liu, Jun; Holland, Michael Kenneth; Temple-Smith, Peter; Williamson, Mark; Verma, Paul John

2013-02-01

Nanog has an important role in pluripotency induction in bovines and snow leopards. To examine whether it was required for wild felids globally, we examined the induction of pluripotency in felids from Asia (Bengal tiger, Panthera tigris), Africa (serval, Leptailurus serval), and the Americas (jaguar, Panthera onca). Dermal fibroblasts were transduced with genes encoding the human transcription factors OCT4, SOX2, KLF4, and cMYC with or without NANOG. Both four- and five-factor induction resulted in colony formation at day 3 in all three species tested; however, we were not able to maintain colonies that were generated without NANOG beyond passage (P) 7. Five-factor induced pluripotent stem cell (iPSC) colonies from wild cats were expanded in vitro on feeder layers and were positive for alkaline phosphatase and protein expression of OCT-4, NANOG, and stage-specific embryonic antigen-4 at P4 and P14. Reverse-transcription polymerase chain reaction confirmed that all five human transgenes were transcribed at P4; however, OCT4, SOX2, and NANOG transgenes were silenced by P14. Endogenous OCT4 and NANOG transcripts were detected at P4 and P14 in all cell lines confirming successful reprogramming. At P14, the iPSCs from all three species remained euploid and differentiated in vivo and in vitro into derivatives of the three germ layers. This study describes an effective method for inducing pluripotency in three endangered wild cats from across the globe and confirms Nanog as an essential factor in the reprogramming event. Efficient production of iPSC from endangered felids creates a unique opportunity for species preservation through gamete production, nuclear transfer, embryo complementation, and future novel technologies.

Nanog Is an Essential Factor for Induction of Pluripotency in Somatic Cells from Endangered Felids

PubMed Central

Verma, Rajneesh; Liu, Jun; Holland, Michael Kenneth; Temple-Smith, Peter; Williamson, Mark

2013-01-01

Abstract Nanog has an important role in pluripotency induction in bovines and snow leopards. To examine whether it was required for wild felids globally, we examined the induction of pluripotency in felids from Asia (Bengal tiger, Panthera tigris), Africa (serval, Leptailurus serval), and the Americas (jaguar, Panthera onca). Dermal fibroblasts were transduced with genes encoding the human transcription factors OCT4, SOX2, KLF4, and cMYC with or without NANOG. Both four- and five-factor induction resulted in colony formation at day 3 in all three species tested; however, we were not able to maintain colonies that were generated without NANOG beyond passage (P) 7. Five-factor induced pluripotent stem cell (iPSC) colonies from wild cats were expanded in vitro on feeder layers and were positive for alkaline phosphatase and protein expression of OCT-4, NANOG, and stage-specific embryonic antigen-4 at P4 and P14. Reverse-transcription polymerase chain reaction confirmed that all five human transgenes were transcribed at P4; however, OCT4, SOX2, and NANOG transgenes were silenced by P14. Endogenous OCT4 and NANOG transcripts were detected at P4 and P14 in all cell lines confirming successful reprogramming. At P14, the iPSCs from all three species remained euploid and differentiated in vivo and in vitro into derivatives of the three germ layers. This study describes an effective method for inducing pluripotency in three endangered wild cats from across the globe and confirms Nanog as an essential factor in the reprogramming event. Efficient production of iPSC from endangered felids creates a unique opportunity for species preservation through gamete production, nuclear transfer, embryo complementation, and future novel technologies. PMID:23514873

Dynamic Optical Coherence Tomography in Dermatology.

PubMed

Ulrich, Martina; Themstrup, Lotte; de Carvalho, Nathalie; Manfredi, Marco; Grana, Costantino; Ciardo, Silvana; Kästle, Raphaela; Holmes, Jon; Whitehead, Richard; Jemec, Gregor B E; Pellacani, Giovanni; Welzel, Julia

2016-01-01

Optical coherence tomography (OCT) represents a non-invasive imaging technology, which may be applied to the diagnosis of non-melanoma skin cancer and which has recently been shown to improve the diagnostic accuracy of basal cell carcinoma. Technical developments of OCT continue to expand the applicability of OCT for different neoplastic and inflammatory skin diseases. Of these, dynamic OCT (D-OCT) based on speckle variance OCT is of special interest as it allows the in vivo evaluation of blood vessels and their distribution within specific lesions, providing additional functional information and consequently greater density of data. In an effort to assess the potential of D-OCT for future scientific and clinical studies, we have therefore reviewed the literature and preliminary unpublished data on the visualization of the microvasculature using D-OCT. Information on D-OCT in skin cancers including melanoma, as well as in a variety of other skin diseases, is presented in an atlas. Possible diagnostic features are suggested, although these require additional validation. © 2016 S. Karger AG, Basel.

RNA-Binding Protein L1TD1 Interacts with LIN28 via RNA and is Required for Human Embryonic Stem Cell Self-Renewal and Cancer Cell Proliferation

PubMed Central

Närvä, Elisa; Rahkonen, Nelly; Emani, Maheswara Reddy; Lund, Riikka; Pursiheimo, Huha-Pekka; Nästi, Juuso; Autio, Reija; Rasool, Omid; Denessiouk, Konstantin; Lähdesmäki, Harri; Rao, Anjana; Lahesmaa, Ritta

2012-01-01

Human embryonic stem cells (hESC) have a unique capacity to self-renew and differentiate into all the cell types found in human body. Although the transcriptional regulators of pluripotency are well studied, the role of cytoplasmic regulators is still poorly characterized. Here, we report a new stem cell-specific RNA-binding protein L1TD1 (ECAT11, FLJ10884) required for hESC self-renewal and cancer cell proliferation. Depletion of L1TD1 results in immediate downregulation of OCT4 and NANOG. Furthermore, we demonstrate that OCT4, SOX2, and NANOG all bind to the promoter of L1TD1. Moreover, L1TD1 is highly expressed in seminomas, and depletion of L1TD1 in these cancer cells influences self-renewal and proliferation. We show that L1TD1 colocalizes and interacts with LIN28 via RNA and directly with RNA helicase A (RHA). LIN28 has been reported to regulate translation of OCT4 in complex with RHA. Thus, we hypothesize that L1TD1 is part of the L1TD1-RHA-LIN28 complex that could influence levels of OCT4. Our results strongly suggest that L1TD1 has an important role in the regulation of stemness. PMID:22162396

4D megahertz optical coherence tomography (OCT): imaging and live display beyond 1 gigavoxel/sec (Conference Presentation)

NASA Astrophysics Data System (ADS)

Huber, Robert A.; Draxinger, Wolfgang; Wieser, Wolfgang; Kolb, Jan Philip; Pfeiffer, Tom; Karpf, Sebastian N.; Eibl, Matthias; Klein, Thomas

2016-03-01

Over the last 20 years, optical coherence tomography (OCT) has become a valuable diagnostic tool in ophthalmology with several 10,000 devices sold today. Other applications, like intravascular OCT in cardiology and gastro-intestinal imaging will follow. OCT provides 3-dimensional image data with microscopic resolution of biological tissue in vivo. In most applications, off-line processing of the acquired OCT-data is sufficient. However, for OCT applications like OCT aided surgical microscopes, for functional OCT imaging of tissue after a stimulus, or for interactive endoscopy an OCT engine capable of acquiring, processing and displaying large and high quality 3D OCT data sets at video rate is highly desired. We developed such a prototype OCT engine and demonstrate live OCT with 25 volumes per second at a size of 320x320x320 pixels. The computer processing load of more than 1.5 TFLOPS was handled by a GTX 690 graphics processing unit with more than 3000 stream processors operating in parallel. In the talk, we will describe the optics and electronics hardware as well as the software of the system in detail and analyze current limitations. The talk also focuses on new OCT applications, where such a system improves diagnosis and monitoring of medical procedures. The additional acquisition of hyperspectral stimulated Raman signals with the system will be discussed.

Interaction of organic cation transporter 3 (SLC22A3) and amphetamine

PubMed Central

Zhu, Hao-Jie; Appel, David I.; Gründemann, Dirk; Markowitz, John S.

2013-01-01

The organic cation transporter (OCT) 3 is widely expressed in various organs in humans, and involved in the disposition of many exogenous and endogenous compounds. Several lines of evidence have suggested that OCT3 expressed in the brain plays an important role in the regulation of neurotransmission. Relative to wild-type (WT) animals, Oct3 knockout (KO) mice have displayed altered behavioral and neurochemical responses to psychostimulants such as amphetamine (AMPH) and methamphetamine. In the present study, both in vitro and in vivo approaches were utilized to explore potential mechanisms underlying the disparate neuropharmacological effects observed following AMPH exposure in Oct3 KO mice. In vitro uptake studies conducted in OCT3 transfected cells indicated that dextroamphetamine (d-AMPH) is not a substrate of OCT3. However, OCT3 was determined to be a high-capacity and low-affinity transporter for the neurotransmitters dopamine (DA), norepinephrine (NE), and serotonin (5-HT). Inhibition studies demonstrated that d-AMPH exerts relatively weak inhibitory effects on the OCT3-mediated uptake of DA, NE, 5-HT, and the model OCT3 substrate 4-(4-(dimethylamino)styryl)-N-methylpyridinium iodide. The IC50 values were determined to be 41.5 ± 7.5 and 24.1 ± 7.0 μM for inhibiting DA and 5-HT uptake, respectively, while 50% inhibition of NE and 4-(4-(dimethylamino)styryl)-N-methylpyridinium iodide uptake was not achieved by even the highest concentration of d-AMPH applied (100 μM). Furthermore, the disposition of d-AMPH in various tissues including the brain, liver, heart, kidney, muscle, intestine, spleen, testis, uterus, and plasma were determined in both male and female Oct3 KO and WT mice. No significant difference was observed between either genotypes or sex in all tested organs and tissues. Our findings suggest that OCT3 is not a prominent factor influencing the disposition of d-AMPH. Additionally, based upon the inhibitory potency observed in vitro, d-AMPH is unlikely to inhibit the uptake of monoamines mediated by OCT3 in the brain. Differentiated neuropharmacological effects of AMPHs noted between Oct3 KO and WT mice appear to be due to the absence of Oct3 mediated uptake of neurotransmitters in the KO mice. PMID:20402963

Interaction of organic cation transporter 3 (SLC22A3) and amphetamine.

PubMed

Zhu, Hao-Jie; Appel, David I; Gründemann, Dirk; Markowitz, John S

2010-07-01

The organic cation transporter (OCT) 3 is widely expressed in various organs in humans, and involved in the disposition of many exogenous and endogenous compounds. Several lines of evidence have suggested that OCT3 expressed in the brain plays an important role in the regulation of neurotransmission. Relative to wild-type (WT) animals, Oct3 knockout (KO) mice have displayed altered behavioral and neurochemical responses to psychostimulants such as amphetamine (AMPH) and methamphetamine. In the present study, both in vitro and in vivo approaches were utilized to explore potential mechanisms underlying the disparate neuropharmacological effects observed following AMPH exposure in Oct3 KO mice. In vitro uptake studies conducted in OCT3 transfected cells indicated that dextroamphetamine (d-AMPH) is not a substrate of OCT3. However, OCT3 was determined to be a high-capacity and low-affinity transporter for the neurotransmitters dopamine (DA), norepinephrine (NE), and serotonin (5-HT). Inhibition studies demonstrated that d-AMPH exerts relatively weak inhibitory effects on the OCT3-mediated uptake of DA, NE, 5-HT, and the model OCT3 substrate 4-(4-(dimethylamino)styryl)-N-methylpyridinium iodide. The IC(50) values were determined to be 41.5 +/- 7.5 and 24.1 +/- 7.0 microM for inhibiting DA and 5-HT uptake, respectively, while 50% inhibition of NE and 4-(4-(dimethylamino)styryl)-N-methylpyridinium iodide uptake was not achieved by even the highest concentration of d-AMPH applied (100 microM). Furthermore, the disposition of d-AMPH in various tissues including the brain, liver, heart, kidney, muscle, intestine, spleen, testis, uterus, and plasma were determined in both male and female Oct3 KO and WT mice. No significant difference was observed between either genotypes or sex in all tested organs and tissues. Our findings suggest that OCT3 is not a prominent factor influencing the disposition of d-AMPH. Additionally, based upon the inhibitory potency observed in vitro, d-AMPH is unlikely to inhibit the uptake of monoamines mediated by OCT3 in the brain. Differentiated neuropharmacological effects of AMPHs noted between Oct3 KO and WT mice appear to be due to the absence of Oct3 mediated uptake of neurotransmitters in the KO mice.

Interaction and Transport of Methamphetamine and its Primary Metabolites by Organic Cation and Multidrug and Toxin Extrusion Transporters.

PubMed

Wagner, David J; Sager, Jennifer E; Duan, Haichuan; Isoherranen, Nina; Wang, Joanne

2017-07-01

Methamphetamine is one of the most abused illicit drugs with roughly 1.2 million users in the United States alone. A large portion of methamphetamine and its metabolites is eliminated by the kidney with renal clearance larger than glomerular filtration clearance. Yet the mechanism of active renal secretion is poorly understood. The goals of this study were to characterize the interaction of methamphetamine and its major metabolites with organic cation transporters (OCTs) and multidrug and toxin extrusion (MATE) transporters and to identify the major transporters involved in the disposition of methamphetamine and its major metabolites, amphetamine and para -hydroxymethamphetamine ( p -OHMA). We used cell lines stably expressing relevant transporters to show that methamphetamine and its metabolites inhibit human OCTs 1-3 (hOCT1-3) and hMATE1/2-K with the greatest potencies against hOCT1 and hOCT2. Methamphetamine and amphetamine are substrates of hOCT2, hMATE1, and hMATE2-K, but not hOCT1 and hOCT3. p -OHMA is transported by hOCT1-3 and hMATE1, but not hMATE2-K. In contrast, organic anion transporters 1 and 3 do not interact with or transport these compounds. Methamphetamine and its metabolites exhibited complex interactions with hOCT1 and hOCT2, suggesting the existence of multiple binding sites. Our studies suggest the involvement of the renal OCT2/MATE pathway in tubular secretion of methamphetamine and its major metabolites and the potential of drug-drug interactions with substrates or inhibitors of the OCTs. This information may be considered when prescribing medications to suspected or known abusers of methamphetamine to mitigate the risk of increased toxicity or reduced therapeutic efficacy. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

Renal uptake of radiolabeled octreotide in human subjects is efficiently inhibited by succinylated gelatin.

PubMed

Vegt, Erik; Wetzels, Jack F M; Russel, Frans G M; Masereeuw, Rosalinde; Boerman, Otto C; van Eerd, Juliette E; Corstens, Frans H M; Oyen, Wim J G

2006-03-01

Peptide receptor-mediated radiotherapy of neuroendocrine and other somatostatin receptor-positive tumors with radiolabeled somatostatin analogs has been applied in several experimental settings. The kidneys are the organs responsible for dose-limiting toxicity attributable to the retention of radiolabeled octreotide in the renal cortex, leading to a relatively high radiation dose that may result in irreversible loss of kidney function. The administration of basic amino acids reduces renal uptake but does have significant side effects. We observed that gelatin-based plasma expanders induced tubular low-molecular-weight proteinuria in healthy volunteers, suggesting that components in these solutions can interfere with the tubular reabsorption of proteins and peptides. Here, we studied the effects of infusion of low doses of the plasma expander succinylated gelatin (GELO) on the renal uptake of 111In-labeled octreotide (111In-OCT). Five healthy volunteers were given 111In-OCT, first in combination with normal saline and 2 wk later in combination with GELO. Scintigraphic images of the kidneys as well as blood and urine samples were analyzed. To exclude a nonspecific hemodynamic effect of the plasma expander, the procedure was repeated with 5 other volunteers who received the carbohydrate-based plasma expander hydroxyethyl starch (HES). Low doses of GELO were able to effectively reduce the kidney retention of 111In-OCT. The renal radiation dose was significantly reduced by 45% +/- 10% (mean +/- SD) (P = 0.006), whereas HES showed no significant effect (0% +/- 12%). The infusion of GELO did not cause any side effects. GELO effectively reduces the renal uptake of 111In-OCT. In contrast to currently used mixtures of amino acids, GELO does not cause any side effects.

Proton Pump Inhibitors Inhibit Metformin Uptake by Organic Cation Transporters (OCTs)

PubMed Central

Nies, Anne T.; Hofmann, Ute; Resch, Claudia; Schaeffeler, Elke; Rius, Maria; Schwab, Matthias

2011-01-01

Metformin, an oral insulin-sensitizing drug, is actively transported into cells by organic cation transporters (OCT) 1, 2, and 3 (encoded by SLC22A1, SLC22A2, or SLC22A3), which are tissue specifically expressed at significant levels in various organs such as liver, muscle, and kidney. Because metformin does not undergo hepatic metabolism, drug-drug interaction by inhibition of OCT transporters may be important. So far, comprehensive data on the interaction of proton pump inhibitors (PPIs) with OCTs are missing although PPIs are frequently used in metformin-treated patients. Using in silico modeling and computational analyses, we derived pharmacophore models indicating that PPIs (i.e. omeprazole, pantoprazole, lansoprazole, rabeprazole, and tenatoprazole) are potent OCT inhibitors. We then established stably transfected cell lines expressing the human uptake transporters OCT1, OCT2, or OCT3 and tested whether these PPIs inhibit OCT-mediated metformin uptake in vitro. All tested PPIs significantly inhibited metformin uptake by OCT1, OCT2, and OCT3 in a concentration-dependent manner. Half-maximal inhibitory concentration values (IC50) were in the low micromolar range (3–36 µM) and thereby in the range of IC50 values of other potent OCT drug inhibitors. Finally, we tested whether the PPIs are also transported by OCTs, but did not identify PPIs as OCT substrates. In conclusion, PPIs are potent inhibitors of the OCT-mediated metformin transport in vitro. Further studies are needed to elucidate the clinical relevance of this drug-drug interaction with potential consequences on metformin disposition and/or efficacy. PMID:21779389

YAP1 Regulates OCT4 Activity and SOX2 Expression to Facilitate Self-Renewal and Vascular Mimicry of Stem-Like Cells.

PubMed

Bora-Singhal, Namrata; Nguyen, Jonathan; Schaal, Courtney; Perumal, Deepak; Singh, Sandeep; Coppola, Domenico; Chellappan, Srikumar

2015-06-01

Non-small cell lung cancer (NSCLC) is highly correlated with smoking and has very low survival rates. Multiple studies have shown that stem-like cells contribute to the genesis and progression of NSCLC. Our results show that the transcriptional coactivator yes-associated protein 1 (YAP1), which is the oncogenic component of the Hippo signaling pathway, is elevated in the stem-like cells from NSCLC and contributes to their self-renewal and ability to form angiogenic tubules. Inhibition of YAP1 by a small molecule or depletion of YAP1 by siRNAs suppressed self-renewal and vascular mimicry of stem-like cells. These effects of YAP1 were mediated through the embryonic stem cell transcription factor, Sox2. YAP1 could transcriptionally induce Sox2 through a physical interaction with Oct4; Sox2 induction occurred independent of TEAD2 transcription factor, which is the predominant mediator of YAP1 functions. The binding of Oct4 to YAP1 could be detected in cell lines as well as tumor tissues; the interaction was elevated in NSCLC samples compared to normal tissue as seen by proximity ligation assays. YAP1 bound to Oct4 through the WW domain, and a peptide corresponding to this region could disrupt the interaction. Delivery of the WW domain peptide to stem-like cells disrupted the interaction and abrogated Sox2 expression, self-renewal, and vascular mimicry. Depleting YAP1 reduced the expression of multiple epithelial-mesenchymal transition genes and prevented the growth and metastasis of tumor xenografts in mice; overexpression of Sox2 in YAP1 null cells rescued these functions. These results demonstrate a novel regulation of stem-like functions by YAP1, through the modulation of Sox2 expression. © 2015 AlphaMed Press.

Hyaluronan-CD44v3 interaction with Oct4-Sox2-Nanog promotes miR-302 expression leading to self-renewal, clonal formation, and cisplatin resistance in cancer stem cells from head and neck squamous cell carcinoma.

PubMed

Bourguignon, Lilly Y W; Wong, Gabriel; Earle, Christine; Chen, Liqun

2012-09-21

Human head and neck squamous cell carcinoma (HNSCC) is a highly malignant cancer associated with major morbidity and mortality. In this study, we determined that human HNSCC-derived HSC-3 cells contain a subpopulation of cancer stem cells (CSCs) characterized by high levels of CD44v3 and aldehyde dehydrogenase-1 (ALDH1) expression. These tumor cells also express several stem cell markers (the transcription factors Oct4, Sox2, and Nanog) and display the hallmark CSC properties of self-renewal/clonal formation and the ability to generate heterogeneous cell populations. Importantly, hyaluronan (HA) stimulates the CD44v3 (an HA receptor) interaction with Oct4-Sox2-Nanog leading to both a complex formation and the nuclear translocation of three CSC transcription factors. Further analysis reveals that microRNA-302 (miR-302) is controlled by an upstream promoter containing Oct4-Sox2-Nanog-binding sites, whereas chromatin immunoprecipitation (ChIP) assays demonstrate that stimulation of miR-302 expression by HA-CD44 is Oct4-Sox2-Nanog-dependent in HNSCC-specific CSCs. This process results in suppression of several epigenetic regulators (AOF1/AOF2 and DNMT1) and the up-regulation of several survival proteins (cIAP-1, cIAP-2, and XIAP) leading to self-renewal, clonal formation, and cisplatin resistance. These CSCs were transfected with a specific anti-miR-302 inhibitor to silence miR-302 expression and block its target functions. Our results demonstrate that the anti-miR-302 inhibitor not only enhances the expression of AOF1/AOF2 and DNMT1 but also abrogates the production of cIAP-1, cIAP-2, and XIAP and HA-CD44v3-mediated cancer stem cell functions. Taken together, these findings strongly support the contention that the HA-induced CD44v3 interaction with Oct4-Sox2-Nanog signaling plays a pivotal role in miR-302 production leading to AOF1/AOF2/DNMT1 down-regulation and survival of protein activation. All of these events are critically important for the acquisition of cancer stem cell properties, including self-renewal, clonal formation, and chemotherapy resistance in HA-CD44v3-activated head and neck cancer.

Hyaluronan-CD44v3 Interaction with Oct4-Sox2-Nanog Promotes miR-302 Expression Leading to Self-renewal, Clonal Formation, and Cisplatin Resistance in Cancer Stem Cells from Head and Neck Squamous Cell Carcinoma*

PubMed Central

Bourguignon, Lilly Y. W.; Wong, Gabriel; Earle, Christine; Chen, Liqun

2012-01-01

Human head and neck squamous cell carcinoma (HNSCC) is a highly malignant cancer associated with major morbidity and mortality. In this study, we determined that human HNSCC-derived HSC-3 cells contain a subpopulation of cancer stem cells (CSCs) characterized by high levels of CD44v3 and aldehyde dehydrogenase-1 (ALDH1) expression. These tumor cells also express several stem cell markers (the transcription factors Oct4, Sox2, and Nanog) and display the hallmark CSC properties of self-renewal/clonal formation and the ability to generate heterogeneous cell populations. Importantly, hyaluronan (HA) stimulates the CD44v3 (an HA receptor) interaction with Oct4-Sox2-Nanog leading to both a complex formation and the nuclear translocation of three CSC transcription factors. Further analysis reveals that microRNA-302 (miR-302) is controlled by an upstream promoter containing Oct4-Sox2-Nanog-binding sites, whereas chromatin immunoprecipitation (ChIP) assays demonstrate that stimulation of miR-302 expression by HA-CD44 is Oct4-Sox2-Nanog-dependent in HNSCC-specific CSCs. This process results in suppression of several epigenetic regulators (AOF1/AOF2 and DNMT1) and the up-regulation of several survival proteins (cIAP-1, cIAP-2, and XIAP) leading to self-renewal, clonal formation, and cisplatin resistance. These CSCs were transfected with a specific anti-miR-302 inhibitor to silence miR-302 expression and block its target functions. Our results demonstrate that the anti-miR-302 inhibitor not only enhances the expression of AOF1/AOF2 and DNMT1 but also abrogates the production of cIAP-1, cIAP-2, and XIAP and HA-CD44v3-mediated cancer stem cell functions. Taken together, these findings strongly support the contention that the HA-induced CD44v3 interaction with Oct4-Sox2-Nanog signaling plays a pivotal role in miR-302 production leading to AOF1/AOF2/DNMT1 down-regulation and survival of protein activation. All of these events are critically important for the acquisition of cancer stem cell properties, including self-renewal, clonal formation, and chemotherapy resistance in HA-CD44v3-activated head and neck cancer. PMID:22847005

Wireless, Web-Based Interactive Control of Optical Coherence Tomography with Mobile Devices.

PubMed

Mehta, Rajvi; Nankivil, Derek; Zielinski, David J; Waterman, Gar; Keller, Brenton; Limkakeng, Alexander T; Kopper, Regis; Izatt, Joseph A; Kuo, Anthony N

2017-01-01

Optical coherence tomography (OCT) is widely used in ophthalmology clinics and has potential for more general medical settings and remote diagnostics. In anticipation of remote applications, we developed wireless interactive control of an OCT system using mobile devices. A web-based user interface (WebUI) was developed to interact with a handheld OCT system. The WebUI consisted of key OCT displays and controls ported to a webpage using HTML and JavaScript. Client-server relationships were created between the WebUI and the OCT system computer. The WebUI was accessed on a cellular phone mounted to the handheld OCT probe to wirelessly control the OCT system. Twenty subjects were imaged using the WebUI to assess the system. System latency was measured using different connection types (wireless 802.11n only, wireless to remote virtual private network [VPN], and cellular). Using a cellular phone, the WebUI was successfully used to capture posterior eye OCT images in all subjects. Simultaneous interactivity by a remote user on a laptop was also demonstrated. On average, use of the WebUI added only 58, 95, and 170 ms to the system latency using wireless only, wireless to VPN, and cellular connections, respectively. Qualitatively, operator usage was not affected. Using a WebUI, we demonstrated wireless and remote control of an OCT system with mobile devices. The web and open source software tools used in this project make it possible for any mobile device to potentially control an OCT system through a WebUI. This platform can be a basis for remote, teleophthalmology applications using OCT.

Molecular Properties of Drugs Interacting with SLC22 Transporters OAT1, OAT3, OCT1, and OCT2: A Machine-Learning Approach.

PubMed

Liu, Henry C; Goldenberg, Anne; Chen, Yuchen; Lun, Christina; Wu, Wei; Bush, Kevin T; Balac, Natasha; Rodriguez, Paul; Abagyan, Ruben; Nigam, Sanjay K

2016-10-01

Statistical analysis was performed on physicochemical descriptors of ∼250 drugs known to interact with one or more SLC22 "drug" transporters (i.e., SLC22A6 or OAT1, SLC22A8 or OAT3, SLC22A1 or OCT1, and SLC22A2 or OCT2), followed by application of machine-learning methods and wet laboratory testing of novel predictions. In addition to molecular charge, organic anion transporters (OATs) were found to prefer interacting with planar structures, whereas organic cation transporters (OCTs) interact with more three-dimensional structures (i.e., greater SP3 character). Moreover, compared with OAT1 ligands, OAT3 ligands possess more acyclic tetravalent bonds and have a more zwitterionic/cationic character. In contrast, OCT1 and OCT2 ligands were not clearly distinquishable form one another by the methods employed. Multiple pharmacophore models were generated on the basis of the drugs and, consistent with the machine-learning analyses, one unique pharmacophore created from ligands of OAT3 possessed cationic properties similar to OCT ligands; this was confirmed by quantitative atomic property field analysis. Virtual screening with this pharmacophore, followed by transport assays, identified several cationic drugs that selectively interact with OAT3 but not OAT1. Although the present analysis may be somewhat limited by the need to rely largely on inhibition data for modeling, wet laboratory/in vitro transport studies, as well as analysis of drug/metabolite handling in Oat and Oct knockout animals, support the general validity of the approach-which can also be applied to other SLC and ATP binding cassette drug transporters. This may make it possible to predict the molecular properties of a drug or metabolite necessary for interaction with the transporter(s), thereby enabling better prediction of drug-drug interactions and drug-metabolite interactions. Furthermore, understanding the overlapping specificities of OATs and OCTs in the context of dynamic transporter tissue expression patterns should help predict net flux in a particular tissue of anionic, cationic, and zwitterionic molecules in normal and pathophysiological states. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Molecular Properties of Drugs Interacting with SLC22 Transporters OAT1, OAT3, OCT1, and OCT2: A Machine-Learning Approach

PubMed Central

Liu, Henry C.; Goldenberg, Anne; Chen, Yuchen; Lun, Christina; Wu, Wei; Bush, Kevin T.; Balac, Natasha; Rodriguez, Paul; Abagyan, Ruben

2016-01-01

Statistical analysis was performed on physicochemical descriptors of ∼250 drugs known to interact with one or more SLC22 “drug” transporters (i.e., SLC22A6 or OAT1, SLC22A8 or OAT3, SLC22A1 or OCT1, and SLC22A2 or OCT2), followed by application of machine-learning methods and wet laboratory testing of novel predictions. In addition to molecular charge, organic anion transporters (OATs) were found to prefer interacting with planar structures, whereas organic cation transporters (OCTs) interact with more three-dimensional structures (i.e., greater SP3 character). Moreover, compared with OAT1 ligands, OAT3 ligands possess more acyclic tetravalent bonds and have a more zwitterionic/cationic character. In contrast, OCT1 and OCT2 ligands were not clearly distinquishable form one another by the methods employed. Multiple pharmacophore models were generated on the basis of the drugs and, consistent with the machine-learning analyses, one unique pharmacophore created from ligands of OAT3 possessed cationic properties similar to OCT ligands; this was confirmed by quantitative atomic property field analysis. Virtual screening with this pharmacophore, followed by transport assays, identified several cationic drugs that selectively interact with OAT3 but not OAT1. Although the present analysis may be somewhat limited by the need to rely largely on inhibition data for modeling, wet laboratory/in vitro transport studies, as well as analysis of drug/metabolite handling in Oat and Oct knockout animals, support the general validity of the approach—which can also be applied to other SLC and ATP binding cassette drug transporters. This may make it possible to predict the molecular properties of a drug or metabolite necessary for interaction with the transporter(s), thereby enabling better prediction of drug-drug interactions and drug-metabolite interactions. Furthermore, understanding the overlapping specificities of OATs and OCTs in the context of dynamic transporter tissue expression patterns should help predict net flux in a particular tissue of anionic, cationic, and zwitterionic molecules in normal and pathophysiological states. PMID:27488918

Learnable despeckling framework for optical coherence tomography images

NASA Astrophysics Data System (ADS)

Adabi, Saba; Rashedi, Elaheh; Clayton, Anne; Mohebbi-Kalkhoran, Hamed; Chen, Xue-wen; Conforto, Silvia; Nasiriavanaki, Mohammadreza

2018-01-01

Optical coherence tomography (OCT) is a prevalent, interferometric, high-resolution imaging method with broad biomedical applications. Nonetheless, OCT images suffer from an artifact called speckle, which degrades the image quality. Digital filters offer an opportunity for image improvement in clinical OCT devices, where hardware modification to enhance images is expensive. To reduce speckle, a wide variety of digital filters have been proposed; selecting the most appropriate filter for an OCT image/image set is a challenging decision, especially in dermatology applications of OCT where a different variety of tissues are imaged. To tackle this challenge, we propose an expandable learnable despeckling framework, we call LDF. LDF decides which speckle reduction algorithm is most effective on a given image by learning a figure of merit (FOM) as a single quantitative image assessment measure. LDF is learnable, which means when implemented on an OCT machine, each given image/image set is retrained and its performance is improved. Also, LDF is expandable, meaning that any despeckling algorithm can easily be added to it. The architecture of LDF includes two main parts: (i) an autoencoder neural network and (ii) filter classifier. The autoencoder learns the FOM based on several quality assessment measures obtained from the OCT image including signal-to-noise ratio, contrast-to-noise ratio, equivalent number of looks, edge preservation index, and mean structural similarity index. Subsequently, the filter classifier identifies the most efficient filter from the following categories: (a) sliding window filters including median, mean, and symmetric nearest neighborhood, (b) adaptive statistical-based filters including Wiener, homomorphic Lee, and Kuwahara, and (c) edge preserved patch or pixel correlation-based filters including nonlocal mean, total variation, and block matching three-dimensional filtering.

Denoising and 4D visualization of OCT images

PubMed Central

Gargesha, Madhusudhana; Jenkins, Michael W.; Rollins, Andrew M.; Wilson, David L.

2009-01-01

We are using Optical Coherence Tomography (OCT) to image structure and function of the developing embryonic heart in avian models. Fast OCT imaging produces very large 3D (2D + time) and 4D (3D volumes + time) data sets, which greatly challenge ones ability to visualize results. Noise in OCT images poses additional challenges. We created an algorithm with a quick, data set specific optimization for reduction of both shot and speckle noise and applied it to 3D visualization and image segmentation in OCT. When compared to baseline algorithms (median, Wiener, orthogonal wavelet, basic non-orthogonal wavelet), a panel of experts judged the new algorithm to give much improved volume renderings concerning both noise and 3D visualization. Specifically, the algorithm provided a better visualization of the myocardial and endocardial surfaces, and the interaction of the embryonic heart tube with surrounding tissue. Quantitative evaluation using an image quality figure of merit also indicated superiority of the new algorithm. Noise reduction aided semi-automatic 2D image segmentation, as quantitatively evaluated using a contour distance measure with respect to an expert segmented contour. In conclusion, the noise reduction algorithm should be quite useful for visualization and quantitative measurements (e.g., heart volume, stroke volume, contraction velocity, etc.) in OCT embryo images. With its semi-automatic, data set specific optimization, we believe that the algorithm can be applied to OCT images from other applications. PMID:18679509

The EWS–Oct-4 fusion gene encodes a transforming gene

PubMed Central

Lee, Jungwoon; Kim, Ja Young; Kang, In Young; Kim, Hye Kyoung; Han, Yong-Mahn; Kim, Jungho

2007-01-01

The t(6;22)(p21;q12) translocation associated with human bone and soft-tissue tumours results in a chimaeric molecule fusing the NTD (N-terminal domain) of the EWS (Ewing's sarcoma) gene to the CTD (C-terminal domain) of the Oct-4 (octamer-4) embryonic gene. Since the N-terminal domains of EWS and Oct-4 are structurally different, in the present study we have assessed the functional consequences of the EWS–Oct-4 fusion. We find that this chimaeric gene encodes a nuclear protein which binds DNA with the same sequence specificity as the parental Oct-4 protein. Comparison of the transactivation properties of EWS–Oct-4 and Oct-4 indicates that the former has higher transactivation activity for a known target reporter gene containing Oct-4 binding. Deletion analysis of the functional domains of EWS–Oct-4 indicates that the EWS (NTD), the POU domain and the CTD of EWS–Oct-4 are necessary for full transactivation potential. EWS–Oct-4 induced the expression of fgf-4 (fibroblast growth factor 4) and nanog, which are potent mitogens as well as Oct-4 downstream target genes whose promoters contain potential Oct-4-binding sites. Finally, ectopic expression of EWS–Oct-4 in Oct-4-null ZHBTc4 ES (embryonic stem) cells resulted in increased tumorigenic growth potential in nude mice. These results suggest that the oncogenic effect of the t(6;22) translocation is due to the EWS–Oct-4 chimaeric protein and that fusion of the EWS NTD to the Oct-4 DNA-binding domain produces a transforming chimaeric product. PMID:17564582

Wireless, Web-Based Interactive Control of Optical Coherence Tomography with Mobile Devices

PubMed Central

Mehta, Rajvi; Nankivil, Derek; Zielinski, David J.; Waterman, Gar; Keller, Brenton; Limkakeng, Alexander T.; Kopper, Regis; Izatt, Joseph A.; Kuo, Anthony N.

2017-01-01

Purpose Optical coherence tomography (OCT) is widely used in ophthalmology clinics and has potential for more general medical settings and remote diagnostics. In anticipation of remote applications, we developed wireless interactive control of an OCT system using mobile devices. Methods A web-based user interface (WebUI) was developed to interact with a handheld OCT system. The WebUI consisted of key OCT displays and controls ported to a webpage using HTML and JavaScript. Client–server relationships were created between the WebUI and the OCT system computer. The WebUI was accessed on a cellular phone mounted to the handheld OCT probe to wirelessly control the OCT system. Twenty subjects were imaged using the WebUI to assess the system. System latency was measured using different connection types (wireless 802.11n only, wireless to remote virtual private network [VPN], and cellular). Results Using a cellular phone, the WebUI was successfully used to capture posterior eye OCT images in all subjects. Simultaneous interactivity by a remote user on a laptop was also demonstrated. On average, use of the WebUI added only 58, 95, and 170 ms to the system latency using wireless only, wireless to VPN, and cellular connections, respectively. Qualitatively, operator usage was not affected. Conclusions Using a WebUI, we demonstrated wireless and remote control of an OCT system with mobile devices. Translational Relevance The web and open source software tools used in this project make it possible for any mobile device to potentially control an OCT system through a WebUI. This platform can be a basis for remote, teleophthalmology applications using OCT. PMID:28138415

In vivo monitoring laser tissue interaction using high resolution Fourier-domain optical coherence tomography

NASA Astrophysics Data System (ADS)

Jo, Hang Chan; Shin, Dong Jun; Ahn, Jin-Chul; Chung, Phil-Sang; Kim, DaeYu

2017-02-01

Laser-induced therapies include laser ablation to remove or cut target tissue by irradiating high-power focused laser beam. These laser treatments are widely used tools for minimally invasive surgery and retinal surgical procedures in clinical settings. In this study, we demonstrate laser tissue interaction images of various sample tissues using high resolution Fourier-domain optical coherence tomography (Fd-OCT). We use a Q-switch diode-pumped Nd:YVO4 nanosecond laser (532nm central wavelength) with a 4W maximum output power at a 20 kHz repetition rate to ablate in vitro and in vivo samples including chicken breast and mouse ear tissues. The Fd-OCT system acquires time-series Bscan images at the same location during the tissue ablation experiments with 532nm laser irradiation. The real-time series of OCT cross-sectional (B-scan) images compare structural changes of 532nm laser ablation using same and different laser output powers. Laser tissue ablation is demonstrated by the width and the depth of the tissue ablation from the B-scan images.

Oct4-GFP expression during transformation of gonocytes into spermatogonial stem cells in the perinatal mouse testis.

PubMed

Li, Ruili; Vannitamby, Amanda; Zhang, Jian-Guo; Fehmel, Emma L; Southwell, Bridget R; Hutson, John M

2015-12-01

In cryptorchidism perinatal failure to switch off Oct4, a germ cell (GC) marker, may lead to carcinoma in situ. We aimed to analyze Oct4 expression during mouse gonocyte transformation into spermatogonial stem cells (SSC). Testes from OG2 (Oct4-promoter driven eGFP) mice at embryonic day (E) 17 and postnatal day P0-10 underwent immunohistochemistry and immunoblotting. Antibodies against MVH, AMH, Ki67, and c-Kit were visualized by confocal microscopy. Numbers of Oct4-GFP(+) GC and Oct4-GFP(-) GC/tubule were counted using ImageJ. Data were analyzed using nonparametric one-way ANOVA. GC from E17-P4 were Oct4-GFP(+). Numbers of Oct4-GFP(-) GC/tubule increased from P6-10, whereas Oct4-GFP(+) GC/tubule numbers remained similar between P6 and P10. Sertoli cells proliferated from E17-P10, whereas GC only proliferated from P2. Gonocytes (Oct4-GFP(+)/c-Kit(-)) central in tubules migrated to the basement membrane to become prospermatogonia (Oct4-GFP(+)/c-Kit(-)) and then SSC (Oct4-GFP(+)/c-Kit(+)) from day 4 and further developed into Oct4-GFP(-)/c-Kit(+) at P6. In Oct4-GFP mice both centrally located gonocytes and prospermatogonia located at the tubular basement membrane were Oct4-GFP(+)/c-Kit(-) before further developing into SSC (Oct4-GFP(+)/c-Kit(+)). This indicates that Oct4 is important in gonocyte transformation into SSC. Understanding this process will aid GC tumor diagnostics and fertility potential in boys with UDT undergoing orchidopexy. Copyright © 2015 Elsevier Inc. All rights reserved.

Evaluation of air-interfaced Calu-3 cell layers for investigation of inhaled drug interactions with organic cation transporters in vitro.

PubMed

Mukherjee, Manali; Pritchard, D I; Bosquillon, C

2012-04-15

A physiologically pertinent in vitro model is urgently needed for probing interactions between inhaled drugs and the organic cation transporters (OCT) in the bronchial epithelium. This study evaluated OCT expression, functionality, inhibition by common inhaled drugs and impact on formoterol transepithelial transport in layers of human bronchial epithelial Calu-3 cells grown at an air-liquid interface. 21 day old Calu-3 layers expressed OCT1, OCT3, OCTN1 and OCTN2 whereas OCT2 could not be detected. Quantification of the cellular uptake of the OCT substrate ASP(+) in presence of inhibitors suggested several OCT were functional at the apical side of the cell layers. ASP(+) uptake was reduced by the bronchodilators formoterol, salbutamol (albuterol), ipratropium and the glucocorticoid budesonide. However, the OCT inhibitory properties of the two β(2)-mimetics were suppressed at therapeutically relevant concentrations. The absorptive permeability of formoterol across the cell layers was enhanced at a high drug concentration shown to decrease ASP(+) uptake by ∼50% as well as in presence of the OCT inhibitor tetraethylammonium (TEA). Secretory transport was unaffected by the drug concentration but was reduced by TEA. Our data indicate air-interfaced Calu-3 layers offer a low-cost in vitro model suitable for assessing inhaled drug-OCT interactions in the bronchial epithelium. Copyright © 2011 Elsevier B.V. All rights reserved.

Specifications and Other Standardization Documents Involving Cellular Plastics (Plastic Foams), Cushioning and Related Materials

DTIC Science & Technology

1976-07-01

FOR MEDICAL MATERIAL REQUIRING CONTROLLED TEMPERATURE RANGES 258 PPP-C-1683(1) 8135 69 10 Oct 73 CUSHIONING MATERIAL, EXPANDED POLYSTYRENE LOOSE FILL...Liquid immersion effect on properties of elastoaeric vulcanizates - 45 Lead deflection characteristics - 264 Loose-fill expanded polystyrene - 25f

Participation of OCT3/4 and beta-catenin during dysgenetic gonadal malignant transformation.

PubMed

Palma, Icela; Peña, Rocio-Yolanda; Contreras, Alejandra; Ceballos-Reyes, Guillermo; Coyote, Ninel; Eraña, Luis; Kofman-Alfaro, Susana; Queipo, Gloria

2008-05-18

Gonadoblastoma (GB) is an in situ tumor consisting of a heterogeneous population of mature and immature germ cells, other cells resembling immature Sertoli/granulosa cells, and Leydig/lutein-like cells, may also be present. GB almost exclusively affects a subset of patients with intersex disorders and in 30% of them overgrowth of the germinal component of the tumor is observed and the lesion is term dysgerminoma/seminoma. Several pathways have been proposed to explain the malignant process, and abnormal OCT3/4 expression is the most robust risk factor for malignant transformation. Some authors have suggested that OCT3/4 and beta-catenin might both be involved in the same oncogenic pathway, as both genes are master regulators of cell differentiation and, overexpression of either gene may result in cancer development. The mechanism by which beta-catenin participates in GB transformation is not completely clear and exploration of the E-cadherin pathway did not conclusively show that this pathway participated in the molecular pathogenesis of GB. Here we analyze seven patients with mixed gonadal dysgenesis and GB, in an effort to elucidate the participation of beta-catenin and E-cadherin, as well as OCT3/4, in the oncogenic pathways involved in the transformation of GB into seminoma/dysgerminoma. We conclude that the proliferation of immature germ cells in GB may be due to an interaction between OCT3/4 and accumulated beta-catenin in the nuclei of the immature germ cells.

Stem cell regulatory function mediated by expression of a novel mouse Oct4 pseudogene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Huey; Shabbir, Arsalan; Molnar, Merced

2007-03-30

Multiple pseudogenes have been proposed for embryonic stem (ES) cell-specific genes, and their abundance suggests that some of these potential pseudogenes may be functional. ES cell-specific expression of Oct4 regulates stem cell pluripotency and self-renewing state. Although Oct4 expression has been reported in adult tissues during gene reprogramming, the detected Oct4 signal might be contributed by Oct4 pseudogenes. Among the multiple Oct4 transcripts characterized here is a {approx}1 kb clone derived from P19 embryonal carcinoma stem cells, which shares a {approx}87% sequence homology with the parent Oct4 gene, and has the potential of encoding an 80-amino acid product (designated asmore » Oct4P1). Adenoviral expression of Oct4P1 in mesenchymal stem cells promotes their proliferation and inhibits their osteochondral differentiation. These dual effects of Oct4P1 are reminiscent of the stem cell regulatory function of the parent Oct4, and suggest that Oct4P1 may be a functional pseudogene or a novel Oct4-related gene with a unique function in stem cells.« less

Pharmacokinetic Interactions Between Isavuconazole and the Drug Transporter Substrates Atorvastatin, Digoxin, Metformin, and Methotrexate in Healthy Subjects

PubMed Central

Yamazaki, Takao; Desai, Amit; Goldwater, Ronald; Han, David; Lasseter, Kenneth C.; Howieson, Corrie; Akhtar, Shahzad; Kowalski, Donna; Lademacher, Christopher; Rammelsberg, Diane

2016-01-01

Abstract This article summarizes 4 phase 1 trials that explored interactions between the novel, triazole antifungal isavuconazole and substrates of the drug transporters breast cancer resistance protein (BCRP), multidrug and toxin extrusion protein‐1 (MATE1), organic anion transporters 1/3 (OAT1/OAT3), organic anion‐transporting polypeptide 1B1 (OATP1B1), organic cation transporters 1/2 (OCT1/OCT2), and P‐glycoprotein (P‐gp). Healthy subjects received single doses of atorvastatin (20 mg; OATP1B1 and P‐gp substrate), digoxin (0.5 mg; P‐gp substrate), metformin (850 mg; OCT1, OCT2, and MATE1 substrate), or methotrexate (7.5 mg; BCRP, OAT1, and OAT3 substrate) in the presence and absence of clinical doses of isavuconazole (200 mg 3 times a day for 2 days; 200 mg once daily thereafter). Coadministration with isavuconazole increased mean area under the plasma concentration‐time curves (90% confidence interval) of atorvastatin, digoxin, and metformin to 137% (129, 145), 125% (117, 134),  and 152% (138, 168) and increased mean maximum plasma concentrations to 103% (88, 121), 133% (119, 149), and 123% (109, 140), respectively. Methotrexate parameters were unaffected by isavuconazole. There were no serious adverse events. These findings indicate that isavuconazole is a weak inhibitor of P‐gp, as well as OCT1, OCT2, MATE1, or a combination thereof but not of BCRP, OATP1B1, OAT1, or OAT3. PMID:27273004

Utilizing optical coherence tomography for CAD/CAM of indirect dental restorations

NASA Astrophysics Data System (ADS)

Chityala, Ravishankar; Vidal, Carola; Jones, Robert

Optical Coherence Tomography (OCT) has seen broad application in dentistry including early carious lesion detection and imaging defects in resin composite restorations. This study investigates expanding the clinical usefulness by investigating methods to use OCT for obtaining three-dimensional (3D) digital impressions, which can be integrated to CAD/CAM manufacturing of indirect restorations. 3D surface topography `before' and `after' a cavity preparation was acquired by an intraoral cross polarization swept source OCT (CP-OCT) system with a Micro-Electro-Mechanical System (MEMS) scanning mirror. Image registration and segmentation methods were used to digitally construct a replacement restoration that modeled the original surface morphology of a hydroxyapatite sample. After high resolution additive manufacturing (e.g. polymer 3D printing) of the replacement restoration, micro-CT imaging was performed to examine the marginal adaptation. This study establishes the protocol for further investigation of integrating OCT with CAD/CAM of indirect dental restorations.

Optical coherence tomography angiography retinal vascular network assessment in multiple sclerosis.

PubMed

Lanzillo, Roberta; Cennamo, Gilda; Criscuolo, Chiara; Carotenuto, Antonio; Velotti, Nunzio; Sparnelli, Federica; Cianflone, Alessandra; Moccia, Marcello; Brescia Morra, Vincenzo

2017-09-01

Optical coherence tomography (OCT) angiography is a new method to assess the density of the vascular networks. Vascular abnormalities are considered involved in multiple sclerosis (MS) pathology. To assess the presence of vascular abnormalities in MS and to evaluate their correlation to disease features. A total of 50 MS patients with and without history of optic neuritis (ON) and 46 healthy subjects were included. All underwent spectral domain (SD)-OCT and OCT angiography. Clinical history, Expanded Disability Status Scale (EDSS), Multiple Sclerosis Severity Score (MSSS) and disease duration were collected. Angio-OCT showed a vessel density reduction in eyes of MS patients when compared to controls. A statistically significant reduction in all SD-OCT and OCT angiography parameters was noticed both in eyes with and without ON when compared with control eyes. We found an inverse correlation between SD-OCT parameters and MSSS ( p = 0.003) and between vessel density parameters and EDSS ( p = 0.007). We report a vessel density reduction in retina of MS patients. We highlight the clinical correlation between vessel density and EDSS, suggesting that angio-OCT could be a good marker of disease and of disability in MS.

Intraoperative optical coherence tomography: past, present, and future

PubMed Central

Ehlers, J P

2016-01-01

To provide an overview of the current state of intraoperative optical coherence tomography (OCT). Literature review of studies pertaining to intraoperative OCT examining both the technology aspects of the imaging platform and the current evidence for patient care. Over the last several years, there have been significant advances in integrative technology for intraoperative OCT. This has resulted in the development of multiple microscope-integrated systems and a rapidly expanding field of image-guided surgical care. Multiple studies have demonstrated the potential role for intraoperative OCT in facilitating surgeon understanding of the surgical environment, tissue configuration, and overall changes to anatomy. In fact, the PIONEER and DISCOVER studies, both demonstrated a potential significant percentage of cases that intraoperative OCT alters surgical decision-making in both anterior and posterior segment surgery. Current areas of exploration and development include OCT-compatible instrumentation, automated tracking, intraoperative OCT software platforms, and surgeon feedback/visualization platforms. Intraoperative OCT is an emerging technology that holds promise for enhancing the surgical care of both anterior segment and posterior segment conditions. Hurdles remain for adoption and widespread utilization, including cost, optimized feedback platforms, and more definitive value for individualized surgical care with image guidance. PMID:26681147

Comparative Exploration of the Structure-Activity Space of Cloned α-Like Octopamine Receptors from a Marine and a Terrestrial Arthropod.

PubMed

Dalwadi, Dhwanil A; Schetz, John A

2017-09-01

The α -like octopamine receptors (OctR) are believed to be the evolutionary precursor to the vertebrate α 2 -adrenergic receptors ( α 2 -ARs) based upon sequence similarity and the ability to interact with norepinephrine and a number of compounds that bind with high affinity to α 2 -ARs. Barnacles and fruit flies are two prominent model marine and terrestrial representatives of the Arthropoda phylum, and although α -like OctRs have been cloned from Balanus improvisus (BiOctR) and Drosophila melanogaster (DmOctR), little is known about the structure-activity space for these important species. A diverse panel of 22 probes spanning different structural classes were employed to interrogate the structure-activity of the BiOctR and DmOctR. While BiOctR and DmOctR exhibited similar functional profiles for mammalian biogenic amine G protein-coupled receptor agonists and antagonists, some ligands had dramatically different mechanisms of action. For instance, significant differences in the efficacy for some agonists were observed, including that vertebrate biogenic amines structurally related to octopamine acted as superagonists at the DmOctR but partial agonists at the BiOctR, and the two species diverged in their sensitivities to the α 2 -AR antagonist [ 3 H]rauwolscine. Furthermore, sodium enhanced [ 3 H]rauwolscine's interactions with the BiOctR, but not at a vertebrate α 2 -AR. Molecular mechanistic studies indicate that rauwolscine interacts with the BiOctR, DmOctR, and α 2C -adrenergic receptor at an allosteric site. In addition, compounds that acted as agonists at a cloned α -like BiOctR also induced a hyperactivity response in Balanus cyprids mediated by the α -like OctR, suggesting that the receptor may serve as a higher throughput proxy for discovering compounds with potential cyprid deterrent properties. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

Molecular cloning and production of caprine recombinant Oct4 protein for generation induced pluripotent stem cells.

PubMed

Singhal, Dinesh K; Singhal, Raxita; Malik, Hruda N; Singh, Surender; Kumar, Sudarshan; Kaushik, Jai K; Mohanty, Ashok K; Malakar, Dhruba

2015-12-01

Oct4, pluripotency marker and transcription factor, expresses in embryonic stem cells. It plays a pivotal role in determination of stem cells fate. Up and down regulation of Oct4 causes differentiation of embryonic stem cells. It is one of the main transcription factors which remained concerned in every study related to induced pluripotent stem cell. Here, we report the production of goat Oct4 protein using plasmid and lentiviral based vectors. Firstly, Oct4 ORF was cloned in pAcGFP1-N1 plasmid vector and positive clones were screened with colony PCR. Oct4 was over-expressed in CHO-K1 cell line and expression was confirmed by observing green florescent protein expression in CHO-K1 cells. Secondly, Oct4 lentiviral expression construct has been prepared using pLenti-gw vector. Oct4 ORF was cloned into pLenti4/V5-DEST vector and viral particles were produced in 293FT cells. Oct4 viral particles were used to infect goat fibroblast cells. Oct4 expression was observed and confirmed in transfected goat fibroblast cells using RT-PCR. Detection of Oct4 protein in western blotting assay affirmed the capacity of over-expression of our Oct4 lentiviral vector. The lentiviral expression construct and recombinant Oct4 protein may be used for reprogramming of somatic cell into induced pluripotent stem cell.

Intravascular OCT

NASA Astrophysics Data System (ADS)

Schmitt, Joseph M.; Adler, Desmond; Xu, Chenyang

Since the first coronary angioplasty was performed in the late 1970s, imaging has played a central role in percutaneous coronary intervention (PCI). Today more than three million PCI procedures are performed worldwide to expand narrowed arteries and to clear blood clots that can cause debilitating symptoms of myocardial ischemia or fatal heart attacks. Although X-ray angiography is still the workhorse imaging modality in the field of interventional cardiology, intravascular imaging has become an indispensable tool for guiding complex PCI procedures. Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) are the two most commonly used catheter-based imaging technologies in coronary procedures. Since the first commercial intravascular OCT systems were introduced in Japan and the European Union in 2004 and in the United States in 2009, the application of intravascular OCT has grown rapidly [3, 15, 16].

Spatiotemporal dynamics of OCT4 protein localization during preimplantation development in mice.

PubMed

Fukuda, Atsushi; Mitani, Atsushi; Miyashita, Toshiyuki; Kobayashi, Hisato; Umezawa, Akihiro; Akutsu, Hidenori

2016-11-01

Spatiotemporal expression of transcription factors is crucial for genomic reprogramming. Pou5f1 (Oct4) is an essential transcription factor for reprogramming. A recent study reported that OCT4A, which is crucial for establishment and maintenance of pluripotent cells, is expressed in oocytes, but maternal OCT4A is dispensable for totipotency induction. Whereas another study reported that OCT4B, which is not related to pluripotency, is predominantly expressed instead of OCT4A during early preimplantation phases in mice. To determine the expression states of OCT4 in murine preimplantation embryos, we conducted in-depth expression and functional analyses. We found that pluripotency-related OCT4 mainly localizes to the cytoplasm in early preimplantation phases, with no major nuclear localization until the 8-16-cell stage despite high expression in both oocytes and early embryos. RNA-sequencing analysis using oocytes and early preimplantation embryos could not identify the splice variants creating alternative forms of OCT4 protein. Forced expression of OCT4 in zygotes by the injection of polyadenylated mRNA clearly showed nuclear localization of OCT4 protein around 3-5-fold greater than physiological levels and impaired developmental competency in a dose-dependent manner. Embryos with modest overexpression of OCT4 could develop to the 16-cell stage; however, more than 50% of the embryos were arrested at this stage, similar to the results for OCT4 depletion. In contrast, extensive overexpression of OCT4 resulted in complete arrest at the 2-cell stage accompanied by downregulation of zygotically activated genes and repetitive elements related to the totipotent state. These results demonstrated that OCT4 protein localization was spatiotemporally altered during preimplantation development, and strict control of Oct4 protein levels was essential for proper totipotential reprogramming. © 2016 Society for Reproduction and Fertility.

Evaluation of the potential interaction between tofacitinib and drugs that undergo renal tubular secretion using metformin, an in vivo marker of renal organic cation transporter 2.

PubMed

Klamerus, Karen J; Alvey, Christine; Li, Lei; Feng, Bo; Wang, Rong; Kaplan, Irina; Shi, Haihong; Dowty, Martin E; Krishnaswami, Sriram

2014-11-01

Tofacitinib is a novel, oral Janus kinase inhibitor. The potential for drug-drug interactions (DDIs) between tofacitinib and drugs that undergo renal tubular secretion was evaluated using metformin as a probe transporter substrate, and genotyping for organic cation transporter (OCT) 1, OCT2 and multidrug and toxin extrusion 1 polymorphisms. Twenty-four healthy male subjects completed this open-label, fixed-sequence study. Subjects were administered a single oral metformin 500 mg dose on Days 1 and 4, and multiple oral tofacitinib 30 mg twice daily doses on Days 2, 3, and 4. Subjects underwent serial blood and urine samplings (Days 1 and 4) to estimate metformin pharmacokinetics. A single blood sample for tofacitinib was collected 2 hours after the morning dose (Day 4). The 90% confidence intervals for the ratios of maximum plasma concentration, area under the curve and renal clearance of metformin, with and without tofacitinib, were contained within the 80-125% acceptance range commonly used to establish a lack of DDI. No deaths, serious adverse events (AEs), severe AEs or discontinuations due to AEs were reported. The study confirms tofacitinib is unlikely to impact the pharmacokinetics of drugs that undergo renal tubular secretion, and concurs with its weak in vitro OCT2 inhibitory profile. © 2014, The American College of Clinical Pharmacology.

The B-Cell Specific Transcription Factor, Oct-2, Promotes Epstein-Barr Virus Latency by Inhibiting the Viral Immediate-Early Protein, BZLF1

PubMed Central

Robinson, Amanda R.; Kwek, Swee Sen; Kenney, Shannon C.

2012-01-01

The Epstein-Barr virus (EBV) latent-lytic switch is mediated by the BZLF1 immediate-early protein. EBV is normally latent in memory B cells, but cellular factors which promote viral latency specifically in B cells have not been identified. In this report, we demonstrate that the B-cell specific transcription factor, Oct-2, inhibits the function of the viral immediate-early protein, BZLF1, and prevents lytic viral reactivation. Co-transfected Oct-2 reduces the ability of BZLF1 to activate lytic gene expression in two different latently infected nasopharyngeal carcinoma cell lines. Furthermore, Oct-2 inhibits BZLF1 activation of lytic EBV promoters in reporter gene assays, and attenuates BZLF1 binding to lytic viral promoters in vivo. Oct-2 interacts directly with BZLF1, and this interaction requires the DNA-binding/dimerization domain of BZLF1 and the POU domain of Oct-2. An Oct-2 mutant (Δ262–302) deficient for interaction with BZLF1 is unable to inhibit BZLF1-mediated lytic reactivation. However, an Oct-2 mutant defective for DNA-binding (Q221A) retains the ability to inhibit BZLF1 transcriptional effects and DNA-binding. Importantly, shRNA-mediated knockdown of endogenous Oct-2 expression in several EBV-positive Burkitt lymphoma and lymphoblastoid cell lines increases the level of lytic EBV gene expression, while decreasing EBNA1 expression. Moreover, treatments which induce EBV lytic reactivation, such as anti-IgG cross-linking and chemical inducers, also decrease the level of Oct-2 protein expression at the transcriptional level. We conclude that Oct-2 potentiates establishment of EBV latency in B cells. PMID:22346751

Nuclear delivery of recombinant OCT4 by chitosan nanoparticles for transgene-free generation of protein-induced pluripotent stem cells.

PubMed

Tammam, Salma; Malak, Peter; Correa, Daphne; Rothfuss, Oliver; Azzazy, Hassan M E; Lamprecht, Alf; Schulze-Osthoff, Klaus

2016-06-21

Protein-based reprogramming of somatic cells is a non-genetic approach for the generation of induced pluripotent stem cells (iPSCs), whereby reprogramming factors, such as OCT4, SOX2, KLF4 and c-MYC, are delivered as functional proteins. The technique is considered safer than transgenic methods, but, unfortunately, most protein-based protocols provide very low reprogramming efficiencies. In this study, we developed exemplarily a nanoparticle (NP)-based delivery system for the reprogramming factor OCT4. To this end, we expressed human OCT4 in Sf9 insect cells using a baculoviral expression system. Recombinant OCT4 showed nuclear localization in Sf9 cells indicating proper protein folding. In comparison to soluble OCT4 protein, encapsulation of OCT4 in nuclear-targeted chitosan NPs strongly stabilized its DNA-binding activity even under cell culture conditions. OCT4-loaded NPs enabled cell treatment with high micromolar concentrations of OCT4 and successfully delivered active OCT4 into human fibroblasts. Chitosan NPs therefore provide a promising tool for the generation of transgene-free iPSCs.

Inducing pluripotency in somatic cells from the snow leopard (Panthera uncia), an endangered felid.

PubMed

Verma, R; Holland, M K; Temple-Smith, P; Verma, P J

2012-01-01

Induced pluripotency is a new approach to produce embryonic stem-like cells from somatic cells that provides a unique means to understand both pluripotency and lineage assignment. To investigate whether this technology could be applied to endangered species, where the limited availability of gametes makes production and research on embryonic stem cells difficult, we attempted generation of induced pluripotent stem (iPS) cells from snow leopard (Panthera uncia) fibroblasts by retroviral transfection with Moloney-based retroviral vectors (pMXs) encoding four factors (OCT4, SOX2, KLF4 and cMYC). This resulted in the formation of small colonies of cells, which could not be maintained beyond four passages (P4). However, addition of NANOG, to the transfection cocktail produced stable iPS cell colonies, which formed as early as D3. Colonies of cells were selected at D5 and expanded in vitro. The resulting cell line was positive for alkaline phosphatase (AP), OCT4, NANOG, and Stage-Specific embryonic Antigen-4 (SSEA-4) at P14. RT-PCR also confirmed that endogenous OCT4 and NANOG were expressed by snow leopard iPS cells from P4. All five human transgenes were transcribed at P4, but OCT4, SOX2 and NANOG transgenes were silenced as early as P14; therefore, reprogramming of the endogenous pluripotent genes had occurred. When injected into immune-deficient mice, snow leopard iPS cells formed teratomas containing tissues representative of the three germ layers. In conclusion, this was apparently the first derivation of iPS cells from the endangered snow leopard and the first report on induced pluripotency in felid species. Addition of NANOG to the reprogramming cocktail was essential for derivation of iPS lines in this felid. The iPS cells provided a unique source of pluripotent cells with utility in conservation through cryopreservation of genetics, as a source of reprogrammed donor cells for nuclear transfer or for directed differentiation to gametes in the future. Copyright © 2012 Elsevier Inc. All rights reserved.

Distinctive expression pattern of OCT4 variants in different types of breast cancer.

PubMed

Soheili, Saamaaneh; Asadi, Malek Hossein; Farsinejad, Alireza

2017-01-01

OCT4 is a key regulator of self-renewal and pluripotency in embryonic stem cells which can potentially encode three spliced variants designated OCT4A, OCT4B and OCT4B1. Based on cancer stem cell concept, it is suggested that the stemness factors misexpressed in cancer cells and potentially is involved in tumorigenesis. Accordingly, in this study, we investigated the potential expression of OCT4 variants in breast cancer tissues. A total of 94 tumoral and peritumoral breast specimens were evaluated with respect to the expression of OCT4 variants using quantitative RT-PCR and immunohistochemical (IHC) analysis. We detected the expression of OCT4 variants in breast tumor tissues with no or very low levels of expression in peritumoral samples of the same patients. While OCT4B was highly expressed in lobular type of breast cancer, OCT4A and OCTB1 variants are highly expressed in low grade (I and II) ductal tumors. Furthermore, the results of this study revealed a considerable association between the expression level of OCT4 variants and the expression of ER, PR, Her2 and P53 factors. All data demonstrated a distinctive expression pattern of OCT4 spliced variants in different types of breast cancer and provide further evidence for the involvement of embryonic genes in carcinogenesis.

OCT4B1 Regulates the Cellular Stress Response of Human Dental Pulp Cells with Inflammation

PubMed Central

Liu, Lu; Huang, Rong; Yang, Ruiqi

2017-01-01

Introduction. Infection and apoptosis are combined triggers for inflammation in dental tissues. Octamer-binding transcription factor 4-B1 (OCT4B1), a novel spliced variant of OCT4 family, could respond to the cellular stress and possess antiapoptotic property. However, its specific role in dental pulpitis remains unknown. Methods. To investigate the effect of OCT4B1 on inflammation of dental pulp cells (DPCs), its expression in inflamed dental pulp tissues and DPCs was examined by in situ hybridization, real-time PCR, and FISH assay. OCT4B1 overexpressed DPCs model was established, confirmed by western blot and immunofluorescence staining, and then stimulated with Lipopolysaccharide (LPS). Apoptotic rate was determined by Hoechst/PI staining and FACS. Cell survival rate was calculated by CCK8 assay. Results. In situ hybridization, real-time PCR, and FISH assay revealed that OCT4B1 was extensively expressed in inflamed dental pulp tissues and DPCs with LPS stimulation. Western blot and immunofluorescence staining showed the expression of OCT4B1 and OCT4B increased after OCT4B1 transfection. Hoechst/PI staining and FACS demonstrated that less red/blue fluorescence was detected and apoptotic percentage decreased (3.45%) after transfection. CCK8 demonstrated that the survival rate of pCDH-OCT4B1-flag cells increased. Conclusions. OCT4B1 plays an essential role in inflammation and apoptosis of DPCs. OCT4B might operate synergistically with OCT4B1 to reduce apoptosis. PMID:28473980

Cited2 Gene Controls Pluripotency and Cardiomyocyte Differentiation of Murine Embryonic Stem Cells through Oct4 Gene*

PubMed Central

Li, Qiang; Ramírez-Bergeron, Diana L.; Dunwoodie, Sally L.; Yang, Yu-Chung

2012-01-01

Cited2 (CBP/p300-interacting transactivator with glutamic acid (E)/aspartic acid (D)-rich tail 2) is a transcriptional modulator critical for the development of multiple organs. Although many Cited2-mediated phenotypes and molecular events have been well characterized using in vivo genetic murine models, Cited2-directed cell fate decision in embryonic stem cells (ESCs) remains elusive. In this study, we examined the role of Cited2 in the maintenance of stemness and pluripotency of murine ESCs by a gene-targeting approach. Cited2 knock-out (Cited2Δ/−, KO) ESCs display defective differentiation. Loss of Cited2 in differentiating ESCs results in delayed silencing of the genes involved in the maintenance of pluripotency and self-renewal of stem cells (Oct4, Klf4, Sox2, and c-Myc) and the disturbance in cardiomyocyte, hematopoietic, and neuronal differentiation. In addition, Cited2 KO ESCs experience a delayed induction of cardiomyocyte differentiation-associated proteins, NFAT3 (along with the reduced expression of NFAT3 target genes, Nkx2.5 and β-MHC), N-cadherin, and smooth muscle actin. CITED2 is recruited to the Oct4 promoter to regulate its expression during early ESC differentiation. This is the first demonstration that Cited2 controls ESC pluripotency and differentiation via direct regulation of Oct4 gene expression. PMID:22761414

A defined Oct4 level governs cell state transitions of pluripotency entry and differentiation into all embryonic lineages.

PubMed

Radzisheuskaya, Aliaksandra; Chia, Gloryn Le Bin; dos Santos, Rodrigo L; Theunissen, Thorold W; Castro, L Filipe C; Nichols, Jennifer; Silva, José C R

2013-06-01

Oct4 is considered a master transcription factor for pluripotent cell self-renewal, but its biology remains poorly understood. Here, we investigated the role of Oct4 using the process of induced pluripotency. We found that a defined embryonic stem cell (ESC) level of Oct4 is required for pluripotency entry. However, once pluripotency is established, the Oct4 level can be decreased up to sevenfold without loss of self-renewal. Unexpectedly, cells constitutively expressing Oct4 at an ESC level robustly differentiated into all embryonic lineages and germline. In contrast, cells with low Oct4 levels were deficient in differentiation, exhibiting expression of naive pluripotency genes in the absence of pluripotency culture requisites. The restoration of Oct4 expression to an ESC level rescued the ability of these to restrict naive pluripotent gene expression and to differentiate. In conclusion, a defined Oct4 level controls the establishment of naive pluripotency as well as commitment to all embryonic lineages.

Simulations and Visualizations of Hurricane Sandy (2012) as Revealed by the NASA CAMVis

NASA Technical Reports Server (NTRS)

Shen, Bo-Wen

2013-01-01

Storm Sandy first appeared as a tropical storm in the southern Caribbean Sea on Oct. 22, 2012, moved northeastward, turned northwestward, and made landfall near Brigantine, New Jersey in late October. Sandy devastated surrounding areas, caused an estimated damage of $50 billion, and became the second costliest tropical cyclone (TC) in U.S. History surpassed only by Hurricane Katrina (2005). To save lives and mitigate economic damage, a central question to be addressed is to what extent the lead time of severe storm prediction such as Sandy can be extended (e.g., Emanuel 2012; Kerr 2012). In this study, we present 10 numerical experiments initialized at 00 and 1200 UTC Oct. 22-26, 2012, with the NASA coupled advanced global modeling and visualization systems (CAMVis). All of the predictions realistically capture Sandy's movement with the northwestward turn prior to its landfall. However, three experiments (initialized at 0000 UTC Oct. 22 and 24 and 1200 UTC Oct. 22) produce larger errors. Among the 10 experiments, the control run initialized at 0000 UTC Oct. 23 produces a remarkable 7-day forecast. To illustrate the impact of environmental flows on the predictability of Sandy, we produce and discuss four-dimensional (4-D) visualizations with the control run. 4-D visualizations clearly demonstrate the following multiscale processes that led to the sinuous track of Sandy: the initial steering impact of an upper-level trough (appearing over the northwestern Caribbean Sea and Gulf of Mexico), the blocking impact of systems to the northeast of Sandy, and the binary interaction with a mid-latitude, upper-level trough that appeared at 130degrees west longitude on Oct. 23, moved to the East Coast and intensified during the period of Oct. 29-30 prior to Sandy's landfall.

Exogenous Oct-4 Inhibits Lens Transdifferentiation in the Newt Notophthalmus viridescens

PubMed Central

Bhavsar, Rital B.; Tsonis, Panagiotis A.

2014-01-01

From the cocktail of four factors that were able to induce pluripotent stem cells from differentiated cells, Oct-4, c-Myc, Sox-2 and Klf4, only Oct-4 was not expressed during regeneration in newts. To explore the possible action of this stemness factor we developed an assay where we introduced exogenous Oct-4 protein to an in vitro system for lens regeneration in newts. We found that exogenous Oct-4 inhibits differentiation of iris pigmented epithelial cells into lens cells and also regulates Sox-2 and Pax-6, both important players during lens development. Thus, presence of Oct-4 hinders transdifferentiation of iris cells. PMID:25019378

Long-range and wide field of view optical coherence tomography for in vivo 3D imaging of large volume object based on akinetic programmable swept source.

PubMed

Song, Shaozhen; Xu, Jingjiang; Wang, Ruikang K

2016-11-01

Current optical coherence tomography (OCT) imaging suffers from short ranging distance and narrow imaging field of view (FOV). There is growing interest in searching for solutions to these limitations in order to expand further in vivo OCT applications. This paper describes a solution where we utilize an akinetic swept source for OCT implementation to enable ~10 cm ranging distance, associated with the use of a wide-angle camera lens in the sample arm to provide a FOV of ~20 x 20 cm 2 . The akinetic swept source operates at 1300 nm central wavelength with a bandwidth of 100 nm. We propose an adaptive calibration procedure to the programmable akinetic light source so that the sensitivity of the OCT system over ~10 cm ranging distance is substantially improved for imaging of large volume samples. We demonstrate the proposed swept source OCT system for in vivo imaging of entire human hands and faces with an unprecedented FOV (up to 400 cm 2 ). The capability of large-volume OCT imaging with ultra-long ranging and ultra-wide FOV is expected to bring new opportunities for in vivo biomedical applications.

Long-range and wide field of view optical coherence tomography for in vivo 3D imaging of large volume object based on akinetic programmable swept source

PubMed Central

Song, Shaozhen; Xu, Jingjiang; Wang, Ruikang K.

2016-01-01

Current optical coherence tomography (OCT) imaging suffers from short ranging distance and narrow imaging field of view (FOV). There is growing interest in searching for solutions to these limitations in order to expand further in vivo OCT applications. This paper describes a solution where we utilize an akinetic swept source for OCT implementation to enable ~10 cm ranging distance, associated with the use of a wide-angle camera lens in the sample arm to provide a FOV of ~20 x 20 cm2. The akinetic swept source operates at 1300 nm central wavelength with a bandwidth of 100 nm. We propose an adaptive calibration procedure to the programmable akinetic light source so that the sensitivity of the OCT system over ~10 cm ranging distance is substantially improved for imaging of large volume samples. We demonstrate the proposed swept source OCT system for in vivo imaging of entire human hands and faces with an unprecedented FOV (up to 400 cm2). The capability of large-volume OCT imaging with ultra-long ranging and ultra-wide FOV is expected to bring new opportunities for in vivo biomedical applications. PMID:27896012

Alternative Splicing of MBD2 Supports Self-Renewal in Human Pluripotent Stem Cells

PubMed Central

Lu, Yu; Loh, Yuin-Han; Li, Hu; Cesana, Marcella; Ficarro, Scott B.; Parikh, Jignesh R.; Salomonis, Nathan; Toh, Cheng-Xu Delon; Andreadis, Stelios T.; Luckey, C. John; Collins, James J.; Daley, George Q.; Marto, Jarrod A.

2014-01-01

Summary Alternative RNA splicing (AS) regulates proteome diversity, including isoform-specific expression of several pluripotency genes. Here, we integrated global gene expression and proteomic analyses and identified a molecular signature suggesting a central role for AS in maintaining human pluripotent stem cell (hPSC) self-renewal. We demonstrate the splicing factor SFRS2 is an OCT4 target gene required for pluripotency. SFRS2 regulates AS of the methyl-CpG-binding protein MBD2, whose isoforms play opposing roles in maintenance of, and reprogramming to, pluripotency. While both MDB2a and MBD2c are enriched at the OCT4 and NANOG promoters, MBD2a preferentially interacts with repressive NuRD chromatin remodeling factors and promotes hPSC differentiation, whereas overexpression of MBD2c enhances reprogramming of fibroblasts to pluripotency. The miR-301 and miR-302 families provide additional regulation by targeting SFRS2 and MDB2a. These data suggest that OCT4, SFRS2, and MBD2 participate in a positive feedback loop, regulating proteome diversity complexity in support of hPSC self-renewal and reprogramming. PMID:24813856

Characterization of Oct4-GFP transgenic mice as a model to study the effect of environmental estrogens on the maturation of male germ cells by using flow cytometry.

PubMed

Porro, Valentina; Pagotto, Romina; Harreguy, María Belén; Ramírez, Sofía; Crispo, Martina; Santamaría, Clarisa; Luque, Enrique H; Rodríguez, Horacio A; Bollati-Fogolín, Mariela

2015-11-01

Oct4 is involved in regulation of pluripotency during normal development and is down-regulated during formation of postnatal reservoir of germ cells. We propose thatOct4/GFP transgenic mouse, which mimics the endogenous expression pattern of Oct4, could be used as a mammalian model to study the effects of environmental estrogens on the development of male germ cells. Oct4/GFP maturation profile was assessed during postnatal days -PND- 3, 5, 7, 10, 14 and 80, using flow cytometry. Then, we exposed pregnant mothers to 17α-ethinylestradiol (EE2) from day post coitum (dpc) 5 to PND7. Percentage of Oct4/GFP-expressing cells and levels of expression of Oct4/GPF were increased in PND7 after EE2 exposure. These observations were confirmed by analysis of GFP and endogenous Oct4 protein in the seminiferous tubules and by a reduction in epididymal sperm count in adult mice. We introduced Oct4/GFP mouse together with flow cytometry as a tool to evaluate changes in male germ cells development. Copyright © 2015 Elsevier Ltd. All rights reserved.

Thermodynamic characterization of the interaction behavior of a hydrophobically modified polyelectrolyte and oppositely charged surfactants in aqueous solution: effect of surfactant alkyl chain length.

PubMed

Bai, Guangyue; Nichifor, Marieta; Lopes, António; Bastos, Margarida

2005-01-13

We have used a precision isothermal titration microcalorimeter (ITC) to measure the enthalpy curves for the interaction of a hydrophobically modified polyelectrolyte (D40OCT30) with oppositely charged surfactants (SC(n)S) in aqueous solution. D40OCT30 is a newly synthesized polymer based on dextran having pendant N-(2-hydroxypropyl)-N,N-dimethyl-N-octylammonium chloride groups randomly distributed along the polymer backbone with degree of substitution of 28.1%. The employed anionic surfactants are sodium octyl sulfate (SC(8)S) and sodium tetradecyl sulfate (SC(14)S). Microcalorimetric results along with turbidity and kinematic viscosity measurements demonstrate systematically the thermodynamic characterization of the interaction of D40OCT30/SC(n)S. A three-dimensional diagram with the derived phase boundaries is drawn to describe the effect of the alkyl chain length of surfactant and of the ratio between surfactant and pendant groups on the interaction. A more complete picture of the interaction mechanism for D40OCT30/SC(n)S systems is proposed here.

Report on the International Rarefied Gas Dynamics Symposium (29th) held in Xi’an, China on 13-18 July 2014

DTIC Science & Technology

2014-11-21

cover in the region where gas expands all the way round the nozzle exit in the vacuum of space. This geome- try is investigated using hybrid NS/DSMC with...Final 3. DATES COVERED (From - To) 19 May 2014 – 18 Oct 2014 4. TITLE AND SUBTITLE Report on Rarefied Gas Dynamics Research Status 5a...Air Force about the current status of research in rarefied gas dynamics and related fields, primarily via the 29th International Symposium on Rarefied

Advanced Visualization and Interactive Display Rapid Innovation and Discovery Evaluation Research (VISRIDER) Program Task 6: Point Cloud Visualization Techniques for Desktop and Web Platforms

DTIC Science & Technology

2017-04-01

ADVANCED VISUALIZATION AND INTERACTIVE DISPLAY RAPID INNOVATION AND DISCOVERY EVALUATION RESEARCH (VISRIDER) PROGRAM TASK 6: POINT CLOUD...To) OCT 2013 – SEP 2014 4. TITLE AND SUBTITLE ADVANCED VISUALIZATION AND INTERACTIVE DISPLAY RAPID INNOVATION AND DISCOVERY EVALUATION RESEARCH...various point cloud visualization techniques for viewing large scale LiDAR datasets. Evaluate their potential use for thick client desktop platforms

MUW Approach of PS OCT

NASA Astrophysics Data System (ADS)

Hitzenberger, Christoph K.; Pircher, Michael

Polarization sensitive (PS) OCT is a functional extension of OCT that exploits the light's polarization state to generate intrinsic, tissue specific contrast and enables quantitative measurements of tissue parameters. This chapter explains the technique, discusses polarization-changing light-tissue interactions and demonstrates the application of PS-OCT to retinal imaging. Two polarization-changing light-tissue interactions are discussed and their use for retinal diagnostics are demonstrated: (i) birefringence, which is found in fibrous tissues like the retinal nerve fiber layer and can be used for glaucoma diagnostics; and (ii) depolarization, which is observed in the retinal pigment epithelium (RPE) and can be used to segment the RPE and associated lesions like drusen or geographic atrophies in age related macular degeneration.

Fast 5DOF needle tracking in iOCT.

PubMed

Weiss, Jakob; Rieke, Nicola; Nasseri, Mohammad Ali; Maier, Mathias; Eslami, Abouzar; Navab, Nassir

2018-06-01

Intraoperative optical coherence tomography (iOCT) is an increasingly available imaging technique for ophthalmic microsurgery that provides high-resolution cross-sectional information of the surgical scene. We propose to build on its desirable qualities and present a method for tracking the orientation and location of a surgical needle. Thereby, we enable the direct analysis of instrument-tissue interaction directly in OCT space without complex multimodal calibration that would be required with traditional instrument tracking methods. The intersection of the needle with the iOCT scan is detected by a peculiar multistep ellipse fitting that takes advantage of the directionality of the modality. The geometric modeling allows us to use the ellipse parameters and provide them into a latency-aware estimator to infer the 5DOF pose during needle movement. Experiments on phantom data and ex vivo porcine eyes indicate that the algorithm retains angular precision especially during lateral needle movement and provides a more robust and consistent estimation than baseline methods. Using solely cross-sectional iOCT information, we are able to successfully and robustly estimate a 5DOF pose of the instrument in less than 5.4 ms on a CPU.

Expression of Oct-4 is significantly associated with the development and prognosis of colorectal cancer

PubMed Central

ZHOU, HUAN; HU, YU; WANG, WEIPENG; MAO, YONG; ZHU, JINGJIE; ZHOU, BIN; SUN, JING; ZHANG, XUEGUANG

2015-01-01

Octamer-binding transcription factor 4 (Oct-4), is an essential transcription factor, which is required for pluripotency and self-renewal in embryonic stem cells and germ cells. It is also involved in maintaining cancer stem-like properties in certain types of tumor, and is an important biomarker for cancer stem cells. The present study investigated whether Oct-4 expression was associated with colorectal cancer (CRC). In order to achieve this, primary CRC tissues, matched non-tumor tissues and benign polyp tissues, representing different stages of carcinogenesis, were obtained, and Oct-4 expression was analyzed using reverse transcription-quantitative polymerase chain reaction, flow cytometry analysis and immunohistochemistry. Furthermore, the medical records of patients with CRC were reviewed, and clinicopathological analysis was performed in order to assess the association between Oct-4 expression and certain clinicopathological parameters. It was shown that the transcription and translation of Oct-4 increased in a stepwise manner, from non-tumor to benign polyp tissues, and from benign polyps to CRC tissues. Oct-4 expression in CRC was significantly correlated with histological grade (P=0.007), lymph node metastasis (P=0.027), distant metastasis (P=0.017) and TNM stage (P=0.041). Kaplan-Meier survival curve analysis demonstrated that Oct-4+ cases had a shorter median survival time (37.0 months) compared with Oct-4− cases (76.0 months; P=0.001). These results indicated that aberrant expression of Oct-4 may be involved in the development of CRC. Thus, Oct-4 may be a biomarker for the prediction, diagnosis or assessment of prognosis in CRC, in addition to a potential target for the treatment of this disease. PMID:26622555

Targeting Tumor Oct4 to Deplete Prostate Tumor and Metastasis Initiating Cells

DTIC Science & Technology

2016-10-01

Award Number: W81XWH-13-1-0461 TITLE: Targeting Tumor Oct4 to Deplete Prostate Tumor- and Metastasis-Initiating Cells PRINCIPAL INVESTIGATOR: Daotai...29 2016 4. TITLE AND SUBTILE Targeting Tumor Oct4 to Deplete Prostate Tumor- and Metastasis-Initiating Cells 5a. CONTRACT NUMBER 5b. GRANT NUMBER...the c-MYC oncogene. POU5F1B is a pseudogene of embryonic Oct4 (POU5F1). A recent study found that tumor Oct4 found in prostate cancer cells is due

N(1)-methylnicotinamide as an endogenous probe for drug interactions by renal cation transporters: studies on the metformin-trimethoprim interaction.

PubMed

Müller, Fabian; Pontones, Constanza A; Renner, Bertold; Mieth, Maren; Hoier, Eva; Auge, Daniel; Maas, Renke; Zolk, Oliver; Fromm, Martin F

2015-01-01

N(1)-methylnicotinamide (NMN) was proposed as an in vivo probe for drug interactions involving renal cation transporters, which, for example, transport the oral antidiabetic drug metformin, based on a study with the inhibitor pyrimethamine. The role of NMN for predicting other interactions with involvement of renal cation transporters (organic cation transporter 2, OCT2; multidrug and toxin extrusion proteins 1 and 2-K, MATE1 and MATE2-K) is unclear. We determined inhibition of metformin or NMN transport by trimethoprim using cell lines expressing OCT2, MATE1, or MATE2-K. Moreover, a randomized, open-label, two-phase crossover study was performed in 12 healthy volunteers. In each phase, 850 mg metformin hydrochloride was administered p.o. in the evening of day 4 and in the morning of day 5. In phase B, 200 mg trimethoprim was administered additionally p.o. twice daily for 5 days. Metformin pharmacokinetics and effects (measured by OGTT) and NMN pharmacokinetics were determined. Trimethoprim inhibited metformin transport with K i values of 27.2, 6.3, and 28.9 μM and NMN transport with IC50 values of 133.9, 29.1, and 0.61 μM for OCT2, MATE1, and MATE2-K, respectively. In the clinical study, trimethoprim increased metformin area under the plasma concentration-time curve (AUC) by 29.5 % and decreased metformin and NMN renal clearances by 26.4 and 19.9 %, respectively (p ≤ 0.01). Moreover, decreases of NMN and metformin renal clearances due to trimethoprim correlated significantly (r S=0.727, p=0.010). These data on the metformin-trimethoprim interaction support the potential utility of N(1)-methylnicotinamide as an endogenous probe for renal drug-drug interactions with involvement of renal cation transporters.

[Correlations between OCT4 expression and clinicopathological factors and prognosis of patients with lung adenocarcinoma].

PubMed

Zhang, Xueyan; Wang, Huimin; Jin, Bo; Dong, Qianggang; Huang, Jinsu; Han, Baohui

2013-04-01

In recent years, cases of lung adenocarcinoma morbidity have consistently grown. OCT4 is the key gene that controls the automatic renewal of stem cells, and regulates the proliferation and differentiation of cancer stem cells. The aim of this study is to detect OCT4 expression in lung adenocarcinoma tissues, and to evaluate its relevance in the metastasis, chemotherapeutic effect, and prognosis in lung adenocarcinoma patients. Immunofluorescence method was employed to detect OCT4 expression in lung adenocarcinoma tissues. The relationship between OCT4 expression and clinical pathological indicators is examined through chi-square test. Moreover, the survival rate is calculated through the Kaplan-Meier survivorship curve. Finally, the relevance between the indicators and patient survival is estimated using Cox analysis. Among the 126 tissue samples of lung adenocarcinoma, 91 showed OCT4 positive cells. OCT4 expression is closely related to metastasis and chemoresistance in lung adenocarcinoma patients, and negatively corresponds to the patients' disease-free survival and survival periods. OCT4 expression is related to metastasis and chemoresistance in lung adenocarcinoma patients, and thus indicates poor prognosis.

High OCT4A levels drive tumorigenicity and metastatic potential of medulloblastoma cells

PubMed Central

Gonçalves da Silva, Patrícia Benites; Teixeira dos Santos, Márcia Cristina; Rodini, Carolina Oliveira; Kaid, Carolini; Leite Pereira, Márcia Cristina; Furukawa, Gabriela; Gimenes da Cruz, Daniel Sanzio; Goldfeder, Mauricio Barbugiani; Reily Rocha, Clarissa Ribeiro; Rosenberg, Carla; Okamoto, Oswaldo Keith

2017-01-01

Medulloblastoma is a highly aggressive pediatric brain tumor, in which sporadic expression of the pluripotency factor OCT4 has been recently correlated with poor patient survival. However the contribution of specific OCT4 isoforms to tumor aggressiveness is still poorly understood. Here, we report that medulloblastoma cells stably overexpressing the OCT4A isoform displayed enhanced clonogenic, tumorsphere generation, and invasion capabilities. Moreover, in an orthotopic metastatic model of medulloblastoma, OCT4A overexpressing cells generated more developed, aggressive and infiltrative tumors, with tumor-bearing mice attaining advanced metastatic disease and shorter survival rates. Pro-oncogenic OCT4A effects were expression-level dependent and accompanied by distinct chromosomal aberrations. OCT4A overexpression in medulloblastoma cells also induced a marked differential expression of non-coding RNAs, including poorly characterized long non-coding RNAs and small nucleolar RNAs. Altogether, our findings support the relevance of pluripotency-related factors in the aggravation of medulloblastoma traits classically associated with poor clinical outcome, and underscore the prognostic and therapeutic value of OCT4A in this challenging type of pediatric brain cancer. PMID:28186969

High OCT4A levels drive tumorigenicity and metastatic potential of medulloblastoma cells.

PubMed

da Silva, Patrícia Benites Gonçalves; Teixeira Dos Santos, Márcia Cristina; Rodini, Carolina Oliveira; Kaid, Carolini; Pereira, Márcia Cristina Leite; Furukawa, Gabriela; da Cruz, Daniel Sanzio Gimenes; Goldfeder, Mauricio Barbugiani; Rocha, Clarissa Ribeiro Reily; Rosenberg, Carla; Okamoto, Oswaldo Keith

2017-03-21

Medulloblastoma is a highly aggressive pediatric brain tumor, in which sporadic expression of the pluripotency factor OCT4 has been recently correlated with poor patient survival. However the contribution of specific OCT4 isoforms to tumor aggressiveness is still poorly understood. Here, we report that medulloblastoma cells stably overexpressing the OCT4A isoform displayed enhanced clonogenic, tumorsphere generation, and invasion capabilities. Moreover, in an orthotopic metastatic model of medulloblastoma, OCT4A overexpressing cells generated more developed, aggressive and infiltrative tumors, with tumor-bearing mice attaining advanced metastatic disease and shorter survival rates. Pro-oncogenic OCT4A effects were expression-level dependent and accompanied by distinct chromosomal aberrations. OCT4A overexpression in medulloblastoma cells also induced a marked differential expression of non-coding RNAs, including poorly characterized long non-coding RNAs and small nucleolar RNAs. Altogether, our findings support the relevance of pluripotency-related factors in the aggravation of medulloblastoma traits classically associated with poor clinical outcome, and underscore the prognostic and therapeutic value of OCT4A in this challenging type of pediatric brain cancer.

Akt-mediated phosphorylation of Oct4 is associated with the proliferation of stem-like cancer cells

PubMed Central

ZHAO, QING-WEI; ZHOU, YAN-WEN; LI, WEN-XIN; KANG, BO; ZHANG, XIAO-QIAN; YANG, YING; CHENG, JIE; YIN, SHENG-YONG; TONG, YING; HE, JIAN-QIN; YAO, HANG-PING; ZHENG, MIN; WANG, YING-JIE

2015-01-01

Oct4 protein encoded by POU5F1 plays a pivotal role in maintaining the self-renewal of pluripotent stem cells; however, its presence in cancer cells remains controversial. In the present study, we provided evidence that the transcripts of authentic OCT4 gene (OCT4A) and its multiple pseudogenes were detected in a variety of cancer cell lines. A few major bands were also detected by western blotting using an anti-Oct4A monoclonal antibody. Moreover, an anti-Oct4-pT235 antibody was used to identify a band in the majority of the tested cancer cell lines that coincided with one of the anti-Oct4A bands which was decreasable by a specific shRNA. The Oct4-pT235 signals were also detected in human glioblastoma and liver cancer specimens by immunofluorescence microscopy and immunohistochemistry. U87 glioblastoma cells were cultured in a neural stem cell medium to induce the formation of neurospheres rich in stem-like cancer cells. The levels of Oct4-pT235 in the sphere cells were markedly increased compared to their monolayer parental cells, a result that was accompanied by upregulation of the PI3K-Akt pathway. Akti-1/2, a specific inhibitor of Akt, effectively reduced the level of Oct4-pT235 and attenuated the proliferation of U87 sphere cells. ITE, an agonist of the aryl hydrocarbon receptor, also significantly attenuated the Akt-mediated phosphorylation of Oct4 in glioblastoma and liver cancer cells, and reduced their tumorigenic potential in a xenograft tumor model. Taken together, we concluded that the Akt-mediated phosphorylation of Oct4A or its homolog protein was associated with the proliferation of stem-like cancer cells that may serve as a novel biomarker and drug target for certain types of cancer. PMID:25625591

Interaction of the new monofunctional anticancer agent Phenanthriplatin with transporters for organic cations

NASA Astrophysics Data System (ADS)

Hucke, Anna; Park, Ga Young; Bauer, Oliver B.; Beyer, Georg; Köppen, Christina; Zeeh, Dorothea; Wehe, Christoph A.; Sperling, Michael; Schröter, Rita; Kantauskaitè, Marta; Hagos, Yohannes; Karst, Uwe; Lippard, Stephen J.; Ciarimboli, Giuliano

2018-05-01

Cancer treatment with platinum compounds is an important achievement of modern chemotherapy. However, despite the beneficial effects, the clinical impact of these agents is hampered by the development of drug resistance as well as dose-limiting side effects. The efficacy but also side effects of platinum complexes can be mediated by uptake through plasma membrane transporters. In the kidneys, plasma membrane transporters are involved in their secretion into the urine. Renal secretion is accomplished by uptake from the blood into the proximal tubules cells, followed by excretion into the urine. The uptake process is mediated mainly by organic cation transporters (OCT), which are expressed in the basolateral domain of the plasma membrane facing the blood. The excretion of platinum into the urine is mediated by exchange with protons via multidrug and toxin extrusion proteins (MATE) expressed in the apical domain of plasma membrane. Recently, the monofunctional, cationic platinum agent phenanthriplatin, which is able to escape common cellular resistance mechanisms, has been synthesized and investigated. In the present study, the interaction of phenanthriplatin with transporters for organic cations has been evaluated. Phenanthriplatin is a high affinity substrate for OCT2, but has a lower apparent affinity for MATEs. The presence of these transporters increased cytotoxicity of phenanthriplatin. Therefore, phenanthriplatin may be especially effective in the treatment of cancers that express OCTs, such as colon cancer cells. However, the interaction of phenanthriplatin with OCTs suggests that its use as chemotherapeutic agent may be complicated by OCT-mediated toxicity. Unlike cisplatin, phenanthriplatin interacts with high specificity with hMATE1 and hMATE2K in addition to hOCT2. This interaction may facilitate its efflux from the cells and thereby decrease overall efficacy and/or toxicity.

Optical coherence tomography compared with intravascular ultrasound and with angiography to guide coronary stent implantation (ILUMIEN III: OPTIMIZE PCI): a randomised controlled trial.

PubMed

Ali, Ziad A; Maehara, Akiko; Généreux, Philippe; Shlofmitz, Richard A; Fabbiocchi, Franco; Nazif, Tamim M; Guagliumi, Giulio; Meraj, Perwaiz M; Alfonso, Fernando; Samady, Habib; Akasaka, Takashi; Carlson, Eric B; Leesar, Massoud A; Matsumura, Mitsuaki; Ozan, Melek Ozgu; Mintz, Gary S; Ben-Yehuda, Ori; Stone, Gregg W

2016-11-26

Percutaneous coronary intervention (PCI) is most commonly guided by angiography alone. Intravascular ultrasound (IVUS) guidance has been shown to reduce major adverse cardiovascular events (MACE) after PCI, principally by resulting in a larger postprocedure lumen than with angiographic guidance. Optical coherence tomography (OCT) provides higher resolution imaging than does IVUS, although findings from some studies suggest that it might lead to smaller luminal diameters after stent implantation. We sought to establish whether or not a novel OCT-based stent sizing strategy would result in a minimum stent area similar to or better than that achieved with IVUS guidance and better than that achieved with angiography guidance alone. In this randomised controlled trial, we recruited patients aged 18 years or older undergoing PCI from 29 hospitals in eight countries. Eligible patients had one or more target lesions located in a native coronary artery with a visually estimated reference vessel diameter of 2·25-3·50 mm and a length of less than 40 mm. We excluded patients with left main or ostial right coronary artery stenoses, bypass graft stenoses, chronic total occlusions, planned two-stent bifurcations, and in-stent restenosis. Participants were randomly assigned (1:1:1; with use of an interactive web-based system in block sizes of three, stratified by site) to OCT guidance, IVUS guidance, or angiography-guided stent implantation. We did OCT-guided PCI using a specific protocol to establish stent length, diameter, and expansion according to reference segment external elastic lamina measurements. All patients underwent final OCT imaging (operators in the IVUS and angiography groups were masked to the OCT images). The primary efficacy endpoint was post-PCI minimum stent area, measured by OCT at a masked independent core laboratory at completion of enrolment, in all randomly allocated participants who had primary outcome data. The primary safety endpoint was procedural MACE. We tested non-inferiority of OCT guidance to IVUS guidance (with a non-inferiority margin of 1·0 mm 2 ), superiority of OCT guidance to angiography guidance, and superiority of OCT guidance to IVUS guidance, in a hierarchical manner. This trial is registered with ClinicalTrials.gov, number NCT02471586. Between May 13, 2015, and April 5, 2016, we randomly allocated 450 patients (158 [35%] to OCT, 146 [32%] to IVUS, and 146 [32%] to angiography), with 415 final OCT acquisitions analysed for the primary endpoint (140 [34%] in the OCT group, 135 [33%] in the IVUS group, and 140 [34%] in the angiography group). The final median minimum stent area was 5·79 mm 2 (IQR 4·54-7·34) with OCT guidance, 5·89 mm 2 (4·67-7·80) with IVUS guidance, and 5·49 mm 2 (4·39-6·59) with angiography guidance. OCT guidance was non-inferior to IVUS guidance (one-sided 97·5% lower CI -0·70 mm 2 ; p=0·001), but not superior (p=0·42). OCT guidance was also not superior to angiography guidance (p=0·12). We noted procedural MACE in four (3%) of 158 patients in the OCT group, one (1%) of 146 in the IVUS group, and one (1%) of 146 in the angiography group (OCT vs IVUS p=0·37; OCT vs angiography p=0·37). OCT-guided PCI using a specific reference segment external elastic lamina-based stent optimisation strategy was safe and resulted in similar minimum stent area to that of IVUS-guided PCI. These data warrant a large-scale randomised trial to establish whether or not OCT guidance results in superior clinical outcomes to angiography guidance. St Jude Medical. Copyright © 2016 Elsevier Ltd. All rights reserved.

Transduction of Oct6 or Oct9 gene concomitant with Myc family gene induced osteoblast-like phenotypic conversion in normal human fibroblasts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mizoshiri, N.; Department of Orthopaedics, Kyoto Prefectural University of Medicine, Kyoto; Kishida, T.

Introduction: Osteoblasts play essential roles in bone formation and regeneration, while they have low proliferation potential. Recently we established a procedure to directly convert human fibroblasts into osteoblasts (dOBs). Transduction of Runx2 (R), Osterix (X), Oct3/4 (O) and L-myc (L) genes followed by culturing under osteogenic conditions induced normal human fibroblasts to express osteoblast-specific genes and produce calcified bone matrix both in vitro and in vivo Intriguingly, a combination of only two factors, Oct3/4 and L-myc, significantly induced osteoblast-like phenotype in fibroblasts, but the mechanisms underlying the direct conversion remains to be unveiled. Materials and Methods: We examined which Oct family genesmore » and Myc family genes are capable of inducing osteoblast-like phenotypic conversion. Results: As result Oct3/4, Oct6 and Oct9, among other Oct family members, had the capability, while N-myc was the most effective Myc family gene. The Oct9 plus N-myc was the best combination to induce direct conversion of human fibroblasts into osteoblast-like cells. Discussion: The present findings may greatly contribute to the elucidation of the roles of the Oct and Myc proteins in osteoblast direct reprogramming. The results may also lead to establishment of novel regenerative therapy for various bone resorption diseases. - Highlights: • Introducing L-myc in a combination with either Oct3/4, Oct6 or Oct9 enables the conversion of fibroblasts to osteoblasts. • A combination of L-myc with Oct3/4 or Oct9 can induce the cells to a phenotype closer to normal osteoblasts. • N-myc was considered the most appropriate Myc family gene for induction of osteoblast-like phenotype in fibroblasts. • The combination of Oct9 plus N-myc has the strongest capability of inducing osteoblast-like phenotype.« less

Intratubular germ cell neoplasia of the human testis: heterogeneous protein expression and relation to invasive potential

PubMed Central

Mitchell, Rod T; Camacho-Moll, Maria; Macdonald, Joni; Anderson, Richard A; Kelnar, Christopher JH; O’Donnell, Marie; Sharpe, Richard M; Smith, Lee B; Grigor, Ken M; Wallace, W Hamish B; Stoop, Hans; Wolffenbuttel, Katja P; Donat, Roland

2014-01-01

Testicular germ cell cancer develops from pre-malignant intratubular germ cell neoplasia, unclassified cells that are believed to arise from failure of normal maturation of fetal germ cells from gonocytes (OCT4+/ MAGEA4−) into pre-spermatogonia (OCT4−/MAGEA4+). Intratubular germ cell neoplasia cell subpopulations based on stage of germ cell differentiation have been described, however the importance of these subpopulations in terms of invasive potential has not been reported. We hypothesised that cells expressing an immature (OCT4+/MAGEA4−) germ cell profile would exhibit an increased proliferation rate compared to those with a mature profile (OCT4+/ MAGEA4+). Therefore, we performed triple immunofluorescence and stereology to quantify the different intratubular germ cell neoplasia cell subpopulations, based on expression of germ cell (OCT4, PLAP, AP2γ, MAGEA4, VASA) and proliferation (Ki67) markers, in testis sections from patients with pre-invasive disease, seminoma and non-seminoma. We compared these subpopulations with normal human fetal testis and with seminoma cells. Heterogeneity of protein expression was demonstrated in intratubular germ cell neoplasia cells with respect to gonocyte and spermatogonial markers. It included an embryonic/fetal germ cell subpopulation lacking expression of the definitive intratubular germ cell neoplasia marker OCT4, that did not correspond to a physiological (fetal) germ cell subpopulation. OCT4+/MAGEA4- cells showed a significantly increased rate of proliferation compared with the OCT4+/MAGEA4+ population (12.8 v 3.4%, p<0.0001) irrespective of histological tumour type, reflected in the predominance of OCT4+/MAGEA4− cells in the invasive tumour component. Surprisingly, OCT4+/MAGEA4− cells in patients with pre-invasive disease showed significantly higher proliferation compared to those with seminoma or non-seminoma (18.1 v 10.2 v 7.2%, p<0.05 respectively). In conclusion, this study has demonstrated that OCT4+/MAGEA4− cells are the most frequent and most proliferative cell population in tubules containing intratubular germ cell neoplasia, which appears to be an important factor in determining invasive potential of intratubular germ cell neoplasia to seminomas. PMID:24457464

[Functional analysis of Oct4 promoter in Xuhuai goat].

PubMed

Wei, Guanghui; Li, Dong; Zuo, Qisheng; Zhang, Yani; Zhu, Rui; Zhang, Lei; Liu, Zhiyong; Qiu, Fenglong; Li, Bichun

2014-08-01

The aim of this study was to determine the activity region of Oct4 (octamer-binding transcription factor 4) promoter in Xuhuai goat, and to investigate the effect of TSA (trichostatin A) and VPA(valproicacid) on Oct4 promoter activity. Specific PCR primers of Oct4 promoter including different lengths of fragments were designed by Primer 5.0, then were amplified and cloned into PGL3-Bacic luciferase reporter vector. All the reconstruction vectors were transfected into gEF, P19 and COS7 cells, respectively. After TSA and VPA treatment, the activity of dual-luciferase reporter gene in these three transfected cells was detected. In addition, the CMV promoter of pEGFP-N1 was replaced by the -1516─+30 bp fragment of Oct4 promoter, GFP fluorescence was used to detect the activity of Oct4 promoter. The results indicated that different fragments of Oct4 promoter showed different degrees of activity in gEF, P19 and COS7 cells, and the maximal activity region of Oct4 promoter was -1516─+30 bp, the basal activity region was -238─+30 bp. Positive regulatory domains existed in the region of -1516─-946 bp and -615─-96 bp, while negative regulatory domains existed in the region of -1936─-1516 bp and -946─-615 bp. The optimum induction concentration to enhance the activity of Oct4 promoter was 1 μmol/L of TSA and 4 mmol/L of VPA. The GFP expression can be started by the fragment of -1516─+30 bp. This study provides an experimental basis for revealing the mechanism of expression and regulation of Oct4 in goat.

Oct4 suppresses IR‑induced premature senescence in breast cancer cells through STAT3- and NF‑κB-mediated IL‑24 production.

PubMed

Kim, Jeong-Yub; Kim, Jeong-Chul; Lee, Ji-Yun; Park, Myung-Jin

2018-07-01

Breast cancer stem cells (BCSCs) are a small subpopulation of breast cancer cells that have been proposed to be a primary cause of failure of therapies, including ionizing radiation (IR). Their embryonic stem-like signature is associated with poor clinical outcome. In the present study, the function of octamer-binding transcription factor 4 (Oct4), an embryonic stem cell factor, in the resistance of BCSCs to IR was investigated. Mammosphere cells exhibited increased expression of stemness-associated genes, including Oct4 and sex‑determining region Y‑box 2 (Sox2), and were more resistant to IR compared with serum-cultured monolayer cells. IR‑resistant MCF7 cells also exhibited significantly increased expression of Oct4. To investigate the possible involvement of Oct4 in IR resistance of breast cancer cells, cells were transfected with Oct4. Ectopic expression of Oct4 increased the clonogenic survival of MCF7 cells following IR, which was reversed by treatment with small interfering RNA (siRNA) targeting Oct4. Oct4 expression decreased phosphorylated histone H2AX (γ-H2AX) focus formation and suppressed IR‑induced premature senescence in these cells. Mammosphere, IR‑resistant and Oct4‑overexpressing MCF7 cells exhibited enhanced phosphorylation of signal transducer and activation of transcription 3 (STAT3) (Tyr705) and inhibitor of nuclear factor κB (NF‑κB), and blockade of these pathways with siRNA against STAT3 and/or specific inhibitors of STAT3 and NF‑κB significantly increased IR‑induced senescence. Secretome analysis revealed that Oct4 upregulated interleukin 24 (IL‑24) expression through STAT3 and NF‑κB signaling, and siRNA against IL‑24 increased IR‑induced senescence, whereas recombinant human IL‑24 suppressed it. The results of the present study indicated that Oct4 confers IR resistance on breast cancer cells by suppressing IR‑induced premature senescence through STAT3- and NF‑κB-mediated IL‑24 production.

Cooperativity between antibiotics and antiseptics: testing the bactericidal effect.

PubMed

Jenull, S; Laggner, H; Hassl, I; Velimirov, B; Huettinger, M; Zemann, N

2017-12-02

Treatment with antibiotics together with local application of antiseptics is common in wound care. We investigated the effectiveness of an antiseptic in two variations: octenidine (Oct) and octenidine+ (Oct+ with isotonic glucose addition). Using the agar diffusion test with cultures of pathogenic Staphylococcus aureus and the non-pathogenic Bordetella petrii, we compared the effectiveness of octenidine to the classical antiseptics beta-isodona (povidone-iodine; PI), chlorhexidine (Chl) and taurolin (Tau) alone, and in combination with various common antibiotics to uncover cooperativity between antiseptics and antibiotics. We detected strong interactions between antibiotics and antiseptics, that either enhanced or reduced the bactericidal efficiency. Effectiveness was dependent on the type of organism tested. Oct applied together with ineffective antibiotics frequently led to effective growth inhibition of Bordetella petrii. With Staphylococcus aureus we did not find such an effect. To this end, we reason that positively charged Oct may associate with antibiotic compounds via electrostatic interactions and guide it more efficiently to the bacterial cell wall. Interaction with antibiotics sometimes led to sequestration and reduced availability of some antiseptic/antibiotic combinations, but never with Oct. These data provide new arguments for decision planning concerning the choice of agent in the treatment of wound infections.

Differential expression of Oct4 variants and pseudogenes in normal urothelium and urothelial cancer.

PubMed

Wezel, Felix; Pearson, Joanna; Kirkwood, Lisa A; Southgate, Jennifer

2013-10-01

The transcription factor octamer-binding protein 4 (Oct4; encoded by POU5F1) has a key role in maintaining embryonic stem cell pluripotency during early embryonic development and it is required for generation of induced pluripotent stem cells. Controversy exists concerning Oct4 expression in somatic tissues, with reports that Oct4 is expressed in normal and in neoplastic urothelium carrying implications for a bladder cancer stem cell phenotype. Here, we show that the pluripotency-associated Oct4A transcript was absent from cultures of highly regenerative normal human urothelial cells and from low-grade to high-grade urothelial carcinoma cell lines, whereas alternatively spliced variants and transcribed pseudogenes were expressed in abundance. Immunolabeling and immunoblotting studies confirmed the absence of Oct4A in normal and neoplastic urothelial cells and tissues, but indicated the presence of alternative isoforms or potentially translated pseudogenes. The stable forced expression of Oct4A in normal human urothelial cells in vitro profoundly inhibited growth and affected morphology, but protein expression was rapidly down-regulated. Our findings demonstrate that pluripotency-associated isoform Oct4A is not expressed by normal or malignant human urothelium and therefore is unlikely to play a role in a cancer stem cell phenotype. However, our findings also indicate that urothelium expresses a variety of other Oct4 splice-variant isoforms and transcribed pseudogenes that warrant further study. Copyright © 2013 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Tissue expansion and fluid absorption by skin tissue following intradermal injections through hollow microneedles

NASA Astrophysics Data System (ADS)

Shrestha, Pranav; Stoeber, Boris

2017-11-01

Hollow microneedles provide a promising alternative to conventional drug delivery techniques due to improved patient compliance and the dose sparing effect. The dynamics of fluid injected through hollow microneedles into skin, which is a heterogeneous and deformable porous medium, have not been investigated extensively in the past. We have introduced the use of Optical Coherence Tomography (OCT) for real-time visualization of fluid injections into excised porcine tissue. The results from ex-vivo experiments, including cross-sectional tissue images from OCT and pressure/flow-rate measurements, show a transient mode of high flow-rate into the tissue followed by a lower steady-state infusion rate. The injected fluid expands the underlying tissue and causes the external free surface of the skin to rise, forming a characteristic intradermal wheal. We have used OCT to visualize the evolution of tissue and free surface deformation, and advancement of the boundary between regions of expanding and stationary tissue. We will show the effect of different injection parameters such as fluid pressure, viscosity and microneedle retraction on the injected volume. This work has been supported through funding from the Collaborative Health Research Program by the Natural Science and Engineering Research Council of Canada and the Canadian Health Research Institute, and through the Canada Research Chairs program.

Evaluation of cystoid change phenotypes in ocular toxoplasmosis using optical coherence tomography.

PubMed

Ouyang, Yanling; Pleyer, Uwe; Shao, Qing; Keane, Pearse A; Stübiger, Nicole; Joussen, Antonia M; Sadda, Srinivas R; Heussen, Florian M

2014-01-01

To present unique cystoid changes occurring in patients with ocular toxoplasmosis observed in spectral domain optical coherence tomography (OCT). Forty-six patients (80 eyes) with a diagnosis of ocular toxoplasmosis, who underwent volume OCT examination between January 2005 and October 2012, were retrospectively collected. Review of clinical examination findings, fundus photographs, fluorescein angiograms (FA) and OCT image sets obtained at initial visits and follow-up. Qualitative and quantitative analyses of cystoid space phenotypes visualized using OCT. Of the 80 eyes included, 17 eyes (15 patients) demonstrated cystoid changes in the macula on OCT. Six eyes (7.5%) had cystoid macular edema (CME), 2 eyes (2.5%) had huge outer retinal cystoid space (HORC), 12 eyes (15%) had cystoid degeneration and additional 3 eyes (3.75%) had outer retinal tubulation due to age related macular degeneration. In one eye with HORC, the lesion was seen in the photoreceptor outer segment, accompanied by photoreceptor elongation and splitting. Three eyes presented with paravascular cystoid degeneration in the inner retina without other macular OCT abnormality. In this study, different phenotypes of cystoid spaces seen in eyes with ocular toxoplasmosis using spectral domain OCT (SD-OCT) were demonstrated. CME presented as an uncommon feature, consistently with previous findings. Identification of rare morphological cystoid features (HORC with/without photoreceptor enlongation or splitting) on clinical examination had provided evidence to previous experimental models, which may also expand the clinical spectrum of the disease. Cystoid degeneration in the inner retina next to the retinal vessels in otherwise "normal" looking macula was observed, which may suggest more often clinical evaluation for those patients. Further studies are needed to verify the relevance of cystoid features seen on SD-OCT in assisting with the diagnosis and management of ocular toxoplasmosis.

Evaluation of Cystoid Change Phenotypes in Ocular Toxoplasmosis Using Optical Coherence Tomography

PubMed Central

Shao, Qing; Keane, Pearse A.; Stübiger, Nicole; Joussen, Antonia M.; Sadda, Srinivas R.; Heussen, Florian M.

2014-01-01

Purpose To present unique cystoid changes occurring in patients with ocular toxoplasmosis observed in spectral domain optical coherence tomography (OCT). Methods Forty-six patients (80 eyes) with a diagnosis of ocular toxoplasmosis, who underwent volume OCT examination between January 2005 and October 2012, were retrospectively collected. Review of clinical examination findings, fundus photographs, fluorescein angiograms (FA) and OCT image sets obtained at initial visits and follow-up. Qualitative and quantitative analyses of cystoid space phenotypes visualized using OCT. Results Of the 80 eyes included, 17 eyes (15 patients) demonstrated cystoid changes in the macula on OCT. Six eyes (7.5%) had cystoid macular edema (CME), 2 eyes (2.5%) had huge outer retinal cystoid space (HORC), 12 eyes (15%) had cystoid degeneration and additional 3 eyes (3.75%) had outer retinal tubulation due to age related macular degeneration. In one eye with HORC, the lesion was seen in the photoreceptor outer segment, accompanied by photoreceptor elongation and splitting. Three eyes presented with paravascular cystoid degeneration in the inner retina without other macular OCT abnormality. Conclusions In this study, different phenotypes of cystoid spaces seen in eyes with ocular toxoplasmosis using spectral domain OCT (SD-OCT) were demonstrated. CME presented as an uncommon feature, consistently with previous findings. Identification of rare morphological cystoid features (HORC with/without photoreceptor enlongation or splitting) on clinical examination had provided evidence to previous experimental models, which may also expand the clinical spectrum of the disease. Cystoid degeneration in the inner retina next to the retinal vessels in otherwise “normal” looking macula was observed, which may suggest more often clinical evaluation for those patients. Further studies are needed to verify the relevance of cystoid features seen on SD-OCT in assisting with the diagnosis and management of ocular toxoplasmosis. PMID:24505261

Differential expression of Oct4 in HPV-positive and HPV-negative cervical cancer cells is not regulated by DNA methyltransferase 3A.

PubMed

Liu, Dongbo; Zhou, Peng; Zhang, Li; Wu, Gengze; Zheng, Yingru; He, Fengtian

2011-10-01

The colony-forming ability of cervical cancer is affected by many factors. Oct4, an important transcription factor, is highly expressed in several tumors and promotes the colony-forming ability of cancer cells. Thus, it is considered a potential target for the treatment of cancer. However, we know little about the expression level of Oct4 and its epigenetic regulatory mechanism in cervical cancer cells. In this study, we are the first to observe that human papillomavirus (HPV)-positive cervical cancer cell lines (HeLa, Caski) have a stronger colony-forming ability than HPV-negative cervical cancer cell lines (C-33A). Moreover, the expression level of Oct4 in both HeLa and Caski cells was also higher than that in C-33A cells. We then confirmed that there was a negative correlation between the expression of Oct4 and DNMT3A in these three types of cervical cancer cells, whereas DNA methyltransferase 1 and 3B had no differences among the cell lines. However, after DNA methylation in both key regulatory regions of the Oct4 gene and the genomic levels were analyzed, we found that DNA methyltransferase 3A could neither regulate the expression of Oct4 nor affect the whole level of genomic DNA methylation. These results suggest three points: (1) Oct4 might be treated as a new target for the treatment of cervical cancer, (2) we could not inhibit the expression of Oct4 by DNA demethylation, and (3) HPV virus might initiate cervical carcinogenesis by upregulation of Oct4 expression.

Quantification of the ciliary muscle and crystalline lens interaction during accommodation with synchronous OCT imaging

PubMed Central

Ruggeri, Marco; de Freitas, Carolina; Williams, Siobhan; Hernandez, Victor M.; Cabot, Florence; Yesilirmak, Nilufer; Alawa, Karam; Chang, Yu-Cherng; Yoo, Sonia H.; Gregori, Giovanni; Parel, Jean-Marie; Manns, Fabrice

2016-01-01

Abstract: Two SD-OCT systems and a dual channel accommodation target were combined and precisely synchronized to simultaneously image the anterior segment and the ciliary muscle during dynamic accommodation. The imaging system simultaneously generates two synchronized OCT image sequences of the anterior segment and ciliary muscle with an imaging speed of 13 frames per second. The system was used to acquire OCT image sequences of a non-presbyopic and a pre-presbyopic subject accommodating in response to step changes in vergence. The image sequences were processed to extract dynamic morphological data from the crystalline lens and the ciliary muscle. The synchronization between the OCT systems allowed the precise correlation of anatomical changes occurring in the crystalline lens and ciliary muscle at identical time points during accommodation. To describe the dynamic interaction between the crystalline lens and ciliary muscle, we introduce accommodation state diagrams that display the relation between anatomical changes occurring in the accommodating crystalline lens and ciliary muscle. PMID:27446660

Quantification of the ciliary muscle and crystalline lens interaction during accommodation with synchronous OCT imaging.

PubMed

Ruggeri, Marco; de Freitas, Carolina; Williams, Siobhan; Hernandez, Victor M; Cabot, Florence; Yesilirmak, Nilufer; Alawa, Karam; Chang, Yu-Cherng; Yoo, Sonia H; Gregori, Giovanni; Parel, Jean-Marie; Manns, Fabrice

2016-04-01

Two SD-OCT systems and a dual channel accommodation target were combined and precisely synchronized to simultaneously image the anterior segment and the ciliary muscle during dynamic accommodation. The imaging system simultaneously generates two synchronized OCT image sequences of the anterior segment and ciliary muscle with an imaging speed of 13 frames per second. The system was used to acquire OCT image sequences of a non-presbyopic and a pre-presbyopic subject accommodating in response to step changes in vergence. The image sequences were processed to extract dynamic morphological data from the crystalline lens and the ciliary muscle. The synchronization between the OCT systems allowed the precise correlation of anatomical changes occurring in the crystalline lens and ciliary muscle at identical time points during accommodation. To describe the dynamic interaction between the crystalline lens and ciliary muscle, we introduce accommodation state diagrams that display the relation between anatomical changes occurring in the accommodating crystalline lens and ciliary muscle.

EZ spheres: a stable and expandable culture system for the generation of pre-rosette multipotent stem cells from human ESCs and iPSCs.

PubMed

Ebert, Allison D; Shelley, Brandon C; Hurley, Amanda M; Onorati, Marco; Castiglioni, Valentina; Patitucci, Teresa N; Svendsen, Soshana P; Mattis, Virginia B; McGivern, Jered V; Schwab, Andrew J; Sareen, Dhruv; Kim, Ho Won; Cattaneo, Elena; Svendsen, Clive N

2013-05-01

We have developed a simple method to generate and expand multipotent, self-renewing pre-rosette neural stem cells from both human embryonic stem cells (hESCs) and human induced pluripotent stem cells (iPSCs) without utilizing embryoid body formation, manual selection techniques, or complex combinations of small molecules. Human ESC and iPSC colonies were lifted and placed in a neural stem cell medium containing high concentrations of EGF and FGF-2. Cell aggregates (termed EZ spheres) could be expanded for long periods using a chopping method that maintained cell-cell contact. Early passage EZ spheres rapidly down-regulated OCT4 and up-regulated SOX2 and nestin expression. They retained the potential to form neural rosettes and consistently differentiated into a range of central and peripheral neural lineages. Thus, they represent a very early neural stem cell with greater differentiation flexibility than other previously described methods. As such, they will be useful for the rapidly expanding field of neurological development and disease modeling, high-content screening, and regenerative therapies based on pluripotent stem cell technology. Copyright © 2013 Elsevier B.V. All rights reserved.

Analysis of scattering statistics and governing distribution functions in optical coherence tomography.

PubMed

Sugita, Mitsuro; Weatherbee, Andrew; Bizheva, Kostadinka; Popov, Ivan; Vitkin, Alex

2016-07-01

The probability density function (PDF) of light scattering intensity can be used to characterize the scattering medium. We have recently shown that in optical coherence tomography (OCT), a PDF formalism can be sensitive to the number of scatterers in the probed scattering volume and can be represented by the K-distribution, a functional descriptor for non-Gaussian scattering statistics. Expanding on this initial finding, here we examine polystyrene microsphere phantoms with different sphere sizes and concentrations, and also human skin and fingernail in vivo. It is demonstrated that the K-distribution offers an accurate representation for the measured OCT PDFs. The behavior of the shape parameter of K-distribution that best fits the OCT scattering results is investigated in detail, and the applicability of this methodology for biological tissue characterization is demonstrated and discussed.

Impact of different concentrations of an octenidine dihydrochloride mouthwash on salivary bacterial counts: a randomized, placebo-controlled cross-over trial.

PubMed

Lorenz, Katrin; Jockel-Schneider, Yvonne; Petersen, Nicole; Stölzel, Peggy; Petzold, Markus; Vogel, Ulrich; Hoffmann, Thomas; Schlagenhauf, Ulrich; Noack, Barbara

2018-03-02

This bi-centric, placebo-controlled, randomized, evaluator-blinded, incomplete cross-over clinical phase II trial was initialized to identify the most appropriate concentration of octenidine dihydrochloride (OCT) in mouth rinses. Rinses of 0.10, 0.15, and 0.20% OCT were compared to a saline placebo rinse regarding the reduction of salivary bacterial counts (SBCs) in 90 gingivitis patients over 4 days. Changes in plaque (PI) and gingival index (GI), taste perception, and safety issues were evaluated. At baseline, the first OCT (0.10, 0.15, 0.20%) rinse resulted in a decrease of SBC (reduction by 3.63-5.44 log 10 colony forming units [CFU]) compared to placebo (p < 0.001). Differences between OCT concentrations were not verified. After 4 days, the last OCT rinse again resulted in a significant SBC decrease (3.69-4.22 log 10 CFU) compared to placebo (p < 0.001). Overall, SBC reduction between baseline and day 4 was significantly higher in OCT 0.15 and 0.20% groups compared to OCT 0.10% and placebo. Mean GI/PIs were significantly lower in OCT groups than in the placebo group (p < 0.001). Differences in GI/PI between OCT groups were not verified. Adverse effects increased with increasing OCT concentrations. Considering antibacterial efficacy, frequency of adverse events, and user acceptance, 0.10% OCT was identified as the preferred concentration to be used in future clinical trials. Due to its low toxicity and pronounced antibacterial properties, octenidine dihydrochloride (OCT) is a promising candidate for the use in antiseptic mouth rinses. OCT concentrations of 0.10% are recommended for future clinical trials evaluating the plaque-reducing properties of OCT mouth rinses. ( www.clinicaltrials.gov , NCT022138552).

Interactions of bilastine, a new oral H₁ antihistamine, with human transporter systems.

PubMed

Lucero, Maria Luisa; Gonzalo, Ana; Ganza, Alvaro; Leal, Nerea; Soengas, Itziar; Ioja, Eniko; Gedey, Szilvia; Jahic, Mirza; Bednarczyk, Dallas

2012-06-01

Membrane transporters play a significant role in facilitating transmembrane drug movement. For new pharmacological agents, it is important to evaluate potential interactions (e.g., substrate specificity and/or inhibition) with human transporters that may affect their pharmacokinetics, efficacy, or toxicity. Bilastine is a new nonsedating H₁ antihistamine indicated for the treatment of allergic rhinoconjunctivitis and urticaria. The in vitro inhibitory effects of bilastine were assessed on 12 human transporters: four efflux [multidrug resistance protein 1 (MDR1) or P-glycoprotein, breast cancer resistance protein (BCRP), multidrug resistance associated protein 2 (MRP2), and bile salt export pump) and eight uptake transporters (sodium taurocholate cotransporting polypeptide, organic cation transporter (OCT)1, organic anion transporter (OAT)1, OAT3, OCT2, OATP2B1, OATP1B1, and OATP1B3). Only mild inhibition was found for MDR1-, OCT1-, and OATP2B1-mediated transport of probe substrates at the highest bilastine concentration assayed (300 μM; half-maximal inhibitory concentration: ≥300 μM). Bilastine transport by MDR1, BCRP, OAT1, OAT3, and OCT2 was also investigated in vitro. Only MDR1 active transport of bilastine was relevant, whereas it did not appear to be a substrate of OCT2, OAT1, or OAT3, nor was it transported substantially by BCRP. Drug-drug interactions resulting from bilastine inhibition of drug transporters that would be generally regarded as clinically relevant are unlikely. Additionally, bilastine did not appear to be a substrate of human BCRP, OAT1, OAT3, or OCT2 and thus is not a potential victim of inhibitors of these transporters. On the other hand, based on in vitro evaluation, clinically relevant interactions with MDR1 inhibitors are anticipated.

Determination of Protein Interactome of Transcription Factor Sox2 in Embryonic Stem Cells Engineered for Inducible Expression of Four Reprogramming Factors*

PubMed Central

Gao, Zhiguang; Cox, Jesse L.; Gilmore, Joshua M.; Ormsbee, Briana D.; Mallanna, Sunil K.; Washburn, Michael P.; Rizzino, Angie

2012-01-01

Unbiased proteomic screens provide a powerful tool for defining protein-protein interaction networks. Previous studies employed multidimensional protein identification technology to identify the Sox2-interactome in embryonic stem cells (ESC) undergoing differentiation in response to a small increase in the expression of epitope-tagged Sox2. Thus far the Sox2-interactome in ESC has not been determined. To identify the Sox2-interactome in ESC, we engineered ESC for inducible expression of different combinations of epitope-tagged Sox2 along with Oct4, Klf4, and c-Myc. Epitope-tagged Sox2 was used to circumvent the lack of suitable Sox2 antibodies needed to perform an unbiased proteomic screen of Sox2-associated proteins. Although i-OS-ESC differentiate when both Oct4 and Sox2 are elevated, i-OSKM-ESC do not differentiate even when the levels of the four transcription factors are coordinately elevated ∼2–3-fold. Our findings with i-OS-ESC and i-OSKM-ESC provide new insights into the reasons why ESC undergo differentiation when Sox2 and Oct4 are elevated in ESC. Importantly, the use of i-OSKM-ESC enabled us to identify the Sox2-interactome in undifferentiated ESC. Using multidimensional protein identification technology, we identified >70 proteins that associate with Sox2 in ESC. We extended these findings by testing the function of the Sox2-assoicated protein Smarcd1 and demonstrate that knockdown of Smarcd1 disrupts the self-renewal of ESC and induces their differentiation. Together, our work provides the first description of the Sox2-interactome in ESC and indicates that Sox2 along with other master regulators is part of a highly integrated protein-protein interaction landscape in ESC. PMID:22334693

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kanai, Dai; Ueda, Atsushi; Akagi, Tadayuki

Embryonic stem (ES) cells, derived from the inner cell mass of blastocysts, have a characteristic cell cycle with truncated G1 and G2 phases. Recent findings that suppression of Oct3/4 expression results in a reduced proliferation rate of ES cells suggest the involvement of Oct3/4 in the regulation of ES cell growth, although the underlying molecular mechanism remains unclear. In the present study, we identified E2F3a as a direct target gene of Oct3/4 in ES cells. Oct3/4 directly bound to the promoter region of the E2F3a gene and positively regulated expression of E2F3a in mouse ES cells. Suppression of E2F3a activitymore » by E2F6 overexpression led to the reduced proliferation in ES cells, which was relieved by co-expression of E2F3a. Furthermore, cell growth retardation caused by loss of Oct3/4 was rescued by E2F3a expression. These results suggest that Oct3/4 upregulates E2F3a expression to promote ES cell growth. - Highlights: • Oct3/4 positively regulates E2F3a expression in ES cells. • Oct3/4 binds to the promoter region of the E2F3a gene. • Overexpression of E2F6, an inhibitor of E2F3a, reduces ES cell growth. • E2F3a recovers growth retardation of ES cells caused by Oct3/4 reduction.« less

OIPAV: an integrated software system for ophthalmic image processing, analysis and visualization

NASA Astrophysics Data System (ADS)

Zhang, Lichun; Xiang, Dehui; Jin, Chao; Shi, Fei; Yu, Kai; Chen, Xinjian

2018-03-01

OIPAV (Ophthalmic Images Processing, Analysis and Visualization) is a cross-platform software which is specially oriented to ophthalmic images. It provides a wide range of functionalities including data I/O, image processing, interaction, ophthalmic diseases detection, data analysis and visualization to help researchers and clinicians deal with various ophthalmic images such as optical coherence tomography (OCT) images and color photo of fundus, etc. It enables users to easily access to different ophthalmic image data manufactured from different imaging devices, facilitate workflows of processing ophthalmic images and improve quantitative evaluations. In this paper, we will present the system design and functional modules of the platform and demonstrate various applications. With a satisfying function scalability and expandability, we believe that the software can be widely applied in ophthalmology field.

Evaluation of the transporter-mediated herb-drug interaction potential of DA-9801, a standardized dioscorea extract for diabetic neuropathy, in human in vitro and rat in vivo.

PubMed

Song, Im-Sook; Kong, Tae Yeon; Jeong, Hyeon-Uk; Kim, Eun Nam; Kwon, Soon-Sang; Kang, Hee Eun; Choi, Sang-Zin; Son, Miwon; Lee, Hye Suk

2014-07-17

Drug transporters play important roles in the absorption, distribution, and elimination of drugs and thereby, modulate drug efficacy and toxicity. With a growing use of poly pharmacy, concurrent administration of herbal extracts that modulate transporter activities with drugs can cause serious adverse reactions. Therefore, prediction and evaluation of drug-drug interaction potential is important in the clinic and in the drug development process. DA-9801, comprising a mixed extract of Dioscoreae rhizoma and Dioscorea nipponica Makino, is a new standardized extract currently being evaluated for diabetic peripheral neuropathy in a phase II clinical study. The inhibitory effects of DA-9801 on the transport functions of organic cation transporter (OCT)1, OCT2, organic anion transporter (OAT)1, OAT3, organic anion transporting polypeptide (OATP)1B1, OATP1B3, P-glycoprotein (P-gp), and breast cancer resistance protein (BCRP) were investigated in HEK293 or LLC-PK1 cells. The effects of DA-9801 on the pharmacokinetics of relevant substrate drugs of these transporters were also examined in vivo in rats. DA-9801 inhibited the in vitro transport activities of OCT1, OCT2, OAT3, and OATP1B1, with IC50 values of 106, 174, 48.1, and 273 μg/mL, respectively, while the other transporters were not inhibited by 300 μg/mL DA-9801. To investigate whether this inhibitory effect of DA-9801 on OCT1, OCT2, and OAT3 could change the pharmacokinetics of their substrates in vivo, we measured the pharmacokinetics of cimetidine, a substrate for OCT1, OCT2, and OAT3, and of furosemide, a substrate for OAT1 and OAT3, by co-administration of DA-9801 at a single oral dose of 1,000 mg/kg. Pre-dose of DA-9801 5 min or 2 h prior to cimetidine administration decreased the Cmax of cimetidine in rats. However, DA-9801 did not affect the elimination parameters such as half-life, clearance, or amount excreted in the urine, suggesting that it did not inhibit elimination process of cimetidine, which is governed by OCT1, OCT2, and OAT3. Moreover, DA-9801 did not affect the pharmacokinetic characteristics of furosemide, as evidenced by its unchanged pharmacokinetic parameters. Inhibitory effects of DA-9801 on OCT1, OCT2, and OAT3 observed in vitro may not necessarily translate into in vivo herb-drug interactions in rats even at its maximum effective dose.

OCT4 expression mediates partial cardiomyocyte reprogramming of mesenchymal stromal cells.

PubMed

Yannarelli, Gustavo; Pacienza, Natalia; Montanari, Sonia; Santa-Cruz, Diego; Viswanathan, Sowmya; Keating, Armand

2017-01-01

Mesenchymal stem/stromal cells (MSCs) are in numerous cell therapy clinical trials, including for injured myocardium. Acquisition of cardiomyocyte characteristics by MSCs may improve cardiac regeneration but the mechanisms regulating this process are unclear. Here, we investigated whether the pluripotency transcription factor OCT4 is involved in the activation of cardiac lineage genetic programs in MSCs. We employed our established co-culture model of MSCs with rat embryonic cardiomyocytes showing co-expression of cardiac markers on MSCs independent of cell fusion. Bone marrow-derived MSCs were isolated from transgenic mice expressing GFP under the control of the cardiac-specific α-myosin heavy chain promoter. After 5 days of co-culture, MSCs expressed cardiac specific genes, including Nkx2.5, atrial natriuretic factor and α-cardiac actin. The frequency of GFP+ cells was 7.6±1.9%, however, these cells retained the stromal cell phenotype, indicating, as expected, only partial differentiation. Global OCT4 expression increased 2.6±0.7-fold in co-cultured MSCs and of interest, 87±5% vs 79±4% of MSCs expressed OCT4 by flow cytometry in controls and after co-culture, respectively. Consistent with the latter observation, the GFP+ cells did not express nuclear OCT4 and showed a significant increase in OCT4 promoter methylation compared with undifferentiated MSCs (92% vs 45%), inferring that OCT4 is regulated by an epigenetic mechanism. We further showed that siRNA silencing of OCT4 in MSCs resulted in a reduced frequency of GFP+ cells in co-culture to less than 1%. Our data infer that OCT4 expression may have a direct effect on partial cardiomyocyte reprogramming of MSCs and suggest a new mechanism(s) associated with MSC multipotency and a requirement for crosstalk with the cardiac microenvironment.

OCT4 expression mediates partial cardiomyocyte reprogramming of mesenchymal stromal cells

PubMed Central

Montanari, Sonia; Santa-Cruz, Diego; Viswanathan, Sowmya; Keating, Armand

2017-01-01

Mesenchymal stem/stromal cells (MSCs) are in numerous cell therapy clinical trials, including for injured myocardium. Acquisition of cardiomyocyte characteristics by MSCs may improve cardiac regeneration but the mechanisms regulating this process are unclear. Here, we investigated whether the pluripotency transcription factor OCT4 is involved in the activation of cardiac lineage genetic programs in MSCs. We employed our established co-culture model of MSCs with rat embryonic cardiomyocytes showing co-expression of cardiac markers on MSCs independent of cell fusion. Bone marrow-derived MSCs were isolated from transgenic mice expressing GFP under the control of the cardiac-specific α-myosin heavy chain promoter. After 5 days of co-culture, MSCs expressed cardiac specific genes, including Nkx2.5, atrial natriuretic factor and α-cardiac actin. The frequency of GFP+ cells was 7.6±1.9%, however, these cells retained the stromal cell phenotype, indicating, as expected, only partial differentiation. Global OCT4 expression increased 2.6±0.7-fold in co-cultured MSCs and of interest, 87±5% vs 79±4% of MSCs expressed OCT4 by flow cytometry in controls and after co-culture, respectively. Consistent with the latter observation, the GFP+ cells did not express nuclear OCT4 and showed a significant increase in OCT4 promoter methylation compared with undifferentiated MSCs (92% vs 45%), inferring that OCT4 is regulated by an epigenetic mechanism. We further showed that siRNA silencing of OCT4 in MSCs resulted in a reduced frequency of GFP+ cells in co-culture to less than 1%. Our data infer that OCT4 expression may have a direct effect on partial cardiomyocyte reprogramming of MSCs and suggest a new mechanism(s) associated with MSC multipotency and a requirement for crosstalk with the cardiac microenvironment. PMID:29216265

The interaction between the meningeal lymphatics and blood-brain barrier

NASA Astrophysics Data System (ADS)

Semyachkina-Glushkovskaya, O.; Abdurashitov, A.; Dubrovsky, A.; Pavlov, A.; Shushunova, N.; Maslyakova, G.; Navolokin, N.; Bucharskaya, A.; Tuchin, V.; Kurths, J.

2018-02-01

Here we show the interaction between the meningeal lymphatic system and the blood-brain barrier (BBB) function. In normal state, the meningeal lymphatic vessels are invisible on optical coherent tomography (OCT), while during the opening of the BBB, meningeal lymphatic vessels are clearly visualized by OCT in the area of cerebral venous sinuses. These results give a significant impulse in the new application of OCT for the study of physiology of meningeal lymphatic system as well as sheds light on novel strategies in the prognosis of the opening of the BBB related with many central nervous system diseases, such as stroke, brain trauma, Alzheimers disease, etc.

Heterodimer formation by Oct4 and Smad3 differentially regulates epithelial-to-mesenchymal transition-associated factors in breast cancer progression.

PubMed

Mandal, Gunjan; Biswas, Subir; Roy Chowdhury, Sougata; Chatterjee, Annesha; Purohit, Suman; Khamaru, Poulomi; Chakraborty, Sayan; Mandal, Palash Kumar; Gupta, Arnab; de la Mare, Jo-Anne; Edkins, Adrienne Lesley; Bhattacharyya, Arindam

2018-06-01

The multifunctional cytokine TGF-β crucially participates in breast cancer (BCa) metastasis and works differently in the disease stages, thus contributing in BCa progression. We address connections between TGF-β and the stem cell-related transcription factor (TF) Oct4 in BCa. In 147 BCa patients with infiltrating duct carcinoma, we identified a significantly higher number of cases with both moderate/high Oct4 expression and high TGF-β in late stages compared to early stages of the disease. In vitro studies showed that TGF-β elevated Oct4 expression, which in turn, regulated Epithelial-to-Mesenchymal transition (EMT)-regulatory gene (Snail and Slug) expression, migratory ability, chemotactic invasiveness and extracellular matrix (ECM) degradation potential of BCa cells. Putative binding sites for Oct4 on the snail, slug and cxcl13 promoters and for Smad3 on the snail and slug promoters were identified. Promoter activities of snail and slug were greater in dual-treated cells than only TGF-β-treated or Oct4-overexpressing cells. CXCL13 mRNA fold changes, however, were low in cells induced with TGF-β, compared to dual-treated or Oct4-overexpressing cells. Our co-IP studies confirmed that Oct4 and Smad3 form heterodimers that recognize specific promoter sequences to promote Snail and Slug expression, but which in turn, indirectly inhibits Smad3-mediated repression of CXCL13 expression, allowing Oct4 to act as a positive TF for CXCL13. Taken together, these data suggest that TGF-β signaling and Oct4 cooperate to induce expression of EMT-related genes Snail, Slug and CXCL13, which accelerates disease progression, particularly in the late stages, and may indicate a poor prognosis for BCa patients. Copyright © 2018 Elsevier B.V. All rights reserved.

Photoreceptor layer map using spectral-domain optical coherence tomography.

PubMed

Lee, Ji Eun; Lim, Dae Won; Bae, Han Yong; Park, Hyun Jin

2009-12-01

To develop a novel method for analysis of the photoreceptor layer map (PLM) generated using spectral-domain optical coherence tomography (OCT). OCT scans were obtained from 20 eyes, 10 with macular holes (MH) and 10 with central serous chorioretinopathy (CSC) using the Macular Cube (512 x 128) protocol of the Cirrus HD-OCT (Carl Zeiss). The scanned data were processed using embedded tools of the advanced visualization. A partial thickness OCT fundus image of the photoreceptor layer was generated by setting the region of interest to a 50-microm thick layer that was parallel and adjacent to the retinal pigment epithelium. The resulting image depicted the photoreceptor layer as a map of the reflectivity in OCT. The PLM was compared with fundus photography, auto-fluorescence, tomography, and retinal thickness map. The signal from the photoreceptor layer of every OCT scan in each case was demonstrated as a single image of PLM in a fundus photograph fashion. In PLM images, detachment of the sensory retina is depicted as a hypo-reflective area, which represents the base of MH and serous detachment in CSC. Relative hypo-reflectivity, which was also noted at closed MH and at recently reattached retina in CSC, was associated with reduced signal from the junction between the inner and outer segments of photoreceptors in OCT images. Using PLM, changes in the area of detachment and reflectivity of the photoreceptor layer could be efficiently monitored. The photoreceptor layer can be analyzed as a map using spectral-domain OCT. In the treatment of both MH and CSC, PLM may provide new pathological information about the photoreceptor layer to expand our understanding of these diseases.

Dynamic methylation and expression of Oct4 in early neural stem cells.

PubMed

Lee, Shih-Han; Jeyapalan, Jennie N; Appleby, Vanessa; Mohamed Noor, Dzul Azri; Sottile, Virginie; Scotting, Paul J

2010-09-01

Neural stem cells are a multipotent population of tissue-specific stem cells with a broad but limited differentiation potential. However, recent studies have shown that over-expression of the pluripotency gene, Oct4, alone is sufficient to initiate a process by which these can form 'induced pluripotent stem cells' (iPS cells) with the same broad potential as embryonic stem cells. This led us to examine the expression of Oct4 in endogenous neural stem cells, as data regarding its expression in neural stem cells in vivo are contradictory and incomplete. In this study we have therefore analysed the expression of Oct4 and other genes associated with pluripotency throughout development of the mouse CNS and in neural stem cells grown in vitro. We find that Oct4 is still expressed in the CNS by E8.5, but that this expression declines rapidly until it is undetectable by E15.5. This decline is coincident with the gradual methylation of the Oct4 promoter and proximal enhancer. Immunostaining suggests that the Oct4 protein is predominantly cytoplasmic in location. We also found that neural stem cells from all ages expressed the pluripotency associated genes, Sox2, c-Myc, Klf4 and Nanog. These data provide an explanation for the varying behaviour of cells from the early neuroepithelium at different stages of development. The expression of these genes also provides an indication of why Oct4 alone is sufficient to induce iPS formation in neural stem cells at later stages.

Pontin functions as an essential coactivator for Oct4-dependent lincRNA expression in mouse embryonic stem cells.

PubMed

Boo, Kyungjin; Bhin, Jinhyuk; Jeon, Yoon; Kim, Joomyung; Shin, Hi-Jai R; Park, Jong-Eun; Kim, Kyeongkyu; Kim, Chang Rok; Jang, Hyonchol; Kim, In-Hoo; Kim, V Narry; Hwang, Daehee; Lee, Ho; Baek, Sung Hee

2015-04-10

The actions of transcription factors, chromatin modifiers and noncoding RNAs are crucial for the programming of cell states. Although the importance of various epigenetic machineries for controlling pluripotency of embryonic stem (ES) cells has been previously studied, how chromatin modifiers cooperate with specific transcription factors still remains largely elusive. Here, we find that Pontin chromatin remodelling factor plays an essential role as a coactivator for Oct4 for maintenance of pluripotency in mouse ES cells. Genome-wide analyses reveal that Pontin and Oct4 share a substantial set of target genes involved in ES cell maintenance. Intriguingly, we find that the Oct4-dependent coactivator function of Pontin extends to the transcription of large intergenic noncoding RNAs (lincRNAs) and in particular linc1253, a lineage programme repressing lincRNA, is a Pontin-dependent Oct4 target lincRNA. Together, our findings demonstrate that the Oct4-Pontin module plays critical roles in the regulation of genes involved in ES cell fate determination.

Cell counting in whole mount tissue volumes using expansion OCT (Conference Presentation)

NASA Astrophysics Data System (ADS)

Liu, Yehe; Gu, Shi; Watanabe, Michiko; Rollins, Andrew M.; Jenkins, Michael W.

2017-02-01

Abnormal cell proliferation and migration during heart development can lead to severe congenital heart defects (CHDs). Studying the spatial distribution of cells during embryonic development helps our understanding of how the heart develops and the etiology of certain CHDs. However, imaging large groups of single cells in intact tissue volumes is challenging. No current technique can accomplish this task in both a time-efficient and cost-effective manner. OCT has potential with its large field of view and micron-scale resolution, but even the highest resolution OCT systems have poor contrast for counting cells and have a small field of view compared to conventional OCT. We propose using a conventional OCT system and processing the sample to enhance cellular contrast. Inspired by the recently developed Expansion Microscopy, we permeated whole-mount embryonic tissue with a superabsorbent monomer solution and polymerized into a hydrogel. When hydrated in DI water, the tissue-hydrogel complex was uniformly enlarged ( 5X in all dimensions) without distorting the microscopic structure. This had a twofold effect: it increased the resolution by a factor of 5 and decreased scattering, which allowed us to resolve cellular level features deep in the tissue with high contrast using conventional OCT. We noted that cell nuclei caused significantly more backscattering than the other subcellular structures after expansion. Based on this property, we were able to distinguish individual cell nuclei, and thus count cells, in expanded OCT images with simple intensity thresholding. We demonstrate the technique with embryonic quail hearts at various developmental stages.

Automated feature extraction for retinal vascular biometry in zebrafish using OCT angiography

NASA Astrophysics Data System (ADS)

Bozic, Ivan; Rao, Gopikrishna M.; Desai, Vineet; Tao, Yuankai K.

2017-02-01

Zebrafish have been identified as an ideal model for angiogenesis because of anatomical and functional similarities with other vertebrates. The scale and complexity of zebrafish assays are limited by the need to manually treat and serially screen animals, and recent technological advances have focused on automation and improving throughput. Here, we use optical coherence tomography (OCT) and OCT angiography (OCT-A) to perform noninvasive, in vivo imaging of retinal vasculature in zebrafish. OCT-A summed voxel projections were low pass filtered and skeletonized to create an en face vascular map prior to connectivity analysis. Vascular segmentation was referenced to the optic nerve head (ONH), which was identified by automatically segmenting the retinal pigment epithelium boundary on the OCT structural volume. The first vessel branch generation was identified as skeleton segments with branch points closest to the ONH, and subsequent generations were found iteratively by expanding the search space outwards from the ONH. Biometric parameters, including length, curvature, and branch angle of each vessel segment were calculated and grouped by branch generation. Despite manual handling and alignment of each animal over multiple time points, we observe distinct qualitative patterns that enable unique identification of each eye from individual animals. We believe this OCT-based retinal biometry method can be applied for automated animal identification and handling in high-throughput organism-level pharmacological assays and genetic screens. In addition, these extracted features may enable high-resolution quantification of longitudinal vascular changes as a method for studying zebrafish models of retinal neovascularization and vascular remodeling.

Octamer-binding protein 4 affects the cell biology and phenotypic transition of lung cancer cells involving β-catenin/E-cadherin complex degradation.

PubMed

Chen, Zhong-Shu; Ling, Dong-Jin; Zhang, Yang-De; Feng, Jian-Xiong; Zhang, Xue-Yu; Shi, Tian-Sheng

2015-03-01

Clinical studies have reported evidence for the involvement of octamer‑binding protein 4 (Oct4) in the tumorigenicity and progression of lung cancer; however, the role of Oct4 in lung cancer cell biology in vitro and its mechanism of action remain to be elucidated. Mortality among lung cancer patients is more frequently due to metastasis rather than their primary tumors. Epithelial‑mesenchymal transition (EMT) is a prominent biological event for the induction of epithelial cancer metastasis. The aim of the present study was to investigate whether Oct4 had the capacity to induce lung cancer cell metastasis via the promoting the EMT in vitro. Moreover, the effect of Oct4 on the β‑catenin/E‑cadherin complex, associated with EMT, was examined using immunofluorescence and immunoprecipitation assays as well as western blot analysis. The results demonstrated that Oct4 enhanced cell invasion and adhesion accompanied by the downregulation of epithelial marker cytokeratin, and upregulation of the mesenchymal markers vimentin and N‑cadherin. Furthermore, Oct4 induced EMT of lung cancer cells by promoting β‑catenin/E‑cadherin complex degradation and regulating nuclear localization of β‑catenin. In conclusion, the present study indicated that Oct4 affected the cell biology of lung cancer cells in vitro through promoting lung cancer cell metastasis via EMT; in addition, the results suggested that the association and degradation of the β‑catenin/E‑cadherin complex was regulated by Oct4 during the process of EMT.

[LincRNA-ROR functions as a ceRNA to regulate Oct4, Sox2, and Nanog expression by sponging miR-145 and its effect on biologic characteristics of colonic cancer stem cells].

PubMed

Yan, Z Y; Sun, X C

2018-04-08

Objective: To investigate the impact of lincRNA-ROR, a ceRNA by binding miR-145 on the expression of the downstream genes Oct4, Sox2 and Nanog, and related biological characteristics of colon cancer stem cells, and to elucidate the clinical significance of this molecular regulatory network. Methods: Fifty-two cases of colorectal cancer tissue and adjacent tissue were collected at Nanyang City Central Hospital and Nanyang Second Hospital, Henan Province, from 2014 to 2016. Real-time quantitative polymerase chain reaction (qPCR) was used to detect the expression of lincRNA-ROR and miR-145 in colorectal cancer tissue and isolated colon cancer cells. The correlation between the expression of lincRNA-ROR, miR-145 and the clinicopathologic features of colon cancer was performed. CD44(-)CD133(-) and CD44(+) CD133(+) cells were isolated from SW1116 by using flow cytometry. The expression of CD44, CD133, Oct4, Sox2, Nanog, lincRNA-ROR and miR-145 in cells were detected by qPCR. The relationship between lincRNA-ROR, miR-145, Oct4, Sox2 and Nanog was analyzed by bioinformatics, dual luciferase reporter assay, qPCR and Western blot. The effects of silencing lincRNA-ROR on the proliferation and chemosensitivity of colon cancer stem cells were detected by MTT, colony formation. Results: LincRNA-ROR was frequently up-regulated and inversely correlated with miR-145 down-regulation in the colon cancer specimens( P <0.05). LincRNA-ROR was related to tumor size, lymph node involvement and distant metastasis( P <0.05), and miR-145 was found related to tumor size and tumor location( P <0.05). CD44(+) CD133(+) cells were successfully isolated from SW1116 by flow cytometry. The levels of CD44, CD133, Oct4, Sox2, Nanog, lincRNA-ROR in CD44(+) CD133(+) cells were significantly increased, while miR-145 was decreased compared with CD44(-)CD133(-)cells( P <0.05). The levels of CD44, CD133, lnc-ROR in CD44(+) CD133(+) cells were significantly reduced upon cell adherence, while miR-145 was significantly increased( P <0.05). Bioinformatics analysis revealed that lincRNA-ROR shared miRNA response elements with core transcription factors Oct4, Sox2 and Nanog. MiR-145 significantly inhibited the expression of lincRNA-ROR, Oct4, Sox2 and Nanog. Silencing lincRNA-ROR significantly inhibited colon cancer stem cells proliferation and increased the sensitivity to chemotherapy. Conclusions: Linc-ROR functions as a key ceRNA to prevent core TFs, e. g., Oct4, Sox2, Nanog, from miR-145-mediated suppression in colon cancer stem cells and regulates cell proliferation and chemosensitivity.The data may provide insights into the pathophysiological interactions of the components of genetic networks in the development of colon cancer and may lead to new therapies in the future.

Anterior Segment Imaging Predicts Incident Gonioscopic Angle Closure.

PubMed

Baskaran, Mani; Iyer, Jayant V; Narayanaswamy, Arun K; He, Yingke; Sakata, Lisandro M; Wu, Renyi; Liu, Dianna; Nongpiur, Monisha E; Friedman, David S; Aung, Tin

2015-12-01

To investigate the incidence of gonioscopic angle closure after 4 years in subjects with gonioscopically open angles but varying degrees of angle closure detected on anterior segment optical coherence tomography (AS OCT; Visante; Carl Zeiss Meditec, Dublin, CA) at baseline. Prospective, observational study. Three hundred forty-two subjects, mostly Chinese, 50 years of age or older, were recruited, of whom 65 were controls with open angles on gonioscopy and AS OCT at baseline, and 277 were cases with baseline open angles on gonioscopy but closed angles (1-4 quadrants) on AS OCT scans. All subjects underwent gonioscopy and AS OCT at baseline (horizontal and vertical single scans) and after 4 years. The examiner performing gonioscopy was masked to the baseline and AS OCT data. Angle closure in a quadrant was defined as nonvisibility of the posterior trabecular meshwork by gonioscopy and visible iridotrabecular contact beyond the scleral spur in AS OCT scans. Gonioscopic angle closure in 2 or 3 quadrants after 4 years. There were no statistically significant differences in age, ethnicity, or gender between cases and controls. None of the control subjects demonstrated gonioscopic angle closure after 4 years. Forty-eight of the 277 subjects (17.3%; 95% confidence interval [CI], 12.8-23; P < 0.0001) with at least 1 quadrant of angle closure on AS OCT at baseline demonstrated gonioscopic angle closure in 2 or more quadrants, whereas 28 subjects (10.1%; 95% CI, 6.7-14.6; P < 0.004) demonstrated gonioscopic angle closure in 3 or more quadrants after 4 years. Individuals with more quadrants of angle closure on baseline AS OCT scans had a greater likelihood of gonioscopic angle closure developing after 4 years (P < 0.0001, chi-square test for trend for both definitions of angle closure). Anterior segment OCT imaging at baseline predicts incident gonioscopic angle closure after 4 years among subjects who have gonioscopically open angles and iridotrabecular contact on AS OCT at baseline. Copyright © 2015 American Academy of Ophthalmology. All rights reserved.

Dynamic methylation and expression of Oct4 in early neural stem cells

PubMed Central

Lee, Shih-Han; Jeyapalan, Jennie N; Appleby, Vanessa; Mohamed Noor, Dzul Azri; Sottile, Virginie; Scotting, Paul J

2010-01-01

Neural stem cells are a multipotent population of tissue-specific stem cells with a broad but limited differentiation potential. However, recent studies have shown that over-expression of the pluripotency gene, Oct4, alone is sufficient to initiate a process by which these can form ‘induced pluripotent stem cells’ (iPS cells) with the same broad potential as embryonic stem cells. This led us to examine the expression of Oct4 in endogenous neural stem cells, as data regarding its expression in neural stem cells in vivo are contradictory and incomplete. In this study we have therefore analysed the expression of Oct4 and other genes associated with pluripotency throughout development of the mouse CNS and in neural stem cells grown in vitro. We find that Oct4 is still expressed in the CNS by E8.5, but that this expression declines rapidly until it is undetectable by E15.5. This decline is coincident with the gradual methylation of the Oct4 promoter and proximal enhancer. Immunostaining suggests that the Oct4 protein is predominantly cytoplasmic in location. We also found that neural stem cells from all ages expressed the pluripotency associated genes, Sox2, c-Myc, Klf4 and Nanog. These data provide an explanation for the varying behaviour of cells from the early neuroepithelium at different stages of development. The expression of these genes also provides an indication of why Oct4 alone is sufficient to induce iPS formation in neural stem cells at later stages. PMID:20646110

JMJD3 suppresses stem cell-like characteristics in breast cancer cells by downregulation of Oct4 independently of its demethylase activity.

PubMed

Xun, Jing; Wang, Dekun; Shen, Long; Gong, Junbo; Gao, Ruifang; Du, Lingfang; Chang, Antao; Song, Xiangrong; Xiang, Rong; Tan, Xiaoyue

2017-03-28

Epigenetic regulator JMJD3 plays an important role in both tumor progression and somatic cell reprogramming. Here, we explored the effect of JMJD3 on the stem cell-like characteristics of breast cancer and its underlying mechanism involving stemness-related transcription factor Oct4. Our data revealed that, in breast cancer cells lines and an orthotopic xenograph mouse model of breast cancer, ectopic overexpression of JMJD3 suppressed stem cell-like characteristics of breast cancer cells, whereas knockdown of JMJD3 promoted these characteristics. Oct4 mediated the suppressive effects of JMJD3 on the stemness of breast cancer cells. The inhibitory effect of JMJD3 on Oct4 was independent of demethylase activity, but mediated via degradation of PHF20. Furthermore, we applied an agonist of the vitamin D receptor, paricalcitol, and found that it induced JMJD3 in breast cancer cells. Our data showed that administration of paricalcitol suppressed stem cell-like characteristics and Oct4 expression. Taken together, JMJD3 inhibits the stem cell-like characteristics in breast cancer by suppression of stemness factor Oct4 in a PHF20-dependent manner. Administration of paricalcitol leads to upregulation of JMJD3 that suppresses Oct4 expression and the stem cell-like characteristics in breast cancer.

The pregnane X receptor down‐regulates organic cation transporter 1 (SLC22A1) in human hepatocytes by competing for (“squelching”) SRC‐1 coactivator

PubMed Central

Hyrsova, Lucie; Smutny, Tomas; Carazo, Alejandro; Moravcik, Stefan; Mandikova, Jana; Trejtnar, Frantisek; Gerbal‐Chaloin, Sabine

2016-01-01

Background and Purpose The organic cation transporter 1 (OCT1) transports cationic drugs into hepatocytes. The high hepatic expression of OCT1 is controlled by the HNF4α and USF transcription factors. Pregnane X receptor (PXR) mediates induction of the principal xenobiotic metabolizing enzymes and transporters in the liver. Here, we have assessed the down‐regulation of OCT1 expression by PXR activation. Experimental Approach We used primary human hepatocytes and related cell lines to measure OCT1 expression and activity, by assaying MPP+ accumulation. Western blotting, qRT‐PCR, the OCT1 promoter gene reporter constructs and chromatin immunoprecipitation assays were also used. Key Results OCT1 mRNA in human hepatocytes was down‐regulated along with reduced [3H]MPP+ accumulation in differentiated HepaRG cells after treatment with rifampicin. Rifampicin and hyperforin as well as the constitutively active PXR mutant T248D suppressed activity of the 1.8 kb OCT1 promoter construct in gene reporter assays. Silencing of both PXR and HNF4α in HepaRG cells blocked the PXR ligand‐mediated down‐regulation of OCT1 expression. The mutation of HNF4α and USF1 (E‐box) responsive elements reversed the PXR‐mediated inhibition in gene reporter assays. Chromatin immunoprecipitation assays indicated that PXR activation sequestrates the SRC‐1 coactivator from the HNF4α response element and E‐box of the OCT1 promoter. Consistent with these findings, exogenous overexpression of the SRC‐1, but not the PGC1α coactivator, relieved the PXR‐mediated repression of OCT1 transactivation. Conclusions and Implications PXR ligands reduced the HNF4α‐mediated and USF‐mediated transactivation of OCT1 gene expression by competing for SRC‐1 and decreased delivery of a model OCT1 substrate into hepatocytes. PMID:26920453

Evidence Based Medicine in Space Flight: Evaluation of Inflight Vision Data for Operational Decision-Making

NASA Technical Reports Server (NTRS)

Van Baalen, Mary; Mason, Sara; Foy, Millennia; Wear, Mary; Taiym, Wafa; Moynihan, Shannan; Alexander, David; Hart, Steve; Tarver, William

2015-01-01

Due to recently identified vision changes associated with space flight, JSC Space and Clinical Operations (SCO) implemented broad mission-related vision testing starting in 2009. Optical Coherence Tomography (OCT), 3 Tesla Brain and Orbit MRIs, Optical Biometry were implemented terrestrially for clinical monitoring. While no inflight vision testing was in place, already available onorbit technology was leveraged to facilitate in-flight clinical monitoring, including visual acuity, Amsler grid, tonometry, and ultrasonography. In 2013, on-orbit testing capabilities were expanded to include contrast sensitivity testing and OCT. As these additional testing capabilities have been added, resource prioritization, particularly crew time, is under evaluation.

Impact on creatinine renal clearance by the interplay of multiple renal transporters: a case study with INCB039110.

PubMed

Zhang, Yan; Warren, Mark S; Zhang, Xuexiang; Diamond, Sharon; Williams, Bill; Punwani, Naresh; Huang, Jane; Huang, Yong; Yeleswaram, Swamy

2015-04-01

Serum creatinine is commonly used as a marker of renal function, but increases in serum creatinine might not represent changes in glomerular filtration rate (GFR). INCB039110 (2-(3-(4-(7H-pyrrolo[2,3-day]pyrimidin-4-yl)-1H-pyrazol-1-yl)-1-(1-(3-fluoro-2-(trifluoromethyl)isonicotinoyl)piperidin-4-yl)azetidin-3-yl)acetonitrile) is an inhibitor of the Janus kinases (JAKs) with selectivity for JAK1. In a phase 1 study, a modest and reversible increase in serum creatinine was observed after treatment with INCB039110. However, a dedicated renal function study with INCB039110, assessed by iohexol plasma clearance, conducted in healthy volunteers indicated no change in GFR. In vitro studies were therefore conducted to investigate the interaction of INCB039110 with five transporters that are likely involved in the renal clearance of creatinine. Cell systems expressing individual or multiple transporters were used, including a novel quintuple-transporter model OAT2/OCT2/OCT3/MATE1/MATE2-K. INCB039110 potently inhibited OCT2-mediated uptake of creatinine as well as MATE1-/MATE2-K-mediated efflux of creatinine. Given the interactions of INCB039110 with multiple transporters affecting creatinine uptake and efflux, an integrated system expressing all five transporters was sought; in that system, INCB039110 caused a dose-dependent decrease in transcellular transport of creatinine with weaker net inhibition compared with the effects on individual transporters. In summary, a molecular mechanism for the increase in serum creatinine by INCB039110 has been established. These studies also underline the limitations of using serum creatinine as a marker of renal function. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

Interaction between Octenidine-based Solution and Sodium Hypochlorite: A Mass Spectroscopy, Proton Nuclear Magnetic Resonance, and Scanning Electron Microscopy-based Observational Study.

PubMed

Thaha, Khaleel Ahamed; Varma, R Luxmi; Nair, Mali G; Sam Joseph, V G; Krishnan, Unni

2017-01-01

Octenisept (OCT; Schülke & Mayr, Nordersdedt, Germany), an antimicrobial, antibiofilm agent and a promising root canal irrigant, can be potentially combined with sodium hypochlorite (NaOCl) during endodontic treatment. The aim of this study was first to identify the precipitate formed on the interaction between OCT and NaOCl and secondly to compare its effect on dentinal tubules with that of precipitate formed on combining chlorhexidine (CHX) and NaOCl. This observational study was conducted in 3 stages. Initially, the color changes and precipitate formation were assessed when the test solution 0.1% OCT and 5.2% NaOCl were mixed. Color changes were compared with those observed when 2% CHX was mixed with 5.2% NaOCl. The residue obtained on combining OCT and NaOCl was subjected to proton nuclear magnetic resonance ( 1 H NMR) and mass spectrometric (MS) analysis. In the final stage, dentinal surfaces irrigated alternatively with OCT and NaOCl were compared using scanning electron microscopy (SEM) with the dentinal surface irrigated with CHX and NaOCl. The OCT-NaOCl mixture changed in color from initial milky white to transparent over time, whereas the CHX-NaOCl mixture showed an immediate peach-brown discoloration. 1 H NMR and MS analysis established that the whitish precipitate obtained on combining OCT and NaOCl solutions correlated with the structure of phenoxyethanol (PE). SEM revealed dense precipitate occluding the dentinal tubules with the CHX and NaOCl group, whereas the precipitate was sparse and partially occluded in the OCT and NaOCl group. The whitish precipitate formed with the OCT-NaOCl mixture was identified as PE, a compound already present in OCT, and it partly occluded the dentinal tubules. Copyright © 2016 American Association of Endodontists. All rights reserved.

A Review of Adaptive Optics Optical Coherence Tomography: Technical Advances, Scientific Applications, and the Future.

PubMed

Jonnal, Ravi S; Kocaoglu, Omer P; Zawadzki, Robert J; Liu, Zhuolin; Miller, Donald T; Werner, John S

2016-07-01

Optical coherence tomography (OCT) has enabled "virtual biopsy" of the living human retina, revolutionizing both basic retina research and clinical practice over the past 25 years. For most of those years, in parallel, adaptive optics (AO) has been used to improve the transverse resolution of ophthalmoscopes to foster in vivo study of the retina at the microscopic level. Here, we review work done over the last 15 years to combine the microscopic transverse resolution of AO with the microscopic axial resolution of OCT, building AO-OCT systems with the highest three-dimensional resolution of any existing retinal imaging modality. We surveyed the literature to identify the most influential antecedent work, important milestones in the development of AO-OCT technology, its applications that have yielded new knowledge, research areas into which it may productively expand, and nascent applications that have the potential to grow. Initial efforts focused on demonstrating three-dimensional resolution. Since then, many improvements have been made in resolution and speed, as well as other enhancements of acquisition and postprocessing techniques. Progress on these fronts has produced numerous discoveries about the anatomy, function, and optical properties of the retina. Adaptive optics OCT continues to evolve technically and to contribute to our basic and clinical knowledge of the retina. Due to its capacity to reveal cellular and microscopic detail invisible to clinical OCT systems, it is an ideal companion to those instruments and has the demonstrable potential to produce images that can guide the interpretation of clinical findings.

Establishment of oct4:gfp transgenic zebrafish line for monitoring cellular multipotency by GFP fluorescence.

PubMed

Kato, Hiroyuki; Abe, Kota; Yokota, Shinpei; Matsuno, Rinta; Mikekado, Tsuyoshi; Yokoi, Hayato; Suzuki, Tohru

2015-01-01

The establishment of induced pluripotent stem (iPS) cell technology in fish could facilitate the establishment of novel cryopreservation techniques for storing selected aquaculture strains as frozen cells. In order to apply iPS cell technology to fish, we established a transgenic zebrafish line, Tg(Tru.oct4:EGFP), using green fluorescent protein (GFP) expression under the control of the oct4 gene promoter as a marker to evaluate multipotency in iPS cell preparations. We used the oct4 promoter from fugu (Takifugu rubripes) due to the compact nature of the fugu genome and to facilitate future applications of this technology in marine fishes. During embryogenesis, maternal GFP fluorescence was observed at the cleavage stage and zygotic GFP expression was observed from the start of the shield stage until approximately 24 h after fertilization. gfp messenger RNA (mRNA) was expressed by whole embryonic cells at the shield stage, and then restricted to the caudal neural tube in the latter stages of embryogenesis. These observations showed that GFP fluorescence and the regulation of gfp mRNA expression by the exogenous fugu oct4 promoter are well suited for monitoring endogenous oct4 mRNA expression in embryos. Bisulfite sequencing revealed that the rate of CpG methylation in the transgenic oct4 promoter was high in adult cells (98%) and low in embryonic cells (37%). These findings suggest that, as with the endogenous oct4 promoter, demethylation and methylation both take place normally in the transgenic oct4 promoter during embryogenesis. The embryonic cells harvested at the shield stage formed embryonic body-like cellular aggregates and maintained GFP fluorescence for 6 d when cultured on Transwell-COL Permeable Supports or a feeder layer of adult fin cells. Loss of GFP fluorescence by cultured cells was correlated with cellular differentiation. We consider that the Tg(Tru.oct4:EGFP) zebrafish line established here is well suited for monitoring multipotency in multipotent zebrafish cell cultures and for iPS cell preparation.

Clinical value of octamer-binding transcription factor 4 as a prognostic marker in patients with digestive system cancers: A systematic review and meta-analysis.

PubMed

Chen, Zhiqiang; Zhang, Long; Zhu, Qin; Wang, Xiaowei; Wu, Jindao; Wang, Xuehao

2017-03-01

The role of octamer-binding transcription factor 4 (Oct4) has been implicated in the clinical prognosis of various kinds of digestive system cancers, but the results remain controversial. The purpose of this meta-analysis is to assess the potential role of Oct4 as a prognostic marker in digestive system tumors. Relevant articles were retrieved from Pubmed, Web of Science, and Cochrane Library up to July 2016. The software Stata 12.0 was used to analyze the outcomes, including overall survival (OS), disease-free survival, recurrence-free survival, and clinicopathological characteristics. A total of 13 eligible studies with 1538 patients were included. Elevated Oct4 expression was significantly associated with poor OS (pooled hazard ratio [HR] = 2.183, 95% confidence interval [CI]: 1.824-2.612), disease-free survival (pooled HR = 1.973, 95% CI: 1.538-2.532), and recurrence-free survival (pooled HR = 2.209, 95% CI: 1.461-3.338) of digestive system malignancies. Subgroup analyses showed that cancer type, sample size, study quality, and laboratory detection method did not alter the significant prognostic value of Oct4. Additionally, Oct4 expression was found to be an independent predictive factor for OS (HR = 2.068, 95% CI: 1.633-2.619). No significant association was found between Oct4 and clinicopathological features of digestive system malignancies. This study provided evidence of Oct4 and/or its closely related homolog protein as a predictive factor for patients with digestive system cancers. More large-scale clinical studies on the prognostic value of Oct4 are warranted. © 2016 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

Molecular aspect of silver nanoparticles regulated embryonic development in Zebrafish (Danio rerio) by Oct-4 expression.

PubMed

Sarkar, Biplab; Verma, Suresh K; Akhtar, Javed; Netam, Surya Prakash; Gupta, Sanjay Kr; Panda, Pritam Kumar; Mukherjee, Koel

2018-09-01

With the enhancement of commercial manifestation of silver nanoparticles, concerned has risen on their accumulation in aquatic system and consequent effects on fish development and metabolism. In this study, experiments were conducted to assess the impacts of silver nanoparticles on early life cycles of fish considering Zebrafish (Danio rerio) as experimental model. Silver nanoparticles were synthesized through chemical reduction method and characterized through UV-visible spectroscopy, dynamic light scattering (DLS), and HR-TEM. Different sub lethal doses of nanosilver were applied (13.6, 21.6, 42.4, 64, and 128 μgL -1 ) to post-fertilization phases of Zebrafish embryos and their interaction effects were monitored up to six days period. No significant morphological variations were observed at 13.6, 21.6, 42.4 μgL -1 dose of silver nanoparticles, whereas 64 and 128 μgL -1 exposure dose exhibited bending in myotome, deformity in tail region, somites, notochord and swelling in anterior and posterior region of embryos and larva. Hatching performances analysis elicited highest hatching success in 13.6 and 21.6 μgL -1 doses of silver nanoparticles followed by positive and negative control, whereas exposure dose of 64 and 128 μgL -1 exhibited comparatively lower success. Western blot analysis were conducted on developing hatchlings with Oct4 antibody and at 13.6 and 21.6 μgL -1 dose,it showed over expression elucidating stimulatory role of nanosilver in these mentioned doses. In silico analysis depicted a firm interaction of nanosilver with Oct4 revealing their key role in growth stimulation of developing embryos. The study demonstrates the function of nanosilver as a growth promoter rather only as a toxicant in fish metabolic system. Copyright © 2018 Elsevier Ltd. All rights reserved.

A nontranscriptional role for Oct4 in the regulation of mitotic entry

PubMed Central

Zhao, Rui; Deibler, Richard W.; Lerou, Paul H.; Ballabeni, Andrea; Heffner, Garrett C.; Cahan, Patrick; Unternaehrer, Juli J.; Kirschner, Marc W.; Daley, George Q.

2014-01-01

Rapid progression through the cell cycle and a very short G1 phase are defining characteristics of embryonic stem cells. This distinct cell cycle is driven by a positive feedback loop involving Rb inactivation and reduced oscillations of cyclins and cyclin-dependent kinase (Cdk) activity. In this setting, we inquired how ES cells avoid the potentially deleterious consequences of premature mitotic entry. We found that the pluripotency transcription factor Oct4 (octamer-binding transcription factor 4) plays an unappreciated role in the ES cell cycle by forming a complex with cyclin–Cdk1 and inhibiting Cdk1 activation. Ectopic expression of Oct4 or a mutant lacking transcriptional activity recapitulated delayed mitotic entry in HeLa cells. Reduction of Oct4 levels in ES cells accelerated G2 progression, which led to increased chromosomal missegregation and apoptosis. Our data demonstrate an unexpected nontranscriptional function of Oct4 in the regulation of mitotic entry. PMID:25324523

Inhibition of Oct 3/4 mitigates the cardiac progenitor-derived myocardial repair in infarcted myocardium.

PubMed

Zhao, Yu Tina; Du, Jianfeng; Chen, Youfang; Tang, Yaoliang; Qin, Gangjian; Lv, Guorong; Zhuang, Shougang; Zhao, Ting C

2015-12-24

Recent evidence has demonstrated that cardiac progenitor cells play an essential role in the induction of angiomyogenesis in infarcted myocardium. We and others have shown that engraftment of c-kit(+) cardiac stem cells (CSCs) into infarcted hearts led to myocardium regeneration and neovascularization, which was associated with an improvement of ventricular function. The purpose of this study is aimed at investigating the functional role of transcription factor (TF) Oct3/4 in facilitating CSCs to promote myocardium regeneration and preserve cardiac performance in the post-MI heart. c-kit(+) CSCs were isolated from adult hearts and re-introduced into the infarcted myocardium in which the mouse MI model was created by permanent ligation of the left anterior descending artery (LAD). The Oct3/4 of CSCs was inhibited by transfection of Oct3/4 siRNA, and transfection of CSCs with control siRNA serves as control groups. Myocardial functions were evaluated by echocardiographic measurement. Histological analysis was employed to assess newly formed cardiogenesis, neovascularization, and cell proliferations. Terminal deoxynucleotidyltransferase (TdT) nick-end labeling (TUNEL) was carried out to assess apoptotic cardiomyocytes. Real time polymerase chain reaction and Western blot were carried out to evaluate the level of Oct 3/4 in CSCs. Two weeks after engraftment, CSCs increased ventricular functional recovery as shown by a serial echocardiographic measurement, which is concomitant with the suppression of cardiac hypertrophy and attenuation of myocardial interstitial fibrosis. Suppression of Oct 3/4 of CSCs abrogated functional improvements and mitigated the hypertrophic response and cardiac remodeling. Transplantation of c-kit(+) CSCs into MI hearts promoted cardiac regeneration and neovascularization, which were abolished with the knockdown of Oct3/4. Additionally, suppression of Oct3/4 abrogated myocyte proliferation in the CSC-engrafted myocardium. Our results indicate that CSCs-derived cardiac regeneration improves the restoration of cardiac function and is mediated through Oct 3/4.

O-GlcNAc transferase regulates transcriptional activity of human Oct4.

PubMed

Constable, Sandii; Lim, Jae-Min; Vaidyanathan, Krithika; Wells, Lance

2017-10-01

O-linked β-N-acetylglucosamine (O-GlcNAc) is a single sugar modification found on many different classes of nuclear and cytoplasmic proteins. Addition of this modification, by the enzyme O-linked N-acetylglucosamine transferase (OGT), is dynamic and inducible. One major class of proteins modified by O-GlcNAc is transcription factors. O-GlcNAc regulates transcription factor properties through a variety of different mechanisms including localization, stability and transcriptional activation. Maintenance of embryonic stem (ES) cell pluripotency requires tight regulation of several key transcription factors, many of which are modified by O-GlcNAc. Octamer-binding protein 4 (Oct4) is one of the key transcription factors required for pluripotency of ES cells and more recently, the generation of induced pluripotent stem (iPS) cells. The action of Oct4 is modulated by the addition of several post-translational modifications, including O-GlcNAc. Previous studies in mice found a single site of O-GlcNAc addition responsible for transcriptional regulation. This study was designed to determine if this mechanism is conserved in humans. We mapped 10 novel sites of O-GlcNAc attachment on human Oct4, and confirmed a role for OGT in transcriptional activation of Oct4 at a site distinct from that found in mouse that allows distinction between different Oct4 target promoters. Additionally, we uncovered a potential new role for OGT that does not include its catalytic function. These results confirm that human Oct4 activity is being regulated by OGT by a mechanism that is distinct from mouse Oct4. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

An enhanced Oct-tree data structure and operations for solid modeling

NASA Technical Reports Server (NTRS)

Fujimura, K.; Toriya, H.; Yamaguchi, K.; Kunii, T. L.

1984-01-01

Oct-trees are enhanced to increase the processing efficiency of geometric operations for interactive CAD use. Further enhancement is made to combine them with surface models for more precise boundary specification as needed by tool path generation in CAM applications.

Overexpression of OCT4A ortholog elevates endogenous XIST in porcine parthenogenic blastocysts.

PubMed

Hwang, Jae Yeon; Choi, Kwang-Hwan; Lee, Dong-Kyung; Kim, Seung-Hun; Kim, Eun Bae; Hyun, Sang-Hwan; Lee, Chang-Kyu

2015-01-01

X-chromosome inactivation (XCI) is an epigenetic process that equalizes expression of X-borne genes between male and female eutherians. This process is observed in early eutherian embryo development in a species-specific manner. Until recently, various pluripotent factors have been suggested to regulate the process of XCI by repressing XIST expression, which is the master inducer for XCI. Recent insights into the process and its regulation have been restricted in mouse species despite the evolutionary diversity of the process and molecular mechanism among the species. OCT4A is one of the represented pluripotent factors, the gate-keeper for maintaining pluripotency, and an XIST repressor. Therefore, in here, we examined the relation between OCT4A and X-linked genes in porcine preimplantation embryos. Three X-linked genes, XIST, LOC102165544, and RLIM, were selected in present study because their orthologues have been known to regulate XCI in mice. Expression levels of OCT4A were positively correlated with XIST and LOC102165544 in female blastocysts. Furthermore, overexpression of exogenous human OCT4A in cleaved parthenotes generated blastocysts with increased XIST expression levels. However, increased XIST expression was not observed when exogenous OCT4A was obtained from early blastocysts. These results suggest the possibility that OCT4A would be directly or indirectly involved in XIST expression in earlier stage porcine embryos rather than blastocysts.

Joint Duty Prerequisite for Promotion to General/Flag Officer

DTIC Science & Technology

1992-03-24

16 Figure 2 JSO Designation Prior to 1 Oct 89 Due to JPE Only 22 Figure 3 JSO Designation Prior to 1 Oct 89 Due to JPE And JDA Prior...to or After 1 Oct 89 . . . . . . . . . 23 Figure 4 JSO Designation Prior to 1 Oct 89 Due to JDAOnly . . . . . . 6. . . . . . . . . . . . . .. . 24...Figure 5 JSO Nomination After 1 Oct 89 Due to JDA After 1 Oct 89 Without JPE . . . . . . ........ . 26 Figure 6 JSO Designation After 1 Oct 90 Due to

Reprogramming fibroblasts into induced pluripotent stem cells with Bmi1

PubMed Central

Moon, Jai-Hee; Heo, June Seok; Kim, Jun Sung; Jun, Eun Kyoung; Lee, Jung Han; Kim, Aeree; Kim, Jonggun; Whang, Kwang Youn; Kang, Yong-Kook; Yeo, Seungeun; Lim, Hee-Joung; Han, Dong Wook; Kim, Dong-Wook; Oh, Sejong; Yoon, Byung Sun; Schöler, Hans R; You, Seungkwon

2011-01-01

Somatic cells can be reprogrammed into induced pluripotent stem (iPS) cells by the transcription factors Oct4, Sox2, and Klf4 in combination with c-Myc. Recently, Sox2 plus Oct4 was shown to reprogram fibroblasts and Oct4 alone was able to reprogram mouse and human neural stem cells (NSCs) into iPS cells. Here, we report that Bmi1 leads to the transdifferentiation of mouse fibroblasts into NSC-like cells, and, in combination with Oct4, can replace Sox2, Klf4 and c-Myc during the reprogramming of fibroblasts into iPS cells. Furthermore, activation of sonic hedgehog signaling (by Shh, purmorphamine, or oxysterol) compensates for the effects of Bmi1, and, in combination with Oct4, reprograms mouse embryonic and adult fibroblasts into iPS cells. One- and two-factor iPS cells are similar to mouse embryonic stem cells in their global gene expression profile, epigenetic status, and in vitro and in vivo differentiation into all three germ layers, as well as teratoma formation and germline transmission in vivo. These data support that converting fibroblasts with Bmi1 or activation of the sonic hedgehog pathway to an intermediate cell type that expresses Sox2, Klf4, and N-Myc allows iPS generation via the addition of Oct4. PMID:21709693

The Histone Acetyltransferase MOF Promotes Induces Generation of Pluripotent Stem Cells.

PubMed

Mu, Xupeng; Yan, Shaohua; Fu, Changhao; Wei, Anhui

2015-08-01

Histone modification plays an important role in maintaining pluripotency and self-renewal of embryonic stem cells (ESCs). The histone acetyltransferase MOF is a key regulator of ESCs; however, the role of MOF in the process of reprogramming back to induced pluripotent stem cells (iPSCs) remains unclear. In this study, we investigated the function of MOF on the generation of iPSCs. We show that iPSCs contain high levels of MOF mRNA, and the expression level of MOF protein is dramatically upregulated following reprogramming. Most importantly, overexpression of MOF improves reprogramming efficiency and facilitates the formation of iPSCs, whereas small hairpin RNA (shRNA)-mediated knockdown of MOF impairs iPSCs generation during reprogramming. Further investigation reveals that MOF interacts with the H3K4 methyltransferase Wdr5 to promote endogenous Oct4 expression during the reprogramming process. Knockdown of MOF reduces H4K16ac and H3K4me3 modification at the Oct4 promoter. In conclusion, our data indicate that MOF is an important epigenetic regulator that is critical for efficient reprogramming.

Generation and characterization of induced pluripotent stem cells from guinea pig fetal fibroblasts.

PubMed

Wu, Yuehong; Li, Ouyang; He, Chengwen; Li, Yong; Li, Min; Liu, Xiaoming Liu; Wang, Yujiong; He, Yulong

2017-06-01

Induced pluripotent stem cells (iPS) represent an important tool to develop disease‑modeling assays, drug testing assays and cell‑based replacement therapies. The application of iPS in these fields requires the development of suitable animal models. Of the suitable species, guinea pigs are particularly important and offer significant advantages. Successful iPS generation has been accomplished in a number of species; however, it has not been reported in the guinea pig. The present study successfully generated iPS from guinea pigs (giPS) using single polycistronic virus transduction with mouse octamer‑binding transcription factor 4 (Oct4), sex determining region Y‑box 2 (Sox2), Kruppel‑like factor 4 and c‑Myc. The giPS cell lines were cultured in media containing leukemia inhibitory factor and guinea pig fibroblast cells were used as feeder cells. These cultures were expanded under feeder‑free culture conditions using ESGRO Complete Plus Clonal Grade medium containing 15% fetal bovine serum on gelatin‑coated dishes. The resultant cells had a normal karyotype, exhibited alkaline phosphatase activity and expressed the pluripotency markers Oct4, Sox2 and Nanog. The cells differentiated in vivo to form teratomas that contained all three germ layers of the tissue cells. The generation of giPS may facilitate future studies investigating the mechanisms underlying innate immunity, particularly for tuberculosis. These experiments provide proof of principle that iPS technology may be adapted to use the guinea pig as a model of human diseases.

Generation and characterization of induced pluripotent stem cells from guinea pig fetal fibroblasts

PubMed Central

Wu, Yuehong; Li, Ouyang; He, Chengwen; Li, Yong; Li, Min; Liu, Xiaoming; Wang, Yujiong; He, Yulong

2017-01-01

Induced pluripotent stem cells (iPS) represent an important tool to develop disease-modeling assays, drug testing assays and cell-based replacement therapies. The application of iPS in these fields requires the development of suitable animal models. Of the suitable species, guinea pigs are particularly important and offer significant advantages. Successful iPS generation has been accomplished in a number of species; however, it has not been reported in the guinea pig. The present study successfully generated iPS from guinea pigs (giPS) using single polycistronic virus transduction with mouse octamer-binding transcription factor 4 (Oct4), sex determining region Y-box 2 (Sox2), Kruppel-like factor 4 and c-Myc. The giPS cell lines were cultured in media containing leukemia inhibitory factor and guinea pig fibroblast cells were used as feeder cells. These cultures were expanded under feeder-free culture conditions using ESGRO Complete Plus Clonal Grade medium containing 15% fetal bovine serum on gelatin-coated dishes. The resultant cells had a normal karyotype, exhibited alkaline phosphatase activity and expressed the pluripotency markers Oct4, Sox2 and Nanog. The cells differentiated in vivo to form teratomas that contained all three germ layers of the tissue cells. The generation of giPS may facilitate future studies investigating the mechanisms underlying innate immunity, particularly for tuberculosis. These experiments provide proof of principle that iPS technology may be adapted to use the guinea pig as a model of human diseases. PMID:28393187

The cation transporters rOCT1 and rOCT2 interact with bicarbonate but play only a minor role for amantadine uptake into rat renal proximal tubules.

PubMed

Goralski, Kerry B; Lou, Ganlu; Prowse, Matthew T; Gorboulev, Valentin; Volk, Christopher; Koepsell, Hermann; Sitar, Daniel S

2002-12-01

In renal proximal tubules, the organic cation transporters rOCT1 and rOCT2 are supposed to mediate the first step in organic cation secretion. We investigated whether previously described differences in amantadine and tetraethylammonium (TEA) uptake into isolated renal proximal tubules could be explained by differences in their transport by rOCT1 and rOCT2. By expressing rOCT1 and rOCT2 in Xenopus oocytes and HEK 293 cells, we demonstrated that both transporters translocated amantadine. In Xenopus oocytes, the inhibitory potency of several rOCT1/2 inhibitors was similar for amantadine compared to TEA uptake and supports amantadine transport by rOCT1 and rOCT2. In proximal tubules, procainamide, quinine, cyanine(863), choline, and guanidine in concentrations that inhibit rOCT1/2-mediated TEA or amantadine uptake in Xenopus oocytes exhibited no effect on amantadine uptake. At variance, these inhibitors blocked TEA uptake into proximal tubules. Amantadine and TEA transport were sensitive to modulation by 25 mM bicarbonate. The effect of bicarbonate on organic cation transport was dependent on substrate (amantadine or TEA), cell system (oocytes, HEK 293 cells, or proximal tubules), and transporter (rOCT1 or rOCT2). In proximal tubules, only amantadine uptake was stimulated by bicarbonate. The data suggested that rat renal proximal tubules contain an organic cation transporter in addition to rOCT1 and rOCT2 that mediates amantadine uptake and requires bicarbonate for optimal function. TEA uptake by the basolateral membrane may be mediated mainly by rOCT1 and rOCT2, but these transporters may be in a different functional or regulatory state when expressed in cells or oocytes compared with expression in vivo.

Of Mice and Snakes: A Tail of Oct4.

PubMed

Shylo, Natalia A; Weatherbee, Scott D

2016-08-08

The vertebrate axial skeleton comprises regions of specialized vertebrae, which vary in length between lineages. Aires et al. (2016) uncover a key role for Oct4 in determining trunk length in mice. Additionally, a heterochronic shift in Oct4 expression may underlie the extreme elongation of the trunk in snakes. Copyright © 2016 Elsevier Inc. All rights reserved.

Analog signal processing for optical coherence imaging systems

NASA Astrophysics Data System (ADS)

Xu, Wei

Optical coherence tomography (OCT) and optical coherence microscopy (OCM) are non-invasive optical coherence imaging techniques, which enable micron-scale resolution, depth resolved imaging capability. Both OCT and OCM are based on Michelson interferometer theory. They are widely used in ophthalmology, gastroenterology and dermatology, because of their high resolution, safety and low cost. OCT creates cross sectional images whereas OCM obtains en face images. In this dissertation, the design and development of three increasingly complicated analog signal processing (ASP) solutions for optical coherence imaging are presented. The first ASP solution was implemented for a time domain OCT system with a Rapid Scanning Optical Delay line (RSOD)-based optical signal modulation and logarithmic amplifier (Log amp) based demodulation. This OCT system can acquire up to 1600 A-scans per second. The measured dynamic range is 106dB at 200A-scan per second. This OCT signal processing electronics includes an off-the-shelf filter box with a Log amp circuit implemented on a PCB board. The second ASP solution was developed for an OCM system with synchronized modulation and demodulation and compensation for interferometer phase drift. This OCM acquired micron-scale resolution, high dynamic range images at acquisition speeds up to 45,000 pixels/second. This OCM ASP solution is fully custom designed on a perforated circuit board. The third ASP solution was implemented on a single 2.2 mm x 2.2 mm complementary metal oxide semiconductor (CMOS) chip. This design is expandable to a multiple channel OCT system. A single on-chip CMOS photodetector and ASP channel was used for coherent demodulation in a time domain OCT system. Cross-sectional images were acquired with a dynamic range of 76dB (limited by photodetector responsivity). When incorporated with a bump-bonded InGaAs photodiode with higher responsivity, the expected dynamic range is close to 100dB.

A Review of Adaptive Optics Optical Coherence Tomography: Technical Advances, Scientific Applications, and the Future

PubMed Central

Jonnal, Ravi S.; Kocaoglu, Omer P.; Zawadzki, Robert J.; Liu, Zhuolin; Miller, Donald T.; Werner, John S.

2016-01-01

Purpose Optical coherence tomography (OCT) has enabled “virtual biopsy” of the living human retina, revolutionizing both basic retina research and clinical practice over the past 25 years. For most of those years, in parallel, adaptive optics (AO) has been used to improve the transverse resolution of ophthalmoscopes to foster in vivo study of the retina at the microscopic level. Here, we review work done over the last 15 years to combine the microscopic transverse resolution of AO with the microscopic axial resolution of OCT, building AO-OCT systems with the highest three-dimensional resolution of any existing retinal imaging modality. Methods We surveyed the literature to identify the most influential antecedent work, important milestones in the development of AO-OCT technology, its applications that have yielded new knowledge, research areas into which it may productively expand, and nascent applications that have the potential to grow. Results Initial efforts focused on demonstrating three-dimensional resolution. Since then, many improvements have been made in resolution and speed, as well as other enhancements of acquisition and postprocessing techniques. Progress on these fronts has produced numerous discoveries about the anatomy, function, and optical properties of the retina. Conclusions Adaptive optics OCT continues to evolve technically and to contribute to our basic and clinical knowledge of the retina. Due to its capacity to reveal cellular and microscopic detail invisible to clinical OCT systems, it is an ideal companion to those instruments and has the demonstrable potential to produce images that can guide the interpretation of clinical findings. PMID:27409507

Synergistic effect of muramyldipeptide with lipopolysaccharide or lipoteichoic acid to induce inflammatory cytokines in human monocytic cells in culture.

PubMed

Yang, S; Tamai, R; Akashi, S; Takeuchi, O; Akira, S; Sugawara, S; Takada, H

2001-04-01

An analog of 1alpha,25-dihydroxyvitamin D3, 22-oxyacalcitriol (OCT), differentiated human monocytic THP-1 and U937 cells to express membrane CD14 and rendered the cells responsive to bacterial cell surface components. Both THP-1 and U937 cells expressed Toll-like receptor 4 (TLR4) on the cell surface and TLR4 mRNA in the cells, irrespective of OCT treatment. In contrast, OCT-treated U937 cells scarcely expressed TLR2 mRNA, while OCT-treated THP-1 cells expressed this transcript. Muramyldipeptide (MDP) by itself exhibited only a weak ability to induce secretion of inflammatory cytokines such as interleukin-8 (IL-8) in the OCT-differentiated THP-1 cells but showed marked synergistic effects with Salmonella lipopolysaccharide (LPS) or lipoteichoic acid (LTA) from Staphylococcus aureus, both of which exhibited strong activities. Combinatory stimulation with LPS plus LTA did not show a synergistic effect on OCT-differentiated THP-1 cells. Similar results were observed in OCT-differentiated U937 cells, although combination experiments were carried out only with MDP plus LPS. Anti-CD14 monoclonal antibody (MAb) MY4, anti-TLR4 MAb HTA125, and the synthetic lipid A precursor LA-14-PP almost completely inhibited the IL-8-inducing activities of LTA as well as LPS on OCT-treated THP-1 cells, but these treatments increased MDP activity. OCT-treated THP-1 cells primed with MDP exhibited enhanced production of IL-8 upon stimulation with LPS, while the cells primed with LPS showed no change in production upon stimulation with MDP. MDP up-regulated mRNA expression of an adapter molecule to TLRs, MyD88, to an extent similar to that for LPS in OCT-treated THP-1 cells. These findings suggested that LTA as well as LPS activated human monocytic cells in a CD14- and TLR4-dependent manner, whereas MDP exhibited activity in a CD14-, TLR4-, and probably TLR2-independent manner and exhibited synergistic and priming effects on the cells for cytokine production in response to various bacterial components.

A homogeneous, Anti-dsDNA antibody-based assay for multicolor detection of cancer stem cell transcription factors.

PubMed

Ma, Jiehua; Shi, Hai; Zhang, Meiling; Li, Chao; Xiang, Yang; Liu, Ping

2018-10-31

Cancer stem cells (CSCs) are responsible for maintaining tumor growth, metastasis and recurrence. The high expression of cancer stem cell transcription factors (Oct4, Sox2 and Nanog) is a valuable prognostic factor, suggesting a higher risk of tumor recurrence and metastasis. So, the development of a convenient and cost-effective method for multiplex assay of these transcription factors (TFs) is highly required. In this work, we have proposed a universal homogeneous assay for multicolor detection of these TFs based on anti-dsDNA antibody-decorated Fe 3 O 4 magnetite nanoparticles (aadMNPs). In the presence of analytes, the dye-labeled dsDNAs are bound by specific TFs, which will inhibit the interactions between the dsDNAs and aadMNPs, generating higher fluorescence that may provide signal readout for the immunosensing process. By using the proposed method, Oct4 can be determined in a linear range from 3 to 1200 ng/mL with a detection limit of 0.035 ng/mL. Furthermore, we have presented assays for the sensitive, selective and rapid detection of Oct4, Sox2 and Nanog in cell extract, as well as the analysis of binding affinity of the mutated binding sequences. This work may provide potential applications in clinical CSCs detections, and may open new opportunity for the study of nucleotide polymorphisms in TF binding sites. Copyright © 2018 Elsevier B.V. All rights reserved.

Molecular and functional characterization of a novel gonadotropin-releasing-hormone receptor isolated from the common octopus (Octopus vulgaris)

PubMed Central

Kanda, Atsuhiro; Takahashi, Toshio; Satake, Honoo; Minakata, Hiroyuki

2005-01-01

GnRH (gonadotropin-releasing hormone) plays a pivotal role in the regulation of reproduction in vertebrates through interaction with a specific receptor. Previously, we isolated a GnRH homo-logue, oct-GnRH, from the common octopus (Octopus vulgaris). In the present study, we have identified a GnRH receptor (oct-GnRHR) specific for oct-GnRH from Octopus brain. Oct-GnRHR includes domains and motifs typical of vertebrate GnRH receptors. The intron-inserted positions are conserved between oct-GnRHR and the chordate GnRHR genes. The oct-GnRHR expressed in Xenopus (South African clawed frog) oocytes was responsive to oct-GnRH, but not to any other HPLC fractions of the Octopus brain extract. These results show that oct-GnRHR is an authentic receptor for oct-GnRH. Southern blotting of reverse-transcription PCR products revealed that the oct-GnRHR mRNA was widely distributed in the central and peripheral nervous systems and in several peripheral tissues. In situ hybridiz-ation showed that oct-GnRHR mRNA was expressed in some regions involved in autonomic functions, feeding, memory and movement. Oct-GnRH was shown to induce steroidogenesis of testosterone, progesterone and 17β-oestradiol in Octopus ovary and testis, where oct-GnRHR was abundantly expressed. These results suggest that oct-GnRH, like its vertebrate counterparts, acts as a multifunctional neurotransmitter, neuromodulator and hormone-like factor, both in Octopus central nervous system and peripheral tissues, and that both structure and functions of the GnRH family are, at least partially, evolutionarily conserved between octopuses and chordates. PMID:16367741

Molecular and functional characterization of a novel gonadotropin-releasing-hormone receptor isolated from the common octopus (Octopus vulgaris).

PubMed

Kanda, Atsuhiro; Takahashi, Toshio; Satake, Honoo; Minakata, Hiroyuki

2006-04-01

GnRH (gonadotropin-releasing hormone) plays a pivotal role in the regulation of reproduction in vertebrates through interaction with a specific receptor. Previously, we isolated a GnRH homologue, oct-GnRH, from the common octopus (Octopus vulgaris). In the present study, we have identified a GnRH receptor (oct-GnRHR) specific for oct-GnRH from Octopus brain. Oct-GnRHR includes domains and motifs typical of vertebrate GnRH receptors. The intron-inserted positions are conserved between oct-GnRHR and the chordate GnRHR genes. The oct-GnRHR expressed in Xenopus (South African clawed frog) oocytes was responsive to oct-GnRH, but not to any other HPLC fractions of the Octopus brain extract. These results show that oct-GnRHR is an authentic receptor for oct-GnRH. Southern blotting of reverse-transcription PCR products revealed that the oct-GnRHR mRNA was widely distributed in the central and peripheral nervous systems and in several peripheral tissues. In situ hybridization showed that oct-GnRHR mRNA was expressed in some regions involved in autonomic functions, feeding, memory and movement. Oct-GnRH was shown to induce steroidogenesis of testosterone, progesterone and 17beta-oestradiol in Octopus ovary and testis, where oct-GnRHR was abundantly expressed. These results suggest that oct-GnRH, like its vertebrate counterparts, acts as a multifunctional neurotransmitter, neuromodulator and hormone-like factor, both in Octopus central nervous system and peripheral tissues, and that both structure and functions of the GnRH family are, at least partially, evolutionarily conserved between octopuses and chordates.

The HPV16 E7 oncoprotein increases the expression of Oct3/4 and stemness-related genes and augments cell self-renewal.

PubMed

Organista-Nava, Jorge; Gómez-Gómez, Yazmín; Ocadiz-Delgado, Rodolfo; García-Villa, Enrique; Bonilla-Delgado, José; Lagunas-Martínez, Alfredo; Tapia, Jesús Santa-Olalla; Lambert, Paul F; García-Carrancá, Alejandro; Gariglio, Patricio

2016-12-01

Oct3/4 is a transcription factor involved in maintenance of the pluripotency and self-renewal of stem cells. The E7 oncoprotein and 17β-estradiol (E 2 ) are key factors in cervical carcinogenesis. In the present study, we aimed to investigate the effect of the HPV16 E7 oncoprotein and E 2 on the expression pattern of Oct3/4, Sox2, Nanog and Fgf4. We also determined whether the E7 oncoprotein is associated with cell self-renewal. The results showed that Oct3/4, Sox2, Nanog and Fgf4 were upregulated by the E7 oncoprotein in vivo and in vitro and implicate E 2 in the upregulation of these factors in vivo. We also demonstrated that E7 is involved in cell self-renewal, suggesting that the HPV16 E7 oncoprotein upregulates Oct3/4, Sox2, Nanog and Fgf4 expression to maintain the self-renewal capacity of cancer stem cells. Copyright © 2016 Elsevier Inc. All rights reserved.

iss049e028067

NASA Image and Video Library

2016-10-03

ISS049e028067 (10/03/2016) --- Hurricane Matthew, a huge category 4 level storm, as seen from the International Space Station Oct. 3, 2016. Packing winds of 140 miles an hour as a Category 4 hurricane, Matthew passed over western Haiti and eastern Cuba Oct. 4 before charging north over the Bahamas Oct. 5 and potentially threatening the east coast of the United States later in the week.

Immunohistochemical analysis of the role and relationship between Notch-1 and Oct-4 expression in urinary bladder carcinoma.

PubMed

Abdou, Asmaa Gaber; El-Wahed, Moshira Mohammed Abd; Kandil, Mona Abd-Elhalim; Samaka, Rehab Monir; Elkady, Noha

2013-10-01

Most tumors contain a minor population of cancer stem cells that are responsible for tumor heterogeneity, resistance to therapy and recurrence. Oct-4 is a transcription factor responsible for self-renewal of stem cells, whereas the Notch family of receptors and ligands may play a pivotal role in the regulation of stem cell maintenance and differentiation. This study aimed at an evaluation of Oct-4 and Notch-1 expression in both carcinoma and stromal cells of 83 cases of primary bladder carcinoma and to study the relationship between them. Notch-1 was expressed in carcinoma and stromal cells of all malignant cases, where expression in both cell types was correlated with parameters indicating differentiation, such as low grade (p < 0.05) and less proliferation (p < 0.05). However, Notch-1 expression in stromal cells was associated with nodal metastasis (p = 0.016) and advanced stage (p = 0.030). 56.6 and 75.9% of carcinoma and stromal cells of malignant cases showed Oct-4 expression, respectively. Oct-4 expression in carcinoma cells or stromal cells was associated with aggressive features of bladder carcinoma, such as poor differentiation (p = 0.001), high proliferation (p < 0.001, 0.030), and liability for recurrence (p = 0.010, p < 0.001). There was an inverse relationship between Notch-1 and Oct-4 expression in carcinoma cells (p = 0.002), but stromal expression of Notch-1 was found to be associated with a nuclear pattern of Oct-4 expression in carcinoma cells (p = 0.030). Oct-4 as a stem cell marker is expressed in carcinoma cells and in stromal cells of bladder carcinoma, where they may cooperate in the progression of bladder carcinoma by acquiring aggressive features, such as a liability for recurrence and dissemination. Notch-1 is also expressed in both carcinoma cells and stromal cells of bladder carcinoma. Although they could share in enhancing differentiation, stromal expression of Notch-1 may have a bad impact, possibly through up-regulation of the active nuclear form of Oct-4 in carcinoma cells. © 2013 APMIS Published by Blackwell Publishing Ltd.

CAG repeat expansion in Huntington disease determines age at onset in a fully dominant fashion

PubMed Central

Lee, J.-M.; Ramos, E.M.; Lee, J.-H.; Gillis, T.; Mysore, J.S.; Hayden, M.R.; Warby, S.C.; Morrison, P.; Nance, M.; Ross, C.A.; Margolis, R.L.; Squitieri, F.; Orobello, S.; Di Donato, S.; Gomez-Tortosa, E.; Ayuso, C.; Suchowersky, O.; Trent, R.J.A.; McCusker, E.; Novelletto, A.; Frontali, M.; Jones, R.; Ashizawa, T.; Frank, S.; Saint-Hilaire, M.H.; Hersch, S.M.; Rosas, H.D.; Lucente, D.; Harrison, M.B.; Zanko, A.; Abramson, R.K.; Marder, K.; Sequeiros, J.; Paulsen, J.S.; Landwehrmeyer, G.B.; Myers, R.H.; MacDonald, M.E.; Durr, Alexandra; Rosenblatt, Adam; Frati, Luigi; Perlman, Susan; Conneally, Patrick M.; Klimek, Mary Lou; Diggin, Melissa; Hadzi, Tiffany; Duckett, Ayana; Ahmed, Anwar; Allen, Paul; Ames, David; Anderson, Christine; Anderson, Karla; Anderson, Karen; Andrews, Thomasin; Ashburner, John; Axelson, Eric; Aylward, Elizabeth; Barker, Roger A.; Barth, Katrin; Barton, Stacey; Baynes, Kathleen; Bea, Alexandra; Beall, Erik; Beg, Mirza Faisal; Beglinger, Leigh J.; Biglan, Kevin; Bjork, Kristine; Blanchard, Steve; Bockholt, Jeremy; Bommu, Sudharshan Reddy; Brossman, Bradley; Burrows, Maggie; Calhoun, Vince; Carlozzi, Noelle; Chesire, Amy; Chiu, Edmond; Chua, Phyllis; Connell, R.J.; Connor, Carmela; Corey-Bloom, Jody; Craufurd, David; Cross, Stephen; Cysique, Lucette; Santos, Rachelle Dar; Davis, Jennifer; Decolongon, Joji; DiPietro, Anna; Doucette, Nicholas; Downing, Nancy; Dudler, Ann; Dunn, Steve; Ecker, Daniel; Epping, Eric A.; Erickson, Diane; Erwin, Cheryl; Evans, Ken; Factor, Stewart A.; Farias, Sarah; Fatas, Marta; Fiedorowicz, Jess; Fullam, Ruth; Furtado, Sarah; Garde, Monica Bascunana; Gehl, Carissa; Geschwind, Michael D.; Goh, Anita; Gooblar, Jon; Goodman, Anna; Griffith, Jane; Groves, Mark; Guttman, Mark; Hamilton, Joanne; Harrington, Deborah; Harris, Greg; Heaton, Robert K.; Helmer, Karl; Henneberry, Machelle; Hershey, Tamara; Herwig, Kelly; Howard, Elizabeth; Hunter, Christine; Jankovic, Joseph; Johnson, Hans; Johnson, Arik; Jones, Kathy; Juhl, Andrew; Kim, Eun Young; Kimble, Mycah; King, Pamela; Klimek, Mary Lou; Klöppel, Stefan; Koenig, Katherine; Komiti, Angela; Kumar, Rajeev; Langbehn, Douglas; Leavitt, Blair; Leserman, Anne; Lim, Kelvin; Lipe, Hillary; Lowe, Mark; Magnotta, Vincent A.; Mallonee, William M.; Mans, Nicole; Marietta, Jacquie; Marshall, Frederick; Martin, Wayne; Mason, Sarah; Matheson, Kirsty; Matson, Wayne; Mazzoni, Pietro; McDowell, William; Miedzybrodzka, Zosia; Miller, Michael; Mills, James; Miracle, Dawn; Montross, Kelsey; Moore, David; Mori, Sasumu; Moser, David J.; Moskowitz, Carol; Newman, Emily; Nopoulos, Peg; Novak, Marianne; O'Rourke, Justin; Oakes, David; Ondo, William; Orth, Michael; Panegyres, Peter; Pease, Karen; Perlman, Susan; Perlmutter, Joel; Peterson, Asa; Phillips, Michael; Pierson, Ron; Potkin, Steve; Preston, Joy; Quaid, Kimberly; Radtke, Dawn; Rae, Daniela; Rao, Stephen; Raymond, Lynn; Reading, Sarah; Ready, Rebecca; Reece, Christine; Reilmann, Ralf; Reynolds, Norm; Richardson, Kylie; Rickards, Hugh; Ro, Eunyoe; Robinson, Robert; Rodnitzky, Robert; Rogers, Ben; Rosenblatt, Adam; Rosser, Elisabeth; Rosser, Anne; Price, Kathy; Price, Kathy; Ryan, Pat; Salmon, David; Samii, Ali; Schumacher, Jamy; Schumacher, Jessica; Sendon, Jose Luis Lópenz; Shear, Paula; Sheinberg, Alanna; Shpritz, Barnett; Siedlecki, Karen; Simpson, Sheila A.; Singer, Adam; Smith, Jim; Smith, Megan; Smith, Glenn; Snyder, Pete; Song, Allen; Sran, Satwinder; Stephan, Klaas; Stober, Janice; Sü?muth, Sigurd; Suter, Greg; Tabrizi, Sarah; Tempkin, Terry; Testa, Claudia; Thompson, Sean; Thomsen, Teri; Thumma, Kelli; Toga, Arthur; Trautmann, Sonja; Tremont, Geoff; Turner, Jessica; Uc, Ergun; Vaccarino, Anthony; van Duijn, Eric; Van Walsem, Marleen; Vik, Stacie; Vonsattel, Jean Paul; Vuletich, Elizabeth; Warner, Tom; Wasserman, Paula; Wassink, Thomas; Waterman, Elijah; Weaver, Kurt; Weir, David; Welsh, Claire; Werling-Witkoske, Chris; Wesson, Melissa; Westervelt, Holly; Weydt, Patrick; Wheelock, Vicki; Williams, Kent; Williams, Janet; Wodarski, Mary; Wojcieszek, Joanne; Wood, Jessica; Wood-Siverio, Cathy; Wu, Shuhua; Yastrubetskaya, Olga; de Yebenes, Justo Garcia; Zhao, Yong Qiang; Zimbelman, Janice; Zschiegner, Roland; Aaserud, Olaf; Abbruzzese, Giovanni; Andrews, Thomasin; Andrich, Jurgin; Antczak, Jakub; Arran, Natalie; Artiga, Maria J. Saiz; Bachoud-Lévi, Anne-Catherine; Banaszkiewicz, Krysztof; di Poggio, Monica Bandettini; Bandmann, Oliver; Barbera, Miguel A.; Barker, Roger A.; Barrero, Francisco; Barth, Katrin; Bas, Jordi; Beister, Antoine; Bentivoglio, Anna Rita; Bertini, Elisabetta; Biunno, Ida; Bjørgo, Kathrine; Bjørnevoll, Inga; Bohlen, Stefan; Bonelli, Raphael M.; Bos, Reineke; Bourne, Colin; Bradbury, Alyson; Brockie, Peter; Brown, Felicity; Bruno, Stefania; Bryl, Anna; Buck, Andrea; Burg, Sabrina; Burgunder, Jean-Marc; Burns, Peter; Burrows, Liz; Busquets, Nuria; Busse, Monica; Calopa, Matilde; Carruesco, Gemma T.; Casado, Ana Gonzalez; Catena, Judit López; Chu, Carol; Ciesielska, Anna; Clapton, Jackie; Clayton, Carole; Clenaghan, Catherine; Coelho, Miguel; Connemann, Julia; Craufurd, David; Crooks, Jenny; Cubillo, Patricia Trigo; Cubo, Esther; Curtis, Adrienne; De Michele, Giuseppe; De Nicola, A.; de Souza, Jenny; de Weert, A. Marit; de Yébenes, Justo Garcia; Dekker, M.; Descals, A. Martínez; Di Maio, Luigi; Di Pietro, Anna; Dipple, Heather; Dose, Matthias; Dumas, Eve M.; Dunnett, Stephen; Ecker, Daniel; Elifani, F.; Ellison-Rose, Lynda; Elorza, Marina D.; Eschenbach, Carolin; Evans, Carole; Fairtlough, Helen; Fannemel, Madelein; Fasano, Alfonso; Fenollar, Maria; Ferrandes, Giovanna; Ferreira, Jaoquim J.; Fillingham, Kay; Finisterra, Ana Maria; Fisher, K.; Fletcher, Amy; Foster, Jillian; Foustanos, Isabella; Frech, Fernando A.; Fullam, Robert; Fullham, Ruth; Gago, Miguel; García, RocioGarcía-Ramos; García, Socorro S.; Garrett, Carolina; Gellera, Cinzia; Gill, Paul; Ginestroni, Andrea; Golding, Charlotte; Goodman, Anna; Gørvell, Per; Grant, Janet; Griguoli, A.; Gross, Diana; Guedes, Leonor; BascuñanaGuerra, Monica; Guerra, Maria Rosalia; Guerrero, Rosa; Guia, Dolores B.; Guidubaldi, Arianna; Hallam, Caroline; Hamer, Stephanie; Hammer, Kathrin; Handley, Olivia J.; Harding, Alison; Hasholt, Lis; Hedge, Reikha; Heiberg, Arvid; Heinicke, Walburgis; Held, Christine; Hernanz, Laura Casas; Herranhof, Briggitte; Herrera, Carmen Durán; Hidding, Ute; Hiivola, Heli; Hill, Susan; Hjermind, Lena. E.; Hobson, Emma; Hoffmann, Rainer; Holl, Anna Hödl; Howard, Liz; Hunt, Sarah; Huson, Susan; Ialongo, Tamara; Idiago, Jesus Miguel R.; Illmann, Torsten; Jachinska, Katarzyna; Jacopini, Gioia; Jakobsen, Oda; Jamieson, Stuart; Jamrozik, Zygmunt; Janik, Piotr; Johns, Nicola; Jones, Lesley; Jones, Una; Jurgens, Caroline K.; Kaelin, Alain; Kalbarczyk, Anna; Kershaw, Ann; Khalil, Hanan; Kieni, Janina; Klimberg, Aneta; Koivisto, Susana P.; Koppers, Kerstin; Kosinski, Christoph Michael; Krawczyk, Malgorzata; Kremer, Berry; Krysa, Wioletta; Kwiecinski, Hubert; Lahiri, Nayana; Lambeck, Johann; Lange, Herwig; Laver, Fiona; Leenders, K.L.; Levey, Jamie; Leythaeuser, Gabriele; Lezius, Franziska; Llesoy, Joan Roig; Löhle, Matthias; López, Cristobal Diez-Aja; Lorenza, Fortuna; Loria, Giovanna; Magnet, Markus; Mandich, Paola; Marchese, Roberta; Marcinkowski, Jerzy; Mariotti, Caterina; Mariscal, Natividad; Markova, Ivana; Marquard, Ralf; Martikainen, Kirsti; Martínez, Isabel Haro; Martínez-Descals, Asuncion; Martino, T.; Mason, Sarah; McKenzie, Sue; Mechi, Claudia; Mendes, Tiago; Mestre, Tiago; Middleton, Julia; Milkereit, Eva; Miller, Joanne; Miller, Julie; Minster, Sara; Möller, Jens Carsten; Monza, Daniela; Morales, Blas; Moreau, Laura V.; Moreno, Jose L. López-Sendón; Münchau, Alexander; Murch, Ann; Nielsen, Jørgen E.; Niess, Anke; Nørremølle, Anne; Novak, Marianne; O'Donovan, Kristy; Orth, Michael; Otti, Daniela; Owen, Michael; Padieu, Helene; Paganini, Marco; Painold, Annamaria; Päivärinta, Markku; Partington-Jones, Lucy; Paterski, Laurent; Paterson, Nicole; Patino, Dawn; Patton, Michael; Peinemann, Alexander; Peppa, Nadia; Perea, Maria Fuensanta Noguera; Peterson, Maria; Piacentini, Silvia; Piano, Carla; Càrdenas, Regina Pons i; Prehn, Christian; Price, Kathleen; Probst, Daniela; Quarrell, Oliver; Quiroga, Purificacion Pin; Raab, Tina; Rakowicz, Maryla; Raman, Ashok; Raymond, Lucy; Reilmann, Ralf; Reinante, Gema; Reisinger, Karin; Retterstol, Lars; Ribaï, Pascale; Riballo, Antonio V.; Ribas, Guillermo G.; Richter, Sven; Rickards, Hugh; Rinaldi, Carlo; Rissling, Ida; Ritchie, Stuart; Rivera, Susana Vázquez; Robert, Misericordia Floriach; Roca, Elvira; Romano, Silvia; Romoli, Anna Maria; Roos, Raymond A.C.; Røren, Niini; Rose, Sarah; Rosser, Elisabeth; Rosser, Anne; Rossi, Fabiana; Rothery, Jean; Rudzinska, Monika; Ruíz, Pedro J. García; Ruíz, Belan Garzon; Russo, Cinzia Valeria; Ryglewicz, Danuta; Saft, Carston; Salvatore, Elena; Sánchez, Vicenta; Sando, Sigrid Botne; Šašinková, Pavla; Sass, Christian; Scheibl, Monika; Schiefer, Johannes; Schlangen, Christiane; Schmidt, Simone; Schöggl, Helmut; Schrenk, Caroline; Schüpbach, Michael; Schuierer, Michele; Sebastián, Ana Rojo; Selimbegovic-Turkovic, Amina; Sempolowicz, Justyna; Silva, Mark; Sitek, Emilia; Slawek, Jaroslaw; Snowden, Julie; Soleti, Francesco; Soliveri, Paola; Sollom, Andrea; Soltan, Witold; Sorbi, Sandro; Sorensen, Sven Asger; Spadaro, Maria; Städtler, Michael; Stamm, Christiane; Steiner, Tanja; Stokholm, Jette; Stokke, Bodil; Stopford, Cheryl; Storch, Alexander; Straßburger, Katrin; Stubbe, Lars; Sulek, Anna; Szczudlik, Andrzej; Tabrizi, Sarah; Taylor, Rachel; Terol, Santiago Duran-Sindreu; Thomas, Gareth; Thompson, Jennifer; Thomson, Aileen; Tidswell, Katherine; Torres, Maria M. Antequera; Toscano, Jean; Townhill, Jenny; Trautmann, Sonja; Tucci, Tecla; Tuuha, Katri; Uhrova, Tereza; Valadas, Anabela; van Hout, Monique S.E.; van Oostrom, J.C.H.; van Vugt, Jeroen P.P.; vanm, Walsem Marleen R.; Vandenberghe, Wim; Verellen-Dumoulin, Christine; Vergara, Mar Ruiz; Verstappen, C.C.P.; Verstraelen, Nichola; Viladrich, Celia Mareca; Villanueva, Clara; Wahlström, Jan; Warner, Thomas; Wehus, Raghild; Weindl, Adolf; Werner, Cornelius J.; Westmoreland, Leann; Weydt, Patrick; Wiedemann, Alexandra; Wild, Edward; Wild, Sue; Witjes-Ané, Marie-Noelle; Witkowski, Grzegorz; Wójcik, Magdalena; Wolz, Martin; Wolz, Annett; Wright, Jan; Yardumian, Pam; Yates, Shona; Yudina, Elizaveta; Zaremba, Jacek; Zaugg, Sabine W.; Zdzienicka, Elzbieta; Zielonka, Daniel; Zielonka, Euginiusz; Zinzi, Paola; Zittel, Simone; Zucker, Birgrit; Adams, John; Agarwal, Pinky; Antonijevic, Irina; Beck, Christopher; Chiu, Edmond; Churchyard, Andrew; Colcher, Amy; Corey-Bloom, Jody; Dorsey, Ray; Drazinic, Carolyn; Dubinsky, Richard; Duff, Kevin; Factor, Stewart; Foroud, Tatiana; Furtado, Sarah; Giuliano, Joe; Greenamyre, Timothy; Higgins, Don; Jankovic, Joseph; Jennings, Dana; Kang, Un Jung; Kostyk, Sandra; Kumar, Rajeev; Leavitt, Blair; LeDoux, Mark; Mallonee, William; Marshall, Frederick; Mohlo, Eric; Morgan, John; Oakes, David; Panegyres, Peter; Panisset, Michel; Perlman, Susan; Perlmutter, Joel; Quaid, Kimberly; Raymond, Lynn; Revilla, Fredy; Robertson, Suzanne; Robottom, Bradley; Sanchez-Ramos, Juan; Scott, Burton; Shannon, Kathleen; Shoulson, Ira; Singer, Carlos; Tabbal, Samer; Testa, Claudia; van, Kammen Dan; Vetter, Louise; Walker, Francis; Warner, John; Weiner, illiam; Wheelock, Vicki; Yastrubetskaya, Olga; Barton, Stacey; Broyles, Janice; Clouse, Ronda; Coleman, Allison; Davis, Robert; Decolongon, Joji; DeLaRosa, Jeanene; Deuel, Lisa; Dietrich, Susan; Dubinsky, Hilary; Eaton, Ken; Erickson, Diane; Fitzpatrick, Mary Jane; Frucht, Steven; Gartner, Maureen; Goldstein, Jody; Griffith, Jane; Hickey, Charlyne; Hunt, Victoria; Jaglin, Jeana; Klimek, Mary Lou; Lindsay, Pat; Louis, Elan; Loy, Clemet; Lucarelli, Nancy; Malarick, Keith; Martin, Amanda; McInnis, Robert; Moskowitz, Carol; Muratori, Lisa; Nucifora, Frederick; O'Neill, Christine; Palao, Alicia; Peavy, Guerry; Quesada, Monica; Schmidt, Amy; Segro, Vicki; Sperin, Elaine; Suter, Greg; Tanev, Kalo; Tempkin, Teresa; Thiede, Curtis; Wasserman, Paula; Welsh, Claire; Wesson, Melissa; Zauber, Elizabeth

2012-01-01

Objective: Age at onset of diagnostic motor manifestations in Huntington disease (HD) is strongly correlated with an expanded CAG trinucleotide repeat. The length of the normal CAG repeat allele has been reported also to influence age at onset, in interaction with the expanded allele. Due to profound implications for disease mechanism and modification, we tested whether the normal allele, interaction between the expanded and normal alleles, or presence of a second expanded allele affects age at onset of HD motor signs. Methods: We modeled natural log-transformed age at onset as a function of CAG repeat lengths of expanded and normal alleles and their interaction by linear regression. Results: An apparently significant effect of interaction on age at motor onset among 4,068 subjects was dependent on a single outlier data point. A rigorous statistical analysis with a well-behaved dataset that conformed to the fundamental assumptions of linear regression (e.g., constant variance and normally distributed error) revealed significance only for the expanded CAG repeat, with no effect of the normal CAG repeat. Ten subjects with 2 expanded alleles showed an age at motor onset consistent with the length of the larger expanded allele. Conclusions: Normal allele CAG length, interaction between expanded and normal alleles, and presence of a second expanded allele do not influence age at onset of motor manifestations, indicating that the rate of HD pathogenesis leading to motor diagnosis is determined by a completely dominant action of the longest expanded allele and as yet unidentified genetic or environmental factors. Neurology® 2012;78:690–695 PMID:22323755

Contribution of different bone marrow-derived cell types in endometrial regeneration using an irradiated murine model.

PubMed

Gil-Sanchis, Claudia; Cervelló, Irene; Khurana, Satish; Faus, Amparo; Verfaillie, Catherine; Simón, Carlos

2015-06-01

To study the involvement of seven types of bone marrow-derived cells (BMDCs) in the endometrial regeneration in mice after total body irradiation. Prospective experimental animal study. University research laboratories. β-Actin-green fluorescent protein (GFP) transgenic C57BL/6-Tg (CAG-EGFP) and C57BL/6J female mice. The BMDCs were isolated from CAG-EGFP mice: unfractionated bone marrow cells, hematopoietic progenitor cells, endothelial progenitor cells (EPCs), and mesenchymal stem cells (MSCs). In addition three murine GFP(+) cell lines were used: mouse Oct4 negative BMDC multipotent adult progenitor cells (mOct4(-)BM-MAPCs), BMDC hypoblast-like stem cells (mOct4(+) BM-HypoSCs), and MSCs. All cell types were injected through the tail vein of 9 Gy-irradiated C57BL/6J female mice. Flow cytometry, cell culture, bone marrow transplantation assays, histologic evaluation, immunohistochemistry, proliferation, apoptosis, and statistical analysis. After 12 weeks, histologic analysis revealed that uteri of mice with mOct4(-)BM-MAPCs and MSC line were significantly smaller than uteri of mice with uncultured BMDCs or mOct4(+) BM-HypoSCs. The percentage of engrafted GFP(+) cells ranged from 0.13%-4.78%. Expression of Ki-67 was lower in all uteri from BMDCs treated mice than in the control, whereas TUNEL(+) cells were increased in the EPCs and mOct4(+)BM-HypoSCs groups. Low number of some BMDCs can be found in regenerating endometrium, including stromal, endotelial, and epithelial compartments. Freshly isolated MSCs and EPCs together with mOct4(+) BM-HypoSCs induced the greatest degree of regeneration, whereas culture isolated MSCs and mOct4(-)BM-MAPCs transplantation may have an inhibitory effect on endometrial regeneration. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Integrated intravascular ultrasound and optical coherence tomography technology: a promising tool to identify vulnerable plaques [INVITED PAPER

PubMed Central

Li, Jiawen; Chen, Zhongping

2017-01-01

Heart attack is mainly caused by the rupture of a vulnerable plaque. IVUS-OCT is a novel medical imaging modality that provides opportunities for accurate assessment of vulnerable plaques in vivo in patients. IVUS provides deep penetration to image the whole necrotic core while OCT enables accurate measurement of the fibrous cap of a plaque owing to its high resolution. In this paper, the authors describe the fundamentals, the technical designs and the applications of IVUS-OCT technology. Results from cadaver specimens are summarized, which indicated the complementary nature of OCT and IVUS for assessment of vulnerable plaques, plaque composition, and stent-tissue interactions. Furthermore, previously reported in vivo animal experiments are reviewed to assess the clinical adaptability of IVUS-OCT. Future directions for this technology are also discussed in this review. PMID:28966987

CRISP-3, a protein with homology to plant defense proteins, is expressed in mouse B cells under the control of Oct2.

PubMed

Pfisterer, P; König, H; Hess, J; Lipowsky, G; Haendler, B; Schleuning, W D; Wirth, T

1996-11-01

The Oct2 transcription factor is expressed throughout the B-lymphoid lineage and plays an essential role during the terminal phase of B-cell differentiation. Several genes specifically expressed in B lymphocytes have been identified that contain a functional octamer motif in their regulatory elements. However, expression of only a single gene, the murine CD36 gene, has been shown to date to be dependent on Oct2. Here, we present the identification and characterization of a further gene, coding for cysteine-rich secreted protein 3 (CRISP-3), whose expression in B cells is regulated by Oct2. We show that CRISP-3 is expressed in the B-lymphoid lineage specifically at the pre-B-cell stage. By using different experimental strategies, including nuclear run-on experiments, we demonstrate that this gene is transcriptionally activated by Oct2. Furthermore, analysis of CRISP-3 expression in primary B cells derived from either wild-type or Oct2-deficient mice demonstrates the dependence on Oct2. Two variant octamer motifs were identified in the upstream promoter region of the crisp-3 gene, and Oct2 interacts with both of them in vitro. Cotransfection experiments with expression vectors for Oct1 and Oct2 together with a reporter driven by the crisp-3 promoter showed that transcriptional activation of this promoter can only be achieved with Oct2. The C-terminal transactivation domain of Oct2 is required for this activation. Finally, introducing specific mutations in the two variant octamer motifs revealed that both of them are important for full transcriptional activation by Oct2.

The ecosystem that powered the translation of OCT from fundamental research to clinical and commercial impact [Invited

PubMed Central

Swanson, Eric A.; Fujimoto, James G.

2017-01-01

25 years is a relatively short period of time for a medical technology to become a standard of care impacting the treatment of millions of people every year. Yet 25 years ago there were no OCT companies, no OCT products, no OCT markets, and only one journal article published using the term OCT (optical coherence tomography). OCT has had a tremendous scientific, clinical, and economic impact on society. Today, it is estimated that there are ~30 Million OCT imaging procedures performed worldwide every year and the OCT system market is approaching $1B per year. OCT has helped diagnose patients with retinal disease at early treatable stages, preventing or greatly reducing irreversible vision loss. The technology has facilitated pharmaceutical development and contributed to fundamental understanding of disease mechanisms in multiple fields. The invention and translation of OCT from fundamental research to daily clinical practice would not have been possible without a complex ecosystem involving interaction among physics, engineering, and clinical medicine; government funding of fundamental and clinical research; collaborative and competitive research in the academic sector; entrepreneurship and industry; addressing real clinical needs; harnessing the innovation that occurs at the boundaries of disciplines; and economic and societal impact. This invited review paper discusses the translation of OCT from fundamental research to clinical practice and commercial impact, as well as describes the ecosystem that helped power OCT to where it is today and will continue to drive future advances. While OCT is an example of a technology that has had a powerful impact, there are many biomedical technologies which are poised for translation to clinical practice, and it is our hope that highlighting this ecosystem will help accelerate their translation and clinical impact. PMID:28663854

The ecosystem that powered the translation of OCT from fundamental research to clinical and commercial impact [Invited].

PubMed

Swanson, Eric A; Fujimoto, James G

2017-03-01

25 years is a relatively short period of time for a medical technology to become a standard of care impacting the treatment of millions of people every year. Yet 25 years ago there were no OCT companies, no OCT products, no OCT markets, and only one journal article published using the term OCT (optical coherence tomography). OCT has had a tremendous scientific, clinical, and economic impact on society. Today, it is estimated that there are ~30 Million OCT imaging procedures performed worldwide every year and the OCT system market is approaching $1B per year. OCT has helped diagnose patients with retinal disease at early treatable stages, preventing or greatly reducing irreversible vision loss. The technology has facilitated pharmaceutical development and contributed to fundamental understanding of disease mechanisms in multiple fields. The invention and translation of OCT from fundamental research to daily clinical practice would not have been possible without a complex ecosystem involving interaction among physics, engineering, and clinical medicine; government funding of fundamental and clinical research; collaborative and competitive research in the academic sector; entrepreneurship and industry; addressing real clinical needs; harnessing the innovation that occurs at the boundaries of disciplines; and economic and societal impact. This invited review paper discusses the translation of OCT from fundamental research to clinical practice and commercial impact, as well as describes the ecosystem that helped power OCT to where it is today and will continue to drive future advances. While OCT is an example of a technology that has had a powerful impact, there are many biomedical technologies which are poised for translation to clinical practice, and it is our hope that highlighting this ecosystem will help accelerate their translation and clinical impact.

Direct activation of human and mouse Oct4 genes using engineered TALE and Cas9 transcription factors

PubMed Central

Hu, Jiabiao; Lei, Yong; Wong, Wing-Ki; Liu, Senquan; Lee, Kai-Chuen; He, Xiangjun; You, Wenxing; Zhou, Rui; Guo, Jun-Tao; Chen, Xiongfong; Peng, Xianlu; Sun, Hao; Huang, He; Zhao, Hui; Feng, Bo

2014-01-01

The newly developed transcription activator-like effector protein (TALE) and clustered regularly interspaced short palindromic repeats/Cas9 transcription factors (TF) offered a powerful and precise approach for modulating gene expression. In this article, we systematically investigated the potential of these new tools in activating the stringently silenced pluripotency gene Oct4 (Pou5f1) in mouse and human somatic cells. First, with a number of TALEs and sgRNAs targeting various regions in the mouse and human Oct4 promoters, we found that the most efficient TALE-VP64s bound around −120 to −80 bp, while highly effective sgRNAs targeted from −147 to −89-bp upstream of the transcription start sites to induce high activity of luciferase reporters. In addition, we observed significant transcriptional synergy when multiple TFs were applied simultaneously. Although individual TFs exhibited marginal activity to up-regulate endogenous gene expression, optimized combinations of TALE-VP64s could enhance endogenous Oct4 transcription up to 30-fold in mouse NIH3T3 cells and 20-fold in human HEK293T cells. More importantly, the enhancement of OCT4 transcription ultimately generated OCT4 proteins. Furthermore, examination of different epigenetic modifiers showed that histone acetyltransferase p300 could enhance both TALE-VP64 and sgRNA/dCas9-VP64 induced transcription of endogenous OCT4. Taken together, our study suggested that engineered TALE-TF and dCas9-TF are useful tools for modulating gene expression in mammalian cells. PMID:24500196

Direct activation of human and mouse Oct4 genes using engineered TALE and Cas9 transcription factors.

PubMed

Hu, Jiabiao; Lei, Yong; Wong, Wing-Ki; Liu, Senquan; Lee, Kai-Chuen; He, Xiangjun; You, Wenxing; Zhou, Rui; Guo, Jun-Tao; Chen, Xiongfong; Peng, Xianlu; Sun, Hao; Huang, He; Zhao, Hui; Feng, Bo

2014-04-01

The newly developed transcription activator-like effector protein (TALE) and clustered regularly interspaced short palindromic repeats/Cas9 transcription factors (TF) offered a powerful and precise approach for modulating gene expression. In this article, we systematically investigated the potential of these new tools in activating the stringently silenced pluripotency gene Oct4 (Pou5f1) in mouse and human somatic cells. First, with a number of TALEs and sgRNAs targeting various regions in the mouse and human Oct4 promoters, we found that the most efficient TALE-VP64s bound around -120 to -80 bp, while highly effective sgRNAs targeted from -147 to -89-bp upstream of the transcription start sites to induce high activity of luciferase reporters. In addition, we observed significant transcriptional synergy when multiple TFs were applied simultaneously. Although individual TFs exhibited marginal activity to up-regulate endogenous gene expression, optimized combinations of TALE-VP64s could enhance endogenous Oct4 transcription up to 30-fold in mouse NIH3T3 cells and 20-fold in human HEK293T cells. More importantly, the enhancement of OCT4 transcription ultimately generated OCT4 proteins. Furthermore, examination of different epigenetic modifiers showed that histone acetyltransferase p300 could enhance both TALE-VP64 and sgRNA/dCas9-VP64 induced transcription of endogenous OCT4. Taken together, our study suggested that engineered TALE-TF and dCas9-TF are useful tools for modulating gene expression in mammalian cells.

Vehicle-Snow Interaction: Modeling, Testing and Validation

DTIC Science & Technology

2009-10-12

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions...information if it does not display a currently valid OMB control number. 1 . REPORT DATE 12 OCT 2009 2. REPORT TYPE N/A 3. DATES COVERED - 4...surface – Snow temperature ~-6 C – Stored in a freezer ~-25 C • Microtribometer – – Temperature ~-10C – Pin sizes ( 1 /8”, 1 /4”, 3/8”, 1 /2”) – Force or

Electrophysiological Measures of Regional Neural Interactive Coupling (Linear and Nonlinear Dependence Relationships Among Multiple Channel Electroencephalographic (EEG) Recordings),

DTIC Science & Technology

1980-01-01

clinical intervention . SG1CUDING CCMENL’ In evaluating the EEGs of subjects it is important to not that . ~major differences in EEG waveshape across...studies in dyslexia . In A.L. Benton and D. Pearl (Fs.), Dyslexia : An Appraisal of Current Knowledge. New York: Oxford University Press, 1978. 4...Electroencephalo- graphy and Clinical Neurophysio !. Oct., 67, 23(4):306-19. 6) Duffy, F.H., Denckla, M.B., Bartels, P.H., and Sandini, G. Dyslexia

OCT2 and MATE1 Provide Bi-directional Agmatine Transport

PubMed Central

Winter, Tate N.; Elmquist, William F.; Fairbanks, Carolyn A.

2015-01-01

Agmatine is a biogenic amine (l-arginine metabolite) of potential relevance to several central nervous system (CNS) conditions. The identities of transporters underlying agmatine and polyamine disposition in mammalian systems are not well defined. The SLC-family organic cation transporters (OCT) OCT1 and OCT2 and multidrug and toxin extrusion transporter-1 (MATE1) are transport systems that may be of importance for the cellular disposition of agmatine and putrescine. We investigated the transport of [3H]-agmatine and [3H]-putrescine in human embryonic kidney (HEK293) cells stably-transfected with hOCT1-, hOCT2-, and hMATE1. Agmatine transport by hOCT1 and hOCT2 was concentration-dependent, whereas only hOCT2 demonstrated pH-dependent transport. hOCT2 exhibited a greater affinity for agmatine (Km = 1.84 ± 0.38 mM) than did hOCT1 (Km = 18.73 ± 4.86 mM). Putrescine accumulation was pH- and concentration-dependent in hOCT2-HEK cells (Km = 11.29 ± 4.26 mM) but not hOCT1-HEK cells. Agmatine accumulation, in contrast to putrescine, was significantly enhanced by hMATE1 over-expression, and was saturable (Km = 240 ± 31 μM; Vmax = 192 ± 10 pmol/min/mg protein). Intracellular agmatine was also trans-stimulated (effluxed) from hMATE1-HEK cells in the presence of an inward proton-gradient. The hMATE1-mediated transport of agmatine was inhibited by polyamines, the prototypical substrates MPP+ and paraquat, as well as guanidine and arcaine, but not l-arginine. These results suggest that agmatine disposition may be influenced by hOCT2 and hMATE1, two transporters critical in the renal elimination of xenobiotic compounds. PMID:21128598

Hydrogen Supplementation of Preservation Solution Improves Viability of Osteochondral Grafts

PubMed Central

Yamada, Takuya; Onuma, Kenji; Kuzuno, Jun; Ujihira, Masanobu; Kurokawa, Ryosuke; Sakai, Rina; Takaso, Masashi

2014-01-01

Allogenic osteochondral tissue (OCT) is used for the treatment of large cartilage defects. Typically, OCTs collected during the disease-screening period are preserved at 4°C; however, the gradual reduction in cell viability during cold preservation adversely affects transplantation outcomes. Therefore, improved storage methods that maintain the cell viability of OCTs are needed to increase the availability of high-quality OCTs and improve treatment outcomes. Here, we evaluated whether long-term hydrogen delivery to preservation solution improved the viability of rat OCTs during cold preservation. Hydrogen-supplemented Dulbecco's Modified Eagles Medium (DMEM) and University of Wisconsin (UW) solution both significantly improved the cell viability of OCTs during preservation at 4°C for 21 days compared to nonsupplemented media. However, the long-term cold preservation of OCTs in DMEM containing hydrogen was associated with the most optimal maintenance of chondrocytes with respect to viability and morphology. Our findings demonstrate that OCTs preserved in DMEM supplemented with hydrogen are a promising material for the repair of large cartilage defects in the clinical setting. PMID:25506061

Inhibition of Focal Adhesion Kinase Signaling by Integrin α6β1 Supports Human Pluripotent Stem Cell Self-Renewal.

PubMed

Villa-Diaz, Luis G; Kim, Jin Koo; Laperle, Alex; Palecek, Sean P; Krebsbach, Paul H

2016-07-01

Self-renewal of human embryonic stem cells and human induced pluripotent stem cells (hiPSCs)-known as pluripotent stem cells (PSC)-is influenced by culture conditions, including the substrate on which they are grown. However, details of the molecular mechanisms interconnecting the substrate and self-renewal of these cells remain unclear. We describe a signaling pathway in hPSCs linking self-renewal and expression of pluripotency transcription factors to integrin α6β1 and inactivation of focal adhesion kinase (FAK). Disruption of this pathway results in hPSC differentiation. In hPSCs, α6β1 is the dominant integrin and FAK is not phosphorylated at Y397, and thus, it is inactive. During differentiation, integrin α6 levels diminish and Y397 FAK is phosphorylated and activated. During reprogramming of fibroblasts into iPSCs, integrin α6 is upregulated and FAK is inactivated. Knockdown of integrin α6 and activation of β1 integrin lead to FAK phosphorylation and reduction of Nanog, Oct4, and Sox2, suggesting that integrin α6 functions in inactivation of integrin β1 and FAK signaling and prevention of hPSC differentiation. The N-terminal domain of FAK, where Y397 is localized, is in the nuclei of hPSCs interacting with Oct4 and Sox2, and this immunolocalization is regulated by Oct4. hPSCs remodel the extracellular microenvironment and deposit laminin α5, the primary ligand of integrin α6β1. Knockdown of laminin α5 resulted in reduction of integrin α6 expression, phosphorylation of FAK and decreased Oct4. In conclusion, hPSCs promote the expression of integrin α6β1, and nuclear localization and inactivation of FAK to supports stem cell self-renewal. Stem Cells 2016;34:1753-1764. © 2016 AlphaMed Press.

Real time display Fourier-domain OCT using multi-thread parallel computing with data vectorization

NASA Astrophysics Data System (ADS)

Eom, Tae Joong; Kim, Hoon Seop; Kim, Chul Min; Lee, Yeung Lak; Choi, Eun-Seo

2011-03-01

We demonstrate a real-time display of processed OCT images using multi-thread parallel computing with a quad-core CPU of a personal computer. The data of each A-line are treated as one vector to maximize the data translation rate between the cores of the CPU and RAM stored image data. A display rate of 29.9 frames/sec for processed OCT data (4096 FFT-size x 500 A-scans) is achieved in our system using a wavelength swept source with 52-kHz swept frequency. The data processing times of the OCT image and a Doppler OCT image with a 4-time average are 23.8 msec and 91.4 msec.

Ultrahigh-Resolution Optical Coherence Tomography in Glaucoma

PubMed Central

Wollstein, Gadi; Paunescu, Leila A.; Ko, Tony H.; Fujimoto, James G.; Kowalevicz, Andrew; Hartl, Ingmar; Beaton, Siobahn; Ishikawa, Hiroshi; Mattox, Cynthia; Singh, Omah; Duker, Jay; Drexler, Wolfgang; Schuman, Joel S.

2007-01-01

Objective Optical coherence tomography (OCT) has been shown to be a valuable tool in glaucoma assessment. We investigated a new ultrahigh-resolution OCT (UHR-OCT) imaging system in glaucoma patients and compared the findings with those obtained by conventional-resolution OCT. Design Retrospective comparative case series. Participants A normal subject and 4 glaucoma patients representing various stages of glaucomatous damage. Testing All participants were scanned with StratusOCT (axial resolution of ~10 μm) and UHR-OCT (axial resolution of ~3 μm) at the same visit. Main Outcome Measure Comparison of OCT findings detected with StratusOCT and UHR-OCT. Results Ultrahigh-resolution OCT provides a detailed cross-sectional view of the scanned retinal area that allows differentiation between retinal layers. These UHR images were markedly better than those obtained by the conventional-resolution OCT. Conclusions Ultrahigh-resolution OCT provides high-resolution images of the ocular posterior segment, which improves the ability to detect retinal abnormalities due to glaucoma. PMID:15691556

Melatonin decreases estrogen receptor binding to estrogen response elements sites on the OCT4 gene in human breast cancer stem cells

PubMed Central

Lopes, Juliana; Arnosti, David; Trosko, James E.; Tai, Mei-Hui; Zuccari, Debora

2016-01-01

Cancer stem cells (CSCs) pose a challenge in cancer treatment, as these cells can drive tumor growth and are resistant to chemotherapy. Melatonin exerts its oncostatic effects through the estrogen receptor (ER) pathway in cancer cells, however its action in CSCs is unclear. Here, we evaluated the effect of melatonin on the regulation of the transcription factor OCT4 (Octamer Binding 4) by estrogen receptor alpha (ERα) in breast cancer stem cells (BCSCs). The cells were grown as a cell suspension or as anchorage independent growth, for the mammospheres growth, representing the CSCs population and treated with 10 nM estrogen (E2) or 10 μM of the environmental estrogen Bisphenol A (BPA) and 1 mM of melatonin. At the end, the cell growth as well as OCT4 and ERα expression and the binding activity of ERα to the OCT4 was assessed. The increase in number and size of mammospheres induced by E2 or BPA was reduced by melatonin treatment. Furthermore, binding of the ERα to OCT4 was reduced, accompanied by a reduction of OCT4 and ERα expression. Thus, melatonin treatment is effective against proliferation of BCSCs in vitro and impacts the ER pathway, demonstrating its potential therapeutic use in breast cancer. PMID:27551335

Isolation of Oct4-Expressing Extraembryonic Endoderm Precursor Cell Lines

PubMed Central

Debeb, Bisrat G.; Galat, Vasiliy; Epple-Farmer, Jessica; Iannaccone, Steve; Woodward, Wendy A.; Bader, Michael; Iannaccone, Philip; Binas, Bert

2009-01-01

Background The extraembryonic endoderm (ExEn) defines the yolk sac, a set of membranes that provide essential support for mammalian embryos. Recent findings suggest that the committed ExEn precursor is present already in the embryonic Inner Cell Mass (ICM) as a group of cells that intermingles with the closely related epiblast precursor. All ICM cells contain Oct4, a key transcription factor that is first expressed at the morula stage. In vitro, the epiblast precursor is most closely represented by the well-characterized embryonic stem (ES) cell lines that maintain the expression of Oct4, but analogous ExEn precursor cell lines are not known and it is unclear if they would express Oct4. Methodology/Principal Findings Here we report the isolation and characterization of permanently proliferating Oct4-expressing rat cell lines (“XEN-P cell lines”), which closely resemble the ExEn precursor. We isolated the XEN-P cell lines from blastocysts and characterized them by plating and gene expression assays as well as by injection into embryos. Like ES cells, the XEN-P cells express Oct4 and SSEA1 at high levels and their growth is stimulated by leukemia inhibitory factor, but instead of the epiblast determinant Nanog, they express the ExEn determinants Gata6 and Gata4. Further, they lack markers characteristic of the more differentiated primitive/visceral and parietal ExEn stages, but exclusively differentiate into these stages in vitro and contribute to them in vivo. Conclusions/Significance Our findings (i) suggest strongly that the ExEn precursor is a self-renewable entity, (ii) indicate that active Oct4 gene expression (transcription plus translation) is part of its molecular identity, and (iii) provide an in vitro model of early ExEn differentiation. PMID:19784378

Icaritin enhances mESC self-renewal through upregulating core pluripotency transcription factors mediated by ERα

PubMed Central

Tsang, Wing Pui; Zhang, Fengjie; He, Qiling; Cai, Waijiao; Huang, Jianhua; Chan, Wai Yee; Shen, Ziyin; Wan, Chao

2017-01-01

Utilization of small molecules in modulation of stem cell self-renewal is a promising approach to expand stem cells for regenerative therapy. Here, we identify Icaritin, a phytoestrogen molecule enhances self-renewal of mouse embryonic stem cells (mESCs). Icaritin increases mESCs proliferation while maintains their self-renewal capacity in vitro and pluripotency in vivo. This coincides with upregulation of key pluripotency transcription factors OCT4, NANOG, KLF4 and SOX2. The enhancement of mESCs self-renewal is characterized by increased population in S-phase of cell cycle, elevation of Cylin E and Cyclin-dependent kinase 2 (CDK2) and downregulation of p21, p27 and p57. PCR array screening reveals that caudal-related homeobox 2 (Cdx2) and Rbl2/p130 are remarkably suppressed in mESCs treated with Icaritin. siRNA knockdown of Cdx2 or Rbl2/p130 upregulates the expression of Cyclin E, OCT4 and SOX2, and subsequently increases cell proliferation and colony forming efficiency of mESCs. We then demonstrate that Icaritin co-localizes with estrogen receptor alpha (ERα) and activates its nuclear translocation in mESCs. The promotive effect of Icaritin on cell cycle and pluripotency regulators are eliminated by siRNA knockdown of ERα in mESCs. The results suggest that Icaritin enhances mESCs self-renewal by regulating cell cycle machinery and core pluripotency transcription factors mediated by ERα. PMID:28091581

Icaritin enhances mESC self-renewal through upregulating core pluripotency transcription factors mediated by ERα.

PubMed

Tsang, Wing Pui; Zhang, Fengjie; He, Qiling; Cai, Waijiao; Huang, Jianhua; Chan, Wai Yee; Shen, Ziyin; Wan, Chao

2017-01-16

Utilization of small molecules in modulation of stem cell self-renewal is a promising approach to expand stem cells for regenerative therapy. Here, we identify Icaritin, a phytoestrogen molecule enhances self-renewal of mouse embryonic stem cells (mESCs). Icaritin increases mESCs proliferation while maintains their self-renewal capacity in vitro and pluripotency in vivo. This coincides with upregulation of key pluripotency transcription factors OCT4, NANOG, KLF4 and SOX2. The enhancement of mESCs self-renewal is characterized by increased population in S-phase of cell cycle, elevation of Cylin E and Cyclin-dependent kinase 2 (CDK2) and downregulation of p21, p27 and p57. PCR array screening reveals that caudal-related homeobox 2 (Cdx2) and Rbl2/p130 are remarkably suppressed in mESCs treated with Icaritin. siRNA knockdown of Cdx2 or Rbl2/p130 upregulates the expression of Cyclin E, OCT4 and SOX2, and subsequently increases cell proliferation and colony forming efficiency of mESCs. We then demonstrate that Icaritin co-localizes with estrogen receptor alpha (ERα) and activates its nuclear translocation in mESCs. The promotive effect of Icaritin on cell cycle and pluripotency regulators are eliminated by siRNA knockdown of ERα in mESCs. The results suggest that Icaritin enhances mESCs self-renewal by regulating cell cycle machinery and core pluripotency transcription factors mediated by ERα.

4-D OCT in Developmental Cardiology

NASA Astrophysics Data System (ADS)

Jenkins, Michael W.; Rollins, Andrew M.

Although strong evidence exists to suggest that altered cardiac function can lead to CHDs, few studies have investigated the influential role of cardiac function and biophysical forces on the development of the cardiovascular system due to a lack of proper in vivo imaging tools. 4-D imaging is needed to decipher the complex spatial and temporal patterns of biomechanical forces acting upon the heart. Numerous solutions over the past several years have demonstrated 4-D OCT imaging of the developing cardiovascular system. This chapter will focus on these solutions and explain their context in the evolution of 4-D OCT imaging. The first sections describe the relevant techniques (prospective gating, direct 4-D imaging, retrospective gating), while later sections focus on 4-D Doppler imaging and measurements of force implementing 4-D OCT Doppler. Finally, the techniques are summarized, and some possible future directions are discussed.

Lack of Influence of Substrate on Ligand Interaction with the Human Multidrug and Toxin Extruder, MATE1

PubMed Central

Martínez-Guerrero, Lucy J.; Morales, Mark; Ekins, Sean

2016-01-01

Multidrug and toxin extruder (MATE) 1 plays a central role in mediating renal secretion of organic cations, a structurally diverse collection of compounds that includes ∼40% of prescribed drugs. Because inhibition of transport activity of other multidrug transporters, including the organic cation transporter (OCT) 2, is influenced by the structure of the transported substrate, the present study screened over 400 drugs as inhibitors of the MATE1-mediated transport of four structurally distinct organic cation substrates: the commonly used drugs: 1) metformin and 2) cimetidine; and two prototypic cationic substrates, 3) 1-methyl-4-phenylpyridinium (MPP), and 4) the novel fluorescent probe, N,N,N-trimethyl-2-[methyl(7-nitrobenzo[c][1,2,5]oxadiazol-4-yl)amino]ethanaminium iodide. Transport was measured in Chinese hamster ovary cells that stably expressed the human ortholog of MATE1. Comparison of the resulting inhibition profiles revealed no systematic influence of substrate structure on inhibitory efficacy. Similarly, IC50 values for 26 structurally diverse compounds revealed no significant influence of substrate structure on the kinetic interaction of inhibitor with MATE1. The IC50 data were used to generate three-dimensional quantitative pharmacophores that identified hydrophobic regions, H-bond acceptor sites, and an ionizable (cationic) feature as key determinants for ligand binding to MATE1. In summary, in contrast to the behavior observed with some other multidrug transporters, including OCT2, the results suggest that substrate identity exerts comparatively little influence on ligand interaction with MATE1. PMID:27418674

76 FR 56971 - Standard Instrument Approach Procedures, and Takeoff Minimums and Obstacle Departure Procedures...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-15

... Blvd., Oklahoma City, OK 73169 or 4. The National Archives and Records Administration (NARA). For...-Oct-11 IL Springfield....... Abraham Lincoln 1/1058 8/19/11 ILS OR LOC Rwy 4, Capital. Amdt 25C 20-Oct... IL Springfield....... Abraham Lincoln 1/1060 8/19/11 RADAR-1, Amdt 9 Capital. 20-Oct-11 IL...

Handheld Optical Coherence Tomography Angiography and Ultra-Wide-Field Optical Coherence Tomography in Retinopathy of Prematurity.

PubMed

Campbell, J Peter; Nudleman, Eric; Yang, Jianlong; Tan, Ou; Chan, R V Paul; Chiang, Michael F; Huang, David; Liu, Gangjun

2017-09-01

Retinopathy of prematurity (ROP) is a leading cause of childhood blindness worldwide. Optical coherence tomography (OCT) has improved the care of adults with vitreoretinal disease, and OCT angiography (OCTA) is demonstrating promise as a technique to visualize the retinal vasculature with lower risk and cost than fluorescein angiography. However, to date, there are no commercially available devices able to obtain ultra-wide-field OCT or OCTA images in neonates. To obtain ultra-wide-field OCT and OCTA images in neonates with ROP using a prototype handheld OCT and OCTA device. This observational case series was conducted from March 1 to April 1, 2017, in an academic medical center among 4 neonates with ROP in the neonatal intensive care unit and in the operating room. Acquisition of wide-field OCT and OCTA images using a handheld prototype OCTA and ultra-wide-field OCT device. Images were obtained from 4 neonates (1 girl and 3 boys; mean age, 38 weeks' postmenstrual age [range, 34-43 weeks]) with various stages of ROP: 3 in the neonatal intensive care unit and 1 in the operating room. The system can obtain noncontact en face OCT images and horizontal line scans with an approximately 40° field of view and up to 100° (ultra-wide-field) using a contact lens-based approach in a single 2-second scan. In addition, 20° × 20° (approximately 4 × 4-mm) OCTA scans were obtained in patients with ROP in a single 2-second scan. Optical coherence tomography and OCTA are gaining popularity in pediatric retinal imaging. This study reports on OCTA and ultra-wide-field OCT images in 4 neonates with various stages of ROP that were obtained using a prototype handheld device. Additional studies will be needed to prove the clinical value of this technology.

Clinicopathologic implication of hepatic progenitor cell marker expression in hepatoblastoma.

PubMed

Yun, Woong Jae; Shin, Eun; Lee, Kyoungbun; Jung, Hae Yoen; Kim, Soo Hee; Park, Young-Nyun; Yu, Eunsil; Jang, Ja-June

2013-09-01

Hepatic progenitor cells (HPCs) are thought to play a role in hepatoblastoma, as hepatoblastomas are characterized by an immature histology and a wide variety of cell lineages. We aimed to investigate the extent of expression of HPCs marker and its clinical implication in hepatoblastoma. We collected 61 hepatoblastomas and 9 childhood hepatocellular carcinomas (HCCs) and performed immunohistochemistry for HPC markers, including cytokeratin 19 (CK19), octamer-binding transcription factor 3/4 (Oct-3/4), epithelial cell adhesion molecule (EpCAM), and delta-like 1 homolog (DLK1). Of the hepatoblastoma samples, 27/61 (44.3%), 21/61 (34.4%), 51/61 (83.6%) and 56/61 (91.8%) exhibited positivity for CK19, Oct-3/4, EpCAM and DLK-1, respectively. For HCCs, the rates of expression were 22.2% (CK19), 77.8% (EpCAM) and 77.8% (DLK-1). Oct-3/4 was not expressed in HCC cells. Hepatoblastomas with a poorly differentiated epithelial component had a higher incidence of CK19 and Oct-3/4 expression than those with a well differentiated epithelial component (p=0.005 and 0.037, respectively). Higher disease stage of hepatoblastoma was correlated with CK19 expression (p=0.043). Oct-3/4-positive hepatoblastomas were associated with short disease-free survival (p=0.035). Both hepatoblastomas and childhood HCCs, therefore, exhibit characteristics of HPCs, and the poor prognosis of patients with Oct-3/4-positive hepatoblastoma suggests that stem-like properties affect hepatoblastoma pathogenicity. Copyright © 2013 Elsevier GmbH. All rights reserved.

Adaptive optics-assisted optical coherence tomography for imaging of patients with age related macular degeneration

NASA Astrophysics Data System (ADS)

Sudo, Kenta; Cense, Barry

2013-03-01

We developed an optical coherence tomography (OCT) prototype with a sample arm that uses a 3.4 mm beam, which is considerably larger than the 1.2 to 1.5 mm beam that is used in commercialized OCT systems. The system is equipped with adaptive optics (AO), and to distinguish it from traditional AO-OCT systems with a larger 6 mm beam we have coined this concept AO-assisted OCT. Compared to commercialized OCT systems, the 3.4 mm aperture combined with AO improves light collection efficiency and imaging lateral resolution. In this paper, the performance of the AOa-OCT system was compared to a standard OCT system and demonstrated for imaging of age-related macular degeneration (AMD). Measurements were performed on the retinas of three human volunteers with healthy eyes and on one eye of a patient diagnosed with AMD. The AO-assisted OCT system imaged retinal structures of healthy human eyes and a patient eye affected by AMD with higher lateral resolution and a 9° by 9° field of view. This combination of a large isoplanatic patch and high lateral resolution can be expected to fill a gap between standard OCT with a 1.2 mm beam and conventional AO-OCT with a 6 mm beam and a 1.5° by 1.5° isoplanatic patch.

Nitrative DNA damage and Oct3/4 expression in urinary bladder cancer with Schistosomahaematobium infection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Ning; Thanan, Raynoo; Department of Environmental and Molecular Medicine, Mie University Graduate School of Medicine, Mie

Highlights: {yields} Oct3/4-positive cells increase in Schistosoma haematobium (SH)-associated bladder cancer. {yields} iNOS-dependent DNA lesion, 8-nitroguanine, was formed in Oct3/4-positive cells. {yields} 8-Nitroguanine formed in stem-like cells plays a role in SH-induced carcinogenesis. {yields} Mutant stem cells may participate in inflammation-related carcinogenesis. -- Abstract: To investigate whether mutant stem cells participate in inflammation-related carcinogenesis, we performed immunohistochemical analysis to examine nitrative and oxidative DNA lesions (8-nitroguanine and 8-oxodG) and a stem cell marker Oct3/4 in bladder tissues obtained from cystitis and bladder cancer patients infected with Schistosomahaematobium (S. haematobium). We also detected the expression of nuclear factor-{kappa}B (NF-{kappa}B) and induciblemore » nitric oxide synthase (iNOS), which lead to 8-nitroguanine formation. The staining intensity of 8-nitroguanine and 8-oxodG was significantly higher in bladder cancer and cystitis tissues than in normal tissues. iNOS expression was colocalized with NF-{kappa}B in 8-nitroguanine-positive tumor cells from bladder cancer patients. Oct3/4 expression was significantly increased in cells from S. haematobium-associated bladder cancer tissues in comparison to normal bladder and cancer tissues without infection. Oct3/4 was also expressed in epithelial cells of cystitis patients. Moreover, 8-nitroguanine was formed in Oct3/4-positive stem cells in S. haematobium-associated cystitis and cancer tissues. In conclusion, inflammation by S.haematobium infection may increase the number of mutant stem cells, in which iNOS-dependent DNA damage occurs via NF-{kappa}B activation, leading to tumor development.« less

Reprogramming cell fate with a genome-scale library of artificial transcription factors.

PubMed

Eguchi, Asuka; Wleklinski, Matthew J; Spurgat, Mackenzie C; Heiderscheit, Evan A; Kropornicka, Anna S; Vu, Catherine K; Bhimsaria, Devesh; Swanson, Scott A; Stewart, Ron; Ramanathan, Parameswaran; Kamp, Timothy J; Slukvin, Igor; Thomson, James A; Dutton, James R; Ansari, Aseem Z

2016-12-20

Artificial transcription factors (ATFs) are precision-tailored molecules designed to bind DNA and regulate transcription in a preprogrammed manner. Libraries of ATFs enable the high-throughput screening of gene networks that trigger cell fate decisions or phenotypic changes. We developed a genome-scale library of ATFs that display an engineered interaction domain (ID) to enable cooperative assembly and synergistic gene expression at targeted sites. We used this ATF library to screen for key regulators of the pluripotency network and discovered three combinations of ATFs capable of inducing pluripotency without exogenous expression of Oct4 (POU domain, class 5, TF 1). Cognate site identification, global transcriptional profiling, and identification of ATF binding sites reveal that the ATFs do not directly target Oct4; instead, they target distinct nodes that converge to stimulate the endogenous pluripotency network. This forward genetic approach enables cell type conversions without a priori knowledge of potential key regulators and reveals unanticipated gene network dynamics that drive cell fate choices.

Reprogramming cell fate with a genome-scale library of artificial transcription factors

PubMed Central

Eguchi, Asuka; Wleklinski, Matthew J.; Spurgat, Mackenzie C.; Heiderscheit, Evan A.; Kropornicka, Anna S.; Vu, Catherine K.; Bhimsaria, Devesh; Swanson, Scott A.; Stewart, Ron; Ramanathan, Parameswaran; Kamp, Timothy J.; Slukvin, Igor; Thomson, James A.; Dutton, James R.; Ansari, Aseem Z.

2016-01-01

Artificial transcription factors (ATFs) are precision-tailored molecules designed to bind DNA and regulate transcription in a preprogrammed manner. Libraries of ATFs enable the high-throughput screening of gene networks that trigger cell fate decisions or phenotypic changes. We developed a genome-scale library of ATFs that display an engineered interaction domain (ID) to enable cooperative assembly and synergistic gene expression at targeted sites. We used this ATF library to screen for key regulators of the pluripotency network and discovered three combinations of ATFs capable of inducing pluripotency without exogenous expression of Oct4 (POU domain, class 5, TF 1). Cognate site identification, global transcriptional profiling, and identification of ATF binding sites reveal that the ATFs do not directly target Oct4; instead, they target distinct nodes that converge to stimulate the endogenous pluripotency network. This forward genetic approach enables cell type conversions without a priori knowledge of potential key regulators and reveals unanticipated gene network dynamics that drive cell fate choices. PMID:27930301

Ocular Coherence Tomography in the Evaluation of Anterior Eye Injuries in Space Flight

NASA Technical Reports Server (NTRS)

Fer, Dan M.; Law, Jennifer; Wells, Julia

2017-01-01

While Ocular Coherence Tomography (OCT) is not a first-line modality to evaluate anterior eye structures terrestrially, it is a resource already available on the International Space Station (ISS) that can be used in medical contingencies that involve the anterior eye. With remote guidance and subject matter expert (SME) support from the ground, a minimally trained crewmember can now use OCT to evaluate anterior eye pathologies on orbit. OCT utilizes low-coherence interferometry to produce detailed cross-sectional and 3D images of the eye in real time. Terrestrially, it has been used to evaluate macular pathologies and glaucoma. Since 2013, OCT has been used onboard the ISS as one part of a suite of hardware to evaluate the Visual Impairment/Intracranial Pressure risk faced by astronauts, specifically assessing changes in the retina and choroid during space flight. The Anterior Segment Module (ASM), an add-on lens, was also flown for research studies, providing an opportunity to evaluate the anterior eye in real time if clinically indicated. Anterior eye pathologies that could be evaluated using OCT were identified. These included corneal abrasions and ulcers, scleritis, and acute angle closure glaucoma. A remote guider script was written to provide ground specialists with step-by-step instructions to guide ISS crewmembers, who do not get trained on the ASM, to evaluate the anterior eye. The instructions were tested on novice subjects and/or operators, whose feedback was incorporated iteratively. The final remote guider script was reviewed by SME optometrists and NASA flight surgeons. The novel application of OCT technology to space flight allows for the acquisition of objective data to diagnose anterior eye pathologies when other modalities are not available. This demonstrates the versatility of OCT and highlights the advantages of using existing hardware and remote guidance skills to expand clinical capabilities in space flight.

Comparison of choroidal thickness using swept-source and spectral-domain optical coherence tomography in normal Indian eyes.

PubMed

Narendran, Siddharth; Manayath, George; Venkatapathy, Narendran

2018-01-01

Choroidal thickness measurements are reported to differ between spectral-domain optical coherence tomography (SD-OCT) and swept-source OCT (SS-OCT). The aim of this study was to assess the comparability of choroidal thickness measurements using SS-OCT and SD-OCT devices among normal participants. This was a prospective study of 31 (62 eyes) normal participants. Choroidal imaging was performed sequentially with the Spectralis OCT (SD-OCT) and the deep range imaging OCT (DRI OCT-1) (SS-OCT) using standardized imaging protocols. The subfoveal choroidal thickness (SFChT) was measured manually by two masked retinal specialists. Paired t -tests and intraclass correlation coefficients (ICCs) were used to compare the measurements. The mean SFChT was 319.5 μm and 325.3 μm for DRI OCT-1 and Spectralis OCT, respectively ( P = 0.001), with a mean difference of 5.9 with ICC of 0.97. The mean difference in choroidal thickness between the OCT devices was larger among eyes with choroidal thickness > 350 μm compared with eyes with thinner choroids (8.0 μm vs. 4.7 μm). SFChT measurements are comparable between DRI OCT-1 and Spectralis OCT. The variability between the devices increases in thicker choroids.

FRET detection of Octamer-4 on a protein nanoarray made by size-dependent self-assembly

PubMed Central

Tran, Phat L.; Gamboa, Jessica R.; You, David J.

2010-01-01

An alternative approach for fabricating a protein array at nanoscale is suggested with a capability of characterization and/or localization of multiple components on a nanoarray. Fluorescent micro- and nanobeads each conjugated with different antibodies are assembled by size-dependent self-assembly (SDSA) onto nanometer wells that were created on a polymethyl methacrylate (PMMA) substrate by electron beam lithography (EBL). Antibody-conjugated beads of different diameters are added serially and electrostatically attached to corresponding wells through electrostatic attraction between the charged beads (confirmed by zeta potential analysis) and exposed p-doped silicon substrate underneath the PMMA layer. This SDSA method is enhanced by vibrated-wire-guide manipulation of droplets on the PMMA surface containing nanometer wells. Saturation rates of antibody-conjugated beads to the nanometer patterns are up to 97% under one component and 58–70% under two components nanoarrays. High-density arrays (up to 40,000 wells) could be fabricated, which can also be multi-component. Target detection utilizes fluorescence resonance energy transfer (FRET) from fluorescent beads to fluorescent-tagged secondary antibodies to Octamer-4 (Oct4), which eliminates the need for multiple steps of rinsing. The 100 nm green beads are covalently conjugated with anti-Oct4 to capture Oct4 peptides (39 kDa); where the secondary anti-Oct4 and F(ab)2 fragment of anti-gIgG tagged with phycoerythrin are then added to function as an indicator of Oct4 detection. FRET signals are detected through confocal microscopes, and further confirmed by Fluorolog3 spectrofluorometer. The success rates of detecting Oct4 are 32% and 14% of the beads in right place under one and two component nanoarrays, respectively. Ratiometric FRET is used to quantify the amount of Oct4 peptides per each bead, which is estimated about 2 molecules per bead. PMID:20652550

Experimental research of adaptive OFDM and OCT precoding with a high SE for VLLC system

NASA Astrophysics Data System (ADS)

Liu, Shuang-ao; He, Jing; Chen, Qinghui; Deng, Rui; Zhou, Zhihua; Chen, Shenghai; Chen, Lin

2017-09-01

In this paper, an adaptive orthogonal frequency division multiplexing (OFDM) modulation scheme with 128/64/32/16-quadrature amplitude modulation (QAM) and orthogonal circulant matrix transform (OCT) precoding is proposed and experimentally demonstrated for a visible laser light communication (VLLC) system with a cost-effective 450-nm blue-light laser diode (LD). The performance of OCT precoding is compared with conventional the adaptive Discrete Fourier Transform-spread (DFT-spread) OFDM scheme, 32 QAM OCT precoding OFDM scheme, 64 QAM OCT precoding OFDM scheme and adaptive OCT precoding OFDM scheme. The experimental results show that OCT precoding can achieve a relatively flat signal-to-noise ratio (SNR) curve, and it can provide performance improvement in bit error rate (BER). Furthermore, the BER of the proposed OFDM signal with a raw bit rate 5.04 Gb/s after 5-m free space transmission is less than 20% of soft-decision forward error correlation (SD-FEC) threshold of 2.4 × 10-2, and the spectral efficiency (SE) of 4.2 bit/s/Hz can be successfully achieved.

Optimization of reprogramming culture conditions for the generation of induced pluripotent stem cells from Col1a1 4F2A-Oct4-GFP mice with high efficiency.

PubMed

Lin, Po-Ying; Hsu, Sheng-Chieh; Chen, Hung-Chi; Len, Wen-Bin; Hsiao, Fang-Chi; Liu, Mei-Chun; Pan, Pei-Ling; Lin, Tsai-Chen; Lee, Ying-Hsuan; Meir, Yaa-Jyuhn James

2018-05-01

A reprogrammable transgenic mouse strain, called Col1a1 4F2A-Oct4-GFP, was bred for the present study. Because the somatic cells of this mouse strain contain only two copies of each Yamanaka factor, these animals are inefficient at producing induced pluripotent stem cells (iPSCs; approx. 0.005%) under traditional culture conditions. With an optimized culture condition, the iPSC production rate of mouse embryonic fibroblasts (MEFs) of Col1a1 4F2A-Oct4-GFP mice (MEF C ol1a1 4F2A-Oct4- GFP ) was increased to approximately 8%. Further, promotion of cell proliferation by serum supplementation did not enhance iPSC production. Inhibition of transforming growth factor β (TGF-β) in the serum by SB431542 neither affected the growth rate of MEF C ol1a1 4F2A-Oct4- GFP nor promoted iPSC production. However, the use of the gamma-irradiated STO-NEO-LIF (γSNL) cells to serve as feeders for iPSC production resulted in a 5-fold higher rate of iPSC production than the use of γMEF ICR feeders. Interestingly, the use of SB431542 with the γMEF ICR -adopted system could eliminate this difference. RT-PCR-based comparative analysis further demonstrated that TGF-β expression was 10-fold higher in γMEF ICR than in γSNL cells. Consistent with previous reports, mesenchymal to epithelial transition was found to participate in the initial steps of reprogramming in the specific context of MEF C ol1a1 4F2A-Oct4- GFP . Moreover, we found that the initial seeding density is one of the pivotal factors for determining a high efficiency of iPSC generation. The iPSCs efficiently generated from our MEF C ol1a1 4F2A-Oct4- GFP resembled mouse embryonic stem cells (mESCs) in aspects of teratoma formation and germline transmission. Depending on the culture conditions, our Col1a1 4F2A-Oct4-GFP mouse system can generate bona fide iPSCs with variable efficiencies, which can serve as a tool for interrogating the route taken by cells during somatic reprogramming. © 2018 Federation of European Biochemical Societies.

The HPV16 E7 oncoprotein increases the expression of Oct3/4 and stemness-related genes and augments cell self-renewal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Organista-Nava, Jorge; Gómez-Gómez, Yazmín

Oct3/4 is a transcription factor involved in maintenance of the pluripotency and self-renewal of stem cells. The E7 oncoprotein and 17β-estradiol (E{sub 2}) are key factors in cervical carcinogenesis. In the present study, we aimed to investigate the effect of the HPV16 E7 oncoprotein and E{sub 2} on the expression pattern of Oct3/4, Sox2, Nanog and Fgf4. We also determined whether the E7 oncoprotein is associated with cell self-renewal. The results showed that Oct3/4, Sox2, Nanog and Fgf4 were upregulated by the E7 oncoprotein in vivo and in vitro and implicate E{sub 2} in the upregulation of these factors inmore » vivo. We also demonstrated that E7 is involved in cell self-renewal, suggesting that the HPV16 E7 oncoprotein upregulates Oct3/4, Sox2, Nanog and Fgf4 expression to maintain the self-renewal capacity of cancer stem cells. -- Graphical abstract: The HPV16 E7 oncoprotein and 17β-estradiol are involved in the upregulation of Oct3/4, Sox2, Nanog and Fgf4 expression to maintain the self-renewal ability of cancer stem cells in cervical cancer. - Highlights: •The HPV16 E7 oncoprotein enhances cellular proliferation and dedifferentiation. •The E7 oncoprotein induces stemness-related genes expression in vivo and in vitro. •The 17β-estradiol induces stemness-related genes expression in vivo. •The HPV16 E7 oncoprotein is involved in the cell self-renewal of cancer cells.« less

Mass spectrometry for identification of proteins that specifically bind to a distal enhancer of the Oct4 gene

NASA Astrophysics Data System (ADS)

Bakhmet, E. I.; Nazarov, I. B.; Artamonova, T. O.; Khodorkovsky, M. A.; Tomilin, A. N.

2017-11-01

Transcription factor Oct4 is a marker of pluripotent stem cells and has a significant role in their self-renewal. Oct4 gene is controlled by three cis-regulatory elements - proximal promoter, proximal enhancer and distal enhancer. All of these elements are targets for binding of regulatory proteins. Distal enhancer is in our research focus because of its activity in early stages of embryonic development. There are two main sequences called site 2A and site 2B that are presented in distal enhancer. For this moment proteins which bind to a site 2A (CCCCTCCCCCC) remain unknown. Using combination of in vitro method electrophoretic mobility shift assay (EMSA) and mass spectromery we identified several candidates that can regulate Oct4 gene expression through site 2A.

Construction of a Dual-Fluorescence Reporter System to Monitor the Dynamic Progression of Pluripotent Cell Differentiation.

PubMed

Sun, Wu-Sheng; Chun, Ju-Lan; Do, Jeong-Tae; Kim, Dong-Hwan; Ahn, Jin-Seop; Kim, Min-Kyu; Hwang, In-Sul; Kwon, Dae-Jin; Hwang, Seong-Soo; Lee, Jeong-Woong

2016-01-01

Oct4 is a crucial germ line-specific transcription factor expressed in different pluripotent cells and downregulated in the process of differentiation. There are two conserved enhancers, called the distal enhancer (DE) and proximal enhancer (PE), in the 5' upstream regulatory sequences (URSs) of the mouse Oct4 gene, which were demonstrated to control Oct4 expression independently in embryonic stem cells (ESCs) and epiblast stem cells (EpiSCs). We analyzed the URSs of the pig Oct4 and identified two similar enhancers that were highly consistent with the mouse DE and PE. A dual-fluorescence reporter was later constructed by combining a DE-free- Oct4 -promoter-driven EGFP reporter cassette with a PE-free- Oct4 -promoter-driven mCherry reporter cassette. Then, it was tested in a mouse ESC-like cell line (F9) and a mouse EpiSC-like cell line (P19) before it is formally used for pig. As a result, a higher red fluorescence was observed in F9 cells, while green fluorescence was primarily detected in P19 cells. This fluorescence expression pattern in the two cell lines was consistent with that in the early naïve pluripotent state and late primed pluripotent state during differentiation of mouse ESCs. Hence, this reporter system will be a convenient tool for screening out ESC-like naïve pluripotent stem cells from other metastable state cells in a heterogenous population.

Genetic variants of organic cation transporter 1 (OCT1) and OCT2 significantly reduce lamivudine uptake.

PubMed

Choi, Min-Koo; Song, Im-Sook

2012-04-01

The study sought to investigate the effect of genetic variants of OCT1 (OCT1-P283L and -P341L) and OCT2 (OCT2-T199I, -T201M and -A270S), which were identified in a Korean population, on the transport of lamivudine in vitro and to compare the substrate dependent effects of OCT1 and OCT2 variants with 1-methyl-4-phenylpyridinium (MPP+), tetraethyl ammonium (TEA), metformin and lamivudine as substrates for these transporters. When the transport kinetics of lamivudine uptake in oocytes overexpressing OCT1 and OCT2 wild-type (WT) and variant proteins were measured, lamivudine uptake mediated by OCT1-WT was saturable, and uptake was decreased in oocytes expressing OCT1-P283L and -P341L variants compared with that in OCT1-WT. The Clint of lamivudine in oocytes expressing OCT1-P283L was decreased by 85.1% compared with OCT1-WT, whereas it was decreased by 48.7% in oocytes expressing OCT1-P341L. The Clint of lamivudine in oocytes expressing OCT2-T199I, -T201M and -A270S was decreased by 86.2%, 88.9% and 73.6%, respectively, compared with OCT2-WT. When comparing various substrates such as MPP+, TEA, metformin and lamivudine, the effects of the OCT1 genetic polymorphisms on their uptake were not identical. However, contrary to the case of OCT1, the uptake of MPP+, TEA, metformin and lamivudine in oocytes expressing OCT2-T199I, -T201M and -A270S variants was decreased significantly compared with that in oocytes expressing OCT2-WT. In conclusion, the effect of genetic variations of OCT1 and OCT2 on the uptake of MPP+, TEA, metformin and lamivudine was substrate-dependent. Copyright © 2012 John Wiley & Sons, Ltd.

Legal Aspects of Offensive Information Operations in Space

DTIC Science & Technology

2005-01-01

decisional interaction with information systems.3 This same thought was expressed during the Second World War by Captain Sir Basil Liddel Hart: “[t]he...JOINT DOCTRINE FOR INFORMATION OPERATIONS, Oct. 9, 1998, at I-3 [hereinafter JOINT PUBLICATION 3-13]. 4. Captain Sir Basil Liddel Hart, Thoughts on...International Affairs) in the Office of the General Counsel, Department of Defense, presentation at Annual Review of the ABA Standing Committee on Law and

Specific knockdown of Oct4 and beta2-microglobulin expression by RNA interference in human embryonic stem cells and embryonic carcinoma cells.

PubMed

Matin, Maryam M; Walsh, James R; Gokhale, Paul J; Draper, Jonathan S; Bahrami, Ahmad R; Morton, Ian; Moore, Harry D; Andrews, Peter W

2004-01-01

We have used RNA interference (RNAi) to downregulate beta2-microglobulin and Oct4 in human embryonal carcinoma (hEC) cells and embryonic stem (hES) cells, demonstrating that RNAi is an effective tool for regulating specific gene activity in these human stem cells. The knockdown of Oct4 but not beta2-microglobulin expression in both EC and ES cells resulted in their differentiation, as indicated by a marked change in morphology, growth rate, and surface antigen phenotype, with respect to SSEA1, SSEA3, and TRA-1-60 expression. Expression of hCG and Gcm1 was also induced following knockdown of Oct4 expression, in both 2102Ep hEC cells and in H7 and H14 hES cells, consistent with the conclusion that, as in the mouse, Oct4 is required to maintain the undifferentiated stem cell state, and that differentiation to trophectoderm occurs in its absence. NTERA2 hEC cells also differentiated, but not to trophectoderm, suggesting their equivalence to a later stage of embryogenesis than other hEC and hES cells.

Translations on Narcotics and Dangerous Drugs, Number 272

DTIC Science & Technology

1976-11-18

Growing Marihuana (Sergio Von Nowaffen; EXCELSIOR, 30 Sep 76) 43 CONTENTS (Continued) Customs Officials Arrest Tourists With Firearms (EL DIARIO...4 Oct 76) 47 Two Arrested for Stockpiling Weapons, Drug Traffic (EL FRONTERIZO, 6 Oct 76) 50 Operations in " Marihuana Triangle" Highly...Successful (EL DIARIO DE NOGALES, 2 Oct 76) 52 Police Seize Large Shipment of Marihuana (EL DIARIO DE NOGALES, 5 Oct 76) 53 Heroin Charge

Increased Systemic Exposure and Stronger Cardiovascular and Metabolic Adverse Reactions to Fenoterol in Individuals with Heritable OCT1 Deficiency.

PubMed

Tzvetkov, Mladen V; Matthaei, Johannes; Pojar, Sherin; Faltraco, Frank; Vogler, Sabrina; Prukop, Thomas; Seitz, Tina; Brockmöller, Jürgen

2018-05-01

Fenoterol is a widely used anti-asthmatic and tocolytic agent, but high plasma concentrations of fenoterol may lead to severe and even fatal adverse reactions. We studied whether heritable deficiency of the liver organic cation transporter 1 (OCT1), a trait observed in 3% of Europeans and white Americans, affects fenoterol plasma concentrations and toxicity. OCT1 transported fenoterol with high affinity, and OCT1 inhibition in human hepatocytes reduced fenoterol uptake threefold. After administration of 180 µg of fenoterol to 39 healthy individuals, the OCT1-deficient individuals (zero active OCT1 alleles; n = 5) showed 1.9-fold greater systemic fenoterol exposure (P = 4.0 × 10 -5 ) and 1.7-fold lower volume of distribution (P = 8.0 × 10 -5 ). Correspondingly, the OCT1-deficient individuals had a 1.5-fold stronger increase in heart rate (P = 0.002), a 3.4-fold greater increase in blood glucose (P = 3.0 × 10 -5 ), and significantly lower serum potassium levels. In conclusion, heritable OCT1 deficiency significantly increases plasma concentrations of fenoterol and may be an important factor underlying the excess mortality associated with fenoterol. © 2017 American Society for Clinical Pharmacology and Therapeutics.

Identification of functional amino acid residues involved in polyamine and agmatine transport by human organic cation transporter 2.

PubMed

Higashi, Kyohei; Imamura, Masataka; Fudo, Satoshi; Uemura, Takeshi; Saiki, Ryotaro; Hoshino, Tyuji; Toida, Toshihiko; Kashiwagi, Keiko; Igarashi, Kazuei

2014-01-01

Polyamine (putrescine, spermidine and spermine) and agmatine uptake by the human organic cation transporter 2 (hOCT2) was studied using HEK293 cells transfected with pCMV6-XL4/hOCT2. The Km values for putrescine and spermidine were 7.50 and 6.76 mM, and the Vmax values were 4.71 and 2.34 nmol/min/mg protein, respectively. Spermine uptake by hOCT2 was not observed at pH 7.4, although it inhibited both putrescine and spermidine uptake. Agmatine was also taken up by hOCT2, with Km value: 3.27 mM and a Vmax value of 3.14 nmol/min/mg protein. Amino acid residues involved in putrescine, agmatine and spermidine uptake by hOCT2 were Asp427, Glu448, Glu456, Asp475, and Glu516. In addition, Glu524 and Glu530 were involved in putrescine and spermidine uptake activity, and Glu528 and Glu540 were weakly involved in putrescine uptake activity. Furthermore, Asp551 was also involved in the recognition of spermidine. These results indicate that the recognition sites for putrescine, agmatine and spermidine on hOCT2 strongly overlap, consistent with the observation that the three amines are transported with similar affinity and velocity. A model of spermidine binding to hOCT2 was constructed based on the functional amino acid residues.

In vivo monitoring of seeds and plant-tissue water absorption using optical coherence tomography and optical coherence microscopy

NASA Astrophysics Data System (ADS)

Sapozhnikova, Veronika V.; Kutis, Irina S.; Kutis, Sergey D.; Kuranov, Roman V.; Gelikonov, Grigory V.; Shabanov, Dmitry V.; Kamensky, Vladislav A.

2004-07-01

First experimental results on OCT imaging of internal structure of plant tissues and in situ OCT monitoring of plant tissue regeneration at different water supply are reported. Experiments for evaluating OCT capabilities were performed on Tradescantia. The investigation of seeds swelling was performed on wheat seeds (Triticum L.), barley seeds (Hordeum L.), long-fibred flax seeds (Linum usitatissimum L.) and cucumber seeds (Cucumis sativus L.). These OCT images correlate with standard microscopy data from the same tissue regions. Seeds were exposed to a low-intensity physical factor-the pulsed gradient magnetic field (GMF) with pulse duration 0.1 s and maximum amplitude 5 mT (4 successive pulses during 0.4 s). OCT and OCM enable effective monitoring of fast reactions in plants and seeds at different water supply.

Oct4 Methylation-Mediated Silencing As an Epigenetic Barrier Preventing Müller Glia Dedifferentiation in a Murine Model of Retinal Injury.

PubMed

Reyes-Aguirre, Luis I; Lamas, Monica

2016-01-01

Müller glia (MG) is the most abundant glial type in the vertebrate retina. Among its many functions, it is capable of responding to injury by dedifferentiating, proliferating, and differentiating into every cell types lost to damage. This regenerative ability is notoriously absent in mammals. We have previously reported that cultured mammalian MG undergoes a partial dedifferentiation, but fails to fully acquire a progenitor phenotype and differentiate into neurons. This might be explained by a mnemonic mechanism comprised by epigenetic traits, such as DNA methylation. To achieve a better understanding of this epigenetic memory, we studied the expression of pluripotency-associated genes, such as Oct4, Nanog , and Lin28 , which have been reported as necessary for regeneration in fish, at early times after NMDA-induced retinal injury in a mouse experimental model. We found that although Oct4 is expressed rapidly after damage (4 hpi), it is silenced at 24 hpi. This correlates with a significant decrease in the DNA methyltransferase Dnmt3b expression, which returns to basal levels at 24 hpi. By MS-PCR, we observed a decrease in Oct4 methylation levels at 4 and 12 hpi, before returning to a fully methylated state at 24 hpi. To demonstrate that these changes are restricted to MG, we separated these cells using a GLAST antibody coupled with magnetic beads. Finally, intravitreous administration of the DNA-methyltransferase inhibitor SGI-1027 induced Oct4 expression at 24 hpi in MG. Our results suggest that mammalian MG injury-induced dedifferentiation could be restricted by DNA methylation, which rapidly silences Oct4 expression, preventing multipotency acquisition.

Oct4 Methylation-Mediated Silencing As an Epigenetic Barrier Preventing Müller Glia Dedifferentiation in a Murine Model of Retinal Injury

PubMed Central

Reyes-Aguirre, Luis I.; Lamas, Monica

2016-01-01

Müller glia (MG) is the most abundant glial type in the vertebrate retina. Among its many functions, it is capable of responding to injury by dedifferentiating, proliferating, and differentiating into every cell types lost to damage. This regenerative ability is notoriously absent in mammals. We have previously reported that cultured mammalian MG undergoes a partial dedifferentiation, but fails to fully acquire a progenitor phenotype and differentiate into neurons. This might be explained by a mnemonic mechanism comprised by epigenetic traits, such as DNA methylation. To achieve a better understanding of this epigenetic memory, we studied the expression of pluripotency-associated genes, such as Oct4, Nanog, and Lin28, which have been reported as necessary for regeneration in fish, at early times after NMDA-induced retinal injury in a mouse experimental model. We found that although Oct4 is expressed rapidly after damage (4 hpi), it is silenced at 24 hpi. This correlates with a significant decrease in the DNA methyltransferase Dnmt3b expression, which returns to basal levels at 24 hpi. By MS-PCR, we observed a decrease in Oct4 methylation levels at 4 and 12 hpi, before returning to a fully methylated state at 24 hpi. To demonstrate that these changes are restricted to MG, we separated these cells using a GLAST antibody coupled with magnetic beads. Finally, intravitreous administration of the DNA-methyltransferase inhibitor SGI-1027 induced Oct4 expression at 24 hpi in MG. Our results suggest that mammalian MG injury-induced dedifferentiation could be restricted by DNA methylation, which rapidly silences Oct4 expression, preventing multipotency acquisition. PMID:27895551

Guidance of aortic ablation using optical coherence tomography.

PubMed

Patel, Nirlep A; Li, Xingde; Stamper, Debra L; Fujimoto, James G; Brezinski, Mark E

2003-04-01

There is a significant need for an imaging modality that is capable of providing guidance for intravascular procedures, as current technologies suffer from significant limitations. In particular, laser ablation of in-stent restenosis, revascularization of chronic total occlusions, and pulmonary vein ablation could benefit from guidance. Optical coherence tomography (OCT), a recently introduced technology, is similar to ultrasound except that it measures the back-reflection of infrared light instead of sound. This study examines the ability of OCT to guide vascular laser ablation. Aorta samples underwent laser ablation using an argon laser at varying power outputs and were monitored with OCT collecting images at 4 frames. Samples were compared to the corresponding histopathology. Arterial layers could be differentiated in the images sequences. This allowed correlation of changes in the OCT image with power and duration in addition to histopathology. OCT provides real-time guidance of arterial ablation. At 4 frames, OCT was successfully able to show the microstructural changes in the vessel wall during laser ablation. Since current ablation procedures often injure surrounding tissue, the ability to minimize collateral damage to the adjoining tissue represents a useful advantage of this system. This study suggests a possible role for OCT in the guidance of intravascular procedures.

Constraining OCT with Knowledge of Device Design Enables High Accuracy Hemodynamic Assessment of Endovascular Implants.

PubMed

O'Brien, Caroline C; Kolandaivelu, Kumaran; Brown, Jonathan; Lopes, Augusto C; Kunio, Mie; Kolachalama, Vijaya B; Edelman, Elazer R

2016-01-01

Stacking cross-sectional intravascular images permits three-dimensional rendering of endovascular implants, yet introduces between-frame uncertainties that limit characterization of device placement and the hemodynamic microenvironment. In a porcine coronary stent model, we demonstrate enhanced OCT reconstruction with preservation of between-frame features through fusion with angiography and a priori knowledge of stent design. Strut positions were extracted from sequential OCT frames. Reconstruction with standard interpolation generated discontinuous stent structures. By computationally constraining interpolation to known stent skeletons fitted to 3D 'clouds' of OCT-Angio-derived struts, implant anatomy was resolved, accurately rendering features from implant diameter and curvature (n = 1 vessels, r2 = 0.91, 0.90, respectively) to individual strut-wall configurations (average displacement error ~15 μm). This framework facilitated hemodynamic simulation (n = 1 vessel), showing the critical importance of accurate anatomic rendering in characterizing both quantitative and basic qualitative flow patterns. Discontinuities with standard approaches systematically introduced noise and bias, poorly capturing regional flow effects. In contrast, the enhanced method preserved multi-scale (local strut to regional stent) flow interactions, demonstrating the impact of regional contexts in defining the hemodynamic consequence of local deployment errors. Fusion of planar angiography and knowledge of device design permits enhanced OCT image analysis of in situ tissue-device interactions. Given emerging interests in simulation-derived hemodynamic assessment as surrogate measures of biological risk, such fused modalities offer a new window into patient-specific implant environments.

Reduced Differentiation Efficiency of Murine Embryonic Stem Cells in Stirred Suspension Bioreactors

PubMed Central

Taiani, Jaymi T.; Krawetz, Roman J.; zur Nieden, Nicole I.; Wu, Yiru Elizabeth; Kallos, Michael S.; Matyas, John R.

2010-01-01

The use of embryonic stem cells (ESCs) for regenerative medicine has generated increased attention due to the favorable attributes of these cells; namely, they are pluripotent and possess long-term self-renewal capacity. The initial aims of the present study were: (i) to use stirred suspension bioreactors to expand and differentiate ESCs into osteogenic and chondrogenic cell types and (ii) to explore if these ESC-derived cells influenced skeletal healing in an in vivo fracture model. We show that differentiation protocols used in static culture are insufficient when applied directly to suspension culture bioreactors. Moreover, when bioreactor-differentiated cells are transplanted into a burr-hole defect in bone, severe disruption of the bone architecture was noted at the fracture site, as determined by microcomputed tomography (microCT) imaging and histopathology. Further characterization of the bioreactor-differentiated cultures revealed that a subpopulation of cells in the resulting aggregates expressed the pluripotency marker Oct-4 in the nucleus. Nuclear Oct-4 expression persisted even after 30 days of culture in the absence of leukemia inhibitory factor (LIF). Remarkably, and unlike ESCs differentiated into skeletal cell types in static cultures, bioreactor-differentiated aggregates implanted subcutaneously into SCID mice formed teratomas. The development of effective ESC differentiation protocols for suspension bioreactors will require a more complete understanding of the environmental conditions within these culture systems and the influence that these conditions have on the regulation of pluripotency and differentiation in ESCs. PMID:19775198

Evaluation of dual flow thrust vectored nozzles with exhaust stream impingement. MS Thesis Final Technical Report, Oct. 1990 - Jul. 1991

NASA Technical Reports Server (NTRS)

Carpenter, Thomas W.

1991-01-01

The main objective of this project was to predict the expansion wave/oblique shock wave structure in an under-expanded jet expanding from a convergent nozzle. The shock structure was predicted by combining the calculated curvature of the free pressure boundary with principles and governing equations relating to oblique shock wave and expansion wave interaction. The procedure was then continued until the shock pattern repeated itself. A mathematical model was then formulated and written in FORTRAN to calculate the oblique shock/expansion wave structure within the jet. In order to study shock waves in expanding jets, Schlieren photography, a form of flow visualization, was employed. Thirty-six Schlieren photographs of jets from both a straight and 15 degree nozzle were taken. An iterative procedure was developed to calculate the shock structure within the jet and predict the non-dimensional values of Prandtl primary wavelength (w/rn), distance to Mach Disc (Ld) and Mach Disc radius (rd). These values were then compared to measurements taken from Schlieren photographs and experimental results. The results agreed closely to measurements from Schlieren photographs and previously obtained data. This method provides excellent results for pressure ratios below that at which a Mach Disc first forms. Calculated values of non-dimensional distance to the Mach Disc (Ld) agreed closely to values measured from Schlieren photographs and published data. The calculated values of non-dimensional Mach Disc radius (rd), however, deviated from published data by as much as 25 percent at certain pressure ratios.

Improved Visualization of Glaucomatous Retinal Damage Using High-speed Ultrahigh-Resolution Optical Coherence Tomography

PubMed Central

Mumcuoglu, Tarkan; Wollstein, Gadi; Wojtkowski, Maciej; Kagemann, Larry; Ishikawa, Hiroshi; Gabriele, Michelle L.; Srinivasan, Vivek; Fujimoto, James G.; Duker, Jay S.; Schuman, Joel S.

2009-01-01

Purpose To test if improving optical coherence tomography (OCT) resolution and scanning speed improves the visualization of glaucomatous structural changes as compared with conventional OCT. Design Prospective observational case series. Participants Healthy and glaucomatous subjects in various stages of disease. Methods Subjects were scanned at a single visit with commercially available OCT (StratusOCT) and high-speed ultrahigh-resolution (hsUHR) OCT. The prototype hsUHR OCT had an axial resolution of 3.4 μm (3 times higher than StratusOCT), with an A-scan rate of 24 000 hertz (60 times faster than StratusOCT). The fast scanning rate allowed the acquisition of novel scanning patterns such as raster scanning, which provided dense coverage of the retina and optic nerve head. Main Outcome Measures Discrimination of retinal tissue layers and detailed visualization of retinal structures. Results High-speed UHR OCT provided a marked improvement in tissue visualization as compared with StratusOCT. This allowed the identification of numerous retinal layers, including the ganglion cell layer, which is specifically prone to glaucomatous damage. Fast scanning and the enhanced A-scan registration properties of hsUHR OCT provided maps of the macula and optic nerve head with unprecedented detail, including en face OCT fundus images and retinal nerve fiber layer thickness maps. Conclusion High-speed UHR OCT improves visualization of the tissues relevant to the detection and management of glaucoma. PMID:17884170

Proinflammatory Cytokines IL-6 and TNF-α Increased Telomerase Activity through NF-κB/STAT1/STAT3 Activation, and Withaferin A Inhibited the Signaling in Colorectal Cancer Cells.

PubMed

Chung, Seyung S; Wu, Yong; Okobi, Quincy; Adekoya, Debbie; Atefi, Mohammad; Clarke, Orette; Dutta, Pranabananda; Vadgama, Jaydutt V

2017-01-01

There are increasing evidences of proinflammatory cytokine involvement in cancer development. Here, we found that two cytokines, IL-6 and TNF- α , activated colorectal cancer cells to be more invasive and stem-like. Combined treatment of IL-6 and TNF- α phosphorylated transcription factors STAT3 in a synergistic manner. STAT3, STAT1, and NF- κ B physically interacted upon the cytokine stimulation. STAT3 was bound to the promoter region of human telomerase reverse transcriptase (hTERT). IL-6 and TNF- α stimulation further enhanced STAT3 binding affinity. Stem cell marker Oct-4 was upregulated in colorectal cancer cells upon IL-6 and TNF- α stimulation. Withaferin A, an anti-inflammatory steroidal lactone, inhibited the IL-6- and TNF- α -induced cancer cell invasion and decreased colonosphere formation. Notably, withaferin A inhibited STAT3 phosphorylation and abolished the STAT3, STAT1, and NF- κ B interactions. Oct-4 expression was also downregulated by withaferin A inhibition. The binding of STAT3 to the hTERT promoter region and telomerase activity showed reduction with withaferin A treatments. Proinflammatory cytokine-induced cancer cell invasiveness is mediated by a STAT3-regulated mechanism in colorectal cancer cells. Our data suggest that withaferin A could be a promising anticancer agent that effectively inhibits the progression of colorectal cancer.

In vivo optical imaging of amblyopia: Digital subtraction autofluorescence and split-spectrum amplitude-decorrelation angiography.

PubMed

Guo, Lei; Tao, Jun; Xia, Fan; Yang, Zhi; Ma, Xiaoli; Hua, Rui

2016-09-01

Amblyopia is a visual impairment that is attributed to either abnormal binocular interactions or visual deprivation. The retina and choroids have been shown to be involved in the development of amblyopia. The purpose of this study was to investigate the retinal and choroidal microstructural abnormalities of amblyopia using digital subtraction autofluorescence and split-spectrum amplitude-decorrelation angiography (SSADA) approaches. This prospective study included 44 eyes of 22 patients with unilateral amblyopia. All patients who received indirect ophthalmoscopy, combined depth imaging spectral domain optical coherence tomography (OCT), SSADA-OCT, and macular blue light (BL-) and near-infrared (NIR-) autofluorescences underwent pupil dilation. The subfoveal choroidal thickness (SFCT) was measured. BL- and NIR-autofluorescences were determined for all patients and used to generate subtraction images with ImageJ software. The superficial, deep layers of the retina, and inner choroid layer were required for SSADA-OCT. For the normal eyes, a regularly increasing signal was observed in the central macula based on the subtraction images. In contrast, a decreased signal for the central patch or a reduced peak was detected in 16 of 22 amblyopic eyes (72.7%). The mean SFCT of the amblyopic eyes was greater than that of the fellow normal eyes (399.25 ± 4.944 µm vs. 280.58 ± 6.491 µm, respectively, P < 0.05). SSADA-OCT revealed a normal choroidal capillary network in all fellow normal eyes. However, 18 of 22 amblyopic eyes (86.4%) exhibited a blurry choroidal capillary network, and 15 of 22 amblyopic eyes (68.2%) displayed a dark atrophic patch. This is the first report of amblyopia using SSADA-OCT and digital subtraction images of autofluorescence. The mechanistic relationship of a thicker choroid and choroidal capillary atrophy with amblyopia remains to be described. The digital subtraction image confirmed the changes in the microstructure of the amblyopic retina as a supplementary approach to detect the progression of amblyopia. Lasers Surg. Med. 48:660-667, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Synchronous imaging of the pulse response of the ciliary muscle and lens with SD-OCT (Conference Presentation)

NASA Astrophysics Data System (ADS)

Chang, Yu-Cherng; Pham, Alex; Williams, Siobhan; Alawa, Karam A.; de Freitas, Carolina; Ruggeri, Marco; Parel, Jean-Marie A.; Manns, Fabrice

2017-02-01

Purpose: To determine the dynamic interaction between ciliary muscle and lens during accommodation and disaccommodation through synchronous imaging of ciliary muscle and lens response to pulse stimulus Methods: The ciliary muscle and lens were imaged simultaneously in a 33 year old subject responding to a 4D pulse stimulus (accommodative stimulus at 1.7 s, disaccommodative stimulus at 7.7 s) using an existing imaging system (Ruggeri et al, 2016) consisting of an Anterior Segment Optical Coherence Tomography system, Ciliary Muscle Optical Coherence Tomography system, and custom-built accommodation module. OCT images were recorded at an effective frame rate of 13.0 frames per second for a total scan time of 11.5 s. An automated segmentation algorithm was applied to images of the anterior segment to detect the boundaries of the cornea and lens, from which lens thickness was extracted. Segmentation of the ciliary muscle was performed manually and then corrected for distortion due to refraction of the beam to obtain measurements of thicknesses at the apex and fixed distances from the scleral spur. Results: The dynamic biometric response to a pulse stimulus at 4D was determined for both the ciliary muscle and lens, suggesting the ciliary muscle and lens interact differently in accommodation and disaccommodation. Conclusions: The study introduces new data and analyses of the ciliary muscle and lens interaction during a complete accommodative response from the relaxed to the accommodated state and back, providing insight into the interplay between individual elements in the accommodative system and how their relationships may change with age.

Medication Interactions: Food, Supplements and Other Drugs

MedlinePlus

... for Heart.org CPR & ECC for Heart.org Shop for Heart.org Causes for Heart.org Advocate ... Aneurysm More Medication Interactions: Food, Supplements and Other Drugs Updated:Oct 15,2014 Some foods — even healthy ...

Identification of Functional Amino Acid Residues Involved in Polyamine and Agmatine Transport by Human Organic Cation Transporter 2

PubMed Central

Higashi, Kyohei; Imamura, Masataka; Fudo, Satoshi; Uemura, Takeshi; Saiki, Ryotaro; Hoshino, Tyuji; Toida, Toshihiko; Kashiwagi, Keiko; Igarashi, Kazuei

2014-01-01

Polyamine (putrescine, spermidine and spermine) and agmatine uptake by the human organic cation transporter 2 (hOCT2) was studied using HEK293 cells transfected with pCMV6-XL4/hOCT2. The Km values for putrescine and spermidine were 7.50 and 6.76 mM, and the Vmax values were 4.71 and 2.34 nmol/min/mg protein, respectively. Spermine uptake by hOCT2 was not observed at pH 7.4, although it inhibited both putrescine and spermidine uptake. Agmatine was also taken up by hOCT2, with Km value: 3.27 mM and a Vmax value of 3.14 nmol/min/mg protein. Amino acid residues involved in putrescine, agmatine and spermidine uptake by hOCT2 were Asp427, Glu448, Glu456, Asp475, and Glu516. In addition, Glu524 and Glu530 were involved in putrescine and spermidine uptake activity, and Glu528 and Glu540 were weakly involved in putrescine uptake activity. Furthermore, Asp551 was also involved in the recognition of spermidine. These results indicate that the recognition sites for putrescine, agmatine and spermidine on hOCT2 strongly overlap, consistent with the observation that the three amines are transported with similar affinity and velocity. A model of spermidine binding to hOCT2 was constructed based on the functional amino acid residues. PMID:25019617

Optical Coherence Tomography Angiography and Ultra-widefield Fluorescein Angiography for Early Detection of Adolescent Sickle Retinopathy.

PubMed

Pahl, Daniel A; Green, Nancy S; Bhatia, Monica; Lee, Margaret T; Chang, Jonathan S; Licursi, Maureen; Briamonte, Courtney; Smilow, Elana; Chen, Royce W S

2017-11-01

Based on standard screening techniques, sickle retinopathy reportedly occurs in 10% of adolescents with sickle cell disease (SCD). We performed a prospective, observational clinical study to determine if ultra-widefield fluorescein angiography (UWFA), spectral-domain optical coherence tomography (SD-OCT), and optical coherence tomography angiography (OCT-A) detect more-frequent retinopathy in adolescents with SCD. Cross-sectional study. Setting: Institutional. Sixteen adolescents with SCD, aged 10-19 years (mean age 14.9 years), and 5 age-equivalent controls (mean age 17.4 years). Examinations including acuity, standard slit-lamp biomicroscopy, UWFA, SD-OCT, and OCT-A were performed. Sickle retinopathy defined by biomicroscopic changes, Goldberg stages I-V, Penman scale, flow void on OCT-A, or macular thinning on SD-OCT. While 22 of 32 SCD eyes (68.8%) had retinopathy on biomicroscopy, by UWFA 4 of 24 (16.7%) SCD eyes had peripheral arterial occlusion (Goldberg I), and 20 of 24 eyes (83.3%) had peripheral arteriovenous anastomoses (Goldberg II) in addition. No patients had Goldberg stages III-V. By SD-OCT and OCT-A, thinning of the macula and flow voids in both the superficial and deep retinal capillary plexus were found in 6 of 30 (20%) eyes. All 24 eyes with adequate UWFA studies demonstrated sickle retinopathy. SD-OCT and OCT-A, which have not been previously reported in the adolescent population, detected abnormal macular thinning and flow abnormalities undetected by biomicroscopy. These findings suggest that pediatric sickle retinopathy may be more prevalent than previously suspected. If these findings are confirmed with larger cross-sectional and prospective analyses, these approaches may enhance early screening for sickle retinopathy. Copyright © 2017 Elsevier Inc. All rights reserved.

Afghanistan: Post-Taliban Governance, Security, and U.S. Policy

DTIC Science & Technology

2013-10-23

for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE 23 OCT 2013 2...York closed, although Taliban representative Abdul Hakim Mujahid continued to operate informally .9 In March 2001, Administration officials received a ...Resolution 2096. Resolution 2096 reiterates the expanded UNAMA mandate, while noting that UNAMA and the international community are moving to a supporting

Imaging of cartilage degeneration progression in vivo using ultrahigh-resolution OCT

NASA Astrophysics Data System (ADS)

Herz, Paul R.; Bourquin, Stephane; Hsiung, Pei-lin; Ko, Tony H.; Schneider, Karl; Fujimoto, James G.; Adams, Samuel, Jr.; Roberts, Mark; Patel, Nirlep; Brezinski, Mark

2003-10-01

Ultrahigh resolution OCT is used to visualize experimentally induced osteoarthritis in a rat knee model. Using a Cr4+:Forsterite laser, ultrahigh image resolutions of 5um are achieved. Progression of osteoarthritic remodeling and cartilage degeneration are quantified. The utility of OCT for the assessment of cartilage integrity is demonstrated.

Quantitative analysis of the polarization characteristics of atherosclerotic plaques

NASA Astrophysics Data System (ADS)

Gubarkova, Ekaterina V.; Kirillin, Michail Y.; Dudenkova, Varvara V.; Kiseleva, Elena B.; Moiseev, Alexander A.; Gelikonov, Grigory V.; Timofeeva, Lidia B.; Fiks, Ilya I.; Feldchtein, Felix I.; Gladkova, Natalia D.

2016-04-01

In this study we demonstrate the capability of cross-polarization optical coherence tomography (CP OCT) to assess collagen and elastin fibers condition in atherosclerotic plaques basing on ratio of the OCT signal levels in cross- and co- polarizations. We consider the depolarization factor (DF) and the effective birefringence (Δn) as quantitative characteristics of CP OCT images. We revealed that calculation of both DF and Δn in the region of interest (fibrous cap) yields a statistically significant difference between stable and unstable plaques (0.46+/-0.21 vs 0.09+/-0.04 for IDF; (4.7+/-1.0)•10-4 vs (2.5+/-0.7)•10-4 for Δn p<0.05). In parallel with CP OCT we used the nonlinear microscopy for analysis of thin cross-section of atherosclerotic plaque, revealing the different average isotropy index of collagen and elastin fibers for stable and unstable plaques (0.30 +/- 0.10 vs 0.70 +/- 0.08; p<0.001). The proposed approach for quantitative assessment of CP OCT images allows cross-scattering and birefringence characterization of stable and unstable atherosclerotic plaques.

Retinal and Optic Nerve Degeneration in Patients with Multiple Sclerosis Followed up for 5 Years.

PubMed

Garcia-Martin, Elena; Ara, Jose R; Martin, Jesus; Almarcegui, Carmen; Dolz, Isabel; Vilades, Elisa; Gil-Arribas, Laura; Fernandez, Francisco J; Polo, Vicente; Larrosa, Jose M; Pablo, Luis E; Satue, Maria

2017-05-01

To quantify retinal nerve fiber layer (RNFL) changes in patients with multiple sclerosis (MS) and healthy controls with a 5-year follow-up and to analyze correlations between disability progression and RNFL degeneration. Observational and longitudinal study. One hundred patients with relapsing-remitting MS and 50 healthy controls. All participants underwent a complete ophthalmic and electrophysiologic exploration and were re-evaluated annually for 5 years. Visual acuity (Snellen chart), color vision (Ishihara pseudoisochromatic plates), visual field examination, optical coherence tomography (OCT), scanning laser polarimetry (SLP), and visual evoked potentials. Expanded Disability Status Scale (EDSS) scores, disease duration, treatments, prior optic neuritis episodes, and quality of life (QOL; based on the 54-item Multiple Sclerosis Quality of Life Scale score). Optical coherence tomography (OCT) revealed changes in all RNFL thicknesses in both groups. In the MS group, changes were detected in average thickness and in the mean deviation using the GDx-VCC nerve fiber analyzer (Laser Diagnostic Technologies, San Diego, CA) and in the P100 latency of visual evoked potentials; no changes were detected in visual acuity, color vision, or visual fields. Optical coherence tomography showed greater differences in the inferior and temporal RNFL thicknesses in both groups. In MS patients only, OCT revealed a moderate correlation between the increase in EDSS and temporal and superior RNFL thinning. Temporal RNFL thinning based on OCT results was correlated moderately with decreased QOL. Multiple sclerosis patients exhibit a progressive axonal loss in the optic nerve fiber layer. Retinal nerve fiber layer thinning based on OCT results is a useful marker for assessing MS progression and correlates with increased disability and reduced QOL. Copyright © 2017 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Virtual Averaging Making Nonframe-Averaged Optical Coherence Tomography Images Comparable to Frame-Averaged Images.

PubMed

Chen, Chieh-Li; Ishikawa, Hiroshi; Wollstein, Gadi; Bilonick, Richard A; Kagemann, Larry; Schuman, Joel S

2016-01-01

Developing a novel image enhancement method so that nonframe-averaged optical coherence tomography (OCT) images become comparable to active eye-tracking frame-averaged OCT images. Twenty-one eyes of 21 healthy volunteers were scanned with noneye-tracking nonframe-averaged OCT device and active eye-tracking frame-averaged OCT device. Virtual averaging was applied to nonframe-averaged images with voxel resampling and adding amplitude deviation with 15-time repetitions. Signal-to-noise (SNR), contrast-to-noise ratios (CNR), and the distance between the end of visible nasal retinal nerve fiber layer (RNFL) and the foveola were assessed to evaluate the image enhancement effect and retinal layer visibility. Retinal thicknesses before and after processing were also measured. All virtual-averaged nonframe-averaged images showed notable improvement and clear resemblance to active eye-tracking frame-averaged images. Signal-to-noise and CNR were significantly improved (SNR: 30.5 vs. 47.6 dB, CNR: 4.4 vs. 6.4 dB, original versus processed, P < 0.0001, paired t -test). The distance between the end of visible nasal RNFL and the foveola was significantly different before (681.4 vs. 446.5 μm, Cirrus versus Spectralis, P < 0.0001) but not after processing (442.9 vs. 446.5 μm, P = 0.76). Sectoral macular total retinal and circumpapillary RNFL thicknesses showed systematic differences between Cirrus and Spectralis that became not significant after processing. The virtual averaging method successfully improved nontracking nonframe-averaged OCT image quality and made the images comparable to active eye-tracking frame-averaged OCT images. Virtual averaging may enable detailed retinal structure studies on images acquired using a mixture of nonframe-averaged and frame-averaged OCT devices without concerning about systematic differences in both qualitative and quantitative aspects.

Virtual Averaging Making Nonframe-Averaged Optical Coherence Tomography Images Comparable to Frame-Averaged Images

PubMed Central

Chen, Chieh-Li; Ishikawa, Hiroshi; Wollstein, Gadi; Bilonick, Richard A.; Kagemann, Larry; Schuman, Joel S.

2016-01-01

Purpose Developing a novel image enhancement method so that nonframe-averaged optical coherence tomography (OCT) images become comparable to active eye-tracking frame-averaged OCT images. Methods Twenty-one eyes of 21 healthy volunteers were scanned with noneye-tracking nonframe-averaged OCT device and active eye-tracking frame-averaged OCT device. Virtual averaging was applied to nonframe-averaged images with voxel resampling and adding amplitude deviation with 15-time repetitions. Signal-to-noise (SNR), contrast-to-noise ratios (CNR), and the distance between the end of visible nasal retinal nerve fiber layer (RNFL) and the foveola were assessed to evaluate the image enhancement effect and retinal layer visibility. Retinal thicknesses before and after processing were also measured. Results All virtual-averaged nonframe-averaged images showed notable improvement and clear resemblance to active eye-tracking frame-averaged images. Signal-to-noise and CNR were significantly improved (SNR: 30.5 vs. 47.6 dB, CNR: 4.4 vs. 6.4 dB, original versus processed, P < 0.0001, paired t-test). The distance between the end of visible nasal RNFL and the foveola was significantly different before (681.4 vs. 446.5 μm, Cirrus versus Spectralis, P < 0.0001) but not after processing (442.9 vs. 446.5 μm, P = 0.76). Sectoral macular total retinal and circumpapillary RNFL thicknesses showed systematic differences between Cirrus and Spectralis that became not significant after processing. Conclusion The virtual averaging method successfully improved nontracking nonframe-averaged OCT image quality and made the images comparable to active eye-tracking frame-averaged OCT images. Translational Relevance Virtual averaging may enable detailed retinal structure studies on images acquired using a mixture of nonframe-averaged and frame-averaged OCT devices without concerning about systematic differences in both qualitative and quantitative aspects. PMID:26835180

Contribution of the organic anion transporter OAT2 to the renal active tubular secretion of creatinine and mechanism for serum creatinine elevations caused by cobicistat

PubMed Central

Lepist, Eve-Irene; Zhang, Xuexiang; Hao, Jia; Huang, Jane; Kosaka, Alan; Birkus, Gabriel; Murray, Bernard P; Bannister, Roy; Cihlar, Tomas; Huang, Yong; Ray, Adrian S

2014-01-01

Many xenobiotics including the pharmacoenhancer cobicistat increase serum creatinine by inhibiting its renal active tubular secretion without affecting the glomerular filtration rate. This study aimed to define the transporters involved in creatinine secretion, applying that knowledge to establish the mechanism for xenobiotic-induced effects. The basolateral uptake transporters organic anion transporter OAT2 and organic cation transporters OCT2 and OCT3 were found to transport creatinine. At physiologic creatinine concentrations, the specific activity of OAT2 transport was over twofold higher than OCT2 or OCT3, establishing OAT2 as a likely relevant creatinine transporter and further challenging the traditional view that creatinine is solely transported by a cationic pathway. The apical multidrug and toxin extrusion transporters MATE1 and MATE2-K demonstrated low-affinity and high-capacity transport. All drugs known to affect creatinine inhibited OCT2 and MATE1. Similar to cimetidine and ritonavir, cobicistat had the greatest effect on MATE1 with a 50% inhibition constant of 0.99 μM for creatinine transport. Trimethoprim potently inhibited MATE2-K, whereas dolutegravir preferentially inhibited OCT2. Cimetidine was unique, inhibiting all transporters that interact with creatinine. Thus, the clinical observation of elevated serum creatinine in patients taking cobicistat is likely a result of OCT2 transport, facilitating intracellular accumulation, and MATE1 inhibition. PMID:24646860

Contribution of the organic anion transporter OAT2 to the renal active tubular secretion of creatinine and mechanism for serum creatinine elevations caused by cobicistat.

PubMed

Lepist, Eve-Irene; Zhang, Xuexiang; Hao, Jia; Huang, Jane; Kosaka, Alan; Birkus, Gabriel; Murray, Bernard P; Bannister, Roy; Cihlar, Tomas; Huang, Yong; Ray, Adrian S

2014-08-01

Many xenobiotics including the pharmacoenhancer cobicistat increase serum creatinine by inhibiting its renal active tubular secretion without affecting the glomerular filtration rate. This study aimed to define the transporters involved in creatinine secretion, applying that knowledge to establish the mechanism for xenobiotic-induced effects. The basolateral uptake transporters organic anion transporter OAT2 and organic cation transporters OCT2 and OCT3 were found to transport creatinine. At physiologic creatinine concentrations, the specific activity of OAT2 transport was over twofold higher than OCT2 or OCT3, establishing OAT2 as a likely relevant creatinine transporter and further challenging the traditional view that creatinine is solely transported by a cationic pathway. The apical multidrug and toxin extrusion transporters MATE1 and MATE2-K demonstrated low-affinity and high-capacity transport. All drugs known to affect creatinine inhibited OCT2 and MATE1. Similar to cimetidine and ritonavir, cobicistat had the greatest effect on MATE1 with a 50% inhibition constant of 0.99 μM for creatinine transport. Trimethoprim potently inhibited MATE2-K, whereas dolutegravir preferentially inhibited OCT2. Cimetidine was unique, inhibiting all transporters that interact with creatinine. Thus, the clinical observation of elevated serum creatinine in patients taking cobicistat is likely a result of OCT2 transport, facilitating intracellular accumulation, and MATE1 inhibition.

Imaging of oral pathological tissue using optical coherence tomography

NASA Astrophysics Data System (ADS)

Canjau, Silvana; Todea, Carmen; Sinescu, Cosmin; Duma, Virgil-Florin; Topala, Florin I.; Podoleanu, Adrian G.

2014-01-01

Oral squamous cell carcinoma (OSCC) constitutes 90% of oral cancer. Early detection is a cornerstone to improve survival. Interaction of light with tissues may highlight changes in tissue structure and metabolism. We propose optical coherence tomography (OCT), as a non-invasive diagnosis method, being a new high-resolution optical technique that permits tri-dimensional (3-D), real-time imaging of near surface abnormalities in complex tissues. In this study half of the excisional biopsy was directed to the pathologist and the other half was assigned for OCT investigation. Histopathology validated the results. Areas of OSCC of the buccal mucosa were identified in the OCT images. The elements obserced included extensive epithelial down-growth, the disruption of the basement membrane, with areas of erosion, an epithelial layer that was highly variable in thickness and invasion into the sub-epithelial layers. Therefore, OCT appears to be a highly promising imaging modality.

Activation of the mouse Oct4 promoter in medaka embryonic stem cells and its use for ablation of spontaneous differentiation.

PubMed

Hong, Yunhan; Winkler, Christoph; Liu, Tongming; Chai, Guixuan; Schartl, Manfred

2004-07-01

The determination and maintenance of the cell fate is ultimately due to differential gene activity. In the mouse, expression of the transcription factor Oct4 is high in totipotent inner cell mass, germ cells and undifferentiated embryonic stem (ES) cells, but dramatically reduced or extinct upon differentiation. Here, we show that medaka blastula embryos and cells of the ES cell line MES1 are able to activate the Oct4 promoter. Ectopic expression of a fusion gene for beta-galactosidase and neomycin resistance from the Oct4 promoter conferred resistance to G418. G418 selection led to a homogeneous population of undifferentiated ES cells which were able to undergo induced or directed differentiation into various cell types including neuron-like cells and melanocytes. Furthermore, GFP-labeled GOF18geo-MES1 cells after differentiation ablation were able to contribute to a wide variety of organ systems derived from all the three germ layers. Most importantly, we show that drug ablation of differentiation on the basis of Oct4 promoter is a useful tool to improve ES cell cultivation and chimera formation: MES1 cells after differentiation ablation appeared to be better donors than the parental MES1 line, as the permissive number of input donor cells increases from 100 to 200, resulting in an enhanced degree of chimerism. Taken together, some transcription factors and cis-acting regulatory sequences controlling totipotency-specific gene expression appear to be conserved between mammals and fish, and medaka ES cells offer an in vitro system for characterizing the expression of totipotency-specific genes such as putative Oct4 homologs from fish.

Macular Diagnostic Ability in OCT for Assessing Glaucoma in High Myopia.

PubMed

Hung, Kuo-Chi; Wu, Pei-Chang; Poon, Yi-Chieh; Chang, Hsueh-Wen; Lai, Ing-Chou; Tsai, Jen-Chia; Lin, Pei-Wen; Teng, Mei-Ching

2016-02-01

To compare the diagnostic abilities of spectral-domain optical coherence tomography (SD-OCT; Spectralis OCT) and time-domain OCT (TD-OCT; Stratus OCT). Changes in macular parameters in highly myopic eyes of glaucoma patients and highly myopic eyes of glaucoma suspects were evaluated and compared. We collected data from 72 highly myopic eyes (spherical equivalent, ≤-6.0D). Forty-one eyes had perimetric glaucoma and 31 eyes were suspected to have glaucoma (control group). All eyes underwent SD-OCT and TD-OCT imaging. Area under the receiver operating characteristic (AUROC) curve and sensitivity were examined on macular volume and thickness parameters at a fixed specificity and compared between groups. The highest TD-OCT AUROC curves were found using outer inferior sector macular thickness (AUROC curve, 0.911) and volume (AUROC curve, 0.909). The highest SD-OCT AUROC curves were found using outer inferior region thickness (AUROC curve, 0.836) and volume (AUROC curve, 0.834). The difference between the two imaging modalities was not statistically significant (thickness, p = 0.141; volume, p = 0.138). The sensitivity of TD-OCT macular outer inferior average thickness was highest and was 88.2%, with a specificity of 80.4%. The sensitivity of TD-OCT average volume measurements in this same region was 76.5%, with a specificity of 91.3%. The SD-OCT average thickness measurements also had the highest sensitivity in this region, which was 78.6%, with a specificity of 82.1%. The SD-OCT volume measurements had a sensitivity of 67.9%, with a specificity of 92.3%. Both SD-OCT and TD-OCT measurements of outer inferior macular thickness and volume can differentiate between eyes of glaucoma patients and glaucoma suspects with high myopia. These independent predictors all had good sensitivity. Based on our results, SD-OCT and TD-OCT have similar diagnostic abilities. These parameters may provide useful additional data in highly myopic eyes to complement standard glaucoma diagnosis tools.

The death-inducer obliterator 1 (Dido1) gene regulates embryonic stem cell self-renewal.

PubMed

Liu, Yinyin; Kim, Hyeung; Liang, Jiancong; Lu, Weisi; Ouyang, Bin; Liu, Dan; Songyang, Zhou

2014-02-21

The regulatory network of factors that center on master transcription factors such as Oct4, Nanog, and Sox2 help maintain embryonic stem (ES) cells and ensure their pluripotency. The target genes of these master transcription factors define the ES cell transcriptional landscape. In this study, we report our findings that Dido1, a target of canonical transcription factors such as Oct4, Sox2, and Nanog, plays an important role in regulating ES cell maintenance. We found that depletion of Dido1 in mouse ES cells led to differentiation, and ectopic expression of Dido1 inhibited differentiation induced by leukemia inhibitory factor withdrawal. We further demonstrated that whereas Nanog and Oct4 could occupy the Dido1 locus and promote its transcription, Dido1 could also target to the loci of pluripotency factors such as Nanog and Oct4 and positively regulate their expression. Through this feedback and feedforward loop, Dido1 is able to regulate self-renewal of mouse ES cells.

Tryptophan derivatives regulate the transcription of Oct4 in stem-like cancer cells.

PubMed

Cheng, Jie; Li, Wenxin; Kang, Bo; Zhou, Yanwen; Song, Jiasheng; Dan, Songsong; Yang, Ying; Zhang, Xiaoqian; Li, Jingchao; Yin, Shengyong; Cao, Hongcui; Yao, Hangping; Zhu, Chenggang; Yi, Wen; Zhao, Qingwei; Xu, Xiaowei; Zheng, Min; Zheng, Shusen; Li, Lanjuan; Shen, Binghui; Wang, Ying-Jie

2015-06-10

The aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor that responds to environmental toxicants, is increasingly recognized as a key player in embryogenesis and tumorigenesis. Here we show that a variety of tryptophan derivatives that act as endogenous AhR ligands can affect the transcription level of the master pluripotency factor Oct4. Among them, ITE enhances the binding of the AhR to the promoter of Oct4 and suppresses its transcription. Reduction of endogenous ITE levels in cancer cells by tryptophan deprivation or hypoxia leads to Oct4 elevation, which can be reverted by administration with synthetic ITE. Consequently, synthetic ITE induces the differentiation of stem-like cancer cells and reduces their tumorigenic potential in both subcutaneous and orthotopic xenograft tumour models. Thus, our results reveal a role of tryptophan derivatives and the AhR signalling pathway in regulating cancer cell stemness and open a new therapeutic avenue to target stem-like cancer cells.

Tryptophan derivatives regulate the transcription of Oct4 in stem-like cancer cells

PubMed Central

Cheng, Jie; Li, Wenxin; Kang, Bo; Zhou, Yanwen; Song, Jiasheng; Dan, Songsong; Yang, Ying; Zhang, Xiaoqian; Li, Jingchao; Yin, Shengyong; Cao, Hongcui; Yao, Hangping; Zhu, Chenggang; Yi, Wen; Zhao, Qingwei; Xu, Xiaowei; Zheng, Min; Zheng, Shusen; Li, Lanjuan; Shen, Binghui; Wang, Ying-Jie

2015-01-01

The aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor that responds to environmental toxicants, is increasingly recognized as a key player in embryogenesis and tumorigenesis. Here we show that a variety of tryptophan derivatives that act as endogenous AhR ligands can affect the transcription level of the master pluripotency factor Oct4. Among them, ITE enhances the binding of the AhR to the promoter of Oct4 and suppresses its transcription. Reduction of endogenous ITE levels in cancer cells by tryptophan deprivation or hypoxia leads to Oct4 elevation, which can be reverted by administration with synthetic ITE. Consequently, synthetic ITE induces the differentiation of stem-like cancer cells and reduces their tumorigenic potential in both subcutaneous and orthotopic xenograft tumour models. Thus, our results reveal a role of tryptophan derivatives and the AhR signalling pathway in regulating cancer cell stemness and open a new therapeutic avenue to target stem-like cancer cells. PMID:26059097

The dyskerin ribonucleoprotein complex as an OCT4/SOX2 coactivator in embryonic stem cells

PubMed Central

Fong, Yick W; Ho, Jaclyn J; Inouye, Carla; Tjian, Robert

2014-01-01

Acquisition of pluripotency is driven largely at the transcriptional level by activators OCT4, SOX2, and NANOG that must in turn cooperate with diverse coactivators to execute stem cell-specific gene expression programs. Using a biochemically defined in vitro transcription system that mediates OCT4/SOX2 and coactivator-dependent transcription of the Nanog gene, we report the purification and identification of the dyskerin (DKC1) ribonucleoprotein complex as an OCT4/SOX2 coactivator whose activity appears to be modulated by a subset of associated small nucleolar RNAs (snoRNAs). The DKC1 complex occupies enhancers and regulates the expression of key pluripotency genes critical for self-renewal in embryonic stem (ES) cells. Depletion of DKC1 in fibroblasts significantly decreased the efficiency of induced pluripotent stem (iPS) cell generation. This study thus reveals an unanticipated transcriptional role of the DKC1 complex in stem cell maintenance and somatic cell reprogramming. DOI: http://dx.doi.org/10.7554/eLife.03573.001 PMID:25407680

In vitro and physiologically‐based pharmacokinetic based assessment of drug–drug interaction potential of canagliflozin

PubMed Central

Dallas, Shannon; Sensenhauser, Carlo; Lim, Heng Keang; Scheers, Ellen; Verboven, Peter; Cuyckens, Filip; Leclercq, Laurent; Evans, David C.; Kelley, Michael F.; Johnson, Mark D.; Snoeys, Jan

2016-01-01

Aims Canagliflozin is a recently approved drug for use in the treatment of type 2 diabetes. The potential for canagliflozin to cause clinical drug–drug interactions (DDIs) was assessed. Methods DDI potential of canagliflozin was investigated using in vitro test systems containing drug metabolizing enzymes or transporters. Basic predictive approaches were applied to determine potential interactions in vivo. A physiologically‐based pharmacokinetic (PBPK) model was developed and clinical DDI simulations were performed to determine the likelihood of cytochrome P450 (CYP) inhibition by canagliflozin. Results Canagliflozin was primarily metabolized by uridine 5′‐diphospho‐glucuronosyltransferase 1A9 and 2B4 enzymes. Canagliflozin was a substrate of efflux transporters (P‐glycoprotein, breast cancer resistance protein and multidrug resistance‐associated protein‐2) but was not a substrate of uptake transporters (organic anion transporter polypeptide isoforms OATP1B1, OATP1B3, organic anion transporters OAT1 and OAT3, and organic cationic transporters OCT1, and OCT2). In inhibition assays, canagliflozin was shown to be a weak in vitro inhibitor (IC50) of CYP3A4 (27 μmol l –1, standard error [SE] 4.9), CYP2C9 (80 μmol l –1, SE 8.1), CYP2B6 (16 μmol l–1, SE 2.1), CYP2C8 (75 μmol l –1, SE 6.4), P‐glycoprotein (19.3 μmol l –1, SE 7.2), and multidrug resistance‐associated protein‐2 (21.5 μmol l –1, SE 3.1). Basic models recommended in DDI guidelines (US Food & Drug Administration and European Medicines Agency) predicted moderate to low likelihood of interaction for these CYPs and efflux transporters. PBPK DDI simulations of canagliflozin with CYP probe substrates (simvastatin, S‐warfarin, bupropion, repaglinide) did not show relevant interaction in humans since mean areas under the concentration‐time curve and maximum plasma concentration ratios for probe substrates with and without canagliflozin and its 95% CIs were within 0.80–1.25. Conclusions In vitro DDI followed by a predictive or PBPK approach was applied to determine DDI potential of canagliflozin. Overall, canagliflozin is neither a perpetrator nor a victim of clinically important interactions. PMID:27862160

BORIS up-regulates OCT4 via histone methylation to promote cancer stem cell-like properties in human liver cancer cells.

PubMed

Liu, Qiuying; Chen, Kefei; Liu, Zhongjian; Huang, Yuan; Zhao, Rongce; Wei, Ling; Yu, Xiaoqin; He, Jingyang; Liu, Jun; Qi, Jianguo; Qin, Yang; Li, Bo

2017-09-10

Accumulating evidence has revealed the importance of cancer stem cells (CSCs) in chemoresistance and recurrence. BORIS, a testes-specific CTCF paralog, has been shown to be associated with stemness traits of embryonic cancer cells and epithelial CSCs. We previously reported that BORIS is correlated with the expression of the CSC marker CD90 in hepatocellular carcinoma (HCC). These results encourage us to wonder whether BORIS exerts functions on CSC-like traits of human liver cancer cells. Here, we report that BORIS was enriched in HCC tissues. Exogenous overexpression of BORIS promoted CSC-like properties, including self-renewal, chemoresistance, migration and invasion in Huh7 and HCCLM3 cells. Conversely, BORIS knockdown suppressed CSC-like properties in SMMC-7721 and HepG2 cells and inhibited tumorigenicity in SMMC-7721 cells. Moreover, BORIS alteration did not affect the DNA methylation status of the minimal promoter and exon 1 region of OCT4. However, BORIS overexpression enhanced the amount of BORIS bound on the OCT4 promoter and increased H3K4me2, while reducing H3K27me3; BORIS depletion decreased BORIS and H3K4me2 on the OCT4 promoter, while increasing H3K27me3. These results revealed that BORIS is associated with the CSC-like traits of human liver cancer cells through the epigenetic regulation of OCT4. Copyright © 2017 Elsevier B.V. All rights reserved.

Computational Fluid Dynamics Requirements at the Naval Postgraduate School.

DTIC Science & Technology

1986-10-01

FIELD ANALYSIS OF WING-FUSELAGE .1?CONFIGURATION r 13. PROFILE- THE EPPLER PROGRAM FOR THE DESIGN AND ANALYSIS OF LOW-SPEED AIRFOILS 14. AERODYNAMIC...POSTORRDUATE SCHOOL(U) VI IJE UNIV MAUSSELS (ELGIUM) C HIRSCH 61 OCT 96 NPS-67-S6-007CR M62271-06-M-0242 UNCLSSIFIED F/0 26/4 NE"I ChE’i...codes Under this group ons can list the codes KELLER BOX METHOD FOR BOUNDARY LAYERS VISCID-INVISCID INTERACTION ON AIRFOIL FLOW OVER WING-BODY JUNCTION

Therapeutic Role of Bmi-1 Inhibitors in Eliminating Prostate Tumor Stem Cells

DTIC Science & Technology

2014-10-01

Res 62:4736-45, (2002). PMC: 12183433. 14. Liu S, Dontu G, Mantle ID, Patel S, Ahn NS, Jackson KW, Suri P, Wicha MS. Hedgehog signaling and Bmi-1...Among these interacting pathways are BMI-1, OCT3/4, Hedgehog (Hh), Wnt/β-catenin, Notch signaling, Hox gene family, PTEN/Akt pathway, efflux...cancer, and cancer stem cells. Nature 414, 105-111 (2001). 50. Liu, S., et al. Hedgehog signaling and Bmi-1 regulate self-renewal of normal and

Optical coherence tomography (OCT) of a murine model of chronic kidney disease

NASA Astrophysics Data System (ADS)

Wang, Hsing-Wen; Guo, Hengchang; Andrews, Peter M.; Anderson, Erik; Chen, Y.

2015-03-01

Chronic Kidney Disease (CKD) is characterized by a progressive loss in renal function over time. Pathology can provide valuable insights into the progression of CKD by analyzing the status of glomeruli and the uriniferous tubules over time. Optical coherence tomography (OCT) is a new procedure that can analyze the microscopic structure of the kidney in a non-invasive manner. This is especially important because there are significant artifacts associated with excision biopsies and immersion fixation procedures. Recently, we have shown that OCT can provide real time images of kidney microstructure and Doppler OCT (DOCT) can image glomerular renal blood flow in vivo without administrating exogenous contrast agents. In this study, we used OCT to evaluate CKD in a model induced by intravenous Adriamycin injection into Munich-Wistar rats. We evaluated tubular density and tubular diameter from OCT images at several post- Adriamycin induction time points and compared them with conventional light microscopic histological imaging. Proteinurea and serum creatinine were used as physiological markers of the extent of CKD. Preliminary OCT results revealed changes in tubular density due to tubular necrosis and interstitial fibrosis within the first 4 weeks following Adriamycin injection. From week 4 to 8 after Adriamycin induction, changes in tubular density and diameter occurred due to both tubular loss and tubular dilation. The results suggest OCT can provide additional information about kidney histopathology in CKD. DOCT revealed reduced blood flow in some glomeruli probably as a consequence of focal glomerularsclerosis.

Common path ball lens probe for optical coherence tomography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Singh, Kanwarpal; Yamada, Daisuke; Tearney, Guillermo J.

2016-02-01

Background: Common path probes are highly desirable for optical coherence tomography (OCT) as they reduce system complexity and cost. In this work we report an all-fiber common path side viewing monolithic probe for coronary artery imaging. Methods: Our common path probe was designed for spectrometer based Fourier domain OCT at 1310 nm wavelength. Light from the fiber expands in the coreless fiber region and then focussed by the ball lens. Reflection from ball lens-air interface served as reference signal. The monolithic ball lens probe was assembled within a 560 µmouter diameter drive shaft which was attached to a rotary junction. The drive shaft was placed inside an outer, transparent sheath of 800 µm diameter. Results: With a source input power of 25 mW, we could achieve sensitivity of 100.5 dB. The axial resolution of the system was found to be 15.6 µm in air and the lateral resolution (full width half maximum) was approximately 49 µm. As proof of principal, images of skin acquired using this probe demonstrated clear visualization of the stratum corneum, epidermis, and papillary dermis, along with sweat ducts. Conclusion: In this work we have demonstrated a monolithic, ball lens common, path probe for OCT imaging. The designed ball lens probe is easy to fabricate using a laser splicer. Based on the features and capability of common path probes to provide a simpler solution for OCT, we believe that this development will be an important enhancement for certain types of catheters.

Spectral Domain Optical Coherence Tomographic Findings of Bietti Crystalline Dystrophy

PubMed Central

Öner, Ferit Hakan

2014-01-01

We analyzed the OCT features of 24 eyes of 12 patients with Bietti crystalline dystrophy (BCD) with the Heidelberg HRA2-OCT. Seventeen of 24 eyes were in intermediate stage of the disease and seven in advanced stage of the disease at the time of latest OCT examination performed in 2014. Outer retinal tubulations and retinal hyperreflective dots were present in 20 of 24 eyes. The remaining four eyes had advanced disease with very thin retina. Appearance of bright plaque on top of RPE-Bruch membrane was present in all eyes. Choroidal hyperreflective spots were noted in 19 of 24 eyes. The remaining five eyes had advanced disease stage with very thin choroid. Mean central macular thickness was 163.08 μm ± 62.52 for all eyes (170.35 μm ± 56.46 in eyes with intermediate disease and 145.42 μm ± 77.2 in eyes with advanced disease). Mean subfoveal choroidal thickness was 95.37 μm ± 55.93 for the study eyes (116.47 ± 46.92 μm in eyes with intermediate disease and 44.14 μm ± 42.43 in eyes with advanced disease). Choroidal hyperreflective spots were noted in 21 of 24 eyes (87.5%). SD-OCT shows the disease progression in retinal and choroidal layers delicately in eyes with BCD and expands our knowledge about the ongoing disease process. PMID:25505979

Segmentation of microcystic macular edema in Cirrus OCT scans with an exploratory longitudinal study

NASA Astrophysics Data System (ADS)

Swingle, Emily K.; Lang, Andrew; Carass, Aaron; Al-Louzi, Omar; Saidha, Shiv; Prince, Jerry L.; Calabresi, Peter A.

2015-03-01

Microcystic macular edema (MME) is a term used to describe pseudocystic spaces in the inner nuclear layer (INL) of the human retina. It has been noted in multiple sclerosis (MS) as well as a variety of other diseases. The processes that lead to MME formation and their change over time have yet to be explained sufficiently. The low rate at which MME occurs within such diverse patient groups makes the identification and consistent quantification of this pathology important for developing patient-specific prognoses. MME is observed in optical coherence tomography (OCT) scans of the retina as changes in light reflectivity in a pattern suggestive of fluid accumulations called pseudocysts. Pseudocysts can be readily identified in higher signal-to-noise ratio (SNR) images, however pseudocysts can be indistinguishable from noise in lower SNR scans. In this work, we expand upon our earlier MME identification methods on Spectralis OCT scans to handle lower quality Cirrus OCT scans. Our approach uses a random forest classifier, trained on manual segmentation of ten subjects, to automatically detect MME. The algorithm has a true positive rate for MME identification of 0.95 and a Dice score of 0.79. We include a preliminary longitudinal study of three patients over four to five years to explore the longitudinal changes of MME. The patients with relapsing-remitting MS and neuromyelitis optica appear to have dynamic pseudocyst volumes, while the MME volume appears stable in the one patient with primary progressive MS.

Expression of drug transporters and drug metabolizing enzymes in the bladder urothelium in man and affinity of the bladder spasmolytic trospium chloride to transporters likely involved in its pharmacokinetics.

PubMed

Bexten, Maria; Oswald, Stefan; Grube, Markus; Jia, Jia; Graf, Tanja; Zimmermann, Uwe; Rodewald, Kathrin; Zolk, Oliver; Schwantes, Ulrich; Siegmund, Werner; Keiser, Markus

2015-01-05

The cationic, water-soluble quaternary trospium chloride (TC) is incompletely absorbed from the gut and undergoes wide distribution but does not pass the blood-brain barrier. It is secreted by the kidneys, liver, and intestine. To evaluate potential transport mechanisms for TC, we measured affinity of the drug to the human uptake and efflux transporters known to be of pharmacokinetic relevance. Affinity of TC to the uptake transporters OATP1A2, -1B1, -1B3, -2B1, OCT1, -2, -3, OCTN2, NTCP, and ASBT and the efflux carriers P-gp, MRP2 and MRP3 transfected in HEK293 and MDCK2 cells was measured. To identify relevant pharmacokinetic mechanisms in the bladder urothelium, mRNA expression of multidrug transporters, drug metabolizing enzymes, and nuclear receptors, and the uptake of TC into primary human bladder urothelium (HBU) cells were measured. TC was shown to be a substrate of OATP1A2 (Km = 6.9 ± 1.3 μmol/L; Vmax = 41.6 ± 1.8 pmol/mg·min), OCT1 (Km = 106 ± 16 μmol/L; Vmax = 269 ± 18 pmol/mg·min), and P-gp (Km = 34.9 ± 7.5 μmol/L; Vmax = 105 ± 9.1 pmol/mg·min, lipovesicle assay). The genetic OATP1A2 variants *2 and *3 were loss-of-function transporters for TC. The mRNA expression analysis identified the following transporter proteins in the human urothelium: ABCB1 (P-gp), ABCC1-5 (MRP1-5), ABCG2 (BCRP), SLCO2B1 (OATP2B1), SLCO4A1 (OATP4A1), SLC22A1 (OCT1), SLC22A3 (OCT3), SLC22A4 (OCTN1), SLC22A5 (OCTN2), and SLC47A1 (MATE1). Immuno-reactive P-gp and OATP1A2 were localized to the apical cell layers. Drug metabolizing enzymes CYP3A5, -2B6, -2B7 -2E1, SULT1A1-4, UGT1A1-10, and UGT2B15, and nuclear receptors NR1H3 and NR1H4 were also expressed on mRNA level. TC was taken up into HBU cells (Km = 18.5 ± 4.8 μmol/L; Vmax = 106 ± 11.3 pmol/mg·min) by mechanisms that could be synergistically inhibited by naringin (IC50 = 10.8 (8.4; 13.8) μmol/L) and verapamil (IC50 = 4.6 (2.8; 7.5) μmol/L), inhibitors of OATP1A2 and OCT1, respectively. Affinity of TC to OCT1 and P-glycoprotein may be the reason for incomplete oral absorption, wide distribution into liver and kidneys, and substantial intestinal and renal secretions. Absence of brain distribution may result from affinity to P-gp and a low affinity to OATP1A2. The human urothelium expresses many drug transporters and drug metabolizing enzymes that may interact with TC and other drugs eliminated into the urine.

Optical coherence tomography for glucose monitoring in blood

NASA Astrophysics Data System (ADS)

Ullah, Hafeez; Hussain, Fayyaz; Ikram, Masroor

2015-08-01

In this review, we have discussed the potential application of the emerging imaging modality, i.e., optical coherence tomography (OCT) for glucose monitoring in biological tissues. OCT provides monitoring of glucose diffusion in different fibrous tissues like in sclera by determining the permeability rate with acceptable accuracy both in type 1 and in type 2 diabetes. The maximum precision of glucose measurement in Intralipid suspensions, for example, with the OCT technique yields the accuracy up to 4.4 mM for 10 % Intralipid and 2.2 mM for 3 % Intralipid.

Automated segmentation of intraretinal layers from macular optical coherence tomography images

NASA Astrophysics Data System (ADS)

Haeker, Mona; Sonka, Milan; Kardon, Randy; Shah, Vinay A.; Wu, Xiaodong; Abràmoff, Michael D.

2007-03-01

Commercially-available optical coherence tomography (OCT) systems (e.g., Stratus OCT-3) only segment and provide thickness measurements for the total retina on scans of the macula. Since each intraretinal layer may be affected differently by disease, it is desirable to quantify the properties of each layer separately. Thus, we have developed an automated segmentation approach for the separation of the retina on (anisotropic) 3-D macular OCT scans into five layers. Each macular series consisted of six linear radial scans centered at the fovea. Repeated series (up to six, when available) were acquired for each eye and were first registered and averaged together, resulting in a composite image for each angular location. The six surfaces defining the five layers were then found on each 3-D composite image series by transforming the segmentation task into that of finding a minimum-cost closed set in a geometric graph constructed from edge/regional information and a priori-determined surface smoothness and interaction constraints. The method was applied to the macular OCT scans of 12 patients with unilateral anterior ischemic optic neuropathy (corresponding to 24 3-D composite image series). The boundaries were independently defined by two human experts on one raw scan of each eye. Using the average of the experts' tracings as a reference standard resulted in an overall mean unsigned border positioning error of 6.7 +/- 4.0 μm, with five of the six surfaces showing significantly lower mean errors than those computed between the two observers (p < 0.05, pixel size of 50 × 2 μm).

Scalable topographies to support proliferation and Oct4 expression by human induced pluripotent stem cells

PubMed Central

Reimer, Andreas; Vasilevich, Aliaksei; Hulshof, Frits; Viswanathan, Priyalakshmi; van Blitterswijk, Clemens A.; de Boer, Jan; Watt, Fiona M.

2016-01-01

It is well established that topographical features modulate cell behaviour, including cell morphology, proliferation and differentiation. To define the effects of topography on human induced pluripotent stem cells (iPSC), we plated cells on a topographical library containing over 1000 different features in medium lacking animal products (xeno-free). Using high content imaging, we determined the effect of each topography on cell proliferation and expression of the pluripotency marker Oct4 24 h after seeding. Features that maintained Oct4 expression also supported proliferation and cell-cell adhesion at 24 h, and by 4 days colonies of Oct4-positive, Sox2-positive cells had formed. Computational analysis revealed that small feature size was the most important determinant of pluripotency, followed by high wave number and high feature density. Using this information we correctly predicted whether any given topography within our library would support the pluripotent state at 24 h. This approach not only facilitates the design of substrates for optimal human iPSC expansion, but also, potentially, identification of topographies with other desirable characteristics, such as promoting differentiation. PMID:26757610

Scalable topographies to support proliferation and Oct4 expression by human induced pluripotent stem cells.

PubMed

Reimer, Andreas; Vasilevich, Aliaksei; Hulshof, Frits; Viswanathan, Priyalakshmi; van Blitterswijk, Clemens A; de Boer, Jan; Watt, Fiona M

2016-01-13

It is well established that topographical features modulate cell behaviour, including cell morphology, proliferation and differentiation. To define the effects of topography on human induced pluripotent stem cells (iPSC), we plated cells on a topographical library containing over 1000 different features in medium lacking animal products (xeno-free). Using high content imaging, we determined the effect of each topography on cell proliferation and expression of the pluripotency marker Oct4 24 h after seeding. Features that maintained Oct4 expression also supported proliferation and cell-cell adhesion at 24 h, and by 4 days colonies of Oct4-positive, Sox2-positive cells had formed. Computational analysis revealed that small feature size was the most important determinant of pluripotency, followed by high wave number and high feature density. Using this information we correctly predicted whether any given topography within our library would support the pluripotent state at 24 h. This approach not only facilitates the design of substrates for optimal human iPSC expansion, but also, potentially, identification of topographies with other desirable characteristics, such as promoting differentiation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salmina, Kristine, E-mail: kristine@biomed.lu.lv; Jankevics, Eriks, E-mail: eriks@biomed.lu.lv; Huna, Anda, E-mail: anima-l@inbox.lv

We have previously documented that transient polyploidy is a potential cell survival strategy underlying the clonogenic re-growth of tumour cells after genotoxic treatment. In an attempt to better define this mechanism, we recently documented the key role of meiotic genes in regulating the DNA repair and return of the endopolyploid tumour cells (ETC) to diploidy through reduction divisions after irradiation. Here, we studied the role of the pluripotency and self-renewal stem cell genes NANOG, OCT4 and SOX2 in this polyploidy-dependent survival mechanism. In irradiation-resistant p53-mutated lymphoma cell-lines (Namalwa and WI-L2-NS) but not sensitive p53 wild-type counterparts (TK6), low background expressionmore » of OCT4 and NANOG was up-regulated by ionising radiation with protein accumulation evident in ETC as detected by OCT4/DNA flow cytometry and immunofluorescence (IF). IF analysis also showed that the ETC generate PML bodies that appear to concentrate OCT4, NANOG and SOX2 proteins, which extend into complex nuclear networks. These polyploid tumour cells resist apoptosis, overcome cellular senescence and undergo bi- and multi-polar divisions transmitting the up-regulated OCT4, NANOG and SOX2 self-renewal cassette to their descendents. Altogether, our observations indicate that irradiation-induced ETC up-regulate key components of germ-line cells, which potentially facilitate survival and propagation of the tumour cell population.« less

JPRS Report, East Europe.

DTIC Science & Technology

1992-11-20

Convention [DELO 6 Nov] 33 Transportation Agreement Talks Held With EC [DELO 2 Nov] 33 Government, Unions Sign Collective Contract [DELO 30 Oct] 34...the standpoint of current payments. Although it is possible that the forint’s de facto convertibility has expanded in a relative sense, it does not...They intend to continue this restriction for a while—and appropriately so, in my view. On the other hand, the forint’s de facto external

USSR Report. Consumer Goods and Domestic Trade, No. 78.

DTIC Science & Technology

1983-11-10

Supplies (Moscow Domestic Service, 12 Oct 83) 50 Expanding Trade in Collective Farm Markets (M. Malyshenko; SOVETSKAYA TORGOVLYA, No 7 , Jul 83...current concerns of our party is the improvement in the quality of life of the Soviet people . This is clearly evident in the Food Program of the USSR...the agricultural organizations must provide the people with stocks of young animals and fowl. Today the collective and state farms sell to the

Korean Affairs Report.

DTIC Science & Technology

1986-11-10

Kim Il-song University (KCNA, 17 Oct 86) 55 KOREANS IN JAPAN Chongnyon Agrees To Found ’International Joint Venture Company ’ (VANTAGE POINT...learned that the Soviet Union promised to build a nuclear power plant in North Korea and that it began to supply North Korea with MiG-23 aircraft in 1985... designed to expand toward Asia and the Pacific with the Soviet Union’s powerful Pacific Fleet—which has been con- sistently strengthened over the past

Structure-based discovery of NANOG variant with enhanced properties to promote self-renewal and reprogramming of pluripotent stem cells

DOE PAGES

Hayashi, Yohei; Caboni, Laura; Das, Debanu; ...

2015-03-30

NANOG (from Irish mythology Tír na nÓg) transcription factor plays a central role in maintaining pluripotency, cooperating with OCT4 (also known as POU5F1 or OCT3/4), SOX2, and other pluripotency factors. Although the physiological roles of the NANOG protein have been extensively explored, biochemical and biophysical properties in relation to its structural analysis are poorly understood. Here we determined the crystal structure of the human NANOG homeodomain (hNANOG HD) bound to an OCT4 promoter DNA, which revealed amino acid residues involved in DNA recognition that are likely to be functionally important. We generated a series of hNANOG HD alanine substitution mutantsmore » based on the protein–DNA interaction and evolutionary conservation and determined their biological activities. Some mutant proteins were less stable, resulting in loss or decreased affinity for DNA binding. Overexpression of the orthologous mouse NANOG (mNANOG) mutants failed to maintain self-renewal of mouse embryonic stem cells without leukemia inhibitory factor. These results suggest that these residues are critical for NANOG transcriptional activity. Interestingly, one mutant, hNANOG L122A, conversely enhanced protein stability and DNA-binding affinity. The mNANOG L122A, when overexpressed in mouse embryonic stem cells, maintained their expression of self-renewal markers even when retinoic acid was added to forcibly drive differentiation. When overexpressed in epiblast stem cells or human induced pluripotent stem cells, the L122A mutants enhanced reprogramming into ground-state pluripotency. These findings indicate that structural and biophysical information on key transcriptional factors provides insights into the manipulation of stem cell behaviors and a framework for rational protein engineering.« less

Structure-based discovery of NANOG variant with enhanced properties to promote self-renewal and reprogramming of pluripotent stem cells

PubMed Central

Hayashi, Yohei; Caboni, Laura; Das, Debanu; Yumoto, Fumiaki; Clayton, Thomas; Deller, Marc C.; Nguyen, Phuong; Farr, Carol L.; Chiu, Hsiu-Ju; Miller, Mitchell D.; Elsliger, Marc-André; Deacon, Ashley M.; Godzik, Adam; Lesley, Scott A.; Tomoda, Kiichiro; Conklin, Bruce R.; Wilson, Ian A.; Yamanaka, Shinya; Fletterick, Robert J.

2015-01-01

NANOG (from Irish mythology Tír na nÓg) transcription factor plays a central role in maintaining pluripotency, cooperating with OCT4 (also known as POU5F1 or OCT3/4), SOX2, and other pluripotency factors. Although the physiological roles of the NANOG protein have been extensively explored, biochemical and biophysical properties in relation to its structural analysis are poorly understood. Here we determined the crystal structure of the human NANOG homeodomain (hNANOG HD) bound to an OCT4 promoter DNA, which revealed amino acid residues involved in DNA recognition that are likely to be functionally important. We generated a series of hNANOG HD alanine substitution mutants based on the protein–DNA interaction and evolutionary conservation and determined their biological activities. Some mutant proteins were less stable, resulting in loss or decreased affinity for DNA binding. Overexpression of the orthologous mouse NANOG (mNANOG) mutants failed to maintain self-renewal of mouse embryonic stem cells without leukemia inhibitory factor. These results suggest that these residues are critical for NANOG transcriptional activity. Interestingly, one mutant, hNANOG L122A, conversely enhanced protein stability and DNA-binding affinity. The mNANOG L122A, when overexpressed in mouse embryonic stem cells, maintained their expression of self-renewal markers even when retinoic acid was added to forcibly drive differentiation. When overexpressed in epiblast stem cells or human induced pluripotent stem cells, the L122A mutants enhanced reprogramming into ground-state pluripotency. These findings demonstrate that structural and biophysical information on key transcriptional factors provides insights into the manipulation of stem cell behaviors and a framework for rational protein engineering. PMID:25825768

Structure-based discovery of NANOG variant with enhanced properties to promote self-renewal and reprogramming of pluripotent stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayashi, Yohei; Caboni, Laura; Das, Debanu

NANOG (from Irish mythology Tír na nÓg) transcription factor plays a central role in maintaining pluripotency, cooperating with OCT4 (also known as POU5F1 or OCT3/4), SOX2, and other pluripotency factors. Although the physiological roles of the NANOG protein have been extensively explored, biochemical and biophysical properties in relation to its structural analysis are poorly understood. Here we determined the crystal structure of the human NANOG homeodomain (hNANOG HD) bound to an OCT4 promoter DNA, which revealed amino acid residues involved in DNA recognition that are likely to be functionally important. We generated a series of hNANOG HD alanine substitution mutantsmore » based on the protein–DNA interaction and evolutionary conservation and determined their biological activities. Some mutant proteins were less stable, resulting in loss or decreased affinity for DNA binding. Overexpression of the orthologous mouse NANOG (mNANOG) mutants failed to maintain self-renewal of mouse embryonic stem cells without leukemia inhibitory factor. These results suggest that these residues are critical for NANOG transcriptional activity. Interestingly, one mutant, hNANOG L122A, conversely enhanced protein stability and DNA-binding affinity. The mNANOG L122A, when overexpressed in mouse embryonic stem cells, maintained their expression of self-renewal markers even when retinoic acid was added to forcibly drive differentiation. When overexpressed in epiblast stem cells or human induced pluripotent stem cells, the L122A mutants enhanced reprogramming into ground-state pluripotency. These findings indicate that structural and biophysical information on key transcriptional factors provides insights into the manipulation of stem cell behaviors and a framework for rational protein engineering.« less

Optical coherence tomography to evaluate variance in the extent of carious lesions in depth.

PubMed

Park, Kyung-Jin; Schneider, Hartmut; Ziebolz, Dirk; Krause, Felix; Haak, Rainer

2018-05-03

Evaluation of variance in the extent of carious lesions in depth at smooth surfaces within the same ICDAS code group using optical coherence tomography (OCT) in vitro and in vivo. (1) Verification/validation of OCT to assess non-cavitated caries: 13 human molars with ICDAS code 2 at smooth surfaces were imaged using OCT and light microscopy. Regions of interest (ROI) were categorized according to the depth of carious lesions. Agreement between histology and OCT was determined by unweighted Cohen's Kappa and Wilcoxon test. (2) Assessment of 133 smooth surfaces using ICDAS and OCT in vitro, 49 surfaces in vivo. ROI were categorized according to the caries extent (ICDAS: codes 0-4, OCT: scoring based on lesion depth). A frequency distribution of the OCT scores for each ICDAS code was determined. (1) Histology and OCT agreed moderately (κ = 0.54, p ≤ 0.001) with no significant difference between both methods (p = 0.25). The lesions (76.9% (10 of 13)) _were equally scored. (2) In vitro, OCT revealed caries in 42% of ROI clinically assessed as sound. OCT detected dentin-caries in 40% of ROIs visually assessed as enamel-caries. In vivo, large differences between ICDAS and OCT were observed. Carious lesions of ICDAS codes 1 and 2 vary largely in their extent in depth.

Sensitivity and specificity of machine learning classifiers and spectral domain OCT for the diagnosis of glaucoma.

PubMed

Vidotti, Vanessa G; Costa, Vital P; Silva, Fabrício R; Resende, Graziela M; Cremasco, Fernanda; Dias, Marcelo; Gomi, Edson S

2012-06-15

Purpose. To investigate the sensitivity and specificity of machine learning classifiers (MLC) and spectral domain optical coherence tomography (SD-OCT) for the diagnosis of glaucoma. Methods. Sixty-two patients with early to moderate glaucomatous visual field damage and 48 healthy individuals were included. All subjects underwent a complete ophthalmologic examination, achromatic standard automated perimetry, and RNFL imaging with SD-OCT (Cirrus HD-OCT; Carl Zeiss Meditec, Inc., Dublin, California, USA). Receiver operating characteristic (ROC) curves were obtained for all SD-OCT parameters. Subsequently, the following MLCs were tested: Classification Tree (CTREE), Random Forest (RAN), Bagging (BAG), AdaBoost M1 (ADA), Ensemble Selection (ENS), Multilayer Perceptron (MLP), Radial Basis Function (RBF), Naive-Bayes (NB), and Support Vector Machine (SVM). Areas under the ROC curves (aROCs) obtained for each parameter and each MLC were compared. Results. The mean age was 57.0±9.2 years for healthy individuals and 59.9±9.0 years for glaucoma patients (p=0.103). Mean deviation values were -4.1±2.4 dB for glaucoma patients and -1.5±1.6 dB for healthy individuals (p<0.001). The SD-OCT parameters with the greater aROCs were inferior quadrant (0.813), average thickness (0.807), 7 o'clock position (0.765), and 6 o'clock position (0.754). The aROCs from classifiers varied from 0.785 (ADA) to 0.818 (BAG). The aROC obtained with BAG was not significantly different from the aROC obtained with the best single SD-OCT parameter (p=0.93). Conclusions. The SD-OCT showed good diagnostic accuracy in a group of patients with early glaucoma. In this series, MLCs did not improve the sensitivity and specificity of SD-OCT for the diagnosis of glaucoma.

Multimodal swept-source spectrally encoded scanning laser ophthalmoscopy and optical coherence tomography at 400 kHz

NASA Astrophysics Data System (ADS)

El-Haddad, Mohamed T.; Joos, Karen M.; Patel, Shriji N.; Tao, Yuankai K.

2017-02-01

Multimodal imaging systems that combine scanning laser ophthalmoscopy (SLO) and optical coherence tomography (OCT) have demonstrated the utility of concurrent en face and volumetric imaging for aiming, eye tracking, bulk motion compensation, mosaicking, and contrast enhancement. However, this additional functionality trades off with increased system complexity and cost because both SLO and OCT generally require dedicated light sources, galvanometer scanners, relay and imaging optics, detectors, and control and digitization electronics. We previously demonstrated multimodal ophthalmic imaging using swept-source spectrally encoded SLO and OCT (SS-SESLO-OCT). Here, we present system enhancements and a new optical design that increase our SS-SESLO-OCT data throughput by >7x and field-of-view (FOV) by >4x. A 200 kHz 1060 nm Axsun swept-source was optically buffered to 400 kHz sweep-rate, and SESLO and OCT were simultaneously digitized on dual input channels of a 4 GS/s digitizer at 1.2 GS/s per channel using a custom k-clock. We show in vivo human imaging of the anterior segment out to the limbus and retinal fundus over a >40° FOV. In addition, nine overlapping volumetric SS-SESLO-OCT volumes were acquired under video-rate SESLO preview and guidance. In post-processing, all nine SESLO images and en face projections of the corresponding OCT volumes were mosaicked to show widefield multimodal fundus imaging with a >80° FOV. Concurrent multimodal SS-SESLO-OCT may have applications in clinical diagnostic imaging by enabling aiming, image registration, and multi-field mosaicking and benefit intraoperative imaging by allowing for real-time surgical feedback, instrument tracking, and overlays of computationally extracted image-based surrogate biomarkers of disease.

14 CFR 21.27 - Issue of type certificate: surplus aircraft of the Armed Forces.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 1 Small reciprocating-engine powered airplanes Before May 16, 1956After May 15, 1956 CAR Part 3, as effective May 15, 1956.CAR Part 3, or FAR Part 23. Small turbine engine-powered airplanes Before Oct. 2... Part 25. Large turbine engine-powered airplanes Before Oct. 2, 1959After Oct. 1, 1959 CAR Part 4b, as...

5 CFR 733.107 - Designated localities.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., 1940). Greenbelt (Oct. 4, 1940). Howard County (April 25, 1974). Hyattsville (Sept. 20, 1940...). Somerset (Nov. 22, 1940). Takoma Park (Oct. 22, 1940). University Park (Jan. 18, 1941). Washington Grove...

Nanofibrous substrates support colony formation and maintain stemness of human embryonic stem cells

PubMed Central

Gauthaman, Kalamegam; Venugopal, Jayarama Reddy; Yee, Fong Chui; Peh, Gary Swee Lim; Ramakrishna, Seeram; Bongso, Ariff

2009-01-01

Inadequate cell numbers in culture is one of the hurdles currently delaying the application of human embryonic stem cells (hESCs) for transplantation therapy. Nanofibrous scaffolds have been effectively used to expand and differentiate non-colony forming multipotent mesenchymal stem cells (MSC) for the repair of tissues or organs. In the present study, we evaluated the influence of nanofibrous scaffolds for hESC proliferation, increase in colony formation, self-renewal properties, undifferentiation and retention of ‘stemness’. Polycaprolactone/collagen (PCL/collagen) and PCL/gelatin nanofibrous scaffolds were fabricated using electrospinning technology. The hESCs were seeded on the nanofibrous scaffolds in the presence or absence of mitomycin-C treated mouse embryonic fibroblasts (MEFs). The hESCs grown on both scaffolds in the presence of the MEFs produced an increase in cell growth of 47.58% (P≤ 0.006) and 40.18% (P≤ 0.005), respectively, over conventional controls of hESCs on MEFs alone. The hESC colonies were also larger in diameter on the scaffolds compared to controls (PCL/collagen, 156.25 ± 7 μM and PCL/gelatin, 135.42 ± 5 μM). Immunohistochemistry of the hESCs grown on the nanofibrous scaffolds with MEFs, demonstrated positive staining for the various stemness-related markers (octamer 4 [OCT-4], tumour rejection antigen-1–60, GCTM-2 and TG-30), and semi-quantitative RT-PCR for the pluripotent stemness genomic markers (NANOG, SOX-2, OCT-4) showed that they were also highly expressed. Continued successful propagation of hESC colonies from nanofibrous scaffolds back to conventional culture on MEFs was also possible. Nanofibrous scaffolds support hESC expansion in an undifferentiated state with retention of stemness characteristics thus having tremendous potential in scaling up cell numbers for transplantation therapy. PMID:19228268

Sperm 1: a POU-domain gene transiently expressed immediately before meiosis I in the male germ cell.

PubMed Central

Andersen, B; Pearse, R V; Schlegel, P N; Cichon, Z; Schonemann, M D; Bardin, C W; Rosenfeld, M G

1993-01-01

Members of the POU-domain gene family encode for transcriptional regulatory molecules that are important for terminal differentiation of several organ systems, including anterior pituitary, sensory neurons, and B lymphocytes. We have identified a POU-domain factor, referred to as sperm 1 (Sprm-1). This factor is most related to the transactivator Oct-3/4, which is expressed in the early embryo, primordial germ cells, and the egg. However, in contrast with Oct-3/4, rat Sprm-1 is selectively expressed during a 36- to 48-hr period immediately preceding meiosis I in male germ cells. Although the POU-domain of Sprm-1 is divergent from the POU-domains of Oct-1 and Oct-2, random-site-selection assay reveals that Sprm-1 preferentially binds to a specific variant of the classic octamer DNA-response element in which the optimal sequence differs from that preferred by Oct-1 and Pit-1. These data suggest that the Sprm-1 gene encodes a DNA-binding protein that may exert a regulatory function in meiotic events that are required for terminal differentiation of the male germ cell. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:7902581

In vivo imaging of coral tissue and skeleton with optical coherence tomography

PubMed Central

Wentzel, Camilla; Jacques, Steven L.; Wagner, Michael

2017-01-01

Application of optical coherence tomography (OCT) for in vivo imaging of tissue and skeleton structure of intact living corals enabled the non-invasive visualization of coral tissue layers (endoderm versus ectoderm), skeletal cavities and special structures such as mesenterial filaments and mucus release from intact living corals. Coral host chromatophores containing green fluorescent protein-like pigment granules appeared hyper-reflective to near-infrared radiation allowing for excellent optical contrast in OCT and a rapid characterization of chromatophore size, distribution and abundance. In vivo tissue plasticity could be quantified by the linear contraction velocity of coral tissues upon illumination resulting in dynamic changes in the live coral tissue surface area, which varied by a factor of 2 between the contracted and expanded state of a coral. Our study provides a novel view on the in vivo organization of coral tissue and skeleton and highlights the importance of microstructural dynamics for coral ecophysiology. PMID:28250104

Micro-optical coherence tomography tracking of magnetic gene transfection via Au-Fe3O4 dumbbell nanoparticles

NASA Astrophysics Data System (ADS)

Shi, Wei; Liu, Xinyu; Wei, Chao; Xu, Zhichuan J.; Sim, Stanley Siong Wei; Liu, Linbo; Xu, Chenjie

2015-10-01

Heterogeneous Au-Fe3O4 dumbbell nanoparticles (NPs) are composed of Au NPs and Fe3O4 NPs that bring in optical and magnetic properties respectively. This article reports the engineering of Au-Fe3O4 NPs as gene carriers for magnetic gene transfection as well as contrast agents for micro-optical coherence tomography (μOCT). As a proof-of-concept, Au-Fe3O4 NPs are used to deliver the green fluorescent protein to HEK 293T cells and their entrance into the cells is monitored through μOCT.Heterogeneous Au-Fe3O4 dumbbell nanoparticles (NPs) are composed of Au NPs and Fe3O4 NPs that bring in optical and magnetic properties respectively. This article reports the engineering of Au-Fe3O4 NPs as gene carriers for magnetic gene transfection as well as contrast agents for micro-optical coherence tomography (μOCT). As a proof-of-concept, Au-Fe3O4 NPs are used to deliver the green fluorescent protein to HEK 293T cells and their entrance into the cells is monitored through μOCT. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr05459a

The Properties of Outer Retinal Band Three Investigated With Adaptive-Optics Optical Coherence Tomography.

PubMed

Jonnal, Ravi S; Gorczynska, Iwona; Migacz, Justin V; Azimipour, Mehdi; Zawadzki, Robert J; Werner, John S

2017-09-01

Optical coherence tomography's (OCT) third outer retinal band has been attributed to the zone of interdigitation between RPE cells and cone outer segments. The purpose of this paper is to investigate the structure of this band with adaptive optics (AO)-OCT. Using AO-OCT, images were obtained from two subjects. Axial structure was characterized by measuring band 3 thickness and separation between bands 2 and 3 in segmented cones. Lateral structure was characterized by correlation of band 3 with band 2 and comparison of their power spectra. Band thickness and separation were also measured in a clinical OCT image of one subject. Band 3 thickness ranged from 4.3 to 6.4 μm. Band 2 correlations ranged between 0.35 and 0.41 and power spectra of both bands confirmed peak frequencies that agree with histologic density measurements. In clinical images, band 3 thickness was between 14 and 19 μm. Measurements of AO-OCT of interband distance were lower than our corresponding clinical OCT measurements. Band 3 originates from a structure with axial extent similar to a single surface. Correlation with band 2 suggests an origin within the cone photoreceptor. These two observations indicate that band 3 corresponds predominantly to cone outer segment tips (COST). Conventional OCT may overestimate both the thickness of band 3 and outer segment length.

The Properties of Outer Retinal Band Three Investigated With Adaptive-Optics Optical Coherence Tomography

PubMed Central

Jonnal, Ravi S.; Gorczynska, Iwona; Migacz, Justin V.; Azimipour, Mehdi; Zawadzki, Robert J.; Werner, John S.

2017-01-01

Purpose Optical coherence tomography's (OCT) third outer retinal band has been attributed to the zone of interdigitation between RPE cells and cone outer segments. The purpose of this paper is to investigate the structure of this band with adaptive optics (AO)-OCT. Methods Using AO-OCT, images were obtained from two subjects. Axial structure was characterized by measuring band 3 thickness and separation between bands 2 and 3 in segmented cones. Lateral structure was characterized by correlation of band 3 with band 2 and comparison of their power spectra. Band thickness and separation were also measured in a clinical OCT image of one subject. Results Band 3 thickness ranged from 4.3 to 6.4 μm. Band 2 correlations ranged between 0.35 and 0.41 and power spectra of both bands confirmed peak frequencies that agree with histologic density measurements. In clinical images, band 3 thickness was between 14 and 19 μm. Measurements of AO-OCT of interband distance were lower than our corresponding clinical OCT measurements. Conclusions Band 3 originates from a structure with axial extent similar to a single surface. Correlation with band 2 suggests an origin within the cone photoreceptor. These two observations indicate that band 3 corresponds predominantly to cone outer segment tips (COST). Conventional OCT may overestimate both the thickness of band 3 and outer segment length. PMID:28877320

Combining Optical Coherence Tomography with Fluorescence Molecular Imaging: Towards Simultaneous Morphology and Molecular Imaging

PubMed Central

Yuan, Shuai; Roney, Celeste A.; Wierwille, Jerry; Chen, Chao-Wei; Xu, Biying; Jiang, James; Ma, Hongzhou; Cable, Alex; Summers, Ronald M.; Chen, Yu

2010-01-01

Optical coherence tomography (OCT) provides high-resolution, cross-sectional imaging of tissue microstructure in situ and in real-time, while fluorescence molecular imaging (FMI) enables the visualization of basic molecular processes. There are great interests in combining these two modalities so that the tissue's structural and molecular information can be obtained simultaneously. This could greatly benefit biomedical applications such as detecting early diseases and monitoring therapeutic interventions. In this research, an optical system that combines OCT and FMI was developed. The system demonstrated that it could co-register en face OCT and FMI images with a 2.4 × 2.4 mm field of view. The transverse resolutions of OCT and FMI of the system are both ~10 μm. Capillary tubes filled with fluorescent dye Cy 5.5 in different concentrations under a scattering medium are used as the phantom. En face OCT images of the phantoms were obtained and successfully co-registered with FMI images that were acquired simultaneously. A linear relationship between FMI intensity and dye concentration was observed. The relationship between FMI intensity and target fluorescence tube depth measured by OCT images was also observed and compared with theoretical modeling. This relationship could help in correcting reconstructed dye concentration. Imaging of colon polyps of APCmin mouse model is presented as an example of biological applications of this co-registered OCT/FMI system. PMID:20009192

An intrapatient comparison of 99mTc-EDDA/HYNIC-TOC with 111In-DTPA-octreotide for diagnosis of somatostatin receptor-expressing tumors.

PubMed

Gabriel, Michael; Decristoforo, Clemens; Donnemiller, Eveline; Ulmer, Hanno; Watfah Rychlinski, Christine; Mather, Stephen J; Moncayo, Roy

2003-05-01

The aim of this study was to compare the imaging abilities of the recently developed somatostatin analog, (99m)Tc-hydrazinonicotinyl-Tyr(3)-octreotide ((99m)Tc-HYNIC-TOC [(99m)Tc-TOC]), with (111)In-diethylenediaminepentaacetic acid-D-Phe(1)-octreotide ((111)In-OCT [Octreoscan]) in patients undergoing routine somatostatin receptor (SSTR) scintigraphy. Forty-one patients (20 men, 21 women; age range, 29-75 y; mean age, 56.7 y) with either histologically proven or biologically and clinically suspected endocrine tumors were enrolled in the study. Four groups were distinguished: (a) patients being evaluated for the detection and localization of neuroendocrine tumors (n = 6), (b) tumor staging (n = 19), (c) patients being investigated to determine the SSTR status of tumor lesions (n = 11), and (d) patient follow-up studies (n = 5). Each patient received a mean activity of 150 MBq (111)In-OCT and 350-400 MBq (99m)Tc-TOC. Scintigraphy with (99m)Tc-TOC was performed 4 h after injection and scintigraphy with (111)In-OCT was performed 4 and 24 h after injection. SPECT studies of areas of interest were performed 4 h after injection for both tracers as well as at 24 h after injection for (111)In-OCT. The time interval between the studies using each tracer ranged from 2 to 22 d (mean interval, 9.3 d). (111)In-OCT and (99m)Tc-TOC showed an equivalent scan result in 32 patients (78%), 9 cases showed discrepancies (22%), false-negative results with (111)In-OCT were seen in 6 cases (14.6%), whereas (99m)Tc-TOC was false-positive in 2 cases (4.9%). (111)In-OCT was true-negative in both cases. The false-positive findings of the (99m)Tc-TOC studies were caused by nonspecific uptake in the bowel. In 1 case, (99m)Tc-TOC correctly identified a metastasis in the lumbar spine but both scan results were false-positive because of an inflammatory process. In 21 patients with SSTR-expressing tumors, the semiquantitative region-of-interest analysis showed that (99m)Tc-TOC achieved higher tumor-to-normal tissue ratios than (111)In-OCT. This study revealed a higher sensitivity of (99m)Tc-TOC as compared with (111)In-OCT as an imaging agent for the localization of SSTR-expressing tumors. To avoid false-positive findings with (99m)Tc-OCT due to nonspecific tracer accumulation, additional scanning at 1-2 h after injection should be done.

[Chamber Angle Assessment in Clinical Practice - A Comparison between Optical Coherence Tomography and Gonioscopy].

PubMed

Mösler, M P; Werner, J U; Lang, G K

2015-07-01

In glaucoma the structures of the anterior chamber are important for classification, therapy, progression and prognosis. In this context anterior segment optical coherence tomography (AS-OCT) gains more relevance. This study compares AS-OCT with gonioscopy in diagnostic performance of chamber angle (CA) assessment. 104 consecutive subjects with glaucoma underwent AS-OCT imaging using the Visante OCT. RESULTS were compared to gonioscopic grading from patient history using the Shaffer system. In addition, anterior chamber depth (ACD) assessment using slitlamp examination was evaluated as a prognostic factor for chamber angle width (CAW) and verified by AS-OCT measurement. Average CAW was 29° (AS-OCT). 17 % of the CAs that were "wide" in gonioscopy (variance 5-55°), showed a "narrow" CA in AS-OCT. 35 % of the CAs that were "narrow" in gonioscopy (variance 0-39°) showed a "wide" CA in AS-OCT. ACD assessment using slitlamp examination is a good predictor for CAW. In this context the technique provides equal informative value as gonioscopy. In cases of "wide" ACDs it is even superior. The critical ACD for an increased risk of angle closure is 2.4 mm. Concerning the critical ACD (< 2.4 mm) the technique gave the possibility to estimate, whether the patients were in the crucial range or not. Average ACD was 2.7 mm (AS-OCT). A strong correlation (correlation coefficient 0.83) between ACD and CAW was observed. Variation of 1 mm in the ACD leads to a change of 18.9° in the CAW. All patients with angle closure glaucoma were below this threshold and 74 % of patients with critical ACD had "narrow" (AS-OCT) CAs. In the case of routine clinical practice with inexperienced residents or circumstances that make gonioscopy difficult or impossible, optical coherence tomography is an effective alternative to the gold standard and is to some extent even superior. Georg Thieme Verlag KG Stuttgart · New York.

Expression of Transcription Factors and Nuclear Receptors in Mixed Germ Cell-Sex Cord Stromal Tumor and Related Tumors of the Gonads.

PubMed

Roth, Lawrence M; Cheng, Liang

2015-11-01

In this study, we compare the expression of OCT4, SALL4, and TSPYL1 in mixed germ cell-sex cord stromal tumor (MGC-SCST) of either gonad to that of normal adult testis, classic and spermatocytic seminoma, intratubular germ cell neoplasia, unclassified, gonadoblastoma, and dysgerminoma to determine the entity or entities that most closely resemble MGC-SCST by immunohistochemistry of germ cells. The most useful transcription factor was OCT4. In addition, to its already described value in distinguishing germinoma and embryonal carcinoma from yolk sac tumor and in differentiating classic from spermatocytic seminoma, we found that OCT4 is useful in confirming or ruling out potential malignancy in MGC-SCST of either gonad. Expression of OCT4 in most ovarian MGC-SCSTs resembles that of dysgerminoma, whereas most testicular examples resemble that of spermatocytic seminoma and normal adult testis. Thus, most MGC-SCSTs of the ovary are potentially malignant, and corresponding tumors of the testis are mostly benign; however, exceptions likely can be detected by the use of OCT4, potentially leading to more appropriate clinical management in some cases. SALL4 is an underutilized transcription factor that is useful in distinguishing testicular MGC-SCST from sex cord stromal tumor, unclassified in those neoplasms where the germ cells are sparse or unevenly distributed. Compared with other transcription factors studied, TSPY and its congener TSPYL1 have little value in the assessment of germ cell tumors because of their relatively wide range of expression in normal adult testis and in germ cell tumors.

Lower Oncogenic Potential of Human Mesenchymal Stem Cells Derived from Cord Blood Compared to Induced Pluripotent Stem Cells

PubMed Central

Foroutan, T.; Najmi, M.; Kazemi, N.; Hasanlou, M.; Pedram, A.

2015-01-01

Background: In regenerative medicine, use of each of the mesenchymal stem cells derived from bone marrow, cord blood, and adipose tissue, has several cons and pros. Mesenchymal stem cells derived from cord blood have been considered the best source for precursor transplantation. Direct reprogramming of a somatic cell into induced pluripotent stem cells by over-expression of 6 transcription factors Oct4, Sox2, Klf4, lin28, Nanog, and c-Myc has great potential for regenerative medicine, eliminating the ethical issues of embryonic stem cells and the rejection problems of using non-autologous cells. Objective: To compare reprogramming and pluripotent markers OCT4, Sox-2, c-Myc, Klf4, Nanog, and lin28 in mesenchymal stem cells derived from cord blood and induced pluripotent stem cells. Methods: We analyzed the expression level of OCT4, Sox-2, c-Myc, Klf4, Nanog and lin28 genes in human mesenchymal stem cells derived from cord blood and induced pluripotent stem cells by cell culture and RT-PCR. Results: The expression level of pluripotent genes OCT4 and Sox-2, Nanog and lin28 in mesenchymal stem cells derived from cord blood were significantly higher than those in induced pluripotent stem cells. In contrast to OCT-4A and Sox-2, Nanog and lin28, the expression level of oncogenic factors c-Myc and Klf4 were significantly higher in induced pluripotent stem cells than in mesenchymal stem cells derived from cord blood. Conclusion: It could be concluded that mesenchymal stem cells derived from human cord blood have lower oncogenic potential compared to induced pluripotent stem cells. PMID:26306155

Comparison of retinal vessel measurements using adaptive optics scanning laser ophthalmoscopy and optical coherence tomography.

PubMed

Arichika, Shigeta; Uji, Akihito; Ooto, Sotaro; Muraoka, Yuki; Yoshimura, Nagahisa

2016-05-01

We compared adaptive optics scanning laser ophthalmoscopy (AOSLO) and optical coherence tomography (OCT) vessel caliber measurements. AOSLO videos were acquired from 28 volunteers with healthy eyes. Artery measurements were made 0.5-1 disc diameters away from the optic disc margin. Individual segmented retinal arterial caliber was measured in synchronization with cardiac pulsation and averaged to obtain final horizontal retinal arterial caliber (ACH) and horizontal retinal arterial lumen (ALH). All OCT images were obtained with the Spectralis OCT, a spectral-domain OCT system. Vertical retinal arterial caliber (ACV) and vertical retinal arterial lumen (ALV) were measured on the same artery measured with AOSLO. Measurements made with the two imaging systems were compared. Average ACH, measured with AOSLO, was 123.4 ± 11.2 and average ALH was 101.8 ± 10.2 µm. Average ACV, measured with OCT, was 125.5 ± 11.4 and average ALV was 99.1 ± 10.6 µm. Both arterial caliber (r = 0.767, p < 0.0001) and arterial lumen (r = 0.81, p < 0.0001) measurements were significantly correlated between imaging modalities. Additionally, ACH and ACV were not significantly different (p = 0.16). However, ALH measurements were significantly higher than ALV measurements (p = 0.03). Vessel measurements made with AOSLO and OCT were well correlated. Moreover, plasma is visible and distinguishable from the retinal vessel wall in AOSLO images but not in OCT images. Therefore, AOSLO may measure vessel width more precisely than OCT.

Equine cloning: in vitro and in vivo development of aggregated embryos.

PubMed

Gambini, Andrés; Jarazo, Javier; Olivera, Ramiro; Salamone, Daniel F

2012-07-01

The production of cloned equine embryos remains highly inefficient. Embryo aggregation has not yet been tested in the equine, and it might represent an interesting strategy to improve embryo development. This study evaluated the effect of cloned embryo aggregation on in vitro and in vivo equine embryo development. Zona-free reconstructed embryos were individually cultured in microwells (nonaggregated group) or as 2- or 3-embryo aggregates (aggregated groups). For in vitro development, they were cultured until blastocyst stage and then either fixed for Oct-4 immunocytochemical staining or maintained in in vitro culture where blastocyst expansion was measured daily until Day 17 or the day on which they collapsed. For in vivo assays, Day 7-8 blastocysts were transferred to synchronized mares and resultant vesicles, and cloned embryos were measured by ultrasonography. Embryo aggregation improved blastocyst rates on a per well basis, and aggregation did not imply additional oocytes to obtain blastocysts. Embryo aggregation improved embryo quality, nevertheless it did not affect Day 8 and Day 16 blastocyst Oct-4 expression patterns. Equine cloned blastocysts expanded and increased their cell numbers when they were maintained in in vitro culture, describing a particular pattern of embryo growth that was unexpectedly independent of embryo aggregation, as all embryos reached similar size after Day 7. Early pregnancy rates were higher using blastocysts derived from aggregated embryos, and advanced pregnancies as live healthy foals also resulted from aggregated embryos. These results indicate that the strategy of aggregating embryos can improve their development, supporting the establishment of equine cloned pregnancies.

Proinflammatory Cytokines IL-6 and TNF-α Increased Telomerase Activity through NF-κB/STAT1/STAT3 Activation, and Withaferin A Inhibited the Signaling in Colorectal Cancer Cells

PubMed Central

Okobi, Quincy; Adekoya, Debbie; Atefi, Mohammad; Clarke, Orette; Dutta, Pranabananda; Vadgama, Jaydutt V.

2017-01-01

There are increasing evidences of proinflammatory cytokine involvement in cancer development. Here, we found that two cytokines, IL-6 and TNF-α, activated colorectal cancer cells to be more invasive and stem-like. Combined treatment of IL-6 and TNF-α phosphorylated transcription factors STAT3 in a synergistic manner. STAT3, STAT1, and NF-κB physically interacted upon the cytokine stimulation. STAT3 was bound to the promoter region of human telomerase reverse transcriptase (hTERT). IL-6 and TNF-α stimulation further enhanced STAT3 binding affinity. Stem cell marker Oct-4 was upregulated in colorectal cancer cells upon IL-6 and TNF-α stimulation. Withaferin A, an anti-inflammatory steroidal lactone, inhibited the IL-6- and TNF-α-induced cancer cell invasion and decreased colonosphere formation. Notably, withaferin A inhibited STAT3 phosphorylation and abolished the STAT3, STAT1, and NF-κB interactions. Oct-4 expression was also downregulated by withaferin A inhibition. The binding of STAT3 to the hTERT promoter region and telomerase activity showed reduction with withaferin A treatments. Proinflammatory cytokine-induced cancer cell invasiveness is mediated by a STAT3-regulated mechanism in colorectal cancer cells. Our data suggest that withaferin A could be a promising anticancer agent that effectively inhibits the progression of colorectal cancer. PMID:28676732

Corticosterone Potentiation of Cocaine-Induced Reinstatement of Conditioned Place Preference in Mice is Mediated by Blockade of the Organic Cation Transporter 3

PubMed Central

McReynolds, Jayme R; Taylor, Analisa; Vranjkovic, Oliver; Ambrosius, Terra; Derricks, Olivia; Nino, Brittany; Kurtoglu, Beliz; Wheeler, Robert A; Baker, David A; Gasser, Paul J; Mantsch, John R

2017-01-01

The mechanisms by which stressful life events increase the risk of relapse in recovering cocaine addicts are not well understood. We previously reported that stress, via elevated corticosterone, potentiates cocaine-primed reinstatement of cocaine seeking following self-administration in rats and that this potentiation appears to involve corticosterone-induced blockade of dopamine clearance via the organic cation transporter 3 (OCT3). In the present study, we use a conditioned place preference/reinstatement paradigm in mice to directly test the hypothesis that corticosterone potentiates cocaine-primed reinstatement by blockade of OCT3. Consistent with our findings following self-administration in rats, pretreatment of male C57/BL6 mice with corticosterone (using a dose that reproduced stress-level plasma concentrations) potentiated cocaine-primed reinstatement of extinguished cocaine-induced conditioned place preference. Corticosterone failed to re-establish extinguished preference alone but produced a leftward shift in the dose–response curve for cocaine-primed reinstatement. A similar potentiating effect was observed upon pretreatment of mice with the non-glucocorticoid OCT3 blocker, normetanephrine. To determine the role of OCT3 blockade in these effects, we examined the abilities of corticosterone and normetanephrine to potentiate cocaine-primed reinstatement in OCT3-deficient and wild-type mice. Conditioned place preference, extinction and reinstatement of extinguished preference in response to low-dose cocaine administration did not differ between genotypes. However, corticosterone and normetanephrine failed to potentiate cocaine-primed reinstatement in OCT3-deficient mice. Together, these data provide the first direct evidence that the interaction of corticosterone with OCT3 mediates corticosterone effects on drug-seeking behavior and establish OCT3 function as an important determinant of susceptibility to cocaine use. PMID:27604564

IGF-1R Promotes Symmetric Self-Renewal and Migration of Alkaline Phosphatase+ Germ Stem Cells through HIF-2α-OCT4/CXCR4 Loop under Hypoxia.

PubMed

Kuo, Yung-Che; Au, Heng-Kien; Hsu, Jue-Liang; Wang, Hsiao-Feng; Lee, Chiung-Ju; Peng, Syue-Wei; Lai, Ssu-Chuan; Wu, Yu-Chih; Ho, Hong-Nerng; Huang, Yen-Hua

2018-02-13

Hypoxia cooperates with endocrine signaling to maintain the symmetric self-renewal proliferation and migration of embryonic germline stem cells (GSCs). However, the lack of an appropriate in vitro cell model has dramatically hindered the understanding of the mechanism underlying this cooperation. Here, using a serum-free system, we demonstrated that hypoxia significantly induced the GSC mesenchymal transition, increased the expression levels of the pluripotent transcription factor OCT4 and migration-associated proteins (SDF-1, CXCR4, IGF-1, and IGF-1R), and activated the cellular expression and translocalization of the CXCR4-downstream proteins ARP3/pFAK. The underlying mechanism involved significant IGF-1/IGF-1R activation of OCT4/CXCR4 expression through HIF-2α regulation. Picropodophyllin-induced inhibition of IGF-1R phosphorylation significantly suppressed hypoxia-induced SDF-1/CXCR4 expression and cell migration. Furthermore, transactivation between IGF-1R and CXCR4 was involved. In summary, we demonstrated that niche hypoxia synergistically cooperates with its associated IGF-1R signaling to regulate the symmetric division (self-renewal proliferation) and cell migration of alkaline phosphatase-positive GSCs through HIF-2α-OCT4/CXCR4 during embryogenesis. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Affordability Constraints in Major Defense Acquisitions

DTIC Science & Technology

2016-11-01

Fence Inc 1 30-May-2014 4-Oct-2012 4-Nov-2015 32 SSC 5-Jul-2012 33 VH-92A (VXX) 5-Apr-2013 17-Apr-2014 34 FAB -T CPT 26-Oct...Development EPAWSS Eagle Passive/Active Warning and Survivability System EPP Extended Planning Period EPS Enhanced Polar System FAB -T CPT Family of

Genome editing reveals a role for OCT4 in human embryogenesis.

PubMed

Fogarty, Norah M E; McCarthy, Afshan; Snijders, Kirsten E; Powell, Benjamin E; Kubikova, Nada; Blakeley, Paul; Lea, Rebecca; Elder, Kay; Wamaitha, Sissy E; Kim, Daesik; Maciulyte, Valdone; Kleinjung, Jens; Kim, Jin-Soo; Wells, Dagan; Vallier, Ludovic; Bertero, Alessandro; Turner, James M A; Niakan, Kathy K

2017-10-05

Despite their fundamental biological and clinical importance, the molecular mechanisms that regulate the first cell fate decisions in the human embryo are not well understood. Here we use CRISPR-Cas9-mediated genome editing to investigate the function of the pluripotency transcription factor OCT4 during human embryogenesis. We identified an efficient OCT4-targeting guide RNA using an inducible human embryonic stem cell-based system and microinjection of mouse zygotes. Using these refined methods, we efficiently and specifically targeted the gene encoding OCT4 (POU5F1) in diploid human zygotes and found that blastocyst development was compromised. Transcriptomics analysis revealed that, in POU5F1-null cells, gene expression was downregulated not only for extra-embryonic trophectoderm genes, such as CDX2, but also for regulators of the pluripotent epiblast, including NANOG. By contrast, Pou5f1-null mouse embryos maintained the expression of orthologous genes, and blastocyst development was established, but maintenance was compromised. We conclude that CRISPR-Cas9-mediated genome editing is a powerful method for investigating gene function in the context of human development.

Screening retinal transplants with Fourier-domain OCT

NASA Astrophysics Data System (ADS)

Rao, Bin

2009-02-01

Transplant technologies have been studied for the recovery of vision loss from retinitis pigmentosa (RP) and age-related macular degeneration (AMD). In several rodent retinal degeneration models and in patients, retinal progenitor cells transplanted as layers to the subretinal space have been shown to restore or preserve vision. The methods for evaluation of transplants are expensive considering the large amount of animals. Alternatively, time-domain Stratus OCT was previously shown to be able to image the morphological structure of transplants to some extent, but could not clearly identify laminated transplants. The efficacy of screening retinal transplants with Fourier-domain OCT was studied on 37 S334ter line 3 rats with retinal degeneration 6-67 days after transplant surgery. The transplants were morphologically categorized as no transplant, detachment, rosettes, small laminated area and larger laminated area with both Fourier-domain OCT and histology. The efficacy of Fourier-domain OCT in screening retinal transplants was evaluated by comparing the categorization results with OCT and histology. Additionally, 4 rats were randomly selected for multiple OCT examinations (1, 5, 9, 14 and 21days post surgery) in order to determine the earliest image time of OCT examination since the transplanted tissue may need some time to show its tendency of growing. Finally, we demonstrated the efficacy of Fourier-domain OCT in screening retinal transplants in early stages and determined the earliest imaging time for OCT. Fourier-domain OCT makes itself valuable in saving resource spent on animals with unsuccessful transplants.

Validation of the UNC OCT Index for the Diagnosis of Early Glaucoma

PubMed Central

Lee, Gary; Budenz, Donald L.; Warren, Joshua L.; Wall, Michael; Artes, Paul H.; Callan, Thomas M.; Flanagan, John G.

2018-01-01

Purpose To independently validate the performance of the University of North Carolina Optical Coherence Tomography (UNC OCT) Index in diagnosing and predicting early glaucoma. Methods Data of 118 normal subjects (118 eyes) and 96 subjects (96 eyes) with early glaucoma defined as visual field mean deviation (MD) greater than −4 decibels (dB), aged 40 to 80 years, and who were enrolled in the Full-Threshold Testing Size III, V, VI comparison study were used in this study. CIRRUS OCT average and quadrants' retinal nerve fiber layer (RNFL); optic disc vertical cup-to-disc ratio (VCDR), cup-to-disc area ratio, and rim area; and average, minimum, and six sectoral ganglion cell-inner plexiform layer (GCIPL) measurements were run through the UNC OCT Index algorithm. Area under the receiver operating characteristic curve (AUC) and sensitivities at 95% and 99% specificity were calculated and compared between single parameters and the UNC OCT Index. Results Mean age was 60.1 ± 11.0 years for normal subjects and 66.5 ± 8.1 years for glaucoma patients (P < 0.001). MD was 0.29 ± 1.04 dB and −1.30 ± 1.35 dB in normal and glaucomatous eyes (P < 0.001), respectively. The AUC of the UNC OCT Index was 0.96. The best single metrics when compared to the UNC OCT Index were VCDR (0.93, P = 0.054), average RNFL (0.92, P = 0.014), and minimum GCIPL (0.91, P = 0.009). The sensitivities at 95% and 99% specificity were 85.4% and 76.0% (UNC OCT Index), 71.9% and 62.5% (VCDR, all P < 0.001), 64.6% and 53.1% (average RNFL, all P < 0.001), and 66.7% and 58.3% (minimum GCIPL, all P < 0.001), respectively. Conclusions The findings confirm that the UNC OCT Index may provide improved diagnostic perforce over that of single OCT parameters and may be a good tool for detection of early glaucoma. Translational Relevance The UNC OCT Index algorithm may be incorporated easily into routine clinical practice and be useful for detecting early glaucoma. PMID:29629238

Validation of the UNC OCT Index for the Diagnosis of Early Glaucoma.

PubMed

Mwanza, Jean-Claude; Lee, Gary; Budenz, Donald L; Warren, Joshua L; Wall, Michael; Artes, Paul H; Callan, Thomas M; Flanagan, John G

2018-04-01

To independently validate the performance of the University of North Carolina Optical Coherence Tomography (UNC OCT) Index in diagnosing and predicting early glaucoma. Data of 118 normal subjects (118 eyes) and 96 subjects (96 eyes) with early glaucoma defined as visual field mean deviation (MD) greater than -4 decibels (dB), aged 40 to 80 years, and who were enrolled in the Full-Threshold Testing Size III, V, VI comparison study were used in this study. CIRRUS OCT average and quadrants' retinal nerve fiber layer (RNFL); optic disc vertical cup-to-disc ratio (VCDR), cup-to-disc area ratio, and rim area; and average, minimum, and six sectoral ganglion cell-inner plexiform layer (GCIPL) measurements were run through the UNC OCT Index algorithm. Area under the receiver operating characteristic curve (AUC) and sensitivities at 95% and 99% specificity were calculated and compared between single parameters and the UNC OCT Index. Mean age was 60.1 ± 11.0 years for normal subjects and 66.5 ± 8.1 years for glaucoma patients ( P < 0.001). MD was 0.29 ± 1.04 dB and -1.30 ± 1.35 dB in normal and glaucomatous eyes ( P < 0.001), respectively. The AUC of the UNC OCT Index was 0.96. The best single metrics when compared to the UNC OCT Index were VCDR (0.93, P = 0.054), average RNFL (0.92, P = 0.014), and minimum GCIPL (0.91, P = 0.009). The sensitivities at 95% and 99% specificity were 85.4% and 76.0% (UNC OCT Index), 71.9% and 62.5% (VCDR, all P < 0.001), 64.6% and 53.1% (average RNFL, all P < 0.001), and 66.7% and 58.3% (minimum GCIPL, all P < 0.001), respectively. The findings confirm that the UNC OCT Index may provide improved diagnostic perforce over that of single OCT parameters and may be a good tool for detection of early glaucoma. The UNC OCT Index algorithm may be incorporated easily into routine clinical practice and be useful for detecting early glaucoma.

SNF5 Is an Essential Executor of Epigenetic Regulation during Differentiation

PubMed Central

You, Jueng Soo; De Carvalho, Daniel D.; Dai, Chao; Liu, Minmin; Pandiyan, Kurinji; Zhou, Xianghong J.; Liang, Gangning; Jones, Peter A.

2013-01-01

Nucleosome occupancy controls the accessibility of the transcription machinery to DNA regulatory regions and serves an instructive role for gene expression. Chromatin remodelers, such as the BAF complexes, are responsible for establishing nucleosome occupancy patterns, which are key to epigenetic regulation along with DNA methylation and histone modifications. Some reports have assessed the roles of the BAF complex subunits and stemness in murine embryonic stem cells. However, the details of the relationships between remodelers and transcription factors in altering chromatin configuration, which ultimately affects gene expression during cell differentiation, remain unclear. Here for the first time we demonstrate that SNF5, a core subunit of the BAF complex, negatively regulates OCT4 levels in pluripotent cells and is essential for cell survival during differentiation. SNF5 is responsible for generating nucleosome-depleted regions (NDRs) at the regulatory sites of OCT4 repressed target genes such as PAX6 and NEUROG1, which are crucial for cell fate determination. Concurrently, SNF5 closes the NDRs at the regulatory regions of OCT4-activated target genes such as OCT4 itself and NANOG. Furthermore, using loss- and gain-of-function experiments followed by extensive genome-wide analyses including gene expression microarrays and ChIP-sequencing, we highlight that SNF5 plays dual roles during differentiation by antagonizing the expression of genes that were either activated or repressed by OCT4, respectively. Together, we demonstrate that SNF5 executes the switch between pluripotency and differentiation. PMID:23637628

SNF5 is an essential executor of epigenetic regulation during differentiation.

PubMed

You, Jueng Soo; De Carvalho, Daniel D; Dai, Chao; Liu, Minmin; Pandiyan, Kurinji; Zhou, Xianghong J; Liang, Gangning; Jones, Peter A

2013-04-01

Nucleosome occupancy controls the accessibility of the transcription machinery to DNA regulatory regions and serves an instructive role for gene expression. Chromatin remodelers, such as the BAF complexes, are responsible for establishing nucleosome occupancy patterns, which are key to epigenetic regulation along with DNA methylation and histone modifications. Some reports have assessed the roles of the BAF complex subunits and stemness in murine embryonic stem cells. However, the details of the relationships between remodelers and transcription factors in altering chromatin configuration, which ultimately affects gene expression during cell differentiation, remain unclear. Here for the first time we demonstrate that SNF5, a core subunit of the BAF complex, negatively regulates OCT4 levels in pluripotent cells and is essential for cell survival during differentiation. SNF5 is responsible for generating nucleosome-depleted regions (NDRs) at the regulatory sites of OCT4 repressed target genes such as PAX6 and NEUROG1, which are crucial for cell fate determination. Concurrently, SNF5 closes the NDRs at the regulatory regions of OCT4-activated target genes such as OCT4 itself and NANOG. Furthermore, using loss- and gain-of-function experiments followed by extensive genome-wide analyses including gene expression microarrays and ChIP-sequencing, we highlight that SNF5 plays dual roles during differentiation by antagonizing the expression of genes that were either activated or repressed by OCT4, respectively. Together, we demonstrate that SNF5 executes the switch between pluripotency and differentiation.

Establishment of rat embryonic stem-like cells from the morula using a combination of feeder layers.

PubMed

Sano, Chiaki; Matsumoto, Asako; Sato, Eimei; Fukui, Emiko; Yoshizawa, Midori; Matsumoto, Hiromichi

2009-08-01

Embryonic stem (ES) cells are characterized by pluripotency, in particular the ability to form a germline on injection into blastocysts. Despite numerous attempts, ES cell lines derived from rat embryos have not yet been established. The reason for this is unclear, although certain intrinsic biological differences among species and/or strains have been reported. Herein, using Wistar-Imamichi rats, specific characteristics of preimplantation embryos are described. At the blastocyst stage, Oct4 (also called Pou5f1) was expressed in both the inner cell mass (ICM) and the trophectoderm (TE), whereas expression of Cdx2 was localized to the TE. In contrast, at an earlier stage, expression of Oct4 was detected in all the nuclei in the morula. These stages were examined using a combination of feeder layers (rat embryonic fibroblast [REF] for primary outgrowth and SIM mouse embryo-derived thioguanine- and ouabain-resistant [STO] cells for passaging) to establish rat ES-like cell lines. The rat ES-like cell lines obtained from the morula maintained expression of Oct4 over long-term culture, whereas cell lines derived from blastocysts lost pluripotency during early passage. The morula-derived ES-like cell lines showed Oct4 expression in a long-term culture, even after cryogenic preservation, thawing and EGFP transfection. These results indicate that rat ES-like cell lines with long-term Oct4 expression can be established from the morula of Wistar-Imamichi rats using a combination of feeder layers.

Plaque Burden Influences Accurate Classification of Fibrous Cap Atheroma by In-Vivo Optical Coherence Tomography in a Porcine Model of Advanced Coronary Atherosclerosis.

PubMed

Poulsen, Christian B; Pedrigi, Ryan M; Pareek, Nilesh; Kilic, Ismail D; Holm, Niels Ramsing; Bentzon, Jacob F; Bøtker, Hans Erik; Falk, Erling; Krams, Rob; de Silva, Ranil

2018-04-03

In-vivo validation of coronary optical coherence tomography (OCT) against histology and the effects of plaque burden (PB) on plaque classification remain unreported. We investigated this in a porcine model with human-like coronary atherosclerosis. Five female Yucatan D374Y-PCSK9 transgenic hypercholesterolemic mini-pigs were implanted with a coronary shear-modifying stent to induce advanced atherosclerosis. OCT frames (n=201) were obtained 34 weeks after implantation. Coronary arteries were perfusion-fixed, serially sectioned and co-registered with OCT using a validated algorithm. Lesions were adjudicated using the Virmani classification and PB assessed from histology. OCT had a high sensitivity, but modest specificity (92.9% and 74.6%), for identifying fibrous cap atheroma (FCA). The reduced specificity for OCT was due to misclassification of plaques with histologically defined pathological intimal thickening (PIT) as FCA (46.1% of the frames with histological PIT were misclassified). PIT lesions misclassified as FCA by OCT had a statistically higher PB than in other OCT frames (median 32.0% versus 13.4%; p<0.0001). Misclassification of PIT lesions by OCT occurred when PB exceeded approximately 20%. Compared with histology, in-vivo OCT classification of FCA had high sensitivity but reduced specificity due to misclassification of PITs with high PB.

Quiescent Oct4+ Neural Stem Cells (NSCs) Repopulate Ablated Glial Fibrillary Acidic Protein+ NSCs in the Adult Mouse Brain.

PubMed

Reeve, Rachel L; Yammine, Samantha Z; Morshead, Cindi M; van der Kooy, Derek

2017-09-01

Adult primitive neural stem cells (pNSCs) are a rare population of glial fibrillary acidic protein (GFAP) - Oct4 + cells in the mouse forebrain subependymal zone bordering the lateral ventricles that give rise to clonal neurospheres in leukemia inhibitory factor in vitro. pNSC neurospheres can be passaged to self-renew or give rise to GFAP + NSCs that form neurospheres in epidermal growth factor and fibroblast growth factor 2, which we collectively refer to as definitive NSCs (dNSCs). Label retention experiments using doxycycline-inducible histone-2B (H2B)-green fluorescent protein (GFP) mice and several chase periods of up to 1 year quantified the adult pNSC cell cycle time as 3-5 months. We hypothesized that while pNSCs are not very proliferative at baseline, they may exist as a reserve pool of NSCs in case of injury. To test this function of pNSCs, we obtained conditional Oct4 knockout mice, Oct4 fl/fl ;Sox1 Cre (Oct4 CKO ), which do not yield adult pNSC-derived neurospheres. When we ablated the progeny of pNSCs, namely all GFAP + dNSCs, in these Oct4 CKO mice, we found that dNSCs did not recover as they do in wild-type mice, suggesting that pNSCs are necessary for dNSC repopulation. Returning to the H2B-GFP mice, we observed that the cytosine β-d-arabinofuranoside ablation of proliferating cells including dNSCs-induced quiescent pNSCs to proliferate and significantly dilute their H2B-GFP label. In conclusion, we demonstrate that pNSCs are the most quiescent stem cells in the adult brain reported to date and that their lineage position upstream of GFAP + dNSCs allows them to repopulate a depleted neural lineage. Stem Cells 2017;35:2071-2082. © 2017 AlphaMed Press.

Prospective, double-blinded, randomised controlled trial assessing the effect of an Octenidine-based hydrogel on bacterial colonisation and epithelialization of skin graft wounds in burn patients.

PubMed

W, Eisenbeiß; F, Siemers; G, Amtsberg; P, Hinz; B, Hartmann; T, Kohlmann; A, Ekkernkamp; U, Albrecht; O, Assadian; A, Kramer

2012-01-01

Moist wound treatment improves healing of skin graft donor site wounds. Microbial colonised wounds represent an increased risk of wound infection; while antimicrobially active, topical antiseptics may impair epithelialization. The aim of this prospective randomised controlled clinical trial was to examine the influence of an Octenidine-dihydrochloride (OCT) hydrogel on bacterial colonisation and epithelialization of skin graft donor sites. The study was designed as a randomised, double-blinded, controlled clinical trial. Skin graft donor sites from a total of 61 patients were covered either with 0.05% OCT (n=31) or an OCT-free placebo wound hydrogel (n=30). Potential interaction with wound healing was assessed by measuring the time until 100% re-epithelialization. In addition, microbial wound colonisation was quantitatively determined in all skin graft donor sites. There was no statistically significant difference in the time for complete epithelialization of skin graft donor sites in the OCT and the placebo group (7.3±0.2 vs. 6.9±0.2 days; p=0.236). Microbial wound colonisation was significantly lower in the OCT group than in the placebo group (p=0.014). The OCT-based hydrogel showed no delay in wound epithelialization and demonstrated a significantly lower bacterial colonisation of skin graft donor site wounds.

Prospective, double-blinded, randomised controlled trial assessing the effect of an Octenidine-based hydrogel on bacterial colonisation and epithelialization of skin graft wounds in burn patients

PubMed Central

W, Eisenbeiß; F, Siemers; G, Amtsberg; P, Hinz; B, Hartmann; T, Kohlmann; A, Ekkernkamp; U, Albrecht; O, Assadian; A, Kramer

2012-01-01

Background: Moist wound treatment improves healing of skin graft donor site wounds. Microbial colonised wounds represent an increased risk of wound infection; while antimicrobially active, topical antiseptics may impair epithelialization. Objectives: The aim of this prospective randomised controlled clinical trial was to examine the influence of an Octenidine-dihydrochloride (OCT) hydrogel on bacterial colonisation and epithelialization of skin graft donor sites. Methods: The study was designed as a randomised, double-blinded, controlled clinical trial. Skin graft donor sites from a total of 61 patients were covered either with 0.05% OCT (n=31) or an OCT-free placebo wound hydrogel (n=30). Potential interaction with wound healing was assessed by measuring the time until 100% re-epithelialization. In addition, microbial wound colonisation was quantitatively determined in all skin graft donor sites. Results: There was no statistically significant difference in the time for complete epithelialization of skin graft donor sites in the OCT and the placebo group (7.3±0.2 vs. 6.9±0.2 days; p=0.236). Microbial wound colonisation was significantly lower in the OCT group than in the placebo group (p=0.014). Conclusions: The OCT-based hydrogel showed no delay in wound epithelialization and demonstrated a significantly lower bacterial colonisation of skin graft donor site wounds. PMID:23071904

Human Ocular Epithelial Cells Endogenously Expressing SOX2 and OCT4 Yield High Efficiency of Pluripotency Reprogramming.

PubMed

Poon, Ming-Wai; He, Jia; Fang, Xiaowei; Zhang, Zhao; Wang, Weixin; Wang, Junwen; Qiu, Fangfang; Tse, Hung-Fat; Li, Wei; Liu, Zuguo; Lian, Qizhou

2015-01-01

A variety of pluripotency reprogramming frequencies from different somatic cells has been observed, indicating cell origin is a critical contributor for efficiency of pluripotency reprogramming. Identifying the cell sources for efficient induced pluripotent stem cells (iPSCs) generation, and defining its advantages or disadvantages on reprogramming, is therefore important. Human ocular tissue-derived conjunctival epithelial cells (OECs) exhibited endogenous expression of reprogramming factors OCT4A (the specific OCT 4 isoform on pluripotency reprogramming) and SOX2. We therefore determined whether OECs could be used for high efficiency of iPSCs generation. We compared the endogenous expression levels of four pluripotency factors and the pluripotency reprograming efficiency of human OECs with that of ocular stromal cells (OSCs). Real-time PCR, microarray analysis, Western blotting and immunostaining assays were employed to compare OECiPSCs with OSCiPSCs on molecular bases of reprogramming efficiency and preferred lineage-differentiation potential. Using the traditional KMOS (KLF4, C-MYC, OCT4 and SOX2) reprogramming protocol, we confirmed that OECs, endogenously expressing reprogramming factors OCT4A and SOX2, yield very high efficiency of iPSCs generation (~1.5%). Furthermore, higher efficiency of retinal pigmented epithelial differentiation (RPE cells) was observed in OECiPSCs compared to OSCiPSCs or skin fibroblast iMR90iPSCs. The findings in this study suggest that conjunctival-derived epithelial (OECs) cells can be easier converted to iPSCs than conjunctival-derived stromal cells (OSCs). This cell type may also have advantages in retinal pigmented epithelial differentiation.

Real-time Graphics Processing Unit Based Fourier Domain Optical Coherence Tomography and Surgical Applications

NASA Astrophysics Data System (ADS)

Zhang, Kang

2011-12-01

In this dissertation, real-time Fourier domain optical coherence tomography (FD-OCT) capable of multi-dimensional micrometer-resolution imaging targeted specifically for microsurgical intervention applications was developed and studied. As a part of this work several ultra-high speed real-time FD-OCT imaging and sensing systems were proposed and developed. A real-time 4D (3D+time) OCT system platform using the graphics processing unit (GPU) to accelerate OCT signal processing, the imaging reconstruction, visualization, and volume rendering was developed. Several GPU based algorithms such as non-uniform fast Fourier transform (NUFFT), numerical dispersion compensation, and multi-GPU implementation were developed to improve the impulse response, SNR roll-off and stability of the system. Full-range complex-conjugate-free FD-OCT was also implemented on the GPU architecture to achieve doubled image range and improved SNR. These technologies overcome the imaging reconstruction and visualization bottlenecks widely exist in current ultra-high speed FD-OCT systems and open the way to interventional OCT imaging for applications in guided microsurgery. A hand-held common-path optical coherence tomography (CP-OCT) distance-sensor based microsurgical tool was developed and validated. Through real-time signal processing, edge detection and feed-back control, the tool was shown to be capable of track target surface and compensate motion. The micro-incision test using a phantom was performed using a CP-OCT-sensor integrated hand-held tool, which showed an incision error less than +/-5 microns, comparing to >100 microns error by free-hand incision. The CP-OCT distance sensor has also been utilized to enhance the accuracy and safety of optical nerve stimulation. Finally, several experiments were conducted to validate the system for surgical applications. One of them involved 4D OCT guided micro-manipulation using a phantom. Multiple volume renderings of one 3D data set were performed with different view angles to allow accurate monitoring of the micro-manipulation, and the user to clearly monitor tool-to-target spatial relation in real-time. The system was also validated by imaging multiple biological samples, such as human fingerprint, human cadaver head and small animals. Compared to conventional surgical microscopes, GPU-based real-time FD-OCT can provide the surgeons with a real-time comprehensive spatial view of the microsurgical region and accurate depth perception.

Width of anterior chamber angle determined by OCT, and correlation to refraction and age in a German working population: the MIPH Eye&Health Study.

PubMed

Vossmerbaeumer, Urs; Schuster, Alexander K; Fischer, Joachim E

2013-12-01

Optical coherence tomography (OCT) of the anterior segment allows quantitative analysis of the geometry of the chamber angle. We performed bilateral spectral-domain OCT measurements in healthy, emmetropic, hyperopic, and myopic subjects to establish correlations between the width of the angle, the refraction, and intraocular pressure of the test persons. Out of 4,617 eyes (2,309 subjects), those with refractive errors of < -4 or > +3 diopters were identified by objective refraction measurement (KR-8800 Kerato-Refractometer, Topcon Inc., Japan) and examined using the anterior segment mode of a spectral-domain 3D OCT-2000 (Topcon Inc., Japan). Non-contact tonometry was performed (CT-80, Topcon Inc., Japan). One hundred and eight eyes of 54 emmetropic subjects (± 0.5 dpt) served as reference group. Previous ocular surgery was exclusion criterion in all groups. Width of the chamber angle was determined using semi-automated software tools and statistical analysis of the data (Pearson correlation, ANOVA with post-hoc test and Bonferroni correction, regression analysis) was performed using SPSS software (SPSS 19.0, Chicago, IL, USA). Six hundred and sixty-eight eyes of 398 persons (292 male, 96 female) were included in the study. Mean hyperopic refraction was +4.24 (+3  to +7.75) dpt, mean myopic refraction was -5.86 (-4 to -11.75) dpt. Valid chamber angle OCT measurements could be obtained from 50 (69.4 %) hyperopic and 400 (71.4 %) myopic eyes meeting the inclusion criteria. The mean width of the chamber angle was determined as 31.8° (range: 13.5 to 45.6, SD 7.49) in the hyperopic group, 40.8° (range: 19.3 to 66.0, SD 8.1) in the myopic group, and 36.3° (range: 21.1 to 51.8, SD 6.8) in the emmetropic reference group. Correlation was highly significant (p > 0.001) between refractive error and the aperture of the chamber angle as measured from OCT. The association of the intraocular pressure and the refraction was also highly significant (p > 0.001) for the three groups. The spectral-domain OCT yielded measurements that could be used for digital analysis of the chamber angle geometry. Our results highlight the correlation between refraction and aperture of the angle in hyperopia and myopia as determined by the 3D OCT-2000: hyperopia is associated with a narrower chamber angle, myopia with a wider aperture of the angle.

Optical Coherence Tomography for Retinal Surgery: Perioperative Analysis to Real-Time Four-Dimensional Image-Guided Surgery.

PubMed

Carrasco-Zevallos, Oscar M; Keller, Brenton; Viehland, Christian; Shen, Liangbo; Seider, Michael I; Izatt, Joseph A; Toth, Cynthia A

2016-07-01

Magnification of the surgical field using the operating microscope facilitated profound innovations in retinal surgery in the 1970s, such as pars plana vitrectomy. Although surgical instrumentation and illumination techniques are continually developing, the operating microscope for vitreoretinal procedures has remained essentially unchanged and currently limits the surgeon's depth perception and assessment of subtle microanatomy. Optical coherence tomography (OCT) has revolutionized clinical management of retinal pathology, and its introduction into the operating suite may have a similar impact on surgical visualization and treatment. In this article, we review the evolution of OCT for retinal surgery, from perioperative analysis to live volumetric (four-dimensional, 4D) image-guided surgery. We begin by briefly addressing the benefits and limitations of the operating microscope, the progression of OCT technology, and OCT applications in clinical/perioperative retinal imaging. Next, we review intraoperative OCT (iOCT) applications using handheld probes during surgical pauses, two-dimensional (2D) microscope-integrated OCT (MIOCT) of live surgery, and volumetric MIOCT of live surgery. The iOCT discussion focuses on technological advancements, applications during human retinal surgery, translational difficulties and limitations, and future directions.

Optical coherence tomography in differential diagnosis of skin pathology

NASA Astrophysics Data System (ADS)

Gladkova, Natalia D.; Petrova, Galina P.; Derpaluk, Elena; Nikulin, Nikolai K.; Snopova, Ludmila; Chumakov, Yuri; Feldchtein, Felix I.; Gelikonov, Valentin M.; Gelikonov, Grigory V.; Kuranov, Roman V.

2000-05-01

The capabilities of optical coherence tomography (OCT) for imaging in vivo of optical patterns of pathomorphological processes in the skin and use of their optical patterns in clinical practice for differential diagnosis of dermatoses are presented. Images of skin tissue 0.8 - 1.5 mm deep were acquired with a resolution of 5, 12 and 20 micrometer using three compact fiber OCT devices developed at the Institute of Applied Physics RAS. The acquisition time of images of skin regions 2 - 6 mm in length was 2 - 4 s. The OCT capabilities were analyzed based on the study of 50 patients with different dermatoses. OCT images were interpreted by comparing with parallel histology. It is shown that OCT can detect in vivo optical patterns of morphological alterations in such general papulous dermatoses as lichen ruber planus and psoriasis, a capability that can be used in differential diagnosis of these diseases. Most informative are OCT images obtained with a resolution of 5 micrometer. The results of our study demonstrate the practical importance of OCT imaging for diagnosis of different dermatoses. OCT is noninvasive and, therefore, makes it possible to perform frequent multifocal examination of skin without any adverse effects.

Optical Coherence Tomography for Retinal Surgery: Perioperative Analysis to Real-Time Four-Dimensional Image-Guided Surgery

PubMed Central

Carrasco-Zevallos, Oscar M.; Keller, Brenton; Viehland, Christian; Shen, Liangbo; Seider, Michael I.; Izatt, Joseph A.; Toth, Cynthia A.

2016-01-01

Magnification of the surgical field using the operating microscope facilitated profound innovations in retinal surgery in the 1970s, such as pars plana vitrectomy. Although surgical instrumentation and illumination techniques are continually developing, the operating microscope for vitreoretinal procedures has remained essentially unchanged and currently limits the surgeon's depth perception and assessment of subtle microanatomy. Optical coherence tomography (OCT) has revolutionized clinical management of retinal pathology, and its introduction into the operating suite may have a similar impact on surgical visualization and treatment. In this article, we review the evolution of OCT for retinal surgery, from perioperative analysis to live volumetric (four-dimensional, 4D) image-guided surgery. We begin by briefly addressing the benefits and limitations of the operating microscope, the progression of OCT technology, and OCT applications in clinical/perioperative retinal imaging. Next, we review intraoperative OCT (iOCT) applications using handheld probes during surgical pauses, two-dimensional (2D) microscope-integrated OCT (MIOCT) of live surgery, and volumetric MIOCT of live surgery. The iOCT discussion focuses on technological advancements, applications during human retinal surgery, translational difficulties and limitations, and future directions. PMID:27409495

Comparing three-dimensional serial optical coherence tomography histology to MRI imaging in the entire mouse brain

NASA Astrophysics Data System (ADS)

Castonguay, Alexandre; Lefebvre, Joël; Pouliot, Philippe; Lesage, Frédéric

2018-01-01

An automated serial histology setup combining optical coherence tomography (OCT) imaging with vibratome sectioning was used to image eight wild type mouse brains. The datasets resulted in thousands of volumetric tiles resolved at a voxel size of (4.9×4.9×6.5) μm3 stitched back together to give a three-dimensional map of the brain from which a template OCT brain was obtained. To assess deformation caused by tissue sectioning, reconstruction algorithms, and fixation, OCT datasets were compared to both in vivo and ex vivo magnetic resonance imaging (MRI) imaging. The OCT brain template yielded a highly detailed map of the brain structure, with a high contrast in white matter fiber bundles and was highly resemblant to the in vivo MRI template. Brain labeling using the Allen brain framework showed little variation in regional brain volume among imaging modalities with no statistical differences. The high correspondence between the OCT template brain and its in vivo counterpart demonstrates the potential of whole brain histology to validate in vivo imaging.

Contribution of MATE1 to Renal Secretion of the NMDA Receptor Antagonist Memantine.

PubMed

Müller, Fabian; Weitz, Dietmar; Derdau, Volker; Sandvoss, Martin; Mertsch, Katharina; König, Jörg; Fromm, Martin F

2017-09-05

The weak base memantine is actively secreted into urine, however the underlying mechanisms are insufficiently understood. Potential candidates involved in memantine renal secretion are organic cation transporter 2 (OCT2) and multidrug and toxin extrusion proteins (MATE1, MATE2-K). The aim of this in vitro study was the examination of the interaction of memantine with OCT2 and MATEs. Memantine transporter inhibition and transport were examined in HEK cells expressing human OCT2, MATE1, or MATE2-K. Monolayers of single- (MDCK-OCT2, MDCK-MATE1) and double-transfected MDCK cells (MDCK-OCT2-MATE1) were used for studies on vectorial, basal to apical memantine transport. Memantine inhibited OCT2-, MATE1-, and MATE2-K-mediated metformin transport with IC 50 values of 3.2, 40.9, and 315.3 μM, respectively. In HEK cells, no relevant memantine uptake by OCT2, MATE1, or MATE2-K was detected. Vectorial transport experiments, however, indicated a role of MATE1 for memantine export: After memantine administration to the basal side of the monolayers, memantine cellular accumulation was considerably lower (MDCK-MATE1 vs MDCK control cells, P < 0.01) and memantine transcellular, basal to apical transport was higher in MATE1 expressing cells (MDCK-MATE1 vs MDCK control cells, P < 0.001 at 60 and 180 min). Both effects were abolished upon addition of the MATE inhibitor cimetidine. These experiments suggest a relevant role of MATE1 for renal secretion of memantine. In the clinical setting, renal elimination of memantine could be impaired by coadministration of MATE inhibitors.

Feasibility of OCT to detect radiation-induced esophageal damage in small animal models (Conference Presentation)

NASA Astrophysics Data System (ADS)

Jelvehgaran, Pouya; Alderliesten, Tanja; Salguero, Javier; Borst, Gerben; Song, Ji-Ying; van Leeuwen, Ton G.; de Boer, Johannes F.; de Bruin, Daniel M.; van Herk, Marcel B.

2016-03-01

Lung cancer survival is poor and radiotherapy patients often suffer serious treatment side effects. The esophagus is particularly sensitive leading to reduced food intake or even fistula formation. Only few direct techniques exist to measure radiation-induced esophageal damage, for which knowledge is needed to improve the balance between risk of tumor recurrence and complications. Optical coherence tomography (OCT) is a minimally-invasive imaging technique that obtains cross-sectional, high-resolution (1-10µm) images and is capable of scanning the esophageal wall up to 2-3mm depth. In this study we investigated the feasibility of OCT to detect esophageal radiation damage in mice. In total 30 mice were included in 4 study groups (1 main and 3 control groups). Mice underwent cone-beam CT imaging for initial setup assessment and dose planning followed by single-fraction dose delivery of 4, 10, 16, and 20Gy on 5mm spots, spaced 10mm apart. Mice were repeatedly imaged using OCT: pre-irradiation and up to 3 months post-irradiation. The control groups received either OCT only, irradiation only, or were sham-operated. We used histopathology as gold standard for radiation-induced damage diagnosis. The study showed edema in both the main and OCT-only groups. Furthermore, radiation-induced damage was primarily found in the highest dose region (distal esophagus). Based on the histopathology reports we were able to identify the radiation-induced damage in the OCT images as a change in tissue scattering related to the type of induced damage. This finding indicates the feasibility and thereby the potentially promising role of OCT in radiation-induced esophageal damage assessment.

Enhanced depth imaging optical coherence tomography of choroidal metastasis in 14 eyes.

PubMed

Al-Dahmash, Saad A; Shields, Carol L; Kaliki, Swathi; Johnson, Timothy; Shields, Jerry A

2014-08-01

To describe the imaging features of choroidal metastasis using enhanced depth imaging optical coherence tomography (EDI-OCT). This retrospective observational case series included 31 eyes with choroidal metastasis. Spectral domain EDI-OCT was performed using Heidelberg Spectralis HRA + OCT. The main outcome measures were imaging features by EDI-OCT. Of 31 eyes with choroidal metastasis imaged with EDI-OCT, 14 (45%) eyes displayed image detail suitable for study. The metastasis originated from carcinoma of the breast (n = 7, 50%), lung (n = 5, 36%), pancreas (n = 1, 7%), and thyroid gland (n = 1, 7%). The mean tumor basal diameter was 6.4 mm, and mean thickness was 2.3 mm by B-scan ultrasonography. The tumor location was submacular in 6 (43%) eyes and extramacular in 8 (57%) eyes. By EDI-OCT, the mean tumor thickness was 987 μm. The most salient EDI-OCT features of the metastasis included anterior compression/obliteration of the overlying choriocapillaris (n = 13, 93%), an irregular (lumpy bumpy) anterior contour (n = 9, 64%), and posterior shadowing (n = 12, 86%). Overlying retinal pigment epithelial abnormalities were noted (n = 11, 78%). Outer retinal features included structural loss of the interdigitation of the cone outer segment tips (n = 9, 64%), the ellipsoid portion of photoreceptors (n = 8, 57%), external limiting membrane (n = 4, 29%), outer nuclear layer (n = 1, 7%), and outer plexiform layer (n = 1, 7%). The inner retinal layers (inner nuclear layer to nerve fiber layer) were normal. Subretinal fluid (n = 11, 79%), subretinal lipofuscin pigment (n = 1, 7%), and intraretinal edema (n = 2, 14%) were identified. The EDI-OCT of choroidal metastasis shows a characteristic lumpy bumpy anterior tumor surface and outer retinal layer disruption with preservation of inner retinal layers.

Comparison of anterior chamber depth measurements by 3-dimensional optical coherence tomography, partial coherence interferometry biometry, Scheimpflug rotating camera imaging, and ultrasound biomicroscopy.

PubMed

Nakakura, Shunsuke; Mori, Etsuko; Nagatomi, Nozomi; Tabuchi, Hitoshi; Kiuchi, Yoshiaki

2012-07-01

To evaluate the congruity of anterior chamber depth (ACD) measurements using 4 devices. Saneikai Tsukazaki Hospital, Himeji City, Japan. Comparative case series. In 1 eye of 42 healthy participants, the ACD was measured by 3-dimensional corneal and anterior segment optical coherence tomography (CAS-OCT), partial coherence interferometry (PCI), Scheimpflug imaging, and ultrasound biomicroscopy (UBM). The differences between the measurements were evaluated by 2-way analysis of variance and post hoc analysis. Agreement between the measurements was evaluated using Bland-Altman analysis. To evaluate the true ACD using PCI, the automatically calculated ACD minus the central corneal thickness measured by CAS-OCT was defined as PCI true. Two ACD measurements were also taken with CAS-OCT. The mean ACD was 3.72 mm ± 0.23 (SD) (PCI), 3.18 ± 0.23 mm (PCI true), 3.24 ± 0.25 mm (Scheimpflug), 3.03 ± 0.25 mm (UBM), 3.14 ± 0.24 mm (CAS-OCT auto), and 3.12 ± 0.24 mm (CAS-OCT manual). A significant difference was observed between PCI biometry, Scheimpflug imaging, and UBM measurements and the other methods. Post hoc analysis showed no significant differences between PCI true and CAS-OCT auto or between CAS-OCT auto and CAS-OCT manual. Strong correlations were observed between all measurements; however, Bland-Altman analysis showed good agreement only between PCI true and Scheimpflug imaging and between CAS-OCT auto and CAS OCT manual. The ACD measurements obtained from PCI biometry, Scheimpflug imaging, CAS-OCT, and UBM were significantly different and not interchangeable except for PCI true and CAS-OCT auto and CAS-OCT auto and CAS-OCT manual. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2012 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

High-resolution Fourier-Domain Optical Coherence Tomography and Microperimetric Findings After Macula-off Retinal Detachment Repair

PubMed Central

Smith, Allison J.; Telander, David G.; Zawadzki, Robert J.; Choi, Stacey S.; Morse, Lawrence S.; Werner, John S.; Park, Susanna S.

2009-01-01

Objective To evaluate the morphologic changes in the macula of subjects with repaired macula-off retinal detachment (RD) using high-resolution Fourier-domain optical coherence tomography (FD OCT) and to perform functional correlation in a subset of patients using microperimetry (MP-1). Design Prospective observational case series. Participants Seventeen eyes from 17 subjects who had undergone anatomically successful repair for macula-off, rhegmatogenous RD at least 3 months earlier and without visually significant maculopathy on funduscopy. Methods FD OCT with axial and transverse resolution of 4.5 μm and 10 to 15 μm, respectively, was used to obtain rapid serial B-scans of the macula, which were compared with that from Stratus OCT. The FD OCT B-scans were used to create a 3-dimensional volume, from which en face C-scans were created. Among 11 patients, MP-1 was performed to correlate morphologic changes with visual function. Main Outcome Measures Stratus OCT scans, FD OCT scans, and MP-1 data. Results Stratus OCT and FD OCT images of the macula were obtained 3 to 30 months (mean 7 months) postoperatively in all eyes. Although Stratus OCT revealed photoreceptor disruption in 2 eyes (12%), FD OCT showed photoreceptor disruption in 13 eyes (76%). This difference was statistically significant (P<0.001, χ2). Both imaging modalities revealed persistent subretinal fluid in 2 eyes (12%) and lamellar hole in 1 eye. Among 7 subjects who had reliable MP-1 data, areas of abnormal function corresponded to areas of photoreceptor layer disruptions or persistent subretinal fluid in 5 subjects (71%); one subject had normal FD OCT and MP-1. Conclusions Photoreceptor disruption after macula-off RD repair is a common abnormality in the macula that is detected better with FD OCT than Stratus OCT. A good correlation between MP-1 abnormality and presence of photoreceptor disruption or subretinal fluid on FD OCT demonstrates that these anatomic abnormalities contribute to decreased visual function after successful repair. PMID:18672289

Reduced Hepatic Uptake and Intestinal Excretion of Organic Cations in Mice with a Targeted Disruption of the Organic Cation Transporter 1 (Oct1 [Slc22a1]) Gene

PubMed Central

Jonker, Johan W.; Wagenaar, Els; Mol, Carla A. A. M.; Buitelaar, Marije; Koepsell, Hermann; Smit, Johan W.; Schinkel, Alfred H.

2001-01-01

The polyspecific organic cation transporter 1 (OCT1 [SLC22A1]) mediates facilitated transport of small (hydrophilic) organic cations. OCT1 is localized at the basolateral membrane of epithelial cells in the liver, kidney, and intestine and could therefore be involved in the elimination of endogenous amines and xenobiotics via these organs. To investigate the pharmacologic and physiologic role of this transport protein, we generated Oct1 knockout (Oct1−/−) mice. Oct1−/− mice appeared to be viable, healthy, and fertile and displayed no obvious phenotypic abnormalities. The role of Oct1 in the pharmacology of substrate drugs was studied by comparing the distribution and excretion of the model substrate tetraethylammonium (TEA) after intravenous administration to wild-type and Oct1−/− mice. In Oct1−/− mice, accumulation of TEA in liver was four to sixfold lower than in wild-type mice, whereas direct intestinal excretion of TEA was reduced about twofold. Excretion of TEA into urine over 1 h was 53% of the dose in wild-type mice, compared to 80% in knockout mice, probably because in Oct1−/− mice less TEA accumulates in the liver and thus more is available for rapid excretion by the kidney. In addition, we found that absence of Oct1 leads to decreased liver accumulation of the anticancer drug metaiodobenzylguanidine and the neurotoxin 1-methyl-4-phenylpyridium. In conclusion, our data show that Oct1 plays an important role in the uptake of organic cations into the liver and in their direct excretion into the lumen of the small intestine. PMID:11463829

Choroidal Round Hyporeflectivities in Geographic Atrophy.

PubMed

Corbelli, Eleonora; Sacconi, Riccardo; De Vitis, Luigi Antonio; Carnevali, Adriano; Rabiolo, Alessandro; Querques, Lea; Bandello, Francesco; Querques, Giuseppe

2016-01-01

In geographic atrophy (GA), choroidal vessels typically appear on structural optical coherence tomography (OCT) as hyperreflective round areas with highly reflective borders. We observed that some GA eyes show choroidal round hyporeflectivities with highly reflective borders beneath the atrophy, and futher investigated the charcteristcs by comparing structural OCT, indocyanine green angiography (ICGA) and OCT angiography (OCT-A). Round hyporeflectivities were individuated from a pool of patients with GA secondary to non-neovascular age-related macular degeneration consecutively presenting between October 2015 and March 2016 at the Medical Retina & Imaging Unit of the University Vita-Salute San Raffaele. Patients underwent a complete ophthalmologic examination including ICGA, structural OCT and OCT-A. The correspondence between choroidal round hyporeflectivities beneath GA on structural OCT and ICGA and OCT-A imaging were analyzed. Fifty eyes of 26 consecutive patients (17 females and 9 males; mean age 76.8±6.2 years) with GA were included. Twenty-nine round hyporeflectivities have been found by OCT in choroidal layers in 21 eyes of 21 patients (42.0%; estimated prevalence of 57.7%). All 29 round hyporeflectivities showed constantly a hyperreflective border and a backscattering on structural OCT, and appeared as hypofluorescent in late phase ICGA and as dark foci with non detectable flow in the choroidal segmentation of OCT-A. Interestingly, the GA area was greater in eyes with compared to eyes without round hyporeflectivities (9.30±5.74 and 5.57±4.48mm2, respectively; p = 0.01). Our results suggest that most round hyporeflectivities beneath GA may represent non-perfused or hypo-perfused choroidal vessels with non-detectable flow.

Cadaveric in-situ testing of optical coherence tomography system-based skull base surgery guidance

NASA Astrophysics Data System (ADS)

Sun, Cuiru; Khan, Osaama H.; Siegler, Peter; Jivraj, Jamil; Wong, Ronnie; Yang, Victor X. D.

2015-03-01

Optical Coherence Tomography (OCT) has extensive potential for producing clinical impact in the field of neurological diseases. A neurosurgical OCT hand-held forward viewing probe in Bayonet shape has been developed. In this study, we test the feasibility of integrating this imaging probe with modern navigation technology for guidance and monitoring of skull base surgery. Cadaver heads were used to simulate relevant surgical approaches for treatment of sellar, parasellar and skull base pathology. A high-resolution 3D CT scan was performed on the cadaver head to provide baseline data for navigation. The cadaver head was mounted on existing 3- or 4-point fixation systems. Tracking markers were attached to the OCT probe and the surgeon-probe-OCT interface was calibrated. 2D OCT images were shown in real time together with the optical tracking images to the surgeon during surgery. The intraoperative video and multimodality imaging data set, consisting of real time OCT images, OCT probe location registered to neurosurgical navigation were assessed. The integration of intraoperative OCT imaging with navigation technology provides the surgeon with updated image information, which is important to deal with tissue shifts and deformations during surgery. Preliminary results demonstrate that the clinical neurosurgical navigation system can provide the hand held OCT probe gross anatomical localization. The near-histological imaging resolution of intraoperative OCT can improve the identification of microstructural/morphology differences. The OCT imaging data, combined with the neurosurgical navigation tracking has the potential to improve image interpretation, precision and accuracy of the therapeutic procedure.

Relationship between intraocular pressure and angle configuration: an anterior segment OCT study.

PubMed

Chong, Rachel S; Sakata, Lisandro M; Narayanaswamy, Arun K; Ho, Sue-Wei; He, Mingguang; Baskaran, Mani; Wong, Tien Yin; Perera, Shamira A; Aung, Tin

2013-03-05

To assess the relationship between intraocular pressure (IOP) and anterior chamber angle (ACA) configuration as assessed by gonioscopy and anterior segment optical coherence tomography (AS-OCT). A total of 2045 subjects aged 50 years and older, were recruited from a community clinic and underwent AS-OCT, Goldmann applanation tonometry, and gonioscopy. A quadrant was classified as closed on gonioscopy if the posterior trabecular meshwork could not be seen. A closed quadrant on AS-OCT was defined by the presence of any contact between the iris and angle wall anterior to the scleral spur. Customized software (Zhongshan Angle Assessment Program, Guangzhou, China) was used to measure AS-OCT parameters on AS-OCT scans, including anterior chamber depth, area, and volume; iris thickness (IT) and curvature; lens vault; angle opening distance; and trabecular-iris space area. IOP values were adjusted for age, sex, diabetes and hypertension status, body mass index, central corneal thickness, and presence of peripheral anterior synechiae. Mean age of study subjects was 63.2 ± 8.0 years, 52.6% were female, and 89.4% were Chinese. Mean IOP was 14.8 ± 2.4 mm Hg (range 826). IOP (mean ± SE) increased with number of quadrants with gonioscopic angle closure (none: 14.6 ± 0.2; one: 14.7 ± 0.3; two: 15.0 ± 0.3; three: 15.0 ± 0.3; four: 15.6 ± 0.3 mm Hg; P < 0.001), and on AS-OCT (none: 14.7 ± 0.2; one: 15.0 ± 0.2; two: 14.8 ± 0.2; three: 15.1 ± 0.3; four: 16.0 ± 0.3 mm Hg; P < 0.001). IOP also increased in association with most of the ACA quantitative parameters measured on AS-OCT images, except for IT and lens vault. There was an association between the extent of angle closure, as assessed on AS-OCT and gonioscopy, with increasing IOP.

Novel microscope-integrated stereoscopic heads-up display for intrasurgical optical coherence tomography

PubMed Central

Shen, Liangbo; Carrasco-Zevallos, Oscar; Keller, Brenton; Viehland, Christian; Waterman, Gar; Hahn, Paul S.; Kuo, Anthony N.; Toth, Cynthia A.; Izatt, Joseph A.

2016-01-01

Intra-operative optical coherence tomography (OCT) requires a display technology which allows surgeons to visualize OCT data without disrupting surgery. Previous research and commercial intrasurgical OCT systems have integrated heads-up display (HUD) systems into surgical microscopes to provide monoscopic viewing of OCT data through one microscope ocular. To take full advantage of our previously reported real-time volumetric microscope-integrated OCT (4D MIOCT) system, we describe a stereoscopic HUD which projects a stereo pair of OCT volume renderings into both oculars simultaneously. The stereoscopic HUD uses a novel optical design employing spatial multiplexing to project dual OCT volume renderings utilizing a single micro-display. The optical performance of the surgical microscope with the HUD was quantitatively characterized and the addition of the HUD was found not to substantially effect the resolution, field of view, or pincushion distortion of the operating microscope. In a pilot depth perception subject study, five ophthalmic surgeons completed a pre-set dexterity task with 50.0% (SD = 37.3%) higher success rate and in 35.0% (SD = 24.8%) less time on average with stereoscopic OCT vision compared to monoscopic OCT vision. Preliminary experience using the HUD in 40 vitreo-retinal human surgeries by five ophthalmic surgeons is reported, in which all surgeons reported that the HUD did not alter their normal view of surgery and that live surgical maneuvers were readily visible in displayed stereoscopic OCT volumes. PMID:27231616

Comparison of slitlamp optical coherence tomography and scanning peripheral anterior chamber depth analyzer to evaluate angle closure in Asian eyes.

PubMed

Wong, Hon-Tym; Chua, Jocelyn L L; Sakata, Lisandro M; Wong, Melissa H Y; Aung, Han T; Aung, Tin

2009-05-01

To evaluate the effectiveness of slitlamp optical coherence tomography (SL-OCT) and Scanning Peripheral Anterior Chamber depth analyzer (SPAC) in detecting angle closure, using gonioscopy as the reference standard. A total of 153 subjects underwent gonioscopy, SL-OCT, and SPAC. The anterior chamber angle (ACA) was classified as closed on gonioscopy if the posterior trabecular meshwork could not be seen; with SL-OCT, closure was determined by contact between the iris and angle wall anterior to the scleral spur; and with SPAC by a numerical grade of 5 or fewer and/or a categorical grade of suspect or potential. A closed ACA was identified in 51 eyes with gonioscopy, 86 eyes with SL-OCT, and 61 eyes with SPAC (gonioscopy vs SL-OCT, P < .001; gonioscopy vs SPAC, P = .10; SL-OCT vs SPAC, P < .001; McNemar test). Of the 51 eyes with a closed ACA on gonioscopy, SL-OCT detected a closed ACA in 43, whereas SPAC identified 41 (P = .79). An open angle in all 4 quadrants was observed in 102 eyes with gonioscopy, but SL-OCT and SPAC identified 43 and 20 of these eyes, respectively, as having angle closure. The overall sensitivity and specificity for SL-OCT were 84% and 58% vs 80% and 80% for SPAC. Using gonioscopy as the reference, SL-OCT and SPAC showed good sensitivity for detecting eyes at risk of angle closure.

Imaging the eye fundus with real-time en-face spectral domain optical coherence tomography

PubMed Central

Bradu, Adrian; Podoleanu, Adrian Gh.

2014-01-01

Real-time display of processed en-face spectral domain optical coherence tomography (SD-OCT) images is important for diagnosis. However, due to many steps of data processing requirements, such as Fast Fourier transformation (FFT), data re-sampling, spectral shaping, apodization, zero padding, followed by software cut of the 3D volume acquired to produce an en-face slice, conventional high-speed SD-OCT cannot render an en-face OCT image in real time. Recently we demonstrated a Master/Slave (MS)-OCT method that is highly parallelizable, as it provides reflectivity values of points at depth within an A-scan in parallel. This allows direct production of en-face images. In addition, the MS-OCT method does not require data linearization, which further simplifies the processing. The computation in our previous paper was however time consuming. In this paper we present an optimized algorithm that can be used to provide en-face MS-OCT images much quicker. Using such an algorithm we demonstrate around 10 times faster production of sets of en-face OCT images than previously obtained as well as simultaneous real-time display of up to 4 en-face OCT images of 200 × 200 pixels2 from the fovea and the optic nerve of a volunteer. We also demonstrate 3D and B-scan OCT images obtained from sets of MS-OCT C-scans, i.e. with no FFT and no intermediate step of generation of A-scans. PMID:24761303

Transgene-free human induced pluripotent stem cell line (HS5-SV.hiPS) generated from cesarean scar-derived fibroblasts.

PubMed

Rungsiwiwut, Ruttachuk; Pavarajarn, Wipawee; Numchaisrika, Pranee; Virutamasen, Pramuan; Pruksananonda, Kamthorn

2016-01-01

Transgene-free human HS5-SV.hiPS line was generated from human cesarean scar-derived fibroblasts using temperature-sensitive Sendai virus vectors carrying Oct4, Sox2, cMyc and Klf4 exogenous transcriptional factors. The viral constructs were eliminated from HS5-SV.hiPS line through heat treatment. Transgene-free HS5-SV.hiPS cells expressed pluripotent associated transcription factors Oct4, Nanog, Sox2, Rex1 and surface markers SSEA-4, TRA-1-60 and OCT4. HS5-SV.hiPS cells formed embryoid bodies and differentiated into three embryonic germ layers in vivo. HS5-SV.hiPS cells maintained their normal karyotype (46, XX) after culture for extended period. HS5-SV.hiPS displayed the similar pattern of DNA fingerprinting to the parenteral scar-derived fibroblasts. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Tuning the Adsorption-Induced Phase Change in the Flexible Metal–Organic Framework Co(bdp)

DOE PAGES

Taylor, Mercedes K.; Runčevski, Tomče; Oktawiec, Julia; ...

2016-11-02

Metal–organic frameworks that flex to undergo structural phase changes upon gas adsorption are promising materials for gas storage and separations, and achieving synthetic control over the pressure at which these changes occur is crucial to the design of such materials for specific applications. To this end, a new family of materials based on the flexible metal–organic framework Co(bdp) (bdp 2– = 1,4-benzenedipyrazolate) has been prepared via the introduction of fluorine, deuterium, and methyl functional groups on the bdp 2– ligand, namely, Co(F-bdp), Co(p-F 2-bdp), Co(o-F 2-bdp), Co(D 4-bdp), and Co(p-Me 2-bdp). These frameworks are isoreticular to the parent framework andmore » exhibit similar structural flexibility, transitioning from a low-porosity, collapsed phase to high-porosity, expanded phases with increasing gas pressure. Powder X-ray diffraction studies reveal that fluorination of the aryl ring disrupts edge-to-face π–π interactions, which work to stabilize the collapsed phase at low gas pressures, while deuteration preserves these interactions and methylation strengthens them. In agreement with these observations, high-pressure CH 4 adsorption isotherms show that the pressure of the CH 4-induced framework expansion can be systematically controlled by ligand functionalization, as materials without edge-to-face interactions in the collapsed phase expand at lower CH 4 pressures, while frameworks with strengthened edge-to-face interactions expand at higher pressures. This work puts forth a general design strategy relevant to many other families of flexible metal–organic frameworks, which will be a powerful tool in optimizing these phase-change materials for industrial applications.« less

Natural history of optical coherence tomography-detected non-flow-limiting edge dissections following drug-eluting stent implantation.

PubMed

Radu, Maria D; Räber, Lorenz; Heo, Jungho; Gogas, Bill D; Jørgensen, Erik; Kelbæk, Henning; Muramatsu, Takashi; Farooq, Vasim; Helqvist, Steffen; Garcia-Garcia, Hector M; Windecker, Stephan; Saunamäki, Kari; Serruys, Patrick W

2014-01-22

Angiographic evidence of edge dissections has been associated with a risk of early stent thrombosis. Optical coherence tomography (OCT) is a high-resolution technology detecting a greater number of edge dissections--particularly non-flow-limiting--compared to angiography. Their natural history and clinical implications remain unclear. The objectives of the present study were to assess the morphology, healing response, and clinical outcomes of OCT-detected edge dissections using serial OCT imaging at baseline and at one year following drug-eluting stent (DES) implantation. Edge dissections were defined as disruptions of the luminal surface in the 5 mm segments proximal and distal to the stent, and categorised as flaps, cavities, double-lumen dissections or fissures. Qualitative and quantitative OCT analyses were performed every 0.5 mm at baseline and one year, and clinical outcomes were assessed. Sixty-three lesions (57 patients) were studied with OCT at baseline and one-year follow-up. Twenty-two non-flow-limiting edge dissections in 21 lesions (20 patients) were identified by OCT; only two (9%) were angiographically visible. Flaps were found in 96% of cases. The median longitudinal dissection length was 2.9 mm (interquartile range [IQR] 1.6-4.2 mm), whereas the circumferential and axial extensions amounted to 1.2 mm (IQR: 0.9-1.7 mm) and 0.6 mm (IQR: 0.4-0.7 mm), respectively. Dissections extended into the media and adventitia in seven (33%) and four (20%) cases, respectively. Eighteen (82%) OCT-detected edge dissections were also evaluated with intravascular ultrasound which identified nine (50%) of these OCT-detected dissections. No stent thrombosis or target lesion revascularisation occurred up to one year. At follow-up, 20 (90%) edge dissections were completely healed on OCT. The two cases exhibiting persistent dissection had the longest flaps (2.81 mm and 2.42 mm) at baseline. OCT-detected edge dissections which are angiographically silent in the majority of cases are not associated with acute stent thrombosis or restenosis up to one-year follow-up.

Inhibitory Effect of Crizotinib on Creatinine Uptake by Renal Secretory Transporter OCT2.

PubMed

Arakawa, Hiroshi; Omote, Saki; Tamai, Ikumi

2017-09-01

Crizotinib, a tyrosine kinase inhibitor, exhibits some cases of an increase in serum creatinine levels. Creatinine is excreted by not only glomerular filtration but also active secretion by organic cation transporters such as organic cation transporter 2 (OCT2). In the present study, we evaluated in vitro inhibitory effect of crizotinib on OCT2 by directly measuring creatinine uptake by OCT2. Coincubation of crizotinib reduced uptake of [ 14 C]creatinine by cultured HEK293 cells expressing OCT2 (HEK293/OCT2) in a concentration-dependent manner with IC 50 values of 1.58 ± 0.24 μM. Preincubation or both preincubation and coincubation (preincubation/coincubation) with crizotinib showed stronger inhibitory effect on [ 14 C]creatinine uptake compared with that in coincubation alone with IC 50 values of 0.499 ± 0.076 and 0.347 ± 0.040 μM, respectively. These IC 50 values of crizotinib on [ 3 H]N-methyl-4-phenylpyridinium acetate uptake by OCT2 were 10-20 times higher than those of [ 14 C]creatinine uptake. Furthermore, preincubation of crizotinib inhibited creatinine uptake by OCT2 in an apparently competitive manner. In conclusion, crizotinib at a clinically relevant concentration has the potential to inhibit creatinine transport by OCT2, suggesting an increase of serum creatinine levels in clinical use. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Optical coherence tomography: potentialities in clinical practice

NASA Astrophysics Data System (ADS)

Zagaynova, Elena; Gladkova, Natalia D.; Shakhov, Andrey; Terentjeva, Anna; Snopova, Ludmila B.; Kuznetzova, Irina A.; Streltzova, Olga; Shakhova, Natalia M.; Kamensky, Vladislav A.; Gelikonov, Grigory V.; Gelikonov, Valentin M.; Kuranov, Roman V.; Myakov, Alex

2004-08-01

Clinical studies using OCT involved 2000 patients in various fields of medicine such as gastroenterology, urology, laryngology, gynecology, dermatology, stomatology, etc. Layered high-contrast images were typical for benign epithelial conditions. OCT distinguish in mucosae: epithelium, connective tissue layer, and smooth-muscle layer. Various benign processes occurring in mucosa manifest in OCT images as changes in the epithelial height, scattering properties and the course of the basement membrane. Lack of the layered structural pattern is the main criterion for dysplastic / malignant images. In clinic: OCT data may be critical for choosing a tissue site for excisional biopsy, OCT can detect tumor borders and their linear dimensions, OCT can be used to plan a resection line in operations and to control adequacy of resection, to monitor whether reparative processes are timely and adequate. OCT sensitivity of the uterine cervix, urinary bladder and larynx is 82, 98, 77%, respectively, specificity - 78, 71, 96%, diagnostic accuracy - 81, 85, 87% with significantly good agreement index of clinicians kappa - 0.65, 0.79, 0.83 (confidence intervals: 0.57-0.73; 0.71-0.88; 0.74-0.91). Error in detection of high grade dysplasia and microinvasive cancer is 21.4% in average. Additional modification of OCT (cross-polarisation OCT, OCM), development of the procedure (biotissue compression, application of chemical agents) can improve the specificity and sensitivity of traditional modality.

Optimizing Soft Tissue Management and Spacer Design in Segmental Bone Defects

DTIC Science & Technology

2015-10-01

were found with Tukey’s HSD post hoc analysis. Several target genes such as Oct4, Sox2, TGFB, and Col1A1 were generally up-regulated in all sections...samples presented several upregulated target genes such as Oct4, Sox2, TGFB, and Col1A1 in all sections. No significant main effects were found for

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teng, Ying; Wang, Xiuwen, E-mail: wangxw12@yahoo.com; Wang, Yawei

Wnt/{beta}-catenin signaling plays an important role not only in cancer, but also in cancer stem cells. In this study, we found that {beta}-catenin and OCT-4 was highly expressed in cisplatin (DDP) selected A549 cells. Stimulating A549 cells with lithium chloride (LiCl) resulted in accumulation of {beta}-catenin and up-regulation of a typical Wnt target gene cyclin D1. This stimulation also significantly enhanced proliferation, clone formation, migration and drug resistance abilities in A549 cells. Moreover, the up-regulation of OCT-4, a stem cell marker, was observed through real-time PCR and Western blotting. In a reverse approach, we inhibited Wnt signaling by knocking downmore » the expression of {beta}-catenin using RNA interference technology. This inhibition resulted in down-regulation of the Wnt target gene cyclin D1 as well as the proliferation, clone formation, migration and drug resistance abilities. Meanwhile, the expression of OCT-4 was reduced after the inhibition of Wnt/{beta}-catenin signaling. Taken together, our study provides strong evidence that canonical Wnt signaling plays an important role in lung cancer stem cell properties, and it also regulates OCT-4, a lung cancer stem cell marker.« less

Oct1 and OCA-B are selectively required for CD4 memory T cell function.

PubMed

Shakya, Arvind; Goren, Alon; Shalek, Alex; German, Cody N; Snook, Jeremy; Kuchroo, Vijay K; Yosef, Nir; Chan, Raymond C; Regev, Aviv; Williams, Matthew A; Tantin, Dean

2015-11-16

Epigenetic changes are crucial for the generation of immunological memory. Failure to generate or maintain these changes will result in poor memory responses. Similarly, augmenting or stabilizing the correct epigenetic states offers a potential method of enhancing memory. Yet the transcription factors that regulate these processes are poorly defined. We find that the transcription factor Oct1 and its cofactor OCA-B are selectively required for the in vivo generation of CD4(+) memory T cells. More importantly, the memory cells that are formed do not respond properly to antigen reencounter. In vitro, both proteins are required to maintain a poised state at the Il2 target locus in resting but previously stimulated CD4(+) T cells. OCA-B is also required for the robust reexpression of multiple other genes including Ifng. ChIPseq identifies ∼50 differentially expressed direct Oct1 and OCA-B targets. We identify an underlying mechanism involving OCA-B recruitment of the histone lysine demethylase Jmjd1a to targets such as Il2, Ifng, and Zbtb32. The findings pinpoint Oct1 and OCA-B as central mediators of CD4(+) T cell memory. © 2015 Shakya et al.

Extracting cardiac shapes and motion of the chick embryo heart outflow tract from four-dimensional optical coherence tomography images

NASA Astrophysics Data System (ADS)

Yin, Xin; Liu, Aiping; Thornburg, Kent L.; Wang, Ruikang K.; Rugonyi, Sandra

2012-09-01

Recent advances in optical coherence tomography (OCT), and the development of image reconstruction algorithms, enabled four-dimensional (4-D) (three-dimensional imaging over time) imaging of the embryonic heart. To further analyze and quantify the dynamics of cardiac beating, segmentation procedures that can extract the shape of the heart and its motion are needed. Most previous studies analyzed cardiac image sequences using manually extracted shapes and measurements. However, this is time consuming and subject to inter-operator variability. Automated or semi-automated analyses of 4-D cardiac OCT images, although very desirable, are also extremely challenging. This work proposes a robust algorithm to semi automatically detect and track cardiac tissue layers from 4-D OCT images of early (tubular) embryonic hearts. Our algorithm uses a two-dimensional (2-D) deformable double-line model (DLM) to detect target cardiac tissues. The detection algorithm uses a maximum-likelihood estimator and was successfully applied to 4-D in vivo OCT images of the heart outflow tract of day three chicken embryos. The extracted shapes captured the dynamics of the chick embryonic heart outflow tract wall, enabling further analysis of cardiac motion.

Oct1 and OCA-B are selectively required for CD4 memory T cell function

PubMed Central

Shakya, Arvind; Goren, Alon; Shalek, Alex; German, Cody N.; Snook, Jeremy; Kuchroo, Vijay K.; Yosef, Nir; Chan, Raymond C.; Regev, Aviv

2015-01-01

Epigenetic changes are crucial for the generation of immunological memory. Failure to generate or maintain these changes will result in poor memory responses. Similarly, augmenting or stabilizing the correct epigenetic states offers a potential method of enhancing memory. Yet the transcription factors that regulate these processes are poorly defined. We find that the transcription factor Oct1 and its cofactor OCA-B are selectively required for the in vivo generation of CD4+ memory T cells. More importantly, the memory cells that are formed do not respond properly to antigen reencounter. In vitro, both proteins are required to maintain a poised state at the Il2 target locus in resting but previously stimulated CD4+ T cells. OCA-B is also required for the robust reexpression of multiple other genes including Ifng. ChIPseq identifies ∼50 differentially expressed direct Oct1 and OCA-B targets. We identify an underlying mechanism involving OCA-B recruitment of the histone lysine demethylase Jmjd1a to targets such as Il2, Ifng, and Zbtb32. The findings pinpoint Oct1 and OCA-B as central mediators of CD4+ T cell memory. PMID:26481684

Super-resolved thickness maps of thin film phantoms and in vivo visualization of tear film lipid layer using OCT

PubMed Central

dos Santos, Valentin Aranha; Schmetterer, Leopold; Triggs, Graham J.; Leitgeb, Rainer A.; Gröschl, Martin; Messner, Alina; Schmidl, Doreen; Garhofer, Gerhard; Aschinger, Gerold; Werkmeister, René M.

2016-01-01

In optical coherence tomography (OCT), the axial resolution is directly linked to the coherence length of the employed light source. It is currently unclear if OCT allows measuring thicknesses below its axial resolution value. To investigate spectral-domain OCT imaging in the super-resolution regime, we derived a signal model and compared it with the experiment. Several island thin film samples of known refractive indices and thicknesses in the range 46 – 163 nm were fabricated and imaged. Reference thickness measurements were performed using a commercial atomic force microscope. In vivo measurements of the tear film were performed in 4 healthy subjects. Our results show that quantitative super-resolved thickness measurement can be performed using OCT. In addition, we report repeatable tear film lipid layer visualization. Our results provide a novel interpretation of the OCT axial resolution limit and open a perspective to deeper extraction of the information hidden in the coherence volume. PMID:27446696

NANOG Plays a Hierarchical Role in the Transcription Network Regulating the Pluripotency and Plasticity of Adipose Tissue-Derived Stem Cells

PubMed Central

Pitrone, Maria; Pizzolanti, Giuseppe; Tomasello, Laura; Coppola, Antonina; Morini, Lorenzo; Pantuso, Gianni; Ficarella, Romina; Guarnotta, Valentina; Perrini, Sebastio; Giorgino, Francesco; Giordano, Carla

2017-01-01

The stromal vascular cell fraction (SVF) of visceral and subcutaneous adipose tissue (VAT and SAT) has increasingly come into focus in stem cell research, since these compartments represent a rich source of multipotent adipose-derived stem cells (ASCs). ASCs exhibit a self-renewal potential and differentiation capacity. Our aim was to study the different expression of the embryonic stem cell markers NANOG (homeobox protein NANOG), SOX2 (SRY (sex determining region Y)-box 2) and OCT4 (octamer-binding transcription factor 4) and to evaluate if there exists a hierarchal role in this network in ASCs derived from both SAT and VAT. ASCs were isolated from SAT and VAT biopsies of 72 consenting patients (23 men, 47 women; age 45 ± 10; BMI between 25 ± 5 and 30 ± 5 range) undergoing elective open-abdominal surgery. Sphere-forming capability was evaluated by plating cells in low adhesion plastic. Stem cell markers CD90, CD105, CD29, CD31, CD45 and CD146 were analyzed by flow cytometry, and the stem cell transcription factors NANOG, SOX2 and OCT4 were detected by immunoblotting and real-time PCR. NANOG, SOX2 and OCT4 interplay was explored by gene silencing. ASCs from VAT and SAT confirmed their mesenchymal stem cell (MSC) phenotype expressing the specific MSC markers CD90, CD105, NANOG, SOX2 and OCT4. NANOG silencing induced a significant OCT4 (70 ± 0.05%) and SOX2 (75 ± 0.03%) downregulation, whereas SOX2 silencing did not affect NANOG gene expression. Adipose tissue is an important source of MSC, and siRNA experiments endorse a hierarchical role of NANOG in the complex transcription network that regulates pluripotency. PMID:28545230

Vitreous Bands Identified by Handheld Spectral-Domain Optical Coherence Tomography Among Premature Infants.

PubMed

Zepeda, Emily M; Shariff, Ayesha; Gillette, Thomas B; Grant, Laura; Ding, Leona; Tarczy-Hornoch, Kristina; Cabrera, Michelle T

2018-05-17

Handheld spectral-domain optical coherence tomography (SD-OCT) can provide insights into the complex interactions occurring at the vitreoretinal interface in retinopathy of prematurity (ROP) to enhance our understanding of ROP pathology. To characterize vitreous bands in premature infants with use of handheld SD-OCT. Prospective cohort study conducted from July 7, 2015, to February 28, 2017, at 2 university-based neonatal intensive care units. Seventy-three premature infants who required routine ROP screening examination were recruited. Informed consent was obtained from all legal guardians. Trained graders who were masked to the clinical assessment analyzed each SD-OCT scan of the right eye for vitreoretinal findings. A third trained grader mediated disagreements. Associations between the presence of vitreous bands in premature infants with ROP diagnoses and the presence of other vitreoretinal SD-OCT findings were investigated. Of the 73 infants recruited, 6 infants' parents withdrew their children from the study, and 2 infants were too hemodynamically unstable for imaging, leaving a total of 65 participants. Of these, 32 (49%) were female, 36 (55%) were white, 10 (15%) were Hispanic, 3 (5%) were Native American, 4 (6%) were African American, 4 (7%) were Asian/Pacific Islander, and 8 (12%) were other. The mean (SD) gestational age was 28 (2.7) weeks, the mean (SD) birth weight was 997 g (286 g), and the mean (SD) postmenstrual age at imaging was 34 (3) weeks (mean [SD] total of 3 [2] imaging sessions). Comparing the 24 infants (37%) who had a right eye vitreous band at any time with the 41 (63%) who did not, no difference in mean birth weight, gestational age, postmenstrual age at imaging, sex, or race/ethnicity was identified. No associations with ROP stage (eg, in 6 [25%] infants with vitreous bands vs 4 [9.8%] in those without; P = .23), presence of plus disease (2 [8%] vs 2 [5%]; P = .84), or type 1 ROP (3 [12%] vs 3 [7%]; P = .66) were identified. Vitreous bands were associated with epiretinal membrane detected on SD-OCT (P = .001) with an odds ratio of 9.4 (95% CI, 2.8-31.3) in 15 [62%] infants with vitreous bands vs 6 [15%] in those without. Vitreous bands were also associated with cystoid macular edema (in 15 [62%] infants with vitreous bands vs 1 [27%] in those without; P = .005) with an odds ratio of 4.5 (95% CI, 1.5-13.3). In this study, the development of vitreous bands was associated with both cystoid macular edema and epiretinal membrane. These findings suggest a tractional pathogenesis to these entities among premature infants. This study did not find a direct association between vitreous bands and severe ROP. Additional study is needed to determine whether vitreous bands represent subclinical hyaloidal organization leading to retinal detachment in advanced ROP.

Identification and functional characterization of genetic variants of human organic cation transporters in a Korean population.

PubMed

Kang, Ho-Jin; Song, Im-Sook; Shin, Ho Jung; Kim, Woo-Young; Lee, Choong-Hee; Shim, Joo-Cheol; Zhou, Hong-Hao; Lee, Sang Seop; Shin, Jae-Gook

2007-04-01

Genetic variants of three human organic cation transporter genes (hOCTs) were extensively explored in a Korean population. The functional changes of hOCT2 variants were evaluated in vitro, and those genetic polymorphisms of hOCTs were compared among different ethnic populations. From direct DNA sequencing, 7 of 13 coding variants were nonsynonymous single-nucleotide polymorphisms (SNPs), including four variants from hOCT1 (F160L, P283L, P341L, and M408V) and three from hOCT2 (T199I, T201M, and A270S), whereas 6 were synonymous SNPs. The linkage disequilibrium analysis presented for three independent LD blocks for each hOCT gene showed no significant linkage among all three hOCT genes. The transporter activities of MDCK cells that overexpress the hOCT2-T199I, -T201M, and -A270S variants showed significantly decreased uptake of [(3)H]methyl-4-phenylpyridinium acetate (MPP(+)) or [(14)C]tetraethylammonium compared with those cells that overexpress wild-type hOCT2, and the estimated kinetic parameters of these variants for [(3)H]MPP(+) uptake in oocytes showed a 2- to 5-fold increase in K(m) values and a 10- to 20-fold decrease in V(max) values. The allele frequencies of the five functional variants hOCT1-P283L, -P341L, and hOCT2-T199I, -T201M, and -A270S were 1.3, 17, 0.7, 0.7, and 11%, respectively, in a Korean population; the frequency distributions of these variants were not significantly different from those of Chinese and Vietnamese populations. These findings suggest that genetic variants of hOCTs are not linked among three genes in a Korean population, and several of the hOCT genetic variants cause decreased transport activity in vitro compared with the wild type, although the clinical relevance of these variants remains to be evaluated.

Functional characterization of the organic cation transporters (OCTs) in human airway pulmonary epithelial cells.

PubMed

Ingoglia, Filippo; Visigalli, Rossana; Rotoli, Bianca Maria; Barilli, Amelia; Riccardi, Benedetta; Puccini, Paola; Dall'Asta, Valeria

2015-07-01

Organic cation transporters (OCT1-3) mediate the transport of organic cations including inhaled drugs across the cell membrane, although their role in lung epithelium hasn't been well understood yet. We address here the expression and functional activity of OCT1-3 in human airway epithelial cells A549, Calu-3 and NCl-H441. Kinetic and inhibition analyses, employing [(3)H]1-methyl-4-phenylpyridinium (MPP+) as substrate, and the compounds quinidine, prostaglandine E2 (PGE2) and corticosterone as preferential inhibitors of OCT1, OCT2, and OCT3, respectively, have been performed. A549 cells present a robust MPP+ uptake mediated by one high-affinity component (Km~50μM) which is identifiable with OCT3. Corticosterone, indeed, completely inhibits MPP+ transport, while quinidine and PGE2 are inactive and SLC22A3/OCT3 silencing with siRNA markedly lowers MPP+ uptake. Conversely, Calu-3 exhibits both a high (Km<20μM) and a low affinity (Km>0.6mM) transport components, referable to OCT3 and OCT1, respectively, as demonstrated by the inhibition analysis performed at proper substrate concentrations and confirmed by the use of specific siRNA. These transporters are active also when cells are grown under air-liquid interface (ALI) conditions. Only a very modest saturable MPP+ uptake is measurable in NCl-H441 cells and the inhibitory effect of quinidine points to OCT1 as the subtype functionally involved in this model. Finally, the characterization of MPP+ transport in human bronchial BEAS-2B cells suggests that OCT1 and OCT3 are operative. These findings could help to identify in vitro models to be employed for studies concerning the specific involvement of each transporter in drug transportation. Copyright © 2015 Elsevier B.V. All rights reserved.

Wide-Field Megahertz OCT Imaging of Patients with Diabetic Retinopathy

PubMed Central

Reznicek, Lukas; Kolb, Jan P.; Klein, Thomas; Mohler, Kathrin J.; Huber, Robert; Kernt, Marcus; Märtz, Josef; Neubauer, Aljoscha S.

2015-01-01

Purpose. To evaluate the feasibility of wide-field Megahertz (MHz) OCT imaging in patients with diabetic retinopathy. Methods. A consecutive series of 15 eyes of 15 patients with diagnosed diabetic retinopathy were included. All patients underwent Megahertz OCT imaging, a close clinical examination, slit lamp biomicroscopy, and funduscopic evaluation. To acquire densely sampled, wide-field volumetric datasets, an ophthalmic 1050 nm OCT prototype system based on a Fourier-domain mode-locked (FDML) laser source with 1.68 MHz A-scan rate was employed. Results. We were able to obtain OCT volume scans from all included 15 patients. Acquisition time was 1.8 seconds. Obtained volume datasets consisted of 2088 × 1044 A-scans of 60° of view. Thus, reconstructed en face images had a resolution of 34.8 pixels per degree in x-axis and 17.4 pixels per degree. Due to the densely sampled OCT volume dataset, postprocessed customized cross-sectional B-frames through pathologic changes such as an individual microaneurysm or a retinal neovascularization could be imaged. Conclusions. Wide-field Megahertz OCT is feasible to successfully image patients with diabetic retinopathy at high scanning rates and a wide angle of view, providing information in all three axes. The Megahertz OCT is a useful tool to screen diabetic patients for diabetic retinopathy. PMID:26273665

Wide-Field Megahertz OCT Imaging of Patients with Diabetic Retinopathy.

PubMed

Reznicek, Lukas; Kolb, Jan P; Klein, Thomas; Mohler, Kathrin J; Wieser, Wolfgang; Huber, Robert; Kernt, Marcus; Märtz, Josef; Neubauer, Aljoscha S

2015-01-01

To evaluate the feasibility of wide-field Megahertz (MHz) OCT imaging in patients with diabetic retinopathy. A consecutive series of 15 eyes of 15 patients with diagnosed diabetic retinopathy were included. All patients underwent Megahertz OCT imaging, a close clinical examination, slit lamp biomicroscopy, and funduscopic evaluation. To acquire densely sampled, wide-field volumetric datasets, an ophthalmic 1050 nm OCT prototype system based on a Fourier-domain mode-locked (FDML) laser source with 1.68 MHz A-scan rate was employed. RESULTS. We were able to obtain OCT volume scans from all included 15 patients. Acquisition time was 1.8 seconds. Obtained volume datasets consisted of 2088 × 1044 A-scans of 60° of view. Thus, reconstructed en face images had a resolution of 34.8 pixels per degree in x-axis and 17.4 pixels per degree. Due to the densely sampled OCT volume dataset, postprocessed customized cross-sectional B-frames through pathologic changes such as an individual microaneurysm or a retinal neovascularization could be imaged. Wide-field Megahertz OCT is feasible to successfully image patients with diabetic retinopathy at high scanning rates and a wide angle of view, providing information in all three axes. The Megahertz OCT is a useful tool to screen diabetic patients for diabetic retinopathy.

Functional involvement of the organic cation transporter 2 (rOct2) in the renal uptake of organic cations in rats.

PubMed

Umehara, K-I; Iwatsubo, T; Noguchi, K; Kamimura, H

2008-01-01

This study examined the contribution made by organic cation transporters (hOCT/rOct) to the saturable component of the renal uptake of 1-methyl-4-phenylpyridinium, tetraethylammonium (TEA), cimetidine and metformin into rOct2-expressing HEK293 cells and rat kidney slices. All the test compounds accumulated in the rat kidney slices in a carrier-mediated manner. The Michaelis- Menten constant (K(m)) values for saturable uptake of TEA, cimetidine and metformin into rat kidney slices were relatively comparable with those for the rOct2-expressing HEK293 cells. In addition, the relative uptake activity values of TEA, cimetidine and metformin in rat kidney slices were similar to those in rOct2-expressing HEK293 cells. This suggests that the saturable components involved in the renal uptake of TEA, cimetidine and metformin are mediated mainly by rOct2. The saturable uptake profile of cationic compounds into rat kidney can be evaluated in both cDNA-expressing cells and rat kidney slices, as well as the transporter expression pattern. This approach can also be used to estimate the saturable uptake mechanism of cationic compounds into the human kidney when human kidney slices and hOCT2-expressing cells are used.

Phase-sensitive optical coherence tomography-based vibrometry using a highly phase-stable akinetic swept laser source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Applegate, Brian E.; Park, Jesung; Carbajal, Esteban

Phase-sensitive Optical Coherence Tomography (PhOCT) is an emerging tool for in vivo investigation of the vibratory function of the intact middle and inner ear. PhOCT is able to resolve micron scale tissue morphology in three dimensions as well as measure picometer scale motion at each spatial position. Most PhOCT systems to date have relied upon the phase stability offered by spectrometer detection. On the other hand swept laser source based PhOCT offers a number of advantages including balanced detection, long imaging depths, and high imaging speeds. Unfortunately the inherent phase instability of traditional swept laser sources has necessitated complex usermore » developed hardware/software solutions to restore phase sensitivity. Here we present recent results using a prototype swept laser that overcomes these issues. The akinetic swept laser is electronically tuned and precisely controls sweeps without any mechanical movement, which results in high phase stability. We have developed an optical fiber based PhOCT system around the akinetic laser source that had a 1550 nm center wavelength and a sweep rate of 140 kHz. The stability of the system was measured to be 4.4 pm with a calibrated reflector, thus demonstrating near shot noise limited performance. Using this PhOCT system, we have acquired structural and vibratory measurements of the middle ear in a mouse model, post mortem. The quality of the results suggest that the akinetic laser source is a superior laser source for PhOCT with many advantages that greatly reduces the required complexity of the imaging system.« less

Optical coherence tomography applied to tests of skin care products in humans--a case study.

PubMed

Vasquez-Pinto, L M C; Maldonado, E P; Raele, M P; Amaral, M M; de Freitas, A Z

2015-02-01

When evaluating skin care products for human skin, quantitative test methods need to be simple, precise and reliable. Optical coherence tomography (OCT), provides high-resolution sectional images of translucent materials to a depth of a few millimeters, a technique usually applied to medical measurements in ophthalmology and dermatology. This study aimed to demonstrate the application of OCT as the main technique for monitoring changes in skin topography during tests of a wrinkle-reduction product in humans. We used a commercial OCT apparatus to perform clinical examinations of skin roughness in treated and non-treated sites in the periorbital region of thirty human voluntaries who were using an anti-aging product commercially available: Natura Chronos® Flavonóides de Passiflora 45+ FPS15, from Natura Cosméticos, Brazil. Measurements were performed days 0, 7, 14 and 28 of treatment. Equipment and software allowed real-time recording of skin roughness parameters and wrinkle depths. The OCT measurements have allowed the monitoring of changes in skin roughness, which have shown reduction in treated sites around 10%. The obtained depth distributions also indicate reduction in the occurrence of wrinkles deeper than 170 μm. The verified results are consistent with those typically obtained after successful treatment with modern anti-aging products. By using the OCT technique, it was possible to quantify changes in skin roughness and in the distribution of depths of skin wrinkles, with adequate sensitivity. OCT imaging allows the direct visualization of the skin topography with resolution of micrometers, a reliable and interactive tool for clinical use. Therefore, for the first time, we demonstrated the use of OCT technique to verify the efficacy of cosmetic products in real time. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Spectral Domain Optical Coherence Tomography Allows the Unification of Clinical Decision Making for the Evaluation of Choroidal Neovascularization Activity.

PubMed

Volz, Cornelia; Grassmann, Felix; Greslechner, Roman; Märker, David Arthur; Peters, Patrick; Helbig, Horst; Gamulescu, Maria-Andreea

2018-06-21

This prospective observational clinical study investigated the benefits of spectral domain optical coherence tomography for specialists and residents in the management of neovascular age-related macular degeneration (AMD). The study involved 49 eyes of 44 patients. Patients were advised to present for reevaluation 4 weeks after the administration of the loading dose of vascular endothelial growth factor (VEGF)-inhibitors (3 intravitreal injections every 4 weeks after diagnosis). They were examined by residents (3-4 years' experience in ophthalmology) and specialists (> 5 years' experience). Each examiner evaluated the clinical situation and the spectral domain optical coherence tomography (SD-OCT) scan. After each evaluation, the examiners independently stated if further anti-VEGF treatment was recommended. The "true outcome" was defined as the specialist decision based on clinical evaluation and SD-OCT. Specialists and residents did not significantly differ in their accuracy in deciding on the correct treatment (p = 0.705 and p = 1), with or without the aid of SD-OCT. Both groups benefited from using SD-OCT to support their recommendations (p = 0.001 and p = 0.0002) and achieved a similar level of accuracy (p = 1 for difference). Residents benefited more than specialists by using SD-OCT to substantiate their recommendation on how to manage exudative AMD after the administration of the loading dose. © 2018 S. Karger AG, Basel.

Photonic integrated Mach-Zehnder interferometer with an on-chip reference arm for optical coherence tomography

PubMed Central

Yurtsever, Günay; Považay, Boris; Alex, Aneesh; Zabihian, Behrooz; Drexler, Wolfgang; Baets, Roel

2014-01-01

Optical coherence tomography (OCT) is a noninvasive, three-dimensional imaging modality with several medical and industrial applications. Integrated photonics has the potential to enable mass production of OCT devices to significantly reduce size and cost, which can increase its use in established fields as well as enable new applications. Using silicon nitride (Si3N4) and silicon dioxide (SiO2) waveguides, we fabricated an integrated interferometer for spectrometer-based OCT. The integrated photonic circuit consists of four splitters and a 190 mm long reference arm with a foot-print of only 10 × 33 mm2. It is used as the core of a spectral domain OCT system consisting of a superluminescent diode centered at 1320 nm with 100 nm bandwidth, a spectrometer with 1024 channels, and an x-y scanner. The sensitivity of the system was measured at 0.25 mm depth to be 65 dB with 0.1 mW on the sample. Using the system, we imaged human skin in vivo. With further optimization in design and fabrication technology, Si3N4/SiO2 waveguides have a potential to serve as a platform for passive photonic integrated circuits for OCT. PMID:24761288

BMP Induction of Cardiogenesis in P19 Cells Requires Prior Cell-Cell Interaction(s)

PubMed Central

ANGELLO, JOHN C.; KAESTNER, STEFANIE; WELIKSON, ROBERT E.; BUSKIN, JEAN N.; HAUSCHKA, STEPHEN D.

2008-01-01

Mouse P19 embryonal carcinoma cells undergo cardiogenesis in response to high density and DMSO. We have derived a clonal subline which undergoes cardiogenesis in response to high density, but without requiring exposure to DMSO. The new subline retains the capacity to differentiate into skeletal muscle and neuronal cells in response to DMSO and retinoic acid. However, upon aggregation, these Oct 4-positive cells, termed P19-SI because they “self-induce” cardiac muscle, exhibit increased mRNAs encoding the mesodermal factor Brachyury, cardiac transcription factors Nkx 2.5 and GATA 4, the transcriptional repressor Msx-1, and cytokines Wnt 3a, Noggin and BMP 4. Exposure of aggregated P19-SI cells to BMP 4, a known inducer of cardiogenesis, accelerates cardiogenesis, as determined by rhythmic beating and myosin staining. However, cardiogenesis is severely inhibited when P19-SI cells are aggregated in the presence of BMP 4. These results demonstrate that cell-cell interaction is required before P19-SI cells can undergo a cardiogenic response to BMP 4. A concurrent increase in the expression of Msx-1 suggests one possible process underlying the inhibition of cardiogenesis. The phenotype of P19-SI cells offers an opportunity to explore new aspects of cardiac induction. PMID:16773658

BMP induction of cardiogenesis in P19 cells requires prior cell-cell interaction(s).

PubMed

Angello, John C; Kaestner, Stefanie; Welikson, Robert E; Buskin, Jean N; Hauschka, Stephen D

2006-08-01

Mouse P19 embryonal carcinoma cells undergo cardiogenesis in response to high density and DMSO. We have derived a clonal subline that undergoes cardiogenesis in response to high density, but without requiring exposure to DMSO. The new subline retains the capacity to differentiate into skeletal muscle and neuronal cells in response to DMSO and retinoic acid. However, upon aggregation, these Oct 4-positive cells, termed P19-SI because they "self-induce" cardiac muscle, exhibit increased mRNAs encoding the mesodermal factor Brachyury, cardiac transcription factors Nkx 2.5 and GATA 4, the transcriptional repressor Msx-1, and cytokines Wnt 3a, Noggin, and BMP 4. Exposure of aggregated P19-SI cells to BMP 4, a known inducer of cardiogenesis, accelerates cardiogenesis, as determined by rhythmic beating and myosin staining. However, cardiogenesis is severely inhibited when P19-SI cells are aggregated in the presence of BMP 4. These results demonstrate that cell-cell interaction is required before P19-SI cells can undergo a cardiogenic response to BMP 4. A concurrent increase in the expression of Msx-1 suggests one possible process underlying the inhibition of cardiogenesis. The phenotype of P19-SI cells offers an opportunity to explore new aspects of cardiac induction.

Colposcopic imaging using visible-light optical coherence tomography.

PubMed

Duan, Lian; McRaven, Michael D; Liu, Wenzhong; Shu, Xiao; Hu, Jianmin; Sun, Cheng; Veazey, Ronald S; Hope, Thomas J; Zhang, Hao F

2017-05-01

High-resolution colposcopic optical coherence tomography (OCT) provides key anatomical measures, such as thickness and minor traumatic injury of vaginal epithelium, of the female reproductive tract noninvasively. This information can be helpful in both fundamental investigations in animal models and disease screenings in humans. We present a fiber-based visible-light OCT and two probe designs for colposcopic application. One probe conducts circular scanning using a DC motor, and the other probe is capable of three-dimensional imaging over a 4.6 × 4.6 - mm 2 area using a pair of galvo scanners. Using this colposcopic vis-OCT with both probes, we acquired high-resolution images from whole isolated macaque vaginal samples and identified biopsy lesions.

Colposcopic imaging using visible-light optical coherence tomography

NASA Astrophysics Data System (ADS)

Duan, Lian; McRaven, Michael D.; Liu, Wenzhong; Shu, Xiao; Hu, Jianmin; Sun, Cheng; Veazey, Ronald S.; Hope, Thomas J.; Zhang, Hao F.

2017-05-01

High-resolution colposcopic optical coherence tomography (OCT) provides key anatomical measures, such as thickness and minor traumatic injury of vaginal epithelium, of the female reproductive tract noninvasively. This information can be helpful in both fundamental investigations in animal models and disease screenings in humans. We present a fiber-based visible-light OCT and two probe designs for colposcopic application. One probe conducts circular scanning using a DC motor, and the other probe is capable of three-dimensional imaging over a 4.6×4.6-mm2 area using a pair of galvo scanners. Using this colposcopic vis-OCT with both probes, we acquired high-resolution images from whole isolated macaque vaginal samples and identified biopsy lesions.

Splitting of IVP bovine blastocyst affects morphology and gene expression of resulting demi-embryos during in vitro culture and in vivo elongation.

PubMed

Velasquez, Alejandra E; Castro, Fidel O; Veraguas, Daniel; Cox, Jose F; Lara, Evelyn; Briones, Mario; Rodriguez-Alvarez, Lleretny

2016-02-01

Embryo splitting might be used to increase offspring yield and for molecular analysis of embryo competence. How splitting affects developmental potential of embryos is unknown. This research aimed to study the effect of bovine blastocyst splitting on morphological and gene expression homogeneity of demi-embryos and on embryo competence during elongation. Grade I bovine blastocyst produced in vitro were split into halves and distributed in nine groups (3 × 3 setting according to age and stage before splitting; age: days 7-9; stage: early, expanded and hatched blastocysts). Homogeneity and survival rate in vitro after splitting (12 h, days 10 and 13) and the effect of splitting on embryo development at elongation after embryo transfer (day 17) were assessed morphologically and by RT-qPCR. The genes analysed were OCT4, SOX2, NANOG, CDX2, TP1, TKDP1, EOMES, and BAX. Approximately 90% of split embryos had a well conserved defined inner cell mass (ICM), 70% of the halves had similar size with no differences in gene expression 12 h after splitting. Split embryos cultured further conserved normal and comparable morphology at day 10 of development; this situation changes at day 13 when embryo morphology and gene expression differed markedly among demi-embryos. Split and non-split blastocysts were transferred to recipient cows and were recovered at day 17. Fifty per cent of non-split embryos were larger than 100 mm (33% for split embryos). OCT4, SOX2, TP1 and EOMES levels were down-regulated in elongated embryos derived from split blastocysts. In conclusion, splitting day-8 blastocysts yields homogenous demi-embryos in terms of developmental capability and gene expression, but the initiation of the filamentous stage seems to be affected by the splitting.

Tiger, Bengal and Domestic Cat Embryos Produced by Homospecific and Interspecific Zona-Free Nuclear Transfer.

PubMed

Moro, L N; Jarazo, J; Buemo, C; Hiriart, M I; Sestelo, A; Salamone, D F

2015-10-01

The aim of this study was to evaluate three different cloning strategies in the domestic cat (Felis silvestris) and to use the most efficient to generate wild felid embryos by interspecific cloning (iSCNT) using Bengal (a hybrid formed by the cross of Felis silvestris and Prionailurus bengalensis) and tiger (Panthera tigris) donor cells. In experiment 1, zona-free (ZP-free) cloning resulted in higher fusion and expanded blastocyst rates with respect to zona included cloning techniques that involved fusion or injection of the donor cell. In experiment 2, ZP-free iSCNT and embryo aggregation (2X) were assessed. Division velocity and blastocyst rates were increased by embryo aggregation in the three species. Despite fewer tiger embryos than Bengal and cat embryos reached the blastocyst stage, Tiger 2X group increased the percentage of blastocysts with respect to Tiger 1X group (3.2% vs 12.1%, respectively). Moreover, blastocyst cell number was almost duplicated in aggregated embryos with respect to non-aggregated ones within Bengal and tiger groups (278.3 ± 61.9 vs 516.8 ± 103.6 for Bengal 1X and Bengal 2X groups, respectively; 41 vs 220 ± 60 for Tiger 1X and Tiger 2X groups, respectively). OCT4 analysis also revealed that tiger blastocysts had higher proportion of OCT4-positive cells with respect to Bengal blastocysts and cat intracytoplasmic sperm injection blastocysts. In conclusion, ZP-free cloning has improved the quality of cat embryos with respect to the other cloning techniques evaluated and was successfully applied in iSCNT complemented with embryo aggregation. © 2015 Blackwell Verlag GmbH.

Advances in optical coherence tomography in dermatology-a review

NASA Astrophysics Data System (ADS)

Olsen, Jonas; Holmes, Jon; Jemec, Gregor B. E.

2018-04-01

Optical coherence tomography (OCT) was introduced as an imaging system, but like ultrasonography, other measures, such as blood perfusion and polarization of light, have enabled the technology to approach clinical utility. This review aims at providing an overview of the advances in clinical research based on the improving technical aspects. OCT provides cross-sectional and en face images down to skin depths of 0.4 to 2.00 mm with optical resolution of 3 to 15 μm. Dynamic optical coherence tomography (D-OCT) enables the visualization of cutaneous microvasculature via detection of rapid changes in the interferometric signal of blood flow. Nonmelanoma skin cancer (NMSC) is the most comprehensively investigated topic, resulting in improved descriptions of morphological features and diagnostic criteria. A refined scoring system for diagnosing NMSC, taking findings from conventional and D-OCT into account, is warranted. OCT diagnosis of melanoma is hampered by the resolution and the optical properties of melanin. D-OCT may be of value in diseases characterized with dynamic changes in the vasculature of the skin and the addition of functional measures is strongly encouraged. In conclusion, OCT in dermatology is still an emerging technology that has great potential for improving further in the future.

User-guided segmentation for volumetric retinal optical coherence tomography images

PubMed Central

Yin, Xin; Chao, Jennifer R.; Wang, Ruikang K.

2014-01-01

Abstract. Despite the existence of automatic segmentation techniques, trained graders still rely on manual segmentation to provide retinal layers and features from clinical optical coherence tomography (OCT) images for accurate measurements. To bridge the gap between this time-consuming need of manual segmentation and currently available automatic segmentation techniques, this paper proposes a user-guided segmentation method to perform the segmentation of retinal layers and features in OCT images. With this method, by interactively navigating three-dimensional (3-D) OCT images, the user first manually defines user-defined (or sketched) lines at regions where the retinal layers appear very irregular for which the automatic segmentation method often fails to provide satisfactory results. The algorithm is then guided by these sketched lines to trace the entire 3-D retinal layer and anatomical features by the use of novel layer and edge detectors that are based on robust likelihood estimation. The layer and edge boundaries are finally obtained to achieve segmentation. Segmentation of retinal layers in mouse and human OCT images demonstrates the reliability and efficiency of the proposed user-guided segmentation method. PMID:25147962

User-guided segmentation for volumetric retinal optical coherence tomography images.

PubMed

Yin, Xin; Chao, Jennifer R; Wang, Ruikang K

2014-08-01

Despite the existence of automatic segmentation techniques, trained graders still rely on manual segmentation to provide retinal layers and features from clinical optical coherence tomography (OCT) images for accurate measurements. To bridge the gap between this time-consuming need of manual segmentation and currently available automatic segmentation techniques, this paper proposes a user-guided segmentation method to perform the segmentation of retinal layers and features in OCT images. With this method, by interactively navigating three-dimensional (3-D) OCT images, the user first manually defines user-defined (or sketched) lines at regions where the retinal layers appear very irregular for which the automatic segmentation method often fails to provide satisfactory results. The algorithm is then guided by these sketched lines to trace the entire 3-D retinal layer and anatomical features by the use of novel layer and edge detectors that are based on robust likelihood estimation. The layer and edge boundaries are finally obtained to achieve segmentation. Segmentation of retinal layers in mouse and human OCT images demonstrates the reliability and efficiency of the proposed user-guided segmentation method.

Crystal Structure of the Dimeric Oct6 (Pou3fl) POU Domain Bound to Palindromic MORE DNA

DOE Office of Scientific and Technical Information (OSTI.GOV)

R Jauch; S Choo; C Ng

POU domains (named after their identification in Pit1, Oct1 unc86) are found in around 15 transcription factors encoded in mammalian genomes many of which feature prominently as key regulators at development bifurcations. For example, the POU III class Octamer binding protein 6 (Oct6) is expressed in embryonic stem cells and during neural development and drives the differentia5tion of myelinated cells in the central and peripheral nervous system. Defects in oct6 expression levels are linked to neurological disorders such as schizophrenia. POU proteins contain a bi-partite DNA binding domain that assembles on various DNA motifs with differentially configured subdomains. Intriguingly, alternativemore » configurations of POU domains on different DNA sites were shown to affect the subsequent recruitment of transcriptional coactivators. Namely, binding of Oct1 to a Palindromic Oct-factor Recognition Element (PORE) was shown to facilitate the recruitment of the OBF1 coactivator whereas More of PORE (MORE) bound Oct1 does not. Moreover, Pit1 was shown to recruit the corepressor N-CoR only when bound to a variant MORE motif with a 2 bp half-site spacing. Therefore, POU proteins are seen as a paradigm for DNA induced allosteric effects on transcription factors modulating their regulatory potential. However, a big unresolved conundrum for the POU class and for most if not all other transcription factor classes is how highly similar proteins regulate different sets of genes causing fundamentally different biological responses. Ultimately, there must be subtle features enabling those factors to engage in contrasting molecular interactions in the cell. Thus, the dissection of the molecular details of the transcription-DNA recognition in general, and the formation of multimeric regulatory complexes, in particular, is highly desirable. To contribute to these efforts they solved the 2.05 {angstrom} crystal structure of Oct6 bound as a symmetrical homodimer to palindromic MORE DNA.« less

Giant Sunspot Erupts with 4th Substantial Flare

NASA Image and Video Library

2017-12-08

The sun emitted a significant solar flare, peaking at 5:40 p.m. EDT on Oct. 24, 2014. The flare erupted from a particularly large active region -- labeled AR 12192 -- on the sun that is the largest in 24 years. This is the fourth substantial flare from this active region since Oct. 19. Read more: www.nasa.gov/content/goddard/giant-sunspot-erupts-with-4t...

In vivo imaging of coral tissue and skeleton with optical coherence tomography.

PubMed

Wangpraseurt, Daniel; Wentzel, Camilla; Jacques, Steven L; Wagner, Michael; Kühl, Michael

2017-03-01

Application of optical coherence tomography (OCT) for in vivo imaging of tissue and skeleton structure of intact living corals enabled the non-invasive visualization of coral tissue layers (endoderm versus ectoderm), skeletal cavities and special structures such as mesenterial filaments and mucus release from intact living corals. Coral host chromatophores containing green fluorescent protein-like pigment granules appeared hyper-reflective to near-infrared radiation allowing for excellent optical contrast in OCT and a rapid characterization of chromatophore size, distribution and abundance. In vivo tissue plasticity could be quantified by the linear contraction velocity of coral tissues upon illumination resulting in dynamic changes in the live coral tissue surface area, which varied by a factor of 2 between the contracted and expanded state of a coral. Our study provides a novel view on the in vivo organization of coral tissue and skeleton and highlights the importance of microstructural dynamics for coral ecophysiology. © 2017 The Author(s).

Comparison of contrast media and low-molecular-weight dextran for frequency-domain optical coherence tomography.

PubMed

Ozaki, Yuichi; Kitabata, Hironori; Tsujioka, Hiroto; Hosokawa, Seiki; Kashiwagi, Manabu; Ishibashi, Kohei; Komukai, Kenichi; Tanimoto, Takashi; Ino, Yasushi; Takarada, Shigeho; Kubo, Takashi; Kimura, Keizo; Tanaka, Atsushi; Hirata, Kumiko; Mizukoshi, Masato; Imanishi, Toshio; Akasaka, Takashi

2012-01-01

Although an intracoronary frequency-domain optical coherence tomography (FD-OCT) system overcomes several limitations of the time-domain OCT (TD-OCT) system, the former requires injection of contrast media for image acquisition. The increased total amount of contrast media for FD-OCT image acquisition may lead to the impairment of renal function. The safety and usefulness of the non-occlusion method with low-molecular-weight dextran L (LMD-L) via a guiding catheter for TD-OCT image acquisition have been reported previously. The aim of the present study was to compare the image quality and quantitative measurements between contrast media and LMD-L for FD-OCT image acquisition in coronary stented lesions. Twenty-two patients with 25 coronary stented lesions were enrolled in this study. FD-OCT was performed with the continuous-flushing method via a guiding catheter. Both contrast media and LMD-L were infused at a rate of 4 ml/s by an autoinjector. With regard to image quality, the prevalence of clear image segments was comparable between contrast media and LMD-L (97.9% vs. 96.5%, P=0.90). Furthermore, excellent correlations were observed between both flushing solutions in terms of minimum lumen area, mean lumen area, and mean stent area. The total volumes of contrast media and of LMD-L needed for OCT image acquisition were similar. FD-OCT image acquisition with LMD-L has the potential to reduce the total amount of contrast media without loss of image quality.

Cardiovascular Optical Coherence Tomography

NASA Astrophysics Data System (ADS)

Yonetsu, Taishi; Villiger, Martin; Bouma, Brett E.; Jang, Ik-Kyung

The potential of optical coherence tomography (OCT) for intravascular imaging and assessing the microstructure of atherosclerosis was suggested already by Huang et al. at the very beginning of OCT [1]. For ophthalmology, the eye provides a natural window for OCT to image the retinal microstructure, and OCT has rapidly become the standard imaging modality to diagnose retinal disease and assess disease progression and response to therapy [1, 2]. Intravascular imaging is more invasive by nature and requires imaging through a catheter probe. This has triggered the development of advanced fiber-optic OCT systems with compact, rotating fiber probes, to image the vessel by circumferentially scanning the luminal wall [3, 4]. In 1998, we established the first cardiac OCT research group at the Massachusetts General Hospital to explore the clinical applications of OCT. The first imaging of rabbit aorta was reported by Fujimoto et al. [5], followed by the first swine measurements in vivo by Tearney et al. [6], and finally the first assessment of coronary arteries in patients by Jang et al. [7]. The scope of this chapter is to highlight the steps taken to bring intravascular OCT from bench to bedside over the last 15 years. We will give a general description of atherosclerosis and its pathophysiology and the specific technical implementation of OCT for intravascular imaging through a fiber-optic probe. The motivation is to provide sufficient medical details to provide a basic introduction to the terminology, principles, and challenges of intracoronary imaging.

What Has Their Bomb Cost the Chinese?

DTIC Science & Technology

1966-02-18

Oct. 1964, p. 5. 2 4Chalmers Johnson, "China’s Manhattan Project ," New York Times Magazine, 25 Oct. 1964, p. 23. 2 6john W. Finney, "Hints of 2...nuclear weapons program.) 28. "INCO Expansion Plans Announced," Wall Street Journal, 22 Apr. 1965, p. 5. 29. Johnson, Chalmers. "China’s Manhattan ... Project ." New York Times Magazine, 25 Oct. 1964, pp. 23 and 117-118. (Estimates number of scientists and technicians used in China’s nuclear development

Work Context Interactions, Work Climate and Turnover.

DTIC Science & Technology

1983-10-01

AD-A133 893 WORK CONTEXT INTERACTIONS WORK CLIMATE AND TURNOVER(U) 1/f MICHIGAN STATE UNIV tAST LANSING B SCHNEIDER OCT 83 RR-83-2 NOSOTA-79-C-0781...CATALOG NUMBER -) L SIL ad utte. TYPE OF REPORT 6 PERIOD COVERED Work Context Interactions, Work Climate and FnlRpr Turnover: Final Report...reverse aide If necesaranmd Identify by block number) Work climate turnover organizational climate interactional psychology realistic job preview job

Evaluation of Melatonin Effect on Human Breast Cancer Stem Cells Using a Threedimensional Growth Method of Mammospheres.

PubMed

Lopes, Juliana Ramos; da Silva Kavagutti, Mayume; de Medeiros, Felipe Arthur Faustino; de Campos Zuccari, Debora Aparecida Pires

2017-01-01

The high rates of women&#039;s death from breast cancer occur due to acquired resistance by patients to certain treatments, enabling the recurrence and/or tumor growth, invasion and metastasis. It has been demonstrated that the presence of cancer stem cells in human tumors, as responsible for recurrence and resistance to therapy. Studies have identified OCT4 as responsible for self-renewal and maintenance of pluripotency of stem cells. Thus, it is interesting to study potential drugs that target this specific population in breast cancer. Melatonin, appears to have oncostatic effects on cancer cells, however, little is known about its therapeutic effect on cancer stem cells. Evaluate the viability and the expression of OCT4 in breast cancer stem cells, MCF-7 and MDA-MB- 231, after melatonin treatment. The cells were grown in a 3-dimensional model of mammospheres, representing the breast cancer stem cell population and treated or not with melatonin. The cell viability of mammospheres were evaluated by MTT assay and the OCT4 expression, a cancer stem cells marker, was verified by immunocitochemistry. Our results demonstrated that the melatonin treatment decreased the cell viability of MCF-7 and MDAMB- 231 mammospheres. Furthermore, it was observed that in both cell lines, the expression of OCT4 was decreased in melatonin-treated cells compared to the control group. This fact suggests that melatonin is effective against breast cancer stem cells inhibiting the cell viability via OCT 4. Based on that, we believe that melatonin has a high potential to be used as an alternative treatment for breast cancer. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Heat shock instructs hESCs to exit from the self-renewal program through negative regulation of OCT4 by SAPK/JNK and HSF1 pathway.

PubMed

Byun, Kyunghee; Kim, Taek-Kyun; Oh, Jeehyun; Bayarsaikhan, Enkhjargal; Kim, Daesik; Lee, Min Young; Pack, Chan-Gi; Hwang, Daehee; Lee, Bonghee

2013-11-01

Environmental factors affect self-renewal of stem cells by modulating the components of self-renewal networks. Heat shock, an environmental factor, induces heat shock factors (HSFs), which up-regulate stress response-related genes. However, the link of heat shock to self-renewal of stem cells has not been elucidated yet. Here, we present the direct link of heat shock to a core stem cell regulator, OCT4, in the self-renewal network through SAPK/JNK and HSF1 pathway. We first showed that heat shock initiated differentiation of human embryonic stem cells (hESCs). Gene expression analysis revealed that heat shock increased the expression of many genes involved in cellular processes related to differentiation of stem cells. We then examined the effects of HSFs induced by heat shock on core self-renewal factors. Among HSFs, heat shock induced mainly HSF1 in hESCs. The HSF1 repressed the expression of OCT4, leading to the differentiation of hESCs and the above differentiation-related gene expression change. We further examined the effects of the upstream MAP (mitogen-activated protein) kinases of HSF1 on the repression of OCT4 expression by HSF1. Among the MAP kinases, SAPK/JNK controlled predominantly the repression of the OCT4 expression by HSF1. The direct link of heat shock to the core self-renewal regulator through SAPK/JNK and HSF1 provides a fundamental basis for understanding the effect of heat and other stresses involving activation of HSF1 on the self-renewal program and further controlling differentiation of hESCs in a broad spectrum of stem cell applications using these stresses. © 2013.

Perspectives of mid-infrared optical coherence tomography for inspection and micrometrology of industrial ceramics

PubMed Central

Su, Rong; Kirillin, Mikhail; Chang, Ernest W.; Sergeeva, Ekaterina; Yun, Seok H.; Mattsson, Lars

2014-01-01

Optical coherence tomography (OCT) is a promising tool for detecting micro channels, metal prints, defects and delaminations embedded in alumina and zirconia ceramic layers at hundreds of micrometers beneath surfaces. The effect of surface roughness and scattering of probing radiation within sample on OCT inspection is analyzed from the experimental and simulated OCT images of the ceramic samples with varying surface roughnesses and operating wavelengths. By Monte Carlo simulations of the OCT images in the mid-IR the optimal operating wavelength is found to be 4 µm for the alumina samples and 2 µm for the zirconia samples for achieving sufficient probing depth of about 1 mm. The effects of rough surfaces and dispersion on the detection of the embedded boundaries are discussed. Two types of image artefacts are found in OCT images due to multiple reflections between neighboring boundaries and inhomogeneity of refractive index. PMID:24977838

Differentiation of female Oct4-GFP embryonic stem cells into germ lineage cells.

PubMed

Ma, Xin; Li, Peng; Sun, Xiang; Sun, Yifeng; Hu, Rong; Yuan, Ping

2018-04-01

Due to high infertility ratio nowadays, it is essential to explore efficient ways of enhancing mammalian reproductivity, in particular female reproductivity. Using female Oct4-GFP embryonic stem cells, we mimic the in vivo development procedure to induce ES cells into epiblast cell-like cells (EpiLCs) and then primordial germ cell-like cells (PGCLCs). GFP positive PGCLCs that showed typical PGC markers and epigenetic modification were efficiently obtained. Further transplantation of the GFP positive PGCLC and native ovary cell mixture into ovary of infertile mice revealed that both MVH and GFP positive cells could be developed in ovary, but no later developmental stage germ cells were observed. This study suggested that Oct4-GFP ES cells may be only suitable for tracing early germ cell development. © 2018 International Federation for Cell Biology.

Comparison of newer IOL power calculation methods for post-corneal refractive surgery eyes

PubMed Central

Wang, Li; Tang, Maolong; Huang, David; Weikert, Mitchell P.; Koch, Douglas D.

2015-01-01

Objective To compare the newer formulae, the optical coherence tomography based intraocular lens (IOL) power formula (OCT formula) and the Barrett True-K formula (True-K), to the methods on the ASCRS calculator in eyes with previous myopic LASIK/PRK. Design Prospective case series. Participants One-hundred and four eyes of 80 patients who had previous myopic LASIK/PRK and subsequent cataract surgery and IOL implantation. Methods Using the actual refraction following cataract surgery as target refraction, predicted IOL power for each method was calculated. The IOL prediction error (PE) was obtained by subtracting the predicted IOL power from the power of IOL implanted. Main outcome measures Arithmetic IOL PEs, variances of mean arithmetic IOL PE, median refractive PE and percent of eyes within 0.5 D and 1.0 D of refractive PE. Results OCT produced smaller variance of IOL PE than did Wang-Koch-Maloney, and Shammas (P<0.05). With the OCT, True-K No History, Wang-Koch-Maloney, Shammas, Haigis-L, and Average of these 5 formulas, respectively, the median refractive PEs were 0.35 D, 0.42 D, 0.51 D, 0.48 D, 0.39 D, and 0.35 D, and the % of eyes within 0.5 D of refractive PE were 68.3%, 58.7%, 50.0%, 52.9%, 55.8%, and 67.3%, and within 1.0 D of RPE, 92.3%, 90.4%, 86.9%, 88.5%, 90.4%, and 94.2%, respectively. The OCT formula had smaller refractive PE compared to Wang-Koch-Maloney and Shammas, and the Average approach produced significantly smaller refractive PE than did all methods except OCT (all P<0.05). Conclusions The OCT and True-K No History are promising formulas. The ASCRS IOL calculator has been updated to include the OCT and Barrett True K formulas. Trial registration Intraocular Lens Power Calculation After Laser Refractive Surgery Based on Optical Coherence Tomography (OCT IOL); Identifier: NCT00532051; www.ClinicalTrials.gov PMID:26459996

Handheld ultrahigh speed swept source optical coherence tomography instrument using a MEMS scanning mirror.

PubMed

Lu, Chen D; Kraus, Martin F; Potsaid, Benjamin; Liu, Jonathan J; Choi, Woojhon; Jayaraman, Vijaysekhar; Cable, Alex E; Hornegger, Joachim; Duker, Jay S; Fujimoto, James G

2013-12-20

We developed an ultrahigh speed, handheld swept source optical coherence tomography (SS-OCT) ophthalmic instrument using a 2D MEMS mirror. A vertical cavity surface-emitting laser (VCSEL) operating at 1060 nm center wavelength yielded a 350 kHz axial scan rate and 10 µm axial resolution in tissue. The long coherence length of the VCSEL enabled a 3.08 mm imaging range with minimal sensitivity roll-off in tissue. Two different designs with identical optical components were tested to evaluate handheld OCT ergonomics. An iris camera aided in alignment of the OCT beam through the pupil and a manual fixation light selected the imaging region on the retina. Volumetric and high definition scans were obtained from 5 undilated normal subjects. Volumetric OCT data was acquired by scanning the 2.4 mm diameter 2D MEMS mirror sinusoidally in the fast direction and linearly in the orthogonal slow direction. A second volumetric sinusoidal scan was obtained in the orthogonal direction and the two volumes were processed with a software algorithm to generate a merged motion-corrected volume. Motion-corrected standard 6 x 6 mm(2) and wide field 10 x 10 mm(2) volumetric OCT data were generated using two volumetric scans, each obtained in 1.4 seconds. High definition 10 mm and 6 mm B-scans were obtained by averaging and registering 25 B-scans obtained over the same position in 0.57 seconds. One of the advantages of volumetric OCT data is the generation of en face OCT images with arbitrary cross sectional B-scans registered to fundus features. This technology should enable screening applications to identify early retinal disease, before irreversible vision impairment or loss occurs. Handheld OCT technology also promises to enable applications in a wide range of settings outside of the traditional ophthalmology or optometry clinics including pediatrics, intraoperative, primary care, developing countries, and military medicine.

Gabor fusion master slave optical coherence tomography

PubMed Central

Cernat, Ramona; Bradu, Adrian; Israelsen, Niels Møller; Bang, Ole; Rivet, Sylvain; Keane, Pearse A.; Heath, David-Garway; Rajendram, Ranjan; Podoleanu, Adrian

2017-01-01

This paper describes the application of the Gabor filtering protocol to a Master/Slave (MS) swept source optical coherence tomography (SS)-OCT system at 1300 nm. The MS-OCT system delivers information from selected depths, a property that allows operation similar to that of a time domain OCT system, where dynamic focusing is possible. The Gabor filtering processing following collection of multiple data from different focus positions is different from that utilized by a conventional swept source OCT system using a Fast Fourier transform (FFT) to produce an A-scan. Instead of selecting the bright parts of A-scans for each focus position, to be placed in a final B-scan image (or in a final volume), and discarding the rest, the MS principle can be employed to advantageously deliver signal from the depths within each focus range only. The MS procedure is illustrated on creating volumes of data of constant transversal resolution from a cucumber and from an insect by repeating data acquisition for 4 different focus positions. In addition, advantage is taken from the tolerance to dispersion of the MS principle that allows automatic compensation for dispersion created by layers above the object of interest. By combining the two techniques, Gabor filtering and Master/Slave, a powerful imaging instrument is demonstrated. The master/slave technique allows simultaneous display of three categories of images in one frame: multiple depth en-face OCT images, two cross-sectional OCT images and a confocal like image obtained by averaging the en-face ones. We also demonstrate the superiority of MS-OCT over its FFT based counterpart when used with a Gabor filtering OCT instrument in terms of the speed of assembling the fused volume. For our case, we show that when more than 4 focus positions are required to produce the final volume, MS is faster than the conventional FFT based procedure. PMID:28270987

Ultrahigh-resolution endoscopic optical coherence tomography

NASA Astrophysics Data System (ADS)

Chen, Yu; Herz, Paul R.; Hsiung, Pei-Lin; Aguirre, Aaron D.; Mashimo, Hiroshi; Desai, Saleem; Pedrosa, Macos; Koski, Amanda; Schmitt, Joseph M.; Fujimoto, James G.

2005-01-01

Early detection of gastrointestinal cancer is essential for the patient treatment and medical care. Endoscopically guided biopsy is currently the gold standard for the diagnosis of early esophageal cancer, but can suffer from high false negative rates due to sampling errors. Optical coherence tomography (OCT) is an emerging medical imaging technology which can generate high resolution, cross-sectional images of tissue in situ and in real time, without the removal of tissue specimen. Although endoscopic OCT has been used successfully to identify certain pathologies in the gastrointestinal tract, the resolution of current endoscopic OCT systems has been limited to 10 - 15 m for clinical procedures. In this study, in vivo imaging of the gastrointestinal tract is demonstrated at a three-fold higher resolution (< 5 m), using a portable, broadband, Cr4+:Forsterite laser as the optical light source. Images acquired from the esophagus, gastro-esophageal junction and colon on animal model display tissue microstructures and architectural details at high resolution, and the features observed in the OCT images are well-matched with histology. The clinical feasibility study is conducted through delivering OCT imaging catheter using standard endoscope. OCT images of normal esophagus, Barrett's esophagus, and esophageal cancers are demonstrated with distinct features. The ability of high resolution endoscopic OCT to image tissue morphology at an unprecedented resolution in vivo would facilitate the development of OCT as a potential imaging modality for early detection of neoplastic changes.

A Randomized, Controlled Study Comparing Two Standardized Closure Methods of Laparoscopic Port Sites

PubMed Central

Chen, Kai; Klapper, Allan S.; Voige, Hayley

2010-01-01

Objectives: To compare octyl-cyanoacrylate tissue adhesive (OCT) with the standard suture technique for the closure of laparoscopic port sites. Methods: This was a randomized clinical trial of 40 patients. All participants had 2 lower abdominal ports, with one port closed using OCT while the opposite port was closed with 4-0 monocryl suture. An evaluation of the wound was performed 2 weeks to 4 weeks after surgery. The Hollander Wound Evaluation Scale (HWES, including step-off of borders, contour irregularities, margin separation, edge inversion, excessive distortion, and overall appearance) was used for cosmetic evaluation. Complications, such as erythema, warmth, tenderness, drainage, and wound infection, were evaluated. Analysis of complications was performed using the chi-square test, and cosmetic evaluation including individual components of the HWES was compared with the t test, P<0.05 considered significant. Results: Eighty wounds were evaluated in 40 patients. The number of patients with complications including erythema (1/40 vs. 16/40), tenderness (1/40 vs. 19/40), and drainage (1/40 vs. 9/40) was lower with OCT than with sutures, respectively (all P<0.001). The ports closed with OCT had higher overall HWES, ie, better cosmetic score (5.92±0.05 vs 5.50±0.13) and lower margin separation (1/40 vs. 10/40) but had higher contour irregularity (6/40 vs. 1/40) (all P<0.05). However, skin contour irregularity was significantly better when OCT was applied using fine tissue forceps (P=0.002). Conclusion: Laparoscopic ports closed with OCT had fewer early complications, such as wound erythema, tenderness, and drainage. Ports closed with OCT had a better cosmetic appearance. PMID:21333194

ATV-4 Undocking

NASA Image and Video Library

2013-10-28

ISS037-E-021218 (28 Oct. 2013) --- The European Space Agency’s fourth Automated Transfer Vehicle (ATV-4), also known as the “Albert Einstein,” begins its relative separation from the International Space Station during the Expedition 37 mission. The ATV-4 undocked from the aft port of the Zvezda Service Module at 4:55 a.m. (EDT) Oct. 28, 2013. The ATV, filled with trash and unneeded items, is scheduled to be sent into Earth’s atmosphere for a planned destructive re-entry over an uninhabited area of the south Pacific Ocean on Nov. 2.

ATV-4 Undocking

NASA Image and Video Library

2013-10-28

ISS037-E-021161 (28 Oct. 2013) --- The European Space Agency’s fourth Automated Transfer Vehicle (ATV-4), also known as the “Albert Einstein,” begins its relative separation from the International Space Station during the Expedition 37 mission. The ATV-4 undocked from the aft port of the Zvezda Service Module at 4:55 a.m. (EDT) Oct. 28, 2013. The ATV, filled with trash and unneeded items, is scheduled to be sent into Earth’s atmosphere for a planned destructive re-entry over an uninhabited area of the south Pacific Ocean on Nov. 2.

ATV-4 Undocking

NASA Image and Video Library

2013-10-28

ISS037-E-021216 (28 Oct. 2013) --- The European Space Agency’s fourth Automated Transfer Vehicle (ATV-4), also known as the “Albert Einstein,” begins its relative separation from the International Space Station during the Expedition 37 mission. The ATV-4 undocked from the aft port of the Zvezda Service Module at 4:55 a.m. (EDT) Oct. 28, 2013. The ATV, filled with trash and unneeded items, is scheduled to be sent into Earth’s atmosphere for a planned destructive re-entry over an uninhabited area of the south Pacific Ocean on Nov. 2.

ATV-4 Undocking

NASA Image and Video Library

2013-10-28

ISS037-E-021195 (28 Oct. 2013) --- The European Space Agency’s fourth Automated Transfer Vehicle (ATV-4), also known as the “Albert Einstein,” begins its relative separation from the International Space Station during the Expedition 37 mission. The ATV-4 undocked from the aft port of the Zvezda Service Module at 4:55 a.m. (EDT) Oct. 28, 2013. The ATV, filled with trash and unneeded items, is scheduled to be sent into Earth’s atmosphere for a planned destructive re-entry over an uninhabited area of the south Pacific Ocean on Nov. 2.

ATV-4 Undocking

NASA Image and Video Library

2013-10-28

ISS037-E-021215 (28 Oct. 2013) --- The European Space Agency’s fourth Automated Transfer Vehicle (ATV-4), also known as the “Albert Einstein,” begins its relative separation from the International Space Station during the Expedition 37 mission. The ATV-4 undocked from the aft port of the Zvezda Service Module at 4:55 a.m. (EDT) Oct. 28, 2013. The ATV, filled with trash and unneeded items, is scheduled to be sent into Earth’s atmosphere for a planned destructive re-entry over an uninhabited area of the south Pacific Ocean on Nov. 2.

Arbitrary-quantum-state preparation of a harmonic oscillator via optimal control

NASA Astrophysics Data System (ADS)

Rojan, Katharina; Reich, Daniel M.; Dotsenko, Igor; Raimond, Jean-Michel; Koch, Christiane P.; Morigi, Giovanna

2014-08-01

The efficient initialization of a quantum system is a prerequisite for quantum technological applications. Here we show that several classes of quantum states of a harmonic oscillator can be efficiently prepared by means of a Jaynes-Cummings interaction with a single two-level system. This is achieved by suitably tailoring external fields which drive the dipole and/or the oscillator. The time-dependent dynamics that leads to the target state is identified by means of optimal control theory (OCT) based on Krotov's method. Infidelities below 10-4 can be reached for the parameters of the experiment of Raimond, Haroche, Brune and co-workers, where the oscillator is a mode of a high-Q microwave cavity and the dipole is a Rydberg transition of an atom. For this specific situation we analyze the limitations on the fidelity due to parameter fluctuations and identify robust dynamics based on pulses found using ensemble OCT. Our analysis can be extended to quantum-state preparation of continuous-variable systems in other platforms, such as trapped ions and circuit QED.

The Frequency of Optical Coherence Tomography Testing in Glaucoma at a Single Academic Medical Center.

PubMed

Griffith, Joseph F; Goldberg, Jeffrey L

2016-03-01

To determine the frequency of optical coherence tomography (OCT) examinations compared with clinical examinations and visual field (VF) tests in patients with 5 types of glaucoma. A retrospective, longitudinal cohort study was conducted of 5154 patients treated between 2003 and 2010 at a single academic medical center. Patients were classified using billing records as having primary open-angle glaucoma, low-tension open-angle glaucoma (NTG), pigmentary open-angle glaucoma, chronic angle-closure glaucoma, or pseudoexfoliation glaucoma. Analysis of variance, χ test, and exact χ test were performed to identify associations between glaucoma type and test frequency. Pigmentary open-angle glaucoma and NTG patients had a higher rate of undergoing at least 2 VFs (94.4%, 94.9%), and chronic angle-closure glaucoma patients had a lower rate of undergoing at least 2 OCTs (25.3%) than all other glaucoma types. NTG patients also had the highest rate of undergoing at least 2 OCTs and at least 2 VFs (36.6%). Overall, the rate of clinical examinations (2.68 examinations/y) exceeded the rates of OCTs (1.39 examinations/y), which exceeded the rate of VF tests (1.24 tests/y). There were no differences in OCT frequency between glaucoma types (0.91 to 1.63 OCTs/y). Within each glaucoma diagnosis, patients had clinical examinations more frequently than OCTs and clinical examinations more frequently than VFs. Primary open-angle glaucoma and pseudoexfoliation glaucoma patients also had OCTs more frequently than VFs. More patients had at least 2 VF tests than at least 2 OCTs (4481 vs. 1679). The relative use of clinical examinations, VF testing, and OCT imaging varies among glaucoma diagnoses.

Truly simultaneous SS-OCT of the anterior and posterior human eye with full anterior chamber and 50° retinal field of views (Conference Presentation)

NASA Astrophysics Data System (ADS)

McNabb, Ryan P.; Viehland, Christian; Keller, Brenton; Vann, Robin R.; Izatt, Joseph A.; Kuo, Anthony N.

2017-02-01

Optical coherence tomography (OCT) has revolutionized clinical observation of the eye and is an indispensable part of the modern ophthalmic practice. Unlike many other ophthalmic imaging techniques, OCT provides three-dimensional information about the imaged eye. However, conventional clinical OCT systems image only the anterior or the posterior eye during a single acquisition. Newer OCT systems have begun to image both during the same acquisition but with compromises such as limited field of view in the posterior eye or requiring rapid switching between the anterior and posterior eye during the scan. We describe here the development and demonstration of an OCT system with truly simultaneous imaging of both the anterior and posterior eye capable of imaging the full anterior chamber width and 50° on the retina (macula, optic nerve, and arcades). The whole eye OCT system was developed using custom optics and optomechanics. Polarization was utilized to separate the imaging channels. We utilized a 200kHz swept-source laser (Axsun Technologies) centered at 1040±50nm of bandwidth. The clock signal generated by the laser was interpolated 4x to generate 5504 samples per laser sweep. With the whole eye OCT system, we simultaneously acquired anterior and posterior segments with repeated B-scans as well as three-dimensional volumes from seven healthy volunteers (other than refractive error). On three of these volunteers, whole eye OCT and partial coherence interferometry (LenStar PCI, Haag-Streit) were used to measure axial eye length. We measured a mean repeatability of ±47µm with whole eye OCT and a mean difference from PCI of -68µm.

Performance characteristics of optical coherence tomography in assessment of Barrett's esophagus and esophageal cancer: systematic review.

PubMed

Kohli, D R; Schubert, M L; Zfass, A M; Shah, T U

2017-11-01

Optical coherence tomography (OCT) can generate high-resolution images of the esophagus that allows cross-sectional visualization of esophageal wall layers. We conducted a systematic review to assess the utility of OCT for diagnosing of esophageal intestinal metaplasia (IM; Barrett's esophagus BE)), dysplasia, cancer and staging of early esophageal cancer. English language human observational studies and clinical trials published in PubMed and Embase were included if they assessed any of the following: (i) in-vivo features and accuracy of OCT at diagnosing esophageal IM, sub-squamous intestinal metaplasia (SSIM), dysplasia, or cancer, and (ii) accuracy of OCT in staging esophageal cancer. Twenty-one of the 2,068 retrieved citations met inclusion criteria. In the two prospective studies that assessed accuracy of OCT at identifying IM, sensitivity was 81%-97%, and specificity was 57%-92%. In the two prospective studies that assessed accuracy of OCT at identifying dysplasia and early cancer, sensitivity was 68%-83%, and specificity was 75%-82%. Observational studies described significant variability in the ability of OCT to accurately identify SSIM. Two prospective studies that compared the accuracy of OCT at staging early squamous cell carcinoma to histologic resection specimens reported accuracy of >90%. Risk of bias and applicability concerns was rated as low among the prospective studies using the QUADAS-2 questionnaire. OCT may identify intestinal metaplasia and dysplasia, but its accuracy may not meet recommended thresholds to replace 4-quadrant biopsies in clinical practice. OCT may be more accurate than EUS at staging early esophageal cancer, but randomized trials and cost-effective analyses are lacking. © The Authors 2017. Published by Oxford University Press on behalf of International Society for Diseases of the Esophagus. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Detection of primary angle closure using anterior segment optical coherence tomography in Asian eyes.

PubMed

Nolan, Winifred P; See, Jovina L; Chew, Paul T K; Friedman, David S; Smith, Scott D; Radhakrishnan, Sunita; Zheng, Ce; Foster, Paul J; Aung, Tin

2007-01-01

To evaluate noncontact anterior segment optical coherence technology (AS-OCT) as a qualitative method of imaging the anterior chamber angle and to determine its ability to detect primary angle closure when compared with gonioscopy in Asian subjects. Prospective observational case series. Two hundred three subjects were recruited from glaucoma clinics in Singapore with diagnoses of primary angle closure, primary open-angle glaucoma, ocular hypertension, or cataract. Both eyes (if eligible) of each patient were included in the study. Exclusion criteria were pseudophakia or previous glaucoma surgery. Images of the nasal, temporal, and inferior angles were obtained with AS-OCT in dark and then light conditions. Gonioscopic angle width was graded using the Spaeth classification for each quadrant in low lighting conditions. Angle closure was defined by AS-OCT as contact between the peripheral iris and angle wall anterior to the scleral spur and by gonioscopy as a Spaeth grade of 0 degree (posterior trabecular meshwork not visible). Comparison of the 2 methods in detecting angle closure was done by eye and by individual. Sensitivities and specificities of AS-OCT were calculated using gonioscopy as the reference standard. Complete data were available for 342 eyes of 200 patients. Of the patients, 70.9% had a clinical diagnosis of treated or untreated primary angle closure. Angle closure in > or =1 quadrants was detected by AS-OCT in 142 (71%) patients (228 [66.7%] eyes) and by gonioscopy in 99 (49.5%) patients (152 [44.4%] eyes). The inferior angle was closed more frequently than the nasal or temporal quadrants using both AS-OCT and gonioscopy. When performed under dark conditions, AS-OCT identified 98% of those subjects found to have angle closure on gonioscopy (95% confidence interval [CI], 92.2-99.6) and led to the characterization of 44.6% of those found to have open angles on gonioscopy to have angle closure as well. With gonioscopy as the reference standard, specificity of AS-OCT in the dark was 55.4% (95% CI, 45.2-65.2) for detecting individuals with angle closure. Anterior segment OCT is a rapid noncontact method of imaging angle structures. It is highly sensitive in detecting angle closure when compared with gonioscopy. More persons are found to have closed angles with AS-OCT than with gonioscopy.

Assessment of dentin remineralization with PS-OCT

NASA Astrophysics Data System (ADS)

Manesh, Saman K.; Darling, Cynthia L.; Fried, Daniel

2009-02-01

Previous studies have demonstrated that polarization sensitive optical coherence tomography (PS-OCT) can be used to image natural root caries lesions, measure non-destructively the severity of dentin demineralization and determine the efficacy of intervention with anti-caries agents including fluoride and lasers. The objective of this study was to determine if PS-OCT could be used to nondestructively measure the formation of a layer of remineralized dentin on the surface of dentin lesions after exposure to a remineralization solution. In this study images of artificial dentin lesions on extracted human teeth were acquired using PS-OCT after exposure to an artificial demineralizing solution at pH 4.9 for six days and after subsequent exposure to a remineralizing solution at pH 7.0 for 20 days. Polarized light microscopy and microradiography were used to examine histological thin sections from the samples for comparison. PS-OCT successfully measured the formation of a layer of increased mineral content near the lesion surface. PLM and TMR corroborated those results. This study demonstrates the potential use of PS-OCT for the nondestructive measurement of the remineralization of dentin surfaces.

Vitamin D3 analog maxacalcitol (OCT) induces hCAP-18/LL-37 production in human oral epithelial cells.

PubMed

Tada, Hiroyuki; Shimizu, Takamitsu; Nagaoka, Isao; Takada, Haruhiko

2016-01-01

Maxacalcitol (22-oxacalcitriol: OCT) is a synthetic vitamin D3 analog with a limited calcemic effect. In this study, we investigated whether OCT increases the production of LL-37/CAP-18, a human cathelicidin antimicrobial peptide, in human gingival/oral epithelial cells. A human gingival epithelial cell line (Ca9-22) and human oral epithelial cell lines (HSC-2, HSC-3, and HSC-4) exhibited the enhanced expression of LL-37 mRNA upon stimulation with OCT as well as active metabolites of vitamins D3 and D2. Among the human epithelial cell lines, Ca9-22 exhibited the strongest response to these vitamin D-related compounds. OCT induced the higher production of CAP-18 (ng/mL order) until 6 days time-dependently in Ca9-22 cells in culture. The periodontal pathogen Porphyromonas gingivalis was killed by treatment with the LL-37 peptide. These findings suggest that OCT induces the production of hCAP-18/LL-37 in a manner similar to that induced by the active metabolite of vitamin D3.

The cysteines of the extracellular loop are crucial for trafficking of human organic cation transporter 2 to the plasma membrane and are involved in oligomerization.

PubMed

Brast, Sabine; Grabner, Alexander; Sucic, Sonja; Sitte, Harald H; Hermann, Edwin; Pavenstädt, Hermann; Schlatter, Eberhard; Ciarimboli, Giuliano

2012-03-01

Human organic cation transporter 2 (hOCT2) is involved in transport of many endogenous and exogenous organic cations, mainly in kidney and brain cells. Because the quaternary structure of transmembrane proteins plays an essential role for their cellular trafficking and function, we investigated whether hOCT2 forms oligomeric complexes, and if so, which part of the transporter is involved in the oligomerization. A yeast 2-hybrid mating-based split-ubiquitin system (mbSUS), fluorescence resonance energy transfer, Western blot analysis, cross-linking experiments, immunofluorescence, and uptake measurements of the fluorescent organic cation 4-(4-(dimethylamino)styryl)-N-methylpyridinium were applied to human embryonic kidney 293 (HEK293) cells transfected with hOCT2 and partly also to freshly isolated human proximal tubules. The role of cysteines for oligomerization and trafficking of the transporter to the plasma membranes was investigated in cysteine mutants of hOCT2. hOCT2 formed oligomers both in the HEK293 expression system and in native human kidneys. The cysteines of the large extracellular loop are important to enable correct folding, oligomeric assembly, and plasma membrane insertion of hOCT2. Mutation of the first and the last cysteines of the loop at positions 51 and 143 abolished oligomer formation. Thus, the cysteines of the extracellular loop are important for correct trafficking of the transporter to the plasma membrane and for its oligomerization.

Laser Cooled Atomic Clocks in Space

NASA Technical Reports Server (NTRS)

Thompson, R. J.; Kohel, J.; Klipstein, W. M.; Seidel, D. J.; Maleki, L.

2000-01-01

The goals of the Glovebox Laser-cooled Atomic Clock Experiment (GLACE) are: (1) first utilization of tunable, frequency-stabilized lasers in space, (2) demonstrate laser cooling and trapping in microgravity, (3) demonstrate longest 'perturbation-free' interaction time for a precision measurement on neutral atoms, (4) Resolve Ramsey fringes 2-10 times narrower than achievable on Earth. The approach taken is: the use of COTS components, and the utilization of prototype hardware from LCAP flight definition experiments. The launch date is scheduled for Oct. 2002. The Microgravity Science Glovebox (MSG) specifications are reviewed, and a picture of the MSG is shown.

Visualization and tissue classification of human breast cancer images using ultrahigh-resolution OCT.

PubMed

Yao, Xinwen; Gan, Yu; Chang, Ernest; Hibshoosh, Hanina; Feldman, Sheldon; Hendon, Christine

2017-03-01

Breast cancer is one of the most common cancers, and recognized as the third leading cause of mortality in women. Optical coherence tomography (OCT) enables three dimensional visualization of biological tissue with micrometer level resolution at high speed, and can play an important role in early diagnosis and treatment guidance of breast cancer. In particular, ultra-high resolution (UHR) OCT provides images with better histological correlation. This paper compared UHR OCT performance with standard OCT in breast cancer imaging qualitatively and quantitatively. Automatic tissue classification algorithms were used to automatically detect invasive ductal carcinoma in ex vivo human breast tissue. Human breast tissues, including non-neoplastic/normal tissues from breast reduction and tumor samples from mastectomy specimens, were excised from patients at Columbia University Medical Center. The tissue specimens were imaged by two spectral domain OCT systems at different wavelengths: a home-built ultra-high resolution (UHR) OCT system at 800 nm (measured as 2.72 μm axial and 5.52 μm lateral) and a commercial OCT system at 1,300 nm with standard resolution (measured as 6.5 μm axial and 15 μm lateral), and their imaging performances were analyzed qualitatively. Using regional features derived from OCT images produced by the two systems, we developed an automated classification algorithm based on relevance vector machine (RVM) to differentiate hollow-structured adipose tissue against solid tissue. We further developed B-scan based features for RVM to classify invasive ductal carcinoma (IDC) against normal fibrous stroma tissue among OCT datasets produced by the two systems. For adipose classification, 32 UHR OCT B-scans from 9 normal specimens, and 28 standard OCT B-scans from 6 normal and 4 IDC specimens were employed. For IDC classification, 152 UHR OCT B-scans from 6 normal and 13 IDC specimens, and 104 standard OCT B-scans from 5 normal and 8 IDC specimens were employed. We have demonstrated that UHR OCT images can produce images with better feature delineation compared with images produced by 1,300 nm OCT system. UHR OCT images of a variety of tissue types found in human breast tissue were presented. With a limited number of datasets, we showed that both OCT systems can achieve a good accuracy in identifying adipose tissue. Classification in UHR OCT images achieved higher sensitivity (94%) and specificity (93%) of adipose tissue than the sensitivity (91%) and specificity (76%) in 1,300 nm OCT images. In IDC classification, similarly, we achieved better results with UHR OCT images, featured an overall accuracy of 84%, sensitivity of 89% and specificity of 71% in this preliminary study. In this study, we provided UHR OCT images of different normal and malignant breast tissue types, and qualitatively and quantitatively studied the texture and optical features from OCT images of human breast tissue at different resolutions. We developed an automated approach to differentiate adipose tissue, fibrous stroma, and IDC within human breast tissues. Our work may open the door toward automatic intraoperative OCT evaluation of early-stage breast cancer. Lasers Surg. Med. 49:258-269, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Automated 3D segmentation of intraretinal layers from optic nerve head optical coherence tomography images

NASA Astrophysics Data System (ADS)

Antony, Bhavna J.; Abràmoff, Michael D.; Lee, Kyungmoo; Sonkova, Pavlina; Gupta, Priya; Kwon, Young; Niemeijer, Meindert; Hu, Zhihong; Garvin, Mona K.

2010-03-01

Optical coherence tomography (OCT), being a noninvasive imaging modality, has begun to find vast use in the diagnosis and management of ocular diseases such as glaucoma, where the retinal nerve fiber layer (RNFL) has been known to thin. Furthermore, the recent availability of the considerably larger volumetric data with spectral-domain OCT has increased the need for new processing techniques. In this paper, we present an automated 3-D graph-theoretic approach for the segmentation of 7 surfaces (6 layers) of the retina from 3-D spectral-domain OCT images centered on the optic nerve head (ONH). The multiple surfaces are detected simultaneously through the computation of a minimum-cost closed set in a vertex-weighted graph constructed using edge/regional information, and subject to a priori determined varying surface interaction and smoothness constraints. The method also addresses the challenges posed by presence of the large blood vessels and the optic disc. The algorithm was compared to the average manual tracings of two observers on a total of 15 volumetric scans, and the border positioning error was found to be 7.25 +/- 1.08 μm and 8.94 +/- 3.76 μm for the normal and glaucomatous eyes, respectively. The RNFL thickness was also computed for 26 normal and 70 glaucomatous scans where the glaucomatous eyes showed a significant thinning (p < 0.01, mean thickness 73.7 +/- 32.7 μm in normal eyes versus 60.4 +/- 25.2 μm in glaucomatous eyes).

Cardiomyocyte differentiation of rat bone marrow multipotent progenitor cells is associated with downregulation of Oct-4 expression.

PubMed

Lu, Tiewei; Pelacho, Beatriz; Hao, Hong; Luo, Min; Zhu, Jing; Verfaillie, Catherine M; Tian, Jie; Liu, Zhenguo

2010-10-01

This study was to determine if bone marrow multipotent adult progenitor cells (MAPCs) underwent cardiac specification and Oct-4 expression during their cardiomyocyte differentiation in vitro. MAPCs were isolated from rat bone marrow, treated with 5-azacytidine (5-aza, 1μM) for 24h, and cultured in a serum-free medium for cardiac differentiation for up to 35 days. The cells started to express early cardiac-specific genes Nkx2.5 and GATA-4 with a significant increase in their mRNA level within 24h after 5-aza treatment. Western blotting analysis and immunofluorescence staining revealed that the cardiac-specific proteins connexin-43 and troponin I were expressed in the cells 7 days after 5-aza treatment. Flow cytometry analysis demonstrated that over 37% of the cells were positive for troponin I by 35 days of differentiation, although the cells did not display spontaneous contraction. On the other hand, the undifferentiated MAPCs expressed a significant level of the stem-cell-specific marker Oct-4 that was dramatically decreased in the cells shortly after the initiation of cardiomyocyte differentiation as evaluated using real-time (RT)-polymerase chain reaction, Western blotting, immunofluorescence staining, and flow cytometry. These data indicated that MAPCs were able to effectively differentiate into cardiomyocyte-like cells after 5-aza induction in association with downregulation of Oct-4 expression.

Integration of Optical Coherence Tomography Scan Patterns to Augment Clinical Data Suite

NASA Technical Reports Server (NTRS)

Mason, S.; Patel, N.; Van Baalen, M.; Tarver, W.; Otto, C.; Samuels, B.; Koslovsky, M.; Schaefer, C.; Taiym, W.; Wear, M.;

Live dynamic OCT imaging of cardiac structure and function in mouse embryos with 43 Hz direct volumetric data acquisition

NASA Astrophysics Data System (ADS)

Wang, Shang; Singh, Manmohan; Lopez, Andrew L.; Wu, Chen; Raghunathan, Raksha; Schill, Alexander; Li, Jiasong; Larin, Kirill V.; Larina, Irina V.

2016-03-01

Efficient phenotyping of cardiac dynamics in live mouse embryos has significant implications on understanding of early mammalian heart development and congenital cardiac defects. Recent studies established optical coherence tomography (OCT) as a powerful tool for live embryonic heart imaging in various animal models. However, current four-dimensional (4D) OCT imaging of the beating embryonic heart largely relies on gated data acquisition or postacquisition synchronization, which brings errors when cardiac cycles lack perfect periodicity and is time consuming and computationally expensive. Here, we report direct 4D OCT imaging of the structure and function of cardiac dynamics in live mouse embryos achieved by employing a Fourier domain mode-locking swept laser source that enables ~1.5 MHz A-line rate. Through utilizing both forward and backward scans of a resonant mirror, we obtained a ~6.4 kHz frame rate, which allows for a direct volumetric data acquisition speed of ~43 Hz, around 20 times of the early-stage mouse embryonic heart rate. Our experiments were performed on mouse embryos at embryonic day 9.5. Time-resolved 3D cardiodynamics clearly shows the heart structure in motion. We present analysis of cardiac wall movement and its velocity from the primitive atrium and ventricle. Our results suggest that the combination of ultrahigh-speed OCT imaging with live embryo culture could be a useful embryonic heart phenotyping approach for mouse mutants modeling human congenital heart diseases.

On-chip Mach-Zehnder interferometer for OCT systems

NASA Astrophysics Data System (ADS)

van Leeuwen, Ton G.; Akca, Imran B.; Angelou, Nikolaos; Weiss, Nicolas; Hoekman, Marcel; Leinse, Arne; Heideman, Rene G.

2018-04-01

By using integrated optics, it is possible to reduce the size and cost of a bulky optical coherence tomography (OCT) system. One of the OCT components that can be implemented on-chip is the interferometer. In this work, we present the design and characterization of a Mach-Zehnder interferometer consisting of the wavelength-independent splitters and an on-chip reference arm. The Si3N4 was chosen as the material platform as it can provide low losses while keeping the device size small. The device was characterized by using a home-built swept source OCT system. A sensitivity value of 83 dB, an axial resolution of 15.2 μm (in air) and a depth range of 2.5 mm (in air) were all obtained.

Retinal measurements using time domain optical coherence tomography imaging before and after myopic Lasik

PubMed Central

Lei, Feng; Burns, Stephen A.; shao, Liqin; Yang, Yabo

2014-01-01

Purpose To compare retinal measurements obtained by time domain optical coherence tomography (OCT) devices before and after myopic laser in situ keratomileusis (Lasik) and to assess the interaction of Lasik and retinal structures as measured by time domain OCT. Methods 53 patients randomly selected participated in the study. Only the right eye of each subject was included in the study. Comprehensive ophthalmic examinations including refraction examination, slitlamp examination, dilated fundus examination, corneal topography, corneal thickness, intraocular pressure, and retinal Stratus OCT scans were acquired for each patient before myopic Lasik and 3 months after surgery. Results Total macular volume (TMV) changed significantly between preoperative and postoperative measurements (p=0.003). No statistical differences were found between preoperative and postoperative disc area, rim area, cup/disk vert. ratio, or average foveal thickness (p>0.05). The variation in TMV correlated significantly with the change in spherical refraction equivalent, maximal corneal curvature, minimal corneal curvature, and corneal ablation depth. Conclusion Most retinal OCT measurements undergo no obvious changes after myopic Lasik. The increased TMV measurements we measured after Lasik seem to be correlated with the alteration in corneal shape. The exact mechanism for this change is not clear, while we examined several possibilities including subclinical macular edema, magnification changes, errors in OCT analysis and IOP, none of these seem to be a likely cause. PMID:22512373

The MATE1 rs2289669 polymorphism affects the renal clearance of metformin following ranitidine treatment.

PubMed

Cho, Sung Kweon; Chung, Jae-Yong

2016-04-01

Human multidrug and toxin extrusion member 1 (MATE1, SLC47A1) and Organic Cation Transporter 2 (OCT2, SLC22A2) play important roles in the renal elimination of various pharmacologic agents, including the anti-diabetic drug metformin. The goal of this study was to determine the association between metformin's pharmacokinetics and pharmacodynamics and the genetic variants of MATE1 (rs2289669) and OCT2 (rs316019) before and after treatment with the potential MATE inhibitor, ranitidine. We recruited 26 healthy Koreans balanced across the OCT2 and MATE1 genetic variants, and conducted a prospective clinical trial to investigate their effects on metformin's pharmacokinetics and pharmacodynamics before and after ranitidine treatment. Neither MATE1 rs2289669 nor OCT2 rs316019 affected metformin's pharmacokinetics and pharmacodynamics before ranitidine treatment. However, the renal clearance of metformin was significantly higher (15.2%) after ranitidine treatment in the MATE1 GG group compared with the MATE1 GA + AA group. Only the effect of MATE1 on the renal clearance of metformin after ranitidine treatment was significant (b = -0.465, p ≤ 0.05) after including demographic data and the OCT2 genotype in the model. Our study suggests that MATE1 rs2289669 may be a significant determinant in the renal clearance of metformin in the case of transporter-mediated drug interactions.

Proteomic analysis of the herpes simplex virus 1 virion protein 16 transactivator protein in infected cells.

PubMed

Suk, Hyung; Knipe, David M

2015-06-01

The herpes simplex virus 1 virion protein 16 (VP16) tegument protein forms a transactivation complex with the cellular proteins host cell factor 1 (HCF-1) and octamer-binding transcription factor 1 (Oct-1) upon entry into the host cell. VP16 has also been shown to interact with a number of virion tegument proteins and viral glycoprotein H to promote viral assembly, but no comprehensive study of the VP16 proteome has been performed at early times postinfection. We therefore performed a proteomic analysis of VP16-interacting proteins at 3 h postinfection. We confirmed the interaction of VP16 with HCF-1 and a large number of cellular Mediator complex proteins, but most surprisingly, we found that the major viral protein associating with VP16 is the infected cell protein 4 (ICP4) immediate-early (IE) transactivator protein. These results raise the potential for a new function for VP16 in associating with the IE ICP4 and playing a role in transactivation of early and late gene expression, in addition to its well-documented function in transactivation of IE gene expression. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optical coherence tomography with a 2.8-mm beam diameter and sensorless defocus and astigmatism correction

NASA Astrophysics Data System (ADS)

Reddikumar, Maddipatla; Tanabe, Ayano; Hashimoto, Nobuyuki; Cense, Barry

2017-02-01

An optical coherence tomography (OCT) system with a 2.8-mm beam diameter is presented. Sensorless defocus correction can be performed with a Badal optometer and astigmatism correction with a liquid crystal device. OCT B-scans were used in an image-based optimization algorithm for aberration correction. Defocus can be corrected from -4.3 D to +4.3 D and vertical and oblique astigmatism from -2.5 D to +2.5 D. A contrast gain of 6.9 times was measured after aberration correction. In comparison with a 1.3-mm beam diameter OCT system, this concept achieved a 3.7-dB gain in dynamic range on a model retina. Both systems were used to image the retina of a human subject. As the correction of the liquid crystal device can take more than 60 s, the subject's spectacle prescription was adopted instead. This resulted in a 2.5 times smaller speckle size compared with the standard OCT system. The liquid crystal device for astigmatism correction does not need a high-voltage amplifier and can be operated at 5 V. The correction device is small (9 mm×30 mm×38 mm) and can easily be implemented in existing designs for OCT.

Optical coherence tomography for the diagnosis of malignant skin tumors: a meta-analysis

NASA Astrophysics Data System (ADS)

Xiong, Yi-Quan; Mo, Yun; Wen, Yu-Qi; Cheng, Ming-Ji; Huo, Shu-Ting; Chen, Xue-Jiao; Chen, Qing

2018-02-01

Optical coherence tomography (OCT) is an emergent imaging tool used for noninvasive diagnosis of skin diseases. The present meta-analysis was carried out to assess the accuracy of OCT for the diagnosis of skin cancer. We conducted a systematic literature search though EMBASE, Medline, PubMed, the Cochrane Library, and Web of Science database for relevant articles published up to June 6, 2017. The quality of the included studies was assessed using the QUADAS-2 tool and the Oxford Levels of Evidence Scale. Statistical analyses were conducted using the software Meta-Disc version 1.4 and STATA version 12.0. A total of 14 studies involving more than 813 patients with a total of 1958 lesions were included in our analyses. The pooled sensitivity and specificity of OCT for skin cancer diagnoses were 91.8% and 86.7%, respectively. Subgroup analysis showed that the pooled sensitivities of OCT for detecting basal cell carcinoma (BCC), squamous cell carcinoma (SCC), actinic keratosis, and malignant melanoma were 92.4%, 92.3%, 73.8%, and 81.0%, respectively. The pooled specificities were 86.9%, 99.5%, 91.5%, and 93.8%, respectively. OCT appears to be useful for the detection of BCC and SCC. It is a valuable diagnostic method when screening for early skin cancers.

Exploring photoreceptor reflectivity via multimodal imaging of outer retinal tubulation in advanced age-related macular degeneration

PubMed Central

Litts, Katie M.; Wang, Xiaolin; Clark, Mark E.; Owsley, Cynthia; Freund, K. Bailey; Curcio, Christine A.; Zhang, Yuhua

2016-01-01

Purpose To investigate the microscopic structure of outer retinal tubulation (ORT) and optical properties of cone photoreceptors in vivo, we studied ORT appearance by multimodal imaging, including spectral domain optical coherence tomography (SD-OCT) and adaptive optics scanning laser ophthalmoscopy (AOSLO). Methods Four eyes of 4 subjects with advanced AMD underwent color fundus photography, infrared reflectance imaging, SD-OCT, and AOSLO with a high-resolution research instrument. ORT was identified in closely spaced (11 μm) SD-OCT volume scans. Results ORT in cross-sectional and en face SD-OCT was a hyporeflective area representing a lumen surrounded by a hyperreflective border consisting of cone photoreceptor mitochondria and external limiting membrane, per previous histology. In contrast, ORT by AOSLO was a hyporeflective structure of the same shape as in en face SD-OCT but lacking visualizable cone photoreceptors. Conclusion Lack of ORT cone reflectivity by AOSLO indicates that cones have lost their normal directionality and waveguiding property due to loss of outer segments and subsequent retinal remodeling. Reflective ORT cones by SD-OCT, in contrast, may depend partly on mitochondria as light scatterers within inner segments of these degenerating cells, a phenomenon enhanced by coherent imaging. Multimodal imaging of ORT provides insight into cone degeneration and reflectivity sources in OCT. PMID:27584549

Volumetric imaging of rod and cone photoreceptor structure with a combined adaptive optics-optical coherence tomography-scanning laser ophthalmoscope

NASA Astrophysics Data System (ADS)

Wells-Gray, Elaine M.; Choi, Stacey S.; Zawadzki, Robert J.; Finn, Susanna C.; Greiner, Cherry; Werner, John S.; Doble, Nathan

2018-03-01

We have designed and implemented a dual-mode adaptive optics (AO) imaging system that combines spectral domain optical coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO) for in vivo imaging of the human retina. The system simultaneously acquires SLO frames and OCT B-scans at 60 Hz with an OCT volume acquisition time of 4.2 s. Transverse eye motion measured from the SLO is used to register the OCT B-scans to generate three-dimensional (3-D) volumes. Key optical design considerations include: minimizing system aberrations through the use of off-axis relay telescopes, conjugate pupil plane requirements, and the use of dichroic beam splitters to separate and recombine the OCT and SLO beams around the nonshared horizontal scanning mirrors. To demonstrate system performance, AO-OCT-SLO images and measurements are taken from three normal human subjects ranging in retinal eccentricity from the fovea out to 15-deg temporal and 20-deg superior. Also presented are en face OCT projections generated from the registered 3-D volumes. The ability to acquire high-resolution 3-D images of the human retina in the midperiphery and beyond has clinical importance in diseases, such as retinitis pigmentosa and cone-rod dystrophy.

A Method for En Face OCT Imaging of Subretinal Fluid in Age-Related Macular Degeneration

PubMed Central

Mohammad, Fatimah; Wanek, Justin; Zelkha, Ruth; Lim, Jennifer I.; Chen, Judy; Shahidi, Mahnaz

2014-01-01

Purpose. The purpose of the study is to report a method for en face imaging of subretinal fluid (SRF) due to age-related macular degeneration (AMD) based on spectral domain optical coherence tomography (SDOCT). Methods. High density SDOCT imaging was performed at two visits in 4 subjects with neovascular AMD and one healthy subject. En face OCT images of a retinal layer anterior to the retinal pigment epithelium were generated. Validity, repeatability, and utility of the method were established. Results. En face OCT images generated by manual and automatic segmentation were nearly indistinguishable and displayed similar regions of SRF. En face OCT images displayed uniform intensities and similar retinal vascular patterns in a healthy subject, while the size and appearance of a hypopigmented fibrotic scar in an AMD subject were similar at 2 visits. In AMD subjects, dark regions on en face OCT images corresponded to reduced or absent light reflectance due to SRF. On en face OCT images, a decrease in SRF areas with treatment was demonstrated and this corresponded with a reduction in the central subfield retinal thickness. Conclusion. En face OCT imaging is a promising tool for visualization and monitoring of SRF area due to disease progression and treatment. PMID:25478209

Sensitivity and specificity of detecting reticular pseudodrusen in multimodal imaging in Japanese patients.

PubMed

Ueda-Arakawa, Naoko; Ooto, Sotaro; Tsujikawa, Akitaka; Yamashiro, Kenji; Oishi, Akio; Yoshimura, Nagahisa

2013-03-01

To identify reticular pseudodrusen (RPD) in age-related macular degeneration using multiple imaging modalities, including the blue channel image of fundus photography, infrared reflectance (IR), fundus autofluorescence, near-infrared fundus autofluorescence, confocal blue reflectance, indocyanine green angiography, and spectral-domain optical coherence tomography (SD-OCT), and to compare the sensitivities and specificities of these modalities for detecting RPD. This study included 220 eyes from 114 patients with newly diagnosed age-related macular degeneration. Patients underwent fundus photography, IR, fundus autofluorescence, near-infrared fundus autofluorescence, confocal blue reflectance, indocyanine green angiography, and SD-OCT in both eyes. Eyes were diagnosed with RPD if they showed reticular patterns on at least two of the seven imaging modalities. Thirty-seven eyes were diagnosed with RPD. However, SD-OCT and IR had the highest sensitivity (94.6%), and at the same time, SD-OCT had a high specificity (98.4%). The blue channel of color fundus photography, confocal blue reflectance, and indocyanine green angiography had a specificity of 100% but had lower sensitivity than that of SD-OCT and IR. For detecting RPD, IR and SD-OCT had the highest sensitivity. Although SD-OCT had the highest sensitivity and specificity, RPD detection should be confirmed using more than one modality for increased accuracy.

DNA Binding and Antitumor Activity of α-Diimineplatinum(II) and Palladium(II) Dithiocarbamate Complexes

PubMed Central

Mansouri-Torshizi, Hassan; Saeidifar, Maryam; Khosravi, Fatemeh; Divsalar, Adeleh; Saboury, Ali Akbar; Hassani, Fatemeh

2011-01-01

The two water-soluble designed platinum(II) complex, [Pt(Oct-dtc)(bpy)]NO3 (Oct-dtc = Octyldithiocarbamate and bpy = 2,2′ -bipyridine) and palladium(II) complex, [Pd(Oct-dtc)(bpy)]NO3, have been synthesized and characterized by elemental analyses, molar conductivity measurements, IR, 1H NMR, and electronic spectra studies. Studies of antitumor activity of these complexes against human cell tumor lines (K562) have been carried out. They show Ic50 values lower than that of cisplatin. The complexes have been investigated for their interaction with calf thymus DNA (CT-DNA) by utilizing the electronic absorption spectroscopy, fluorescence spectra, and ethidium bromide displacement and gel filtration techniques. Both of these water-soluble complexes bound cooperatively and intercalatively to the CT-DNA at very low concentrations. Several binding and thermodynamic parameters are also described. PMID:22110410

Investigation into the efficacy and safety of octreotide LAR in Japanese patients with acromegaly: Shizuoka study.

PubMed

Oki, Yutaka; Inoue, Tatsuhide; Imura, Mitsuo; Tanaka, Tokutaro; Genma, Rieko; Iwabuchi, Masayasu; Hataya, Yuji; Matsuzawa, Yuji; Iino, Kazumi; Nishizawa, Shigeru; Nakamura, Hirotoshi

2009-01-01

The efficacy and safety of the long-acting repeatable formulation of octreotide (OCT-LAR) treatment in patients suffering from acromegaly was investigated retrospectively in Shizuoka prefecture, Japan. Thirty patients (11 male, 19 female; average age, 48.9 years old), 29 of whom had undergone transsphenoidal surgery previously, were treated with OCT-LAR. OCT-LAR was injected i.m. every 4 weeks with an intended protocol of 20 mg over 24 months, however, 46.7% of patients required the dose of OCT-LAR to be increased. The final average dose of OCT-LAR was 25.0 +/- 6.8 mg. Administering OCT-LAR significantly decreased serum GH and insulin-like growth factor 1 (IGF-1) levels (from 13.7 +/- 11.9 to 5.8 +/- 7.3 microg/L and from 585 +/- 263 to 339 +/- 193.7 microg/L after 3 months, respectively). Among patients treated with OCT-LAR, 56.7% expressed

Targeting Tumor Oct4 to Deplete Prostate Tumor and Metastasis Initiating Cells

DTIC Science & Technology

2017-12-01

Nie, POU5F1B, an OCT4 Retrogene, Suppresses Uncontrolled Tumor Growth. Keystone Meeting on Molecular and Cellular Basis of Growth and Regeneration...Daotai Nie. Cancer Stem Cells in Resistance to Cytotoxic Drugs: Implications in Chemotherapy. B. Bonavida (ed.), Molecular Mechanisms of Tumor Cell...retrogene of the master embryonic stem cell gene POU5F1 is associated with prostate cancer susceptibility. American journal of human genetics 94

Abscisic acid related compounds and lignans in prunes (Prunus domestica L.) and their oxygen radical absorbance capacity (ORAC).

PubMed

Kikuzaki, Hiroe; Kayano, Shin-ichi; Fukutsuka, Naoko; Aoki, Asuka; Kasamatsu, Kumi; Yamasaki, Yuka; Mitani, Takahiko; Nakatani, Nobuji

2004-01-28

Four new abscisic acid related compounds (1-4), together with (+)-abscisic acid (5), (+)-beta-D-glucopyranosyl abscisate (6), (6S,9R)-roseoside (7), and two lignan glucosides ((+)-pinoresinol mono-beta-D-glucopyranoside (8) and 3-(beta-D-glucopyranosyloxymethyl)-2- (4-hydroxy-3-methoxyphenyl)-5-(3-hydroxypropyl)-7-methoxy-(2R,3S)-dihydrobenzofuran (9)) were isolated from the antioxidative ethanol extract of prunes (Prunus domestica L.). The structures of 1-4 were elucidated on the basis of NMR and MS spectrometric data to be rel-5-(3S,8S-dihydroxy-1R,5S-dimethyl-7-oxa-6-oxobicyclo[3,2,1]oct-8-yl)-3-methyl-2Z,4E-pentadienoic acid (1), rel-5-(3S,8S-dihydroxy-1R,5S-dimethyl-7-oxa-6-oxobicyclo[3,2,1]oct-8-yl)-3-methyl-2Z,4E-pentadienoic acid 3'-O-beta-d-glucopyranoside (2), rel-5-(1R,5S-dimethyl-3R,4R,8S-trihydroxy-7-oxa-6-oxobicyclo[3,2,1]oct-8-yl)-3-methyl-2Z,4E-pentadienoic acid (3), and rel-5-(1R,5S-dimethyl-3R,4R,8S-trihydroxy-7-oxabicyclo[3,2,1]- oct-8-yl)-3-methyl-2Z,4E-pentadienoic acid (4). The antioxidant activities of these isolated compounds were evaluated on the basis of oxygen radical absorbance capacity (ORAC). The ORAC values of abscisic acid related compounds (1-7) were very low. Two lignans (8 and 9) were more effective antioxidants whose ORAC values were 1.09 and 2.33 micromol of Trolox equiv/micromol, respectively.

Craniopharyngiomas express embryonic stem cell markers (SOX2, OCT4, KLF4, and SOX9) as pituitary stem cells but do not coexpress RET/GFRA3 receptors.

PubMed

Garcia-Lavandeira, Montserrat; Saez, Carmen; Diaz-Rodriguez, Esther; Perez-Romero, Sihara; Senra, Ana; Dieguez, Carlos; Japon, Miguel A; Alvarez, Clara V

2012-01-01

Adult stem cells maintain some markers expressed by embryonic stem cells and express other specific markers depending on the organ where they reside. Recently, stem/progenitor cells in the rodent and human pituitary have been characterized as expressing GFRA2/RET, PROP1, and stem cell markers such as SOX2 and OCT4 (GPS cells). Our objective was to detect other specific markers of the pituitary stem cells and to investigate whether craniopharyngiomas (CRF), a tumor potentially derived from Rathke's pouch remnants, express similar markers as normal pituitary stem cells. We conducted mRNA and Western blot studies in pituitary extracts, and immunohistochemistry and immunofluorescence on sections from normal rat and human pituitaries and 20 CRF (18 adamantinomatous and two papillary). Normal pituitary GPS stem cells localized in the marginal zone (MZ) express three key embryonic stem cell markers, SOX2, OCT4, and KLF4, in addition to SOX9 and PROP1 and β-catenin overexpression. They express the RET receptor and its GFRA2 coreceptor but also express the coreceptor GFRA3 that could be detected in the MZ of paraffin pituitary sections. CRF maintain the expression of SOX2, OCT4, KLF4, SOX9, and β-catenin. However, RET and GFRA3 expression was altered in CRF. In 25% (five of 20), both RET and GFRA3 were detected but not colocalized in the same cells. The other 75% (15 of 20) lose the expression of RET, GFRA3, or both proteins simultaneously. Human pituitary adult stem/progenitor cells (GPS) located in the MZ are characterized by expression of embryonic stem cell markers SOX2, OCT4, and KLF4 plus the specific pituitary embryonic factor PROP1 and the RET system. Redundancy in RET coreceptor expression (GFRA2 and GFRA3) suggest an important systematic function in their physiological behavior. CRF share the stem cell markers suggesting a common origin with GPS. However, the lack of expression of the RET/GFRA system could be related to the cell mislocation and deregulated growth of CRF.

In-line quality control of moving objects by means of spectral-domain OCT

NASA Astrophysics Data System (ADS)

Markl, Daniel; Hannesschläger, Günther; Buchsbaum, Andreas; Sacher, Stephan; Khinast, Johannes G.; Leitner, Michael

2014-08-01

In-line quality control of intermediate and final products is essential in various industries. This may imply determining the thickness of a foil or evaluating the homogeneity of coating applied to a pharmaceutical tablet. Such a qualitative and quantitative monitoring in a depth-resolved manner can be accomplished using optical coherence tomography (OCT). In-line quality control based on OCT requires additional consideration of motion effects for the system design as well as for data interpretation. This study focuses on transverse motion effects that can arise in spectral-domain (SD-) OCT systems. The impact of a transverse movement is analyzed for a constant relative speed difference up to 0.7 m/s between sample and sensor head. In particular, transverse motion is affecting OCT system properties such as the beam displacement (distance between adjacent A-scans) and transverse resolution. These properties were evaluated theoretically and experimentally for OCT images of a resolution target and pharmaceutical film-coated tablets. Both theoretical and experimental analyses highlight the shift of the transverse resolution limiting factor from the optics to the beam displacement above a relative speed difference between sensor head and sample of 0.42 m/s (for the presented SD-OCT setup). Speeds above 0.4 m/s are often demanded when monitoring industrial processes, such as a coating process when producing film-coated tablets. This emphasizes the importance of a fast data acquisition when using OCT as in-line quality control tool.

Single-cell RNA sequencing reveals metallothionein heterogeneity during hESC differentiation to definitive endoderm.

PubMed

Lu, Junjie; Baccei, Anna; Lummertz da Rocha, Edroaldo; Guillermier, Christelle; McManus, Sean; Finney, Lydia A; Zhang, Cheng; Steinhauser, Matthew L; Li, Hu; Lerou, Paul H

2018-04-01

Differentiation of human pluripotent stem cells towards definitive endoderm (DE) is the critical first step for generating cells comprising organs such as the gut, liver, pancreas and lung. This in-vitro differentiation process generates a heterogeneous population with a proportion of cells failing to differentiate properly and maintaining expression of pluripotency factors such as Oct4. RNA sequencing of single cells collected at four time points during a 4-day DE differentiation identified high expression of metallothionein genes in the residual Oct4-positive cells that failed to differentiate to DE. Using X-ray fluorescence microscopy and multi-isotope mass spectrometry, we discovered that high intracellular zinc level corresponds with persistent Oct4 expression and failure to differentiate. This study improves our understanding of the cellular heterogeneity during in-vitro directed differentiation and provides a valuable resource to improve DE differentiation efficiency. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Loss-of-function polymorphisms in the organic cation transporter OCT1 are associated with reduced postoperative tramadol consumption.

PubMed

Stamer, Ulrike M; Musshoff, Frank; Stüber, Frank; Brockmöller, Jürgen; Steffens, Michael; Tzvetkov, Mladen V

2016-11-01

The organic cation transporter OCT1 (SLC22A1) mediates uptake and metabolism of the active tramadol metabolite (+)O-desmethyltramadol in the liver. In this study, the influence of OCT1 genetic polymorphisms on pharmacokinetics and analgesic efficacy of tramadol in patients recovering from surgery was analyzed in addition to the CYP2D6 genotype. Postoperative patients who received tramadol through patient-controlled analgesia were enrolled. Genotypes resulting in 0, 1, or 2 active OCT1 alleles were determined as well as CYP2D6 genotypes. The primary endpoint was the 24-hour postoperative tramadol consumption in patients with 0 vs at least 1 active OCT1 allele. Secondary endpoint was the OCT1-dependent plasma concentration (areas under the concentration-time curves) of the active tramadol metabolite (+)O-desmethyltramadol. Of 205 patients, 19, 82, and 104 carried 0, 1, and 2 active OCT1 alleles, respectively. Cumulative tramadol consumption through patient-controlled analgesia was lowest in patients with 0 active OCT1 allele compared with the group of patients with 1 or 2 active alleles (343 ± 235 vs 484 ± 276 mg; P = 0.03). Multiple regression revealed that the number of active OCT1 alleles (P = 0.014), CYP2D6 (P = 0.001), pain scores (P < 0.001), and the extent of surgery (0.034) had a significant influence on tramadol consumption. Plasma areas under the concentration-time curves of (+)O-desmethyltramadol were 111.8 (95% confidence interval: 63.4-160.1), 80.2 (65.1-95.3), and 64.5 (51.9-77.2) h·ng·mL in carriers of 0, 1, or 2 active OCT1 alleles (P = 0.03). Loss of OCT1 function resulted in reduced tramadol consumption and increased plasma concentrations of (+)O-desmethyltramadol in patients recovering from surgery. Therefore, analyzing OCT1 next to CYP2D6 genotype might further improve future genotype-dependent dose recommendations for tramadol.

Monitoring of interaction of low-frequency electric field with biological tissues upon optical clearing with optical coherence tomography.

PubMed

Peña, Adrián F; Doronin, Alexander; Tuchin, Valery V; Meglinski, Igor

2014-08-01

The influence of a low-frequency electric field applied to soft biological tissues ex vivo at normal conditions and upon the topical application of optical clearing agents has been studied by optical coherence tomography (OCT). The electro-kinetic response of tissues has been observed and quantitatively evaluated by the double correlation OCT approach, utilizing consistent application of an adaptive Wiener filtering and Fourier domain correlation algorithm. The results show that fluctuations, induced by the electric field within the biological tissues are exponentially increased in time. We demonstrate that in comparison to impedance measurements and the mapping of the temperature profile at the surface of the tissue samples, the double correlation OCT approach is much more sensitive to the changes associated with the tissues' electro-kinetic response. We also found that topical application of the optical clearing agent reduces the tissues' electro-kinetic response and is cooling the tissue, thus reducing the temperature induced by the electric current by a few degrees. We anticipate that dcOCT approach can find a new application in bioelectrical impedance analysis and monitoring of the electric properties of biological tissues, including the resistivity of high water content tissues and its variations.

VIH from the mud crab is specifically expressed in the eyestalk and potentially regulated by transactivator of Sox9/Oct4/Oct1.

PubMed

Liu, Chunyun; Jia, Xiwei; Zou, Zhihua; Wang, Xiaowei; Wang, Yilei; Zhang, Ziping

2018-01-01

Vitellogenesis-inhibiting hormone (VIH) is known to regulate ovarian maturation by suppressing the synthesis of vitellogenin (Vtg) in crustaceans, which belongs to a member of crustacean hyperglycemic hormone (CHH) family synthesized and secreted from the X-organ/sinus gland complex of eyestalks. In this study, the cDNA, genomic DNA (gDNA) and the 5'-upstream regulatory (promoter region) sequences of VIH gene were obtained by conventional PCR, genome walker and tail-PCR techniques according to our transcriptomic database of Scylla paramamosain. The full-length cDNA of SpVIH is 634bp including 105bp 5'UTR, 151bp 3'UTR and 378bp ORF that encodes a peptide of 125 amino acids. The full length gDNA of SpVIH is 790bp containing two exons and one intron. The 5'-flanking promoter regions of SpVIH we isolated are 3070bp from the translation initiation (ATG) and 2398bp from the predicted transcription initiation (A), which consists of putative core promoter region and multiple potential transcription factor binding sites. SpVIH was only expressed in eyestalk. The expression level of SpVIH in eyestalk of female crab decreased gradually along with the development of ovary. As there is not cell line of crabs available, we chose the mature transfection system HEK293FT cell lines to explore the mechanism of transcription regulation of SpVIH in crabs. Sequential deletion assays using luciferase reporter gene in HEK293FT cells revealed that the possible promoter activity regions (including positive and negative transcription factors binding sites simultaneously) presented between pSpVIH-4 and pSpVIH-6. In order to further identify the crucial transcription factors binding site in this region, the site-directed mutagenesis of Sox9/Oct4/Oct1 binding site of pSpVIH-4 was created. The results demonstrated that the transcriptional activity of pSpVIH-4△ decreased significantly (p<0.05). Thus, it is reasonable to deduce that the Sox9/Oct4/Oct1 may be the essential positive transcription factors which regulate the expression of SpVIH. Copyright © 2017 Elsevier Inc. All rights reserved.

Intrinsic factors and the embryonic environment influence the formation of extragonadal teratomas during gestation.

PubMed

Economou, Constantinos; Tsakiridis, Anestis; Wymeersch, Filip J; Gordon-Keylock, Sabrina; Dewhurst, Robert E; Fisher, Dawn; Medvinsky, Alexander; Smith, Andrew J H; Wilson, Valerie

2015-10-09

Pluripotent cells are present in early embryos until the levels of the pluripotency regulator Oct4 drop at the beginning of somitogenesis. Elevating Oct4 levels in explanted post-pluripotent cells in vitro restores their pluripotency. Cultured pluripotent cells can participate in normal development when introduced into host embryos up to the end of gastrulation. In contrast, pluripotent cells efficiently seed malignant teratocarcinomas in adult animals. In humans, extragonadal teratomas and teratocarcinomas are most frequently found in the sacrococcygeal region of neonates, suggesting that these tumours originate from cells in the posterior of the embryo that either reactivate or fail to switch off their pluripotent status. However, experimental models for the persistence or reactivation of pluripotency during embryonic development are lacking. We manually injected embryonic stem cells into conceptuses at E9.5 to test whether the presence of pluripotent cells at this stage correlates with teratocarcinoma formation. We then examined the effects of reactivating embryonic Oct4 expression ubiquitously or in combination with Nanog within the primitive streak (PS)/tail bud (TB) using a transgenic mouse line and embryo chimeras carrying a PS/TB-specific heterologous gene expression cassette respectively. Here, we show that pluripotent cells seed teratomas in post-gastrulation embryos. However, at these stages, induced ubiquitous expression of Oct4 does not lead to restoration of pluripotency (indicated by Nanog expression) and tumour formation in utero, but instead causes a severe phenotype in the extending anteroposterior axis. Use of a more restricted T(Bra) promoter transgenic system enabling inducible ectopic expression of Oct4 and Nanog specifically in the posteriorly-located primitive streak (PS) and tail bud (TB) led to similar axial malformations to those induced by Oct4 alone. These cells underwent induction of pluripotency marker expression in Epiblast Stem Cell (EpiSC) explants derived from somitogenesis-stage embryos, but no teratocarcinoma formation was observed in vivo. Our findings show that although pluripotent cells with teratocarcinogenic potential can be produced in vitro by the overexpression of pluripotency regulators in explanted somitogenesis-stage somatic cells, the in vivo induction of these genes does not yield tumours. This suggests a restrictive regulatory role of the embryonic microenvironment in the induction of pluripotency.

Optical Coherence Tomography Angiography Features of Diabetic Retinopathy

PubMed Central

Hwang, Thomas S.; Jia, Yali; Gao, Simon S.; Bailey, Steven T.; Lauer, Andreas K.; Flaxel, Christina J.; Wilson, David J.; Huang, David

2015-01-01

Purpose To describe the optical coherence tomography (OCT) angiography features of diabetic retinopathy Methods Using a 70kHz OCT and the split-spectrum amplitude decorrelation angiography (SSADA) algorithm, 6 × 6 mm 3-dimensional angiograms of the macula of 4 patients with diabetic retinopathy were obtained and compared with fluorescein angiography (FA) for features catalogued by the Early Treatment of Diabetic Retinopathy Study. Results OCT angiography detected enlargement and distortion of the foveal avascular zone, retinal capillary dropout, and pruning of arteriolar branches. Areas of capillary loss obscured by fluorescein leakage on FA were more clearly defined on OCT angiography. Some areas of focal leakage on FA that were thought to be microaneurysms were found to be small tufts of neovascularization that extended above the inner limiting membrane. Conclusion OCT angiography does not show leakage, but can better delineate areas of capillary dropout and detect early retinal neovascularization. This new noninvasive angiography technology may be useful for routine surveillance of proliferative and ischemic changes in diabetic retinopathy. PMID:26308529

Optical Coherence Tomography Findings of Exophytic Retinal Capillary Hemangiomas of the Posterior Pole

PubMed Central

Chin, Eric K.; Trikha, Rupan; Morse, Lawrence S.; Zawadzki, Robert J.; Werner, John S.; Park, Susanna S.

2013-01-01

Exophytic retinal capillary hemangiomas (RCH) can be a diagnostic challenge in subjects without von Hippel-Lin-dau disease (VHL). This report of two cases describes the optical coherence tomographic (OCT) characteristics of RCH in two eyes of a subject with VHL and in one eye of an otherwise normal subject. Three different OCT instruments were used (Stratus, Cirrus and/or custom high resolution Fourier-domain OCT with 4.5 μm axial resolution) depending on availability. All instruments localized the tumor to the outer retina. A sharp border between the tumor and overlying inner retina was noted. The tumor bulged into the subretinal space and showed marked shadowing. Associated cystoid macular edema and sub-retinal fluid were noted. High-resolution Fourier-domain OCT showed a focal photoreceptor layer rip in the adjacent tumor-free macula in one eye with poor vision after treatment. OCT may be a useful tool in diagnosing RCH and studying associated morphologic changes. PMID:20337341

Noninvasive characterisation of foot reflexology areas by swept source-optical coherence tomography in patients with low back pain.

PubMed

Dalal, Krishna; Elanchezhiyan, D; Das, Raunak; Dalal, Devjyoti; Pandey, Ravindra Mohan; Chatterjee, Subhamoy; Upadhyay, Ashish Datt; Maran, V Bharathi; Chatterjee, Jyotirmoy

2013-01-01

Objective. When exploring the scientific basis of reflexology techniques, elucidation of the surface and subsurface features of reflexology areas (RAs) is crucial. In this study, the subcutaneous features of RAs related to the lumbar vertebrae were evaluated by swept source-optical coherence tomography (SS-OCT) in subjects with and without low back pain (LBP). Methods. Volunteers without LBP (n = 6 (male : female = 1 : 1)) and subjects with LBP (n = 15 (male : female = 2 : 3)) were clinically examined in terms of skin colour (visual perception), localised tenderness (visual analogue scale) and structural as well as optical attributes as per SS-OCT. From each subject, 6 optical tomograms were recorded from equidistant transverse planes along the longitudinal axis of the RAs, and from each tomogram, 25 different spatial locations were considered for recording SS-OCT image attributes. The images were analysed with respect to the optical intensity distributions and thicknesses of different skin layers by using AxioVision Rel. 4.8.2 software. The SS-OCT images could be categorised into 4 pathological grades (i.e., 0, 1, 2, and 3) according to distinctness in the visible skin layers. Results. Three specific grades for abnormalities in SS-OCT images were identified considering gradual loss of distinctness and increase in luminosity of skin layers. Almost 90.05% subjects were of mixed type having predominance in certain grades. Conclusion. The skin SS-OCT system demonstrated a definite association of the surface features of healthy/unhealthy RAs with cutaneous features and the clinical status of the lumbar vertebrae.

Histogram Matching Extends Acceptable Signal Strength Range on Optical Coherence Tomography Images

PubMed Central

Chen, Chieh-Li; Ishikawa, Hiroshi; Wollstein, Gadi; Bilonick, Richard A.; Sigal, Ian A.; Kagemann, Larry; Schuman, Joel S.

2015-01-01

Purpose. We minimized the influence of image quality variability, as measured by signal strength (SS), on optical coherence tomography (OCT) thickness measurements using the histogram matching (HM) method. Methods. We scanned 12 eyes from 12 healthy subjects with the Cirrus HD-OCT device to obtain a series of OCT images with a wide range of SS (maximal range, 1–10) at the same visit. For each eye, the histogram of an image with the highest SS (best image quality) was set as the reference. We applied HM to the images with lower SS by shaping the input histogram into the reference histogram. Retinal nerve fiber layer (RNFL) thickness was automatically measured before and after HM processing (defined as original and HM measurements), and compared to the device output (device measurements). Nonlinear mixed effects models were used to analyze the relationship between RNFL thickness and SS. In addition, the lowest tolerable SSs, which gave the RNFL thickness within the variability margin of manufacturer recommended SS range (6–10), were determined for device, original, and HM measurements. Results. The HM measurements showed less variability across a wide range of image quality than the original and device measurements (slope = 1.17 vs. 4.89 and 1.72 μm/SS, respectively). The lowest tolerable SS was successfully reduced to 4.5 after HM processing. Conclusions. The HM method successfully extended the acceptable SS range on OCT images. This would qualify more OCT images with low SS for clinical assessment, broadening the OCT application to a wider range of subjects. PMID:26066749

Noninvasive Characterisation of Foot Reflexology Areas by Swept Source-Optical Coherence Tomography in Patients with Low Back Pain

PubMed Central

Dalal, Krishna; Elanchezhiyan, D.; Das, Raunak; Dalal, Devjyoti; Pandey, Ravindra Mohan; Chatterjee, Subhamoy; Upadhyay, Ashish Datt; Maran, V. Bharathi; Chatterjee, Jyotirmoy

2013-01-01

Objective. When exploring the scientific basis of reflexology techniques, elucidation of the surface and subsurface features of reflexology areas (RAs) is crucial. In this study, the subcutaneous features of RAs related to the lumbar vertebrae were evaluated by swept source-optical coherence tomography (SS-OCT) in subjects with and without low back pain (LBP). Methods. Volunteers without LBP (n = 6 (male : female = 1 : 1)) and subjects with LBP (n = 15 (male : female = 2 : 3)) were clinically examined in terms of skin colour (visual perception), localised tenderness (visual analogue scale) and structural as well as optical attributes as per SS-OCT. From each subject, 6 optical tomograms were recorded from equidistant transverse planes along the longitudinal axis of the RAs, and from each tomogram, 25 different spatial locations were considered for recording SS-OCT image attributes. The images were analysed with respect to the optical intensity distributions and thicknesses of different skin layers by using AxioVision Rel. 4.8.2 software. The SS-OCT images could be categorised into 4 pathological grades (i.e., 0, 1, 2, and 3) according to distinctness in the visible skin layers. Results. Three specific grades for abnormalities in SS-OCT images were identified considering gradual loss of distinctness and increase in luminosity of skin layers. Almost 90.05% subjects were of mixed type having predominance in certain grades. Conclusion. The skin SS-OCT system demonstrated a definite association of the surface features of healthy/unhealthy RAs with cutaneous features and the clinical status of the lumbar vertebrae. PMID:23662156

OCT imaging in chronic obstructive pulmonary disease

NASA Astrophysics Data System (ADS)

Ohtani, K.; Lopez Lisbona, R. M.; Lee, A. M. D.; Hyun, C.; Shaipanich, T.; McWilliams, A.; Lane, P.; Coxson, H. O.; MacAulay, C.; Lam, S.

2013-03-01

Introduction: A recent ex-vivo study using micro-CT in patients with chronic obstructive pulmonary disease (COPD) showed that narrowing and disappearance of small conducting airways precedes the onset of emphysematous destruction in COPD. Until recently, the airway remodeling process could not be studied in detail in-vivo. In this study, we investigated the repeatability of navigating an Optical Coherence Tomography (OCT) catheter to image the same airways in smokers with and without COPD. Method: OCT imaging was performed by inserting the catheter through a sub-segmental airway to a small bronchiole. Three-dimensional OCT imaging of 5 cm of airway segments was obtained. The catheter was removed and reinsertion into the same airway was attempted. The number of airway generations and quantitative measurements of the airway wall area were investigated. Results: Sixty-three airways in 30 subjects were analyzed. Repeated insertion into the same airway was observed at 53.8 %, 92.3% and 70.8% of the time in the upper, middle and lower lobes respectively. The percentage differences of paired measurements of airway wall area between matched and unmatched airways in bronchioles were 5.8 +/- 4.6 % and 7.3 +/- 5.4 % respectively Conclusions: Repeated OCT imaging of airways is possible in the majority of cases except in the upper lobes. For airways that are not completely matched, some of the airway segments can still be used for comparison by careful alignment of the airway. OCT may be a useful method to study the remodeling process in small airways and the effect of therapeutic intervention.

Full-field optical coherence tomography used for security and document identity

NASA Astrophysics Data System (ADS)

Chang, Shoude; Mao, Youxin; Sherif, Sherif; Flueraru, Costel

2006-09-01

The optical coherence tomography (OCT) is an emerging technology for high-resolution cross-sectional imaging of 3D structures. In the past years, OCT systems have been used mainly for medical, especially ophthalmological diagnostics. Concerning the nature of OCT system being capable to explore the internal features of an object, we apply the OCT technology to directly retrieve the 2D information pre-stored in a multiple-layer information carrier. The standard depth-resolution of an OCT system is at micrometer level. If a 20mm by 20mm sampling area with a 1024 x 1024 CCD array is used in the OCT system having 10 μm, an information carrier having a volume of 20mm x 20mm x 2mm could contain 200 Mega-pixel images. Because of its tiny size and large information volume, the information carrier, with its OCT retrieving system, will have potential applications in documents security and object identification. In addition, as the information carrier can be made by low-scattering transparent material, the signal/noise ratio will be improved dramatically. As a consequence, the specific hardware and complicated software can also be greatly simplified. Owing to non-scanning along X-Y axis, the full-field OCT could be the simplest and most economic imaging system for extracting information from such a multilayer information carrier. In this paper, deign and implementation of a full-field OCT system is described and the related algorithms are introduced. In our experiments, a four layers information carrier is used, which contains 4 layers of image pattern, two text images and two fingerprint images. The extracted tomography images of each layer are also provided.

Optical Coherence Tomography Minimum Intensity as an Objective Measure for the Detection of Hydroxychloroquine Toxicity.

PubMed

Allahdina, Ali M; Stetson, Paul F; Vitale, Susan; Wong, Wai T; Chew, Emily Y; Ferris, Fredrick L; Sieving, Paul A; Cukras, Catherine

2018-04-01

As optical coherence tomography (OCT) minimum intensity (MI) analysis provides a quantitative assessment of changes in the outer nuclear layer (ONL), we evaluated the ability of OCT-MI analysis to detect hydroxychloroquine toxicity. Fifty-seven predominantly female participants (91.2% female; mean age, 55.7 ± 10.4 years; mean time on hydroxychloroquine, 15.0 ± 7.5 years) were enrolled in a case-control study and categorized into affected (i.e., with toxicity, n = 19) and unaffected (n = 38) groups using objective multifocal electroretinographic (mfERG) criteria. Spectral-domain OCT scans of the macula were analyzed and OCT-MI values quantitated for each subfield of the Early Treatment Diabetic Retinopathy Study (ETDRS) grid. A two-sample U-test and a cross-validation approach were used to assess the sensitivity and specificity of toxicity detection according to OCT-MI criteria. The medians of the OCT-MI values in all nine of the ETDRS subfields were significantly elevated in the affected group relative to the unaffected group (P < 0.005 for all comparisons), with the largest difference found for the inner inferior subfield (P < 0.0001). The receiver operating characteristic analysis of median MI values of the inner inferior subfields showed high sensitivity and high specificity in the detection of toxicity with area under the curve = 0.99. Retinal changes secondary to hydroxychloroquine toxicity result in increased OCT reflectivity in the ONL that can be detected and quantitated using OCT-MI analysis. Analysis of OCT-MI values demonstrates high sensitivity and specificity for detecting the presence of hydroxychloroquine toxicity in this cohort and may contribute additionally to current screening practices.

Optical Coherence Tomography Minimum Intensity as an Objective Measure for the Detection of Hydroxychloroquine Toxicity

PubMed Central

Allahdina, Ali M.; Stetson, Paul F.; Vitale, Susan; Wong, Wai T.; Chew, Emily Y.; Ferris, Fredrick L.; Sieving, Paul A.

2018-01-01

Purpose As optical coherence tomography (OCT) minimum intensity (MI) analysis provides a quantitative assessment of changes in the outer nuclear layer (ONL), we evaluated the ability of OCT-MI analysis to detect hydroxychloroquine toxicity. Methods Fifty-seven predominantly female participants (91.2% female; mean age, 55.7 ± 10.4 years; mean time on hydroxychloroquine, 15.0 ± 7.5 years) were enrolled in a case-control study and categorized into affected (i.e., with toxicity, n = 19) and unaffected (n = 38) groups using objective multifocal electroretinographic (mfERG) criteria. Spectral-domain OCT scans of the macula were analyzed and OCT-MI values quantitated for each subfield of the Early Treatment Diabetic Retinopathy Study (ETDRS) grid. A two-sample U-test and a cross-validation approach were used to assess the sensitivity and specificity of toxicity detection according to OCT-MI criteria. Results The medians of the OCT-MI values in all nine of the ETDRS subfields were significantly elevated in the affected group relative to the unaffected group (P < 0.005 for all comparisons), with the largest difference found for the inner inferior subfield (P < 0.0001). The receiver operating characteristic analysis of median MI values of the inner inferior subfields showed high sensitivity and high specificity in the detection of toxicity with area under the curve = 0.99. Conclusions Retinal changes secondary to hydroxychloroquine toxicity result in increased OCT reflectivity in the ONL that can be detected and quantitated using OCT-MI analysis. Analysis of OCT-MI values demonstrates high sensitivity and specificity for detecting the presence of hydroxychloroquine toxicity in this cohort and may contribute additionally to current screening practices. PMID:29677357

Single-shot dimension measurements of the mouse eye using SD-OCT.

PubMed

Jiang, Minshan; Wu, Pei-Chang; Fini, M Elizabeth; Tsai, Chia-Ling; Itakura, Tatsuo; Zhang, Xiangyang; Jiao, Shuliang

2012-01-01

The authors demonstrate the feasibility and advantage of spectral-domain optical coherence tomography (SD-OCT) for single-shot ocular biometric measurement during the development of the mouse eye. A high-resolution SD-OCT system was built for single-shot imaging of the whole mouse eye in vivo. The axial resolution and imaging depth of the system are 4.5 μm (in tissue) and 5.2 mm, respectively. The system is capable of acquiring a cross-sectional OCT image consisting of 2,048 depth scans in 85 ms. The imaging capability of the SD-OCT system was validated by imaging the normal ocular growth and experimental myopia model using C57BL/6J mice. The biometric dimensions of the mouse eye can be calculated directly from one snapshot of the SD-OCT image. The biometric parameters of the mouse eye including axial length, corneal thickness, anterior chamber depth, lens thickness, vitreous chamber depth, and retinal thickness were successfully measured by the SD-OCT. In the normal ocular growth group, the axial length increased significantly from 28 to 82 days of age (P < .001). The lens thickness increased and the vitreous chamber depth decreased significantly during this period (P < .001 and P = .001, respectively). In the experimental myopia group, there were significant increases in vitreous chamber depth and axial length in comparison to the control eyes (P = .040 and P < .001, respectively). SD-OCT is capable of providing single-shot direct, fast, and high-resolution measurements of the dimensions of young and adult mouse eyes. As a result, SD-OCT is a potentially powerful tool that can be easily applied to research in eye development and myopia using small animal models. Copyright 2012, SLACK Incorporated.

Quantitative RNFL attenuation coefficient measurements by RPE-normalized OCT data

NASA Astrophysics Data System (ADS)

Vermeer, K. A.; van der Schoot, J.; Lemij, H. G.; de Boer, J. F.

2012-03-01

We demonstrate significantly different scattering coefficients of the retinal nerve fiber layer (RNFL) between normal and glaucoma subjects. In clinical care, SD-OCT is routinely used to assess the RNFL thickness for glaucoma management. In this way, the full OCT data set is conveniently reduced to an easy to interpret output, matching results from older (non- OCT) instruments. However, OCT provides more data, such as the signal strength itself, which is due to backscattering in the retinal layers. For quantitative analysis, this signal should be normalized to adjust for local differences in the intensity of the beam that reaches the retina. In this paper, we introduce a model that relates the OCT signal to the attenuation coefficient of the tissue. The average RNFL signal (within an A-line) was then normalized based on the observed RPE signal, resulting in normalized RNFL attenuation coefficient maps. These maps showed local defects matching those found in thickness data. The average (normalized) RNFL attenuation coefficient of a fixed band around the optic nerve head was significantly lower in glaucomatous eyes than in normal eyes (3.0mm-1 vs. 4.9mm-1, P<0.01, Mann-Whitney test).

Comparative OCT imaging of the human esophagus: How well can we localize the muscularis mucosae?

NASA Astrophysics Data System (ADS)

Cilesiz, Inci F.; Fockens, Paul; Kerindongo, Raphaela P.; Faber, Dirk J.; Tytgat, Guido N. J.; ten Kate, Febo; van Leeuwen, Ton G. J. M.

2002-06-01

Early diagnosis with esophageal cancer limited to the mucosa will allow for local endoscopic treatment and improve prognosis. We compared with histology OCT images of healthy human esophageal tissue from two systems operating at 800 and 1275 nm to investigate which wavelength was best suited for detailed OCT imaging of the esophageal wall, and to localize the muscularis mucosae. Within an hour of surgical resection, an esophageal specimen was cleaned of excess blood and soaked in formalin for a minimum of 48 hours. In order to precisely localize the different layers of the esophageal wall on an OCT image, well-defined structures within the esophageal wall were sought. Following OCT imaging the specimen was prepared for routine histology. We observed that our 1275 nm system with 12 micrometers resolution was superior in terms of penetration. As compared to histology, the 4 micrometers resolution of our 800 nm system made fine details more visible. Using either system, a minimally trained eye could recognize the muscularis mucosae as a hypo-reflective layer. Although different conditions may apply in vivo, our ex vivo study paves the path to precise interpretation of OCT images of the esophageal wall.

Targeting Tumor Oct4 to Deplete Prostate Tumor- and Metastasis-Initiating Cells

DTIC Science & Technology

2015-10-01

and stem cell To investigate whether POU5F1B overrxpression can induce cancer stem cell -related genes expression, we did cancer stem cell ...future 15. SUBJECT TERMS OCT4, cancer stem cells , prostate cancer, metastasis, tumor formation 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT...described in last report. Here we describe some findings previously not reported. 1.1 POU5F1B expression in prostatic tissue As cancer stem cell marker

JPRS Report, East Europe

DTIC Science & Technology

1987-12-16

Romania’s claim to Transylvania. Romania carried out its threats and signed a provisional peace treaty with Germany on 7 March 1918 . The cable sent by...Oct 87] 3 Economist Weighs Structural Reforms in Soviet-Type Economies [L1STY No 5, Oct 87] 4 HUNGARY U.S. Plan for Central Europe in 1918 ...in 1918 Examined 25000003 Budapest HISTORIA in Hungarian No 4, 1987 pp 16-20 [Article by Magda Adam, former Wilson Center fellow: "An Amercian

B-cell transcription factors Pax-5, Oct-2, BOB.1, Bcl-6, and MUM1 are useful markers for the diagnosis of nodular lymphocyte predominant Hodgkin lymphoma.

PubMed

Herbeck, Rosemarie; Teodorescu Brînzeu, D; Giubelan, Marioara; Lazăr, Elena; Dema, Alis; Ioniţă, Hortensia

2011-01-01

In some instances, the overlap in morphologic features and antigen expression between nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) and classical Hodgkin lymphoma (cHL) can cause confusion in the diagnosis. In these cases, the transcription factors (TFs) B-cell specific activator protein (BSAP)/Pax-5, octamer binding protein-2 (Oct-2), B-lymphocyte-specific co-activator BOB.1/OBF.1, Bcl-6 protein and multiple myeloma-1/interferon regulatory factor-4 (MUM1/IRF-4) may aid in clarifying the diagnosis. Twenty-two cases of NLPHL were studied for the immunohistochemical expression of Pax-5, Oct-2, BOB.1, Bcl-6 protein and MUM1/IRF-4. Our results sustain the usefulness of the selected set of TFs to diagnose and distinguish NLPHL from cHL since Pax-5, Oct-2, BOB.1 and Bcl-6 are consistently expressed by lymphocyte predominant (LP) cells and reported by others to be often unexpressed in Hodgkin and Reed-Sternberg cells. By contrast, MUM1/IRF-4 protein scored negative in the majority of LP cells, but is reported to be expressed in almost all cases of cHL. Thus, although the expression of transcription factors is very heterogeneous, their simultaneous implementation for positive and differential diagnosis may be useful.

Pluripotency gene network dynamics: System views from parametric analysis.

PubMed

Akberdin, Ilya R; Omelyanchuk, Nadezda A; Fadeev, Stanislav I; Leskova, Natalya E; Oschepkova, Evgeniya A; Kazantsev, Fedor V; Matushkin, Yury G; Afonnikov, Dmitry A; Kolchanov, Nikolay A

2018-01-01

Multiple experimental data demonstrated that the core gene network orchestrating self-renewal and differentiation of mouse embryonic stem cells involves activity of Oct4, Sox2 and Nanog genes by means of a number of positive feedback loops among them. However, recent studies indicated that the architecture of the core gene network should also incorporate negative Nanog autoregulation and might not include positive feedbacks from Nanog to Oct4 and Sox2. Thorough parametric analysis of the mathematical model based on this revisited core regulatory circuit identified that there are substantial changes in model dynamics occurred depending on the strength of Oct4 and Sox2 activation and molecular complexity of Nanog autorepression. The analysis showed the existence of four dynamical domains with different numbers of stable and unstable steady states. We hypothesize that these domains can constitute the checkpoints in a developmental progression from naïve to primed pluripotency and vice versa. During this transition, parametric conditions exist, which generate an oscillatory behavior of the system explaining heterogeneity in expression of pluripotent and differentiation factors in serum ESC cultures. Eventually, simulations showed that addition of positive feedbacks from Nanog to Oct4 and Sox2 leads mainly to increase of the parametric space for the naïve ESC state, in which pluripotency factors are strongly expressed while differentiation ones are repressed.

Feature tracking for automated volume of interest stabilization on 4D-OCT images

NASA Astrophysics Data System (ADS)

Laves, Max-Heinrich; Schoob, Andreas; Kahrs, Lüder A.; Pfeiffer, Tom; Huber, Robert; Ortmaier, Tobias

2017-03-01

A common representation of volumetric medical image data is the triplanar view (TV), in which the surgeon manually selects slices showing the anatomical structure of interest. In addition to common medical imaging such as MRI or computed tomography, recent advances in the field of optical coherence tomography (OCT) have enabled live processing and volumetric rendering of four-dimensional images of the human body. Due to the region of interest undergoing motion, it is challenging for the surgeon to simultaneously keep track of an object by continuously adjusting the TV to desired slices. To select these slices in subsequent frames automatically, it is necessary to track movements of the volume of interest (VOI). This has not been addressed with respect to 4DOCT images yet. Therefore, this paper evaluates motion tracking by applying state-of-the-art tracking schemes on maximum intensity projections (MIP) of 4D-OCT images. Estimated VOI location is used to conveniently show corresponding slices and to improve the MIPs by calculating thin-slab MIPs. Tracking performances are evaluated on an in-vivo sequence of human skin, captured at 26 volumes per second. Among investigated tracking schemes, our recently presented tracking scheme for soft tissue motion provides highest accuracy with an error of under 2.2 voxels for the first 80 volumes. Object tracking on 4D-OCT images enables its use for sub-epithelial tracking of microvessels for image-guidance.

Three-dimensional choroidal segmentation in spectral OCT volumes using optic disc prior information

NASA Astrophysics Data System (ADS)

Hu, Zhihong; Girkin, Christopher A.; Hariri, Amirhossein; Sadda, SriniVas R.

2016-03-01

Recently, much attention has been focused on determining the role of the peripapillary choroid - the layer between the outer retinal pigment epithelium (RPE)/Bruchs membrane (BM) and choroid-sclera (C-S) junction, whether primary or secondary in the pathogenesis of glaucoma. However, the automated choroidal segmentation in spectral-domain optical coherence tomography (SD-OCT) images of optic nerve head (ONH) has not been reported probably due to the fact that the presence of the BM opening (BMO, corresponding to the optic disc) can deflect the choroidal segmentation from its correct position. The purpose of this study is to develop a 3D graph-based approach to identify the 3D choroidal layer in ONH-centered SD-OCT images using the BMO prior information. More specifically, an initial 3D choroidal segmentation was first performed using the 3D graph search algorithm. Note that varying surface interaction constraints based on the choroidal morphological model were applied. To assist the choroidal segmentation, two other surfaces of internal limiting membrane and innerouter segment junction were also segmented. Based on the segmented layer between the RPE/BM and C-S junction, a 2D projection map was created. The BMO in the projection map was detected by a 2D graph search. The pre-defined BMO information was then incorporated into the surface interaction constraints of the 3D graph search to obtain more accurate choroidal segmentation. Twenty SD-OCT images from 20 healthy subjects were used. The mean differences of the choroidal borders between the algorithm and manual segmentation were at a sub-voxel level, indicating a high level segmentation accuracy.

Role of progenitor cell producing normal vagina by metaplasia in laparoscopic peritoneal vaginoplasty

PubMed Central

Mhatre, Pravin N.; Narkhede, Hemraj R.; Pawar, P. Amol; Mhatre, P. Jyoti; Kumar, Das Dhanjit

2016-01-01

CONTEXT: Host of vaginoplasty techniques have been described. None has been successful in developing normal vagina. Laparoscopic peritoneal vaginoplasty (LPV) is performed in Mayer–Rokitansky–Küster–Hauser syndrome (MRKHS) culminating in normal vagina. AIMS: This study aims to confirm normal development of neovagina by anatomical and functional parameters of histology, cytology, and ultrasonography (USG) in LPV. To identify peritoneal progenitor cell by OCT4/SOX2 markers. To demonstrate the metaplastic conversion of peritoneum to neovagina and the progenitor cell concentration, distribution pattern. SETTINGS AND DESIGN: This is prospective experimental study, conducted at teaching hospital and private hospital. SUBJECTS AND METHODS: Fifteen women of MRKHS underwent LPV followed by histology, cytology, two-/three-dimensional USG of neovagina. Four women underwent peritoneal biopsy for identification of progenitor cells with OCT4/SOX2 markers. One patient underwent serial biopsies for 4 weeks for histology and progenitor cell immunohistochemistry. RESULTS: Normal vaginal histology and cytology were apparent. USG of neovagina showed normal appearance and blood flow. Two peritoneal samples confirmed the presence of progenitor cells. Serial biopsies demonstrated the epithelial change from single to multilayer with stromal compaction and neoangiogenesis. The progenitor cells concentration and different distribution patterns were described using SOX2/OCT4 markers. CONCLUSIONS: We have shown successful peritoneal metaplastic conversion to normal vagina in LPV. The progenitor cell was identified in normal peritoneum using SOX2/OCT4 markers. The progenitor cell concentration and pattern were demonstrated at various stages of neovaginal development. PMID:28216908

Comparison of Automated Analysis of Cirrus HD-OCT™ Spectral Domain Optical Coherence Tomography with Stereo Photos of the Optic Disc

PubMed Central

Sharma, Ashish; Oakley, Jonathan D.; Schiffman, Joyce C.; Budenz, Donald L.; Anderson, Douglas R.

2010-01-01

OBJECTIVE To evaluate a new automated analysis of optic disc images obtained by spectral domain optical coherence tomography (SD-OCT). Areas of the optic disc, cup, and neural rim in SD-OCT images were compared with these areas from stereoscopic photographs, to represent the current traditional optic nerve evaluation. The repeatability of measurements by each method was determined and compared. DESIGN Evaluation of diagnostic technology. PARTICIPANTS 119 healthy eyes, 23 eyes with glaucoma, and 7 suspect eyes METHODS Optic disc and cup margins were traced from stereoscopic photographs by three individuals independently. Optic disc margins and rim widths were determined automatically in SD-OCT. A subset of photographs was examined and traced a second time, and duplicate SD-OCT images were also analyzed. MAIN OUTCOME MEASUREMENTS Agreement among photograph readers, between duplicate readings, and between SD-OCT and photographs were quantified by the intraclass correlation coefficient (ICC), by the root mean square (RMS), and the standard deviation (SD) of the differences. RESULTS Optic disc areas tended to be slightly larger when judged in photographs than by SD-OCT, while cup areas were similar. Cup and optic disc areas showed good correlation (0.8) between average photographic reading and SD-OCT, but only fair correlation of rim areas (0.4). The SD-OCT was highly reproducible (ICC of 0.96 to 0.99). Each reader was also consistent with himself on duplicate readings of 21 photographs (ICC 0.80 to 0.88 for rim area, 0.95 to 0.98 for all other measurements), but reproducibility was not as good as SD-OCT. Measurements derived from SD-OCT did not differ from photographic readings more than the readings of photographs by different readers differed from each other. CONCLUSIONS Designation of the cup and optic disc boundaries by an automated analysis of SD-OCT was within the range of variable designations by different readers from color stereoscopic photographs, but use of different landmarks typically made the designation of the optic disc size somewhat smaller in the automated analysis. There was better repeatability among measurements from SD-OCT than from among readers of photographs. The repeatability of automated measurement of SD-OCT images is promising for use both in diagnosis and in monitoring of progression. PMID:21397334

Screening for previous refractive surgery in eye bank corneas by using optical coherence tomography.

PubMed

Lin, Roger C; Li, Yan; Tang, Maolong; McLain, Marcy; Rollins, Andrew M; Izatt, Joseph A; Huang, David

2007-06-01

To use optical coherence tomography (OCT) to detect previous refractive surgery in donor corneas. We constructed a tabletop OCT scanner operating at 1310-nm wavelength. Donor corneas at the Cleveland Eye Bank were scanned while sealed within the sterile container immersed in Optisol GS. OCT scanning was performed with 7.6-mm-long lines (512 axial scans) along 8 meridians. Anterior and posterior corneal surfaces were automatically mapped using image processing software that we developed. Curvature was computed from the best parabolic fit in the central 5-mm diameter. Layered analysis of the stromal reflectivity was also performed. Twenty-nine corneas from 19 donors were examined. Five had a history of laser in situ keratomileusis (LASIK). The flap interfaces could not be visualized on slit-lamp or OCT images but were confirmed by histology. The death-to-scan time was 22.1 +/- 11.4 (SD) hours for normal corneas and 100.6 +/- 57.5 hours for LASIK corneas. The anterior surface power was 67.5 +/- 2.5 D in control corneas and 64.5 +/- 2.4 D in LASIK corneas (P = 0.023). There was no significance between the 2 groups in terms of posterior curvature and thickness parameters. The anterior/posterior reflectivity ratio in the central 4-mm diameter was significantly lower in post-LASIK corneas than in control (P < 0.05). OCT provides thickness, topography, and reflectivity maps of donor corneas without taking them out of preservation medium and container. The anterior curvature and the anterior/posterior stromal reflectivity ratio may be useful for detecting previous LASIK.

Akt-Signal Integration Is Involved in the Differentiation of Embryonal Carcinoma Cells

PubMed Central

Chen, Bo; Xue, Zheng; Yang, Guanghui; Shi, Bingyang; Yang, Ben; Yan, Yuemin; Wang, Xue; Han, Daishu; Huang, Yue; Dong, Wenji

2013-01-01

The mechanism by which Akt modulates stem cell homeostasis is still incompletely defined. Here we demonstrate that Akt phosphorylates special AT-rich sequences binding protein 1 (SATB1) at serine 47 and protects SATB1 from apoptotic cleavage. Meanwhile, Akt phosphorylates Oct4 at threonine 228 and Klf4 at threonine 399, and accelerates their degradation. Moreover, PI3K/Akt signaling enhances the binding of SATB1 to Sox2, thereby probably impairing the formation of Oct4/Sox2 regulatory complexes. During retinoic acid (RA)-induced differentiation of mouse F9 embryonal carcinoma cells (ECCs), the Akt activation profile as well as its substrate spectrum is strikingly correlated with the down-regulation of Oct4, Klf4 and Nanog, which suggests Akt activation is coupled to the onset of differentiation. Accordingly, Akt-mediated phosphorylation is crucial for the capability of SATB1 to repress Nanog expression and to activate transcription of Bcl2 and Nestin genes. Taken together, we conclude that Akt is involved in the differentiation of ECCs through coordinated phosphorylations of pluripotency/differentiation factors. PMID:23762260

The Relationship between OCT-measured Central Retinal Thickness and Visual Acuity in Diabetic Macular Edema

PubMed Central

2008-01-01

Objective To compare optical coherence tomography (OCT)-measured retinal thickness and visual acuity in eyes with diabetic macular edema (DME) both before and after macular laser photocoagulation. Design Cross-sectional and longitudinal study. Participants 210 subjects (251 eyes) with DME enrolled in a randomized clinical trial of laser techniques. Methods Retinal thickness was measured with OCT and visual acuity was measured with the electronic-ETDRS procedure. Main Outcome Measures OCT-measured center point thickness and visual acuity Results The correlation coefficients for visual acuity versus OCT center point thickness were 0.52 at baseline and 0.49, 0.36, and 0.38 at 3.5, 8, and 12 months post-laser photocoagulation. The slope of the best fit line to the baseline data was approximately 4.4 letters (95% C.I.: 3.5, 5.3) better visual acuity for every 100 microns decrease in center point thickness at baseline with no important difference at follow-up visits. Approximately one-third of the variation in visual acuity could be predicted by a linear regression model that incorporated OCT center point thickness, age, hemoglobin A1C, and severity of fluorescein leakage in the center and inner subfields. The correlation between change in visual acuity and change in OCT center point thickening 3.5 months after laser treatment was 0.44 with no important difference at the other follow-up times. A subset of eyes showed paradoxical improvements in visual acuity with increased center point thickening (7–17% at the three time points) or paradoxical worsening of visual acuity with a decrease in center point thickening (18%–26% at the three time points). Conclusions There is modest correlation between OCT-measured center point thickness and visual acuity, and modest correlation of changes in retinal thickening and visual acuity following focal laser treatment for DME. However, a wide range of visual acuity may be observed for a given degree of retinal edema and paradoxical increases in center point thickening with increases in visual acuity as well as paradoxical decreases in center point thickening with decreases in visual acuity were not uncommon. Thus, although OCT measurements of retinal thickness represent an important tool in clinical evaluation, they cannot reliably substitute as a surrogate for visual acuity at a given point in time. This study does not address whether short-term changes on OCT are predictive of long-term effects on visual acuity. PMID:17123615

Light-Induced Thickening of Photoreceptor Outer Segment Layer Detected by Ultra-High Resolution OCT Imaging.

PubMed

Li, Yichao; Fariss, Robert N; Qian, Jennifer W; Cohen, Ethan D; Qian, Haohua

2016-07-01

We examined if light induces changes in the retinal structure that can be observed using optical coherence tomography (OCT). Normal C57BL/6J mice (age 3-6 months) adapted to either room light (15 minutes to ∼5 hours, 50-500 lux) or darkness (overnight) were imaged using a Bioptigen UHR-OCT system. Confocal histologic images were obtained from mice killed under light- or dark-adapted conditions. The OCT image of eyes adapted to room light exhibited significant increases (6.1 ± 0.8 μm, n = 13) in total retina thickness compared to the same eyes after overnight dark adaptation. These light-adapted retinal thickness changes occurred mainly in the outer retina, with the development of a hyporeflective band between the RPE and photoreceptor-tip layers. Histologic analysis revealed a light-evoked elongation between the outer limiting membrane and Bruch's membrane from 45.8 ± 1.7 μm in the dark (n = 5) to 52.1 ± 3.7 μm (n = 5) in the light. Light-adapted retinas showed an increase of actin staining in RPE apical microvilli at the same location as the hyporeflective band observed in OCT images. Elongation of the outer retina could be detected even with brief light exposures, increasing 2.1 ± 0.3 μm after 15 minutes (n = 9), and 4.1 ± 1.0 μm after 2 hours (n = 6). Conversely, dark-adaptation caused outer retinal shortening of 1.4 ± 0.4 μm (n = 7) and 3.0 ± 0.5 μm (n = 8) after 15 minutes and 2 hours, respectively. Light-adaption induces an increase in the thickness of the outer retina and the appearance of a hyporeflective band in the OCT image. This is consistent with previous reports of light-induced fluid accumulation in the subretinal space.

Dynamic measurement of the optical properties of bovine enamel demineralization models using four-dimensional optical coherence tomography

NASA Astrophysics Data System (ADS)

Aden, Abdirahman; Anthony, Arthi; Brigi, Carel; Merchant, Muhammad Sabih; Siraj, Huda; Tomlins, Peter H.

2017-07-01

Dental enamel mineral loss is multifactorial and is consequently explored using a variety of in vitro models. Important factors include the presence of acidic pH and its specific ionic composition, which can both influence lesion characteristics. Optical coherence tomography (OCT) has been demonstrated as a promising tool for studying dental enamel demineralization. However, OCT-based characterization and comparison of demineralization model dynamics are challenging without a consistent experimental environment. Therefore, an automated four-dimensional OCT system was integrated with a multispecimen flow cell to measure and compare the optical properties of subsurface enamel demineralization in different models. This configuration was entirely automated, thus mitigating any need to disturb the specimens and ensuring spatial registration of OCT image volumes at multiple time points. Twelve bovine enamel disks were divided equally among three model groups. The model demineralization solutions were citric acid (pH 3.8), acetic acid (pH 4.0), and acetic acid with added calcium and phosphate (pH 4.4). Bovine specimens were exposed to the solution continuously for 48 h. Three-dimensional OCT data were obtained automatically from each specimen at a minimum of 1-h intervals from the same location within each specimen. Lesion dynamics were measured in terms of the depth below the surface to which the lesion extended and the attenuation coefficient. The net loss of surface enamel was also measured for comparison. Similarities between the dynamics of each model were observed, although there were also distinct characteristic differences. Notably, the attenuation coefficients showed a systematic offset and temporal shift with respect to the different models. Furthermore, the lesion depth curves displayed a discontinuous increase several hours after the initial acid challenge. This work demonstrated the capability of OCT to distinguish between different enamel demineralization models by making dynamic quantitative measurements of lesion properties. This has important implications for future applications in clinical dentistry.

Ultrahigh-resolution high-speed retinal imaging using spectral-domain optical coherence tomography

NASA Astrophysics Data System (ADS)

Cense, Barry; Nassif, Nader A.; Chen, Teresa C.; Pierce, Mark C.; Yun, Seok-Hyun; Hyle Park, B.; Bouma, Brett E.; Tearney, Guillermo J.; de Boer, Johannes F.

2004-05-01

We present the first ultrahigh-resolution optical coherence tomography (OCT) structural intensity images and movies of the human retina in vivo at 29.3 frames per second with 500 A-lines per frame. Data was acquired at a continuous rate of 29,300 spectra per second with a 98% duty cycle. Two consecutive spectra were coherently summed to improve sensitivity, resulting in an effective rate of 14,600 A-lines per second at an effective integration time of 68 μs. The turn-key source was a combination of two super luminescent diodes with a combined spectral width of more than 150 nm providing 4.5 mW of power. The spectrometer of the spectraldomain OCT (SD-OCT) setup was centered around 885 nm with a bandwidth of 145 nm. The effective bandwidth in the eye was limited to approximately 100 nm due to increased absorption of wavelengths above 920 nm in the vitreous. Comparing the performance of our ultrahighresolution SD-OCT system with a conventional high-resolution time domain OCT system, the A-line rate of the spectral-domain OCT system was 59 times higher at a 5.4 dB lower sensitivity. With use of a software based dispersion compensation scheme, coherence length broadening due to dispersion mismatch between sample and reference arms was minimized. The coherence length measured from a mirror in air was equal to 4.0 μm (n= 1). The coherence length determined from the specular reflection of the foveal umbo in vivo in a healthy human eye was equal to 3.5 μm (n = 1.38). With this new system, two layers at the location of the retinal pigmented epithelium seem to be present, as well as small features in the inner and outer plexiform layers, which are believed to be small blood vessels.

Design and evaluation of an intraocular B-scan OCT-guided 36-gauge needle

NASA Astrophysics Data System (ADS)

Shen, Jin H.; Joos, Karen M.

2015-03-01

Optical coherence tomography imaging is widely used in ophthalmology and optometry clinics for diagnosing retinal disorders. External microscope-mounted OCT operating room systems have imaged retinal changes immediately following surgical manipulations. However, the goal is to image critical surgical maneuvers in real time. External microscope-mounted OCT systems have some limitations with problems tracking constantly moving intraocular surgical instruments, and formation of absolute shadows by the metallic surgical instruments upon the underlying tissues of interest. An intraocular OCT-imaging probe was developed to resolve these problems. A disposable 25-gauge probe tip extended beyond the handpiece, with a 36-gauge needle welded to a disposable tip with its end extending an additional 3.5 mm. A sealed 0.35 mm diameter GRIN lens protected the fiber scanner and focused the scanning beam at a 3 to 4 mm distance. The OCT engine was a very high-resolution spectral-domain optical coherence tomography (SDOCT) system (870 nm, Bioptigen, Inc. Durham, NC) which produced 2000 A-scan lines per B-scan image at a frequency of 5 Hz with the fiber optic oscillations matched to this frequency. Real-time imaging of the needle tip as it touched infrared paper was performed. The B-scan OCT-needle was capable of real-time performance and imaging of the phantom material. In the future, the B-scan OCT-guided needle will be used to perform sub-retinal injections.

Resolution characteristics of optical coherence tomography for dental use.

PubMed

Watanabe, Hiroshi; Kuribayashi, Ami; Sumi, Yasunori; Kurabayashi, Tohru

2017-03-01

The purpose of this study was to clarify the resolution characteristics of optical coherence tomography (OCT) for dental use. Two types of swept-source optical coherence tomography machines were employed in this study. To clarify their resolution characteristics, we newly developed a glass chart device with a ladder pattern of wavelengths, which ranged from 4 × 2 μm to 1024 × 2 μm, as well as a star-target pattern, a grid pattern and a spatial frequency response pattern. The resolving powers and characteristics of the OCTs were subjectively evaluated. The Santec OCT-2000 ™ (Santec Co., Komaki, Japan) had a resolving power of 64 μm in both the horizontal X and vertical Y directions, while the OCT from Yoshida had a resolving power of 64 μm in the horizontal X direction and 128 µm in the vertical Y direction. The resolving power of the depth Z direction could not be obtained from this study. With the Yoshida OCT, the star-target pattern seemed to be non-symmetrical, owing to an edge enhancement effect, which was revealed when the ladder patterns were placed in a horizontal direction. This study successfully clarified the resolution characteristics of two types of OCTs. The obtained data may be useful for diagnostic purposes, and the glass chart device used in this study may be useful for OCT quality assurance programmes.

Assessment of collagen changes in ovarian tissue by extracting optical scattering coefficient from OCT images

NASA Astrophysics Data System (ADS)

Yang, Yi; Wang, Tianheng; Biswal, Nrusingh; Wang, Xiaohong; Sanders, Melinda; Brewer, Molly; Zhu, Quing

2012-01-01

Optical scattering coefficient from ex-vivo unfixed normal and malignant ovarian tissue was quantitatively extracted by fitting optical coherence tomography (OCT) A-line signals to a single scattering model. 1097 average A-line measurements at a wavelength of 1310nm were performed at 108 sites obtained from 18 ovaries. The average scattering coefficient obtained from normal group consisted of 833 measurements from 88 sites was 2.41 mm-1 (+/-0.59), while the average coefficient obtained from malignant group consisted of 264 measurements from 20 sites was 1.55 mm-1 (+/-0.46). Using a threshold of 2 mm-1 for each ovary, a sensitivity of 100% and a specificity of 100% were achieved. The amount of collagen within OCT imaging depth was analyzed from the tissue histological section stained with Sirius Red. The average collagen area fraction (CAF) obtained from normal group was 48.4% (+/-12.3%), while the average CAF obtained from malignant group was 11.4% (+/-4.7%). Statistical significance of the collagen content was found between the two groups (p < 0.001). The preliminary data demonstrated that quantitative extraction of optical scattering coefficient from OCT images could be a potential powerful method for ovarian cancer detection and diagnosis.

Organic cation transporter 3 modulates murine basophil functions by controlling intracellular histamine levels

PubMed Central

Schneider, Elke; Machavoine, François; Pléau, Jean-Marie; Bertron, Anne-France; Thurmond, Robin L.; Ohtsu, Hiroshi; Watanabe, Takehiko; Schinkel, Alfred H.; Dy, Michel

2005-01-01

In this study, we identify the bidirectional organic cation transporter 3 (OCT3/Slc22a3) as the molecule responsible for histamine uptake by murine basophils. We demonstrate that OCT3 participates in the control of basophil functions because exogenous histamine can inhibit its own synthesis—and that of interleukin (IL)-4, IL-6, and IL-13—through this means of transport. Furthermore, ligands of H3/H4 histamine receptors or OCT3 inhibit histamine uptake, and outward transport of newly synthesized histamine. By doing so, they increase the histamine content of basophils, which explains why they mimic the effect of exogenous histamine. These drugs were no longer effective in histamine-free histidine decarboxylase (HDC)-deficient mice, in contrast with histamine itself. Histamine was not taken up and lost its inhibitory effect in mice deficient for OCT3, which proved its specific involvement. Intracellular histamine levels were increased strongly in IL-3–induced OCT3 −/− bone marrow basophils, and explained why they generated fewer cytokines than their wild-type counterpart. Their production was enhanced when histamine synthesis was blocked by the specific HDC inhibitor α-fluoro-methyl histidine, and underscored the determinant role of histamine in the inhibitory effect. We postulate that pharmacologic modulation of histamine transport might become instrumental in the control of basophil functions during allergic diseases. PMID:16061728

White matter segmentation by estimating tissue optical attenuation from volumetric OCT massive histology of whole rodent brains

NASA Astrophysics Data System (ADS)

Lefebvre, Joël.; Castonguay, Alexandre; Lesage, Frédéric

2017-02-01

A whole rodent brain was imaged using an automated massive histology setup and an Optical Coherence Tomography (OCT) microscope. Thousands of OCT volumetric tiles were acquired, each covering a size of about 2.5x2.5x0.8 mm3 with a sampling resolution of 4.9x4.9x6.5 microns. This paper shows the techniques for reconstruction, attenuation compensation and segmentation of the sliced brains. The tile positions within the mosaic were evaluated using a displacement model of the motorized stage and pairwise coregistration. Volume blending was then performed by solving the 3D Laplace equation, and consecutive slices were assembled using the cross-correlation of their 2D image gradient. This reconstruction algorithm resulted in a 3D map of optical reflectivity for the whole brain at micrometric resolution. OCT tissue slices were then used to estimate the local attenuation coefficient based on a single scattering photon model. The attenuation map obtained exhibits a high contrast for all white matter fibres, regardless of their orientation. The tissue optical attenuation from the intrinsic OCT reflectivity contributes to better white matter tissue segmentation. The combined 3D maps of reflectivity and attenuation is a step toward the study of white matter at a microscopic scale for the whole brain in small animals.

Ultrahigh-Resolution Optical Coherence Tomography of Surgically Closed Macular Holes

PubMed Central

Ko, Tony H.; Witkin, Andre J.; Fujimoto, James G.; Chan, Annie; Rogers, Adam H.; Baumal, Caroline R.; Schuman, Joel S.; Drexler, Wolfgang; Reichel, Elias; Duker, Jay S.

2007-01-01

Objective To evaluate retinal anatomy using ultrahigh-resolution optical coherence tomography (OCT) in eyes after successful surgical repair of full-thickness macular hole. Methods Twenty-two eyes of 22 patients were diagnosed as having macular hole, underwent pars plana vitrectomy, and had flat/closed macular anatomy after surgery, as confirmed with biomicroscopic and OCT examination findings. An ultrahigh-resolution–OCT system developed for retinal imaging, with the capability to achieve approximately 3-μm axial resolution, was used to evaluate retinal anatomy after hole repair. Results Despite successful closure of the macular hole, all 22 eyes had macular abnormalities on ultrahigh-resolution–OCT images after surgery. These abnormalities were separated into the following 5 categories: (1) outer foveal defects in 14 eyes (64%), (2) persistent foveal detachment in 4 (18%), (3) moderately reflective foveal lesions in 12 (55%), (4) epiretinal membranes in 14 (64%), and (5) nerve fiber layer defects in 3 (14%). Conclusions With improved visualization of fine retinal architectural features, ultrahigh-resolution OCT can visualize persistent retinal abnormalities despite anatomically successful macular hole surgery. Outer foveal hyporeflective disruptions of the junction between the inner and outer segments of the photoreceptors likely represent areas of foveal photoreceptor degeneration. Moderately reflective lesions likely represent glial cell proliferation at the site of hole reapproximation. Thin epiretinal membranes do not seem to decrease visual acuity and may play a role in reestablishing foveal anatomy after surgery. PMID:16769836

Induced pluripotent stem cells from goat fibroblasts.

PubMed

Song, Hui; Li, Hui; Huang, Mingrui; Xu, Dan; Gu, Chenghao; Wang, Ziyu; Dong, Fulu; Wang, Feng

2013-12-01

Embryonic stem cells (ESCs) are a powerful model for genetic engineering, studying developmental biology, and modeling disease. To date, ESCs have been established from the mouse (Evans and Kaufman, 1981, Nature 292:154-156), non-human primates (Thomson et al., , Proc Nat Acad Sci USA 92:7844-7848), humans (Thomson et al., 1998, Science 282:1145-1147), and rats (Buehr et al., , Cell 135:1287-1298); however, the derivation of ESCs from domesticated ungulates such as goats, sheep, cattle, and pigs have not been successful. Alternatively, induced pluripotent stem cells (iPSCs) can be generated by reprogramming somatic cells with several combinations of genes encoding transcription factors (OCT3/4, SOX2, KLF4, cMYC, LIN28, and NANOG). To date, iPSCs have been isolated from various species, but only limited information is available regarding goat iPSCs (Ren et al., 2011, Cell Res 21:849-853). The objectives of this study were to generate goat iPSCs from fetal goat primary ear fibroblasts using lentiviral transduction of four human transcription factors: OCT4, SOX2, KLF4, and cMYC. The goat iPSCs were successfully generated by co-culture with mitomycin C-treated mouse embryonic fibroblasts using medium supplemented with knockout serum replacement and human basic fibroblast growth factor. The goat iPSCs colonies are flat, compact, and closely resemble human iPSCs. They have a normal karyotype; stain positive for alkaline phosphatase, OCT4, and NANOG; express endogenous pluripotency genes (OCT4, SOX2, cMYC, and NANOG); and can spontaneously differentiate into three germ layers in vitro and in vivo. © 2013 Wiley Periodicals, Inc.

Intravascular imaging comparison of two metallic limus-eluting stents abluminally coated with biodegradable polymers: IVUS and OCT results of the DESTINY trial.

PubMed

Costa, J Ribamar; Chamié, Daniel; Abizaid, Alexandre A C; Ribeiro, Expedito; Meireles, George C; Prudente, Maurício; Campos, Carlos A; Castro, Juliana P; Costa, Ricardo; Lemos, Pedro A

2017-02-01

We sought to compare, by means of IVUS and OCT imaging, the performance of a novel sirolimus-eluting drug-eluting stent (DES) with biodegradable polymer (Inspiron™) to the Biomatrix™ DES. From the DESTINY trial, a total of 70 randomized patients (2:1) were enrolled in the IVUS substudy (Inspiron™, n = 46; Biomatrix™: n = 20) while 25 patients were evaluated with OCT (Inspiron™, n = 19; Biomatrix™: n = 06) at 9-month follow-up. The main endpoints were % of neointimal tissue obstruction (IVUS) and neointimal stut coverage (OCT) at 9 months. Patients treated with both DES had very little NIH formation at 9 months either by IVUS (% of NIH obstruction of 4.9 ± 4.1 % with Inspiron™ vs. 2.7 ± 2.9 % with Biomatrix™, p = 0.03) or by OCT (neointimal thickness of 144.2 ± 72.5 µm Inspiron™ vs. 115.0 ± 53.9 µm with Biomatrix™, p = 0.45). Regarding OCT strut-level assessment, again both devices showed excellent 9-month performance, with high rates of strut coverage (99.49 ± 1.01 % with Inspiron™ vs. 97.62 ± 2.21 % with Biomatrix™, p < 0.001) and very rare malapposition (0.29 ± 1.06 % with Inspiron™ vs. 0.53 ± 0.82 % with Biomatrix™, p = 0.44). Patients with any uncovered struts were more frequently identified in the Biomatrix™ group (9.78 ± 7.13 vs. 2.29 ± 3.91 %, p < 0.001). In the present study, midterm IVUS and OCT evaluations showed that both new generation DES with biodegradable polymer were effective in terms of suppressing excessive neointimal response, with very high rates of apposed and covered struts, suggesting a consistent and benign healing pattern.

Enhanced Visualization of Subtle Outer Retinal Pathology by En Face Optical Coherence Tomography and Correlation with Multi-Modal Imaging

PubMed Central

Chew, Avenell L.; Lamey, Tina; McLaren, Terri; De Roach, John

2016-01-01

Purpose To present en face optical coherence tomography (OCT) images generated by graph-search theory algorithm-based custom software and examine correlation with other imaging modalities. Methods En face OCT images derived from high density OCT volumetric scans of 3 healthy subjects and 4 patients using a custom algorithm (graph-search theory) and commercial software (Heidelberg Eye Explorer software (Heidelberg Engineering)) were compared and correlated with near infrared reflectance, fundus autofluorescence, adaptive optics flood-illumination ophthalmoscopy (AO-FIO) and microperimetry. Results Commercial software was unable to generate accurate en face OCT images in eyes with retinal pigment epithelium (RPE) pathology due to segmentation error at the level of Bruch’s membrane (BM). Accurate segmentation of the basal RPE and BM was achieved using custom software. The en face OCT images from eyes with isolated interdigitation or ellipsoid zone pathology were of similar quality between custom software and Heidelberg Eye Explorer software in the absence of any other significant outer retinal pathology. En face OCT images demonstrated angioid streaks, lesions of acute macular neuroretinopathy, hydroxychloroquine toxicity and Bietti crystalline deposits that correlated with other imaging modalities. Conclusions Graph-search theory algorithm helps to overcome the limitations of outer retinal segmentation inaccuracies in commercial software. En face OCT images can provide detailed topography of the reflectivity within a specific layer of the retina which correlates with other forms of fundus imaging. Our results highlight the need for standardization of image reflectivity to facilitate quantification of en face OCT images and longitudinal analysis. PMID:27959968

Functional assessment of the visual pathway with multifocal visual evoked potentials, and their relationship with disability in patients with multiple sclerosis.

PubMed

Blanco, Román; Pérez-Rico, Consuelo; Puertas-Muñoz, Inmaculada; Ayuso-Peralta, Lucía; Boquete, Luciano; Arévalo-Serrano, Juan

2014-02-01

To objectively evaluate the visual function, and the relationship between disability and optic nerve dysfunction, in patients with multiple sclerosis (MS) and optic neuritis (ON), using multifocal visual evoked potentials (mfVEP). This observational, cross-sectional study assessed 28 consecutive patients with clinically definite MS, according to the McDonald criteria, and 19 age-matched healthy subjects. Disability was recorded using the Expanded Disability Status Scale (EDSS) score. The patients' mfVEP were compared to their clinical, psychophysical (Humphrey perimetry) and structural (optic coherence tomography (OCT)) diagnostic test data. We observed a significant agreement between mfVEP amplitude and Humphrey perimetry/OCT in MS-ON eyes, and between mfVEP amplitude and OCT in MS but non-ON eyes. We found significant differences in EDSS score between patients with abnormal and normal mfVEP amplitudes. Abnormal mfVEP amplitude defects (from interocular and monocular probability analysis) were found in 67.9% and 73.7% of the MS-ON and MS-non-ON group eyes, respectively. Delayed mfVEP latencies (interocular and monocular probability analysis) were seen in 70.3% and 73.7% of the MS-ON and MS-non-ON groups, respectively. We found a significant relationship between mfVEP amplitude and disease severity, as measured by EDSS score, that suggested there is a role for mfVEP amplitude as a functional biomarker of axonal loss in MS.

Comparison of drusen area detected by spectral domain optical coherence tomography and color fundus imaging.

PubMed

Yehoshua, Zohar; Gregori, Giovanni; Sadda, SriniVas R; Penha, Fernando M; Goldhardt, Raquel; Nittala, Muneeswar G; Konduru, Ranjith K; Feuer, William J; Gupta, Pooja; Li, Ying; Rosenfeld, Philip J

2013-04-03

To compare the measurements of drusen area from manual segmentation of color fundus photographs with those generated by an automated algorithm designed to detect elevations of the retinal pigment epithelium (RPE) on spectral domain optical coherence tomography (SD-OCT) images. Fifty eyes with drusen secondary to nonexudative age-related macular degeneration were enrolled. All eyes were imaged with a high-definition OCT instrument using a 200 × 200 A-scan raster pattern covering a 6 mm × 6 mm area centered on the fovea. Digital color fundus images were taken on the same day. Drusen were traced manually on the fundus photos by graders at the Doheny Image Reading Center, whereas quantitative OCT measurements of drusen were obtained by using a fully automated algorithm. The color fundus images were registered to the OCT data set and measurements within corresponding 3- and 5-mm circles centered at the fovea were compared. The mean areas (± SD [range]) for the 3-mm circles were SD-OCT = 1.57 (± 1.08 [0.03-4.44]); 3-mm color fundus = 1.92 (± 1.08 [0.20-3.95]); 5-mm SD-OCT = 2.12 (± 1.55 [0.03-5.40]); and 5-mm color fundus = 3.38 (± 1.90 [0.39-7.49]). The mean differences between color images and the SD-OCT (color - SD-OCT) were 0.36 (± 0.93) (P = 0.008) for the 3-mm circle and 1.26 (± 1.38) (P < 0.001) for the 5-mm circle measurements. Intraclass correlation coefficients of agreements for 3- and 5-mm measurements were 0.599 and 0.540, respectively. There was only fair agreement between drusen area measurements obtained from SD-OCT images and color fundus photos. Drusen area measurements on color fundus images were larger than those with SD-OCT scans. This difference can be attributed to the fact that the OCT algorithm defines drusen in terms of RPE deformations above a certain threshold, and will not include small, flat drusen and subretinal drusenoid deposits. The two approaches provide complementary information about drusen.

Reduction of cytotoxicity of benzalkonium chloride and octenidine by Brilliant Blue G.

PubMed

Bartok, Melinda; Tandon, Rashmi; Alfaro-Espinoza, Gabriela; Ullrich, Matthias S; Gabel, Detlef

2015-01-01

The irritative effects of preservatives found in ophthalmologic solution, or of antiseptics used for skin disinfection is a consistent problem for the patients. The reduction of the toxic effects of these compounds is desired. Brilliant Blue G (BBG) has shown to meet the expected effect in presence of benzalkonium chloride (BAK), a well known preservative in ophthalmic solutions, and octenidine dihydrochloride (Oct), used as antiseptic in skin and wound disinfection. BBG shows a significant protective effect on human corneal epithelial (HCE) cells against BAK and Oct toxicity, increasing the cell survival up to 51 % at the highest BAK or Oct concentration tested, which is 0.01 %, both at 30 min incubation. Although BBG is described as a P2x7 receptor antagonist, other selective P2x7 receptor antagonists, OxATP (adenosine 5'-triphosphate-2',3'-dialdehyde) and DPPH (N'-(3,5-dichloropyridin-4-yl)-3-phenylpropanehydrazide), did not reduce the cytotoxicity of neither BAK nor Oct. Therefore we assume that the protective effect of BBG is not due to its action on the P2x7 receptor. Brilliant Blue R (BBR), a dye similar to BBG, was also tested for protective effect on BAK and Oct toxicity. In presence of BAK no significant protective effect was observed. Instead, with Oct a comparable protective effect was seen with that of BBG. To assure that the bacteriostatic effect is not affected by the combinations of BAK/BBG, Oct/BBG and Oct/BBR, bacterial growth inhibition was analyzed on different Gram-negative and Gram-positive bacteria. All combinations of BAK or Oct with BBG hinder growth of Gram-positive bacteria. The combinations of 0.001 % Oct and BBR above 0.025 % do not hinder the growth of B. subtilis. For Gram-negative bacteria, BBG and BBR reduce, but do not abolish, the antimicrobial effect of BAK nor of Oct. In conclusion, the addition of BBG at bacterial inhibitory concentrations is suggested in the ready-to-use ophthalmic preparations and antiseptic solutions.

Reduction of cytotoxicity of benzalkonium chloride and octenidine by Brilliant Blue G

PubMed Central

Bartok, Melinda; Tandon, Rashmi; Alfaro-Espinoza, Gabriela; Ullrich, Matthias S.; Gabel, Detlef

2015-01-01

The irritative effects of preservatives found in ophthalmologic solution, or of antiseptics used for skin disinfection is a consistent problem for the patients. The reduction of the toxic effects of these compounds is desired. Brilliant Blue G (BBG) has shown to meet the expected effect in presence of benzalkonium chloride (BAK), a well known preservative in ophthalmic solutions, and octenidine dihydrochloride (Oct), used as antiseptic in skin and wound disinfection. BBG shows a significant protective effect on human corneal epithelial (HCE) cells against BAK and Oct toxicity, increasing the cell survival up to 51 % at the highest BAK or Oct concentration tested, which is 0.01 %, both at 30 min incubation. Although BBG is described as a P2x7 receptor antagonist, other selective P2x7 receptor antagonists, OxATP (adenosine 5’-triphosphate-2’,3’-dialdehyde) and DPPH (N’-(3,5-dichloropyridin-4-yl)-3-phenylpropanehydrazide), did not reduce the cytotoxicity of neither BAK nor Oct. Therefore we assume that the protective effect of BBG is not due to its action on the P2x7 receptor. Brilliant Blue R (BBR), a dye similar to BBG, was also tested for protective effect on BAK and Oct toxicity. In presence of BAK no significant protective effect was observed. Instead, with Oct a comparable protective effect was seen with that of BBG. To assure that the bacteriostatic effect is not affected by the combinations of BAK/BBG, Oct/BBG and Oct/BBR, bacterial growth inhibition was analyzed on different Gram-negative and Gram-positive bacteria. All combinations of BAK or Oct with BBG hinder growth of Gram-positive bacteria. The combinations of 0.001 % Oct and BBR above 0.025 % do not hinder the growth of B. subtilis. For Gram-negative bacteria, BBG and BBR reduce, but do not abolish, the antimicrobial effect of BAK nor of Oct. In conclusion, the addition of BBG at bacterial inhibitory concentrations is suggested in the ready-to-use ophthalmic preparations and antiseptic solutions. PMID:26417355

Ultrahigh speed Spectral / Fourier domain OCT ophthalmic imaging at 70,000 to 312,500 axial scans per second

PubMed Central

Potsaid, Benjamin; Gorczynska, Iwona; Srinivasan, Vivek J.; Chen, Yueli; Jiang, James; Cable, Alex; Fujimoto, James G.

2009-01-01

We demonstrate ultrahigh speed spectral / Fourier domain optical coherence tomography (OCT) using an ultrahigh speed CMOS line scan camera at rates of 70,000 - 312,500 axial scans per second. Several design configurations are characterized to illustrate trade-offs between acquisition speed, resolution, imaging range, sensitivity and sensitivity roll-off performance. Ultrahigh resolution OCT with 2.5 - 3.0 micron axial image resolution is demonstrated at ∼ 100,000 axial scans per second. A high resolution spectrometer design improves sensitivity roll-off and imaging range performance, trading off imaging speed to 70,000 axial scans per second. Ultrahigh speed imaging at >300,000 axial scans per second with standard image resolution is also demonstrated. Ophthalmic OCT imaging of the normal human retina is investigated. The high acquisition speeds enable dense raster scanning to acquire densely sampled volumetric three dimensional OCT (3D-OCT) data sets of the macula and optic disc with minimal motion artifacts. Imaging with ∼ 8 - 9 micron axial resolution at 250,000 axial scans per second, a 512 × 512 × 400 voxel volumetric 3D-OCT data set can be acquired in only ∼ 1.3 seconds. Orthogonal registration scans are used to register OCT raster scans and remove residual axial eye motion, resulting in 3D-OCT data sets which preserve retinal topography. Rapid repetitive imaging over small volumes can visualize small retinal features without motion induced distortions and enables volume registration to remove eye motion. Cone photoreceptors in some regions of the retina can be visualized without adaptive optics or active eye tracking. Rapid repetitive imaging of 3D volumes also provides dynamic volumetric information (4D-OCT) which is shown to enhance visualization of retinal capillaries and should enable functional imaging. Improvements in the speed and performance of 3D-OCT volumetric imaging promise to enable earlier diagnosis and improved monitoring of disease progression and response to therapy in ophthalmology, as well as have a wide range of research and clinical applications in other areas. PMID:18795054

Memristor-Based Computing Architecture: Design Methodologies and Circuit Techniques

DTIC Science & Technology

2013-03-01

MEMRISTOR-BASED COMPUTING ARCHITECTURE : DESIGN METHODOLOGIES AND CIRCUIT TECHNIQUES POLYTECHNIC INSTITUTE OF NEW YORK UNIVERSITY...TECHNICAL REPORT 3. DATES COVERED (From - To) OCT 2010 – OCT 2012 4. TITLE AND SUBTITLE MEMRISTOR-BASED COMPUTING ARCHITECTURE : DESIGN METHODOLOGIES...schemes for a memristor-based reconfigurable architecture design have not been fully explored yet. Therefore, in this project, we investigated

A human bone marrow mesodermal-derived cell population with hemogenic potential.

PubMed

Mokhtari, Saloomeh; Colletti, Evan; Yin, Weihong; Sanada, Chad; Lamar, Zanetta; Simmons, Paul J; Walker, Steven; Bishop, Colin; Atala, Anthony; Zanjani, Esmail D; Porada, Christopher D; Almeida-Porada, Graça

2018-02-02

The presence, within the human bone marrow, of cells with both endothelial and hemogenic potential has been controversial. Herein, we identify, within the human fetal bone marrow, prior to establishment of hematopoiesis, a unique APLNR+, Stro-1+ cell population, co-expressing markers of early mesodermal precursors and/or hemogenic endothelium. In adult marrow, cells expressing similar markers are also found, but at very low frequency. These adult-derived cells can be extensively culture expanded in vitro without loss of potential, they preserve a biased hemogenic transcriptional profile, and, upon in vitro induction with OCT4, assume a hematopoietic phenotype. In vivo, these cells, upon transplantation into a fetal microenvironment, contribute to the vasculature, and generate hematopoietic cells that provide multilineage repopulation upon serial transplantation. The identification of this human somatic cell population provides novel insights into human ontogenetic hematovascular potential, which could lead to a better understanding of, and new target therapies for, malignant and nonmalignant hematologic disorders.

Efficient generation of rat induced pluripotent stem cells using a non-viral inducible vector.

PubMed

Merkl, Claudia; Saalfrank, Anja; Riesen, Nathalie; Kühn, Ralf; Pertek, Anna; Eser, Stefan; Hardt, Markus Sebastian; Kind, Alexander; Saur, Dieter; Wurst, Wolfgang; Iglesias, Antonio; Schnieke, Angelika

2013-01-01

Current methods of generating rat induced pluripotent stem cells are based on viral transduction of pluripotency inducing genes (Oct4, Sox2, c-myc and Klf4) into somatic cells. These activate endogenous pluripotency genes and reprogram the identity of the cell to an undifferentiated state. Epigenetic silencing of exogenous genes has to occur to allow normal iPS cell differentiation. To gain more control over the expression of exogenous reprogramming factors, we used a novel doxycycline-inducible plasmid vector encoding Oct4, Sox2, c-Myc and Klf4. To ensure efficient and controlled generation of iPS cells by plasmid transfection we equipped the reprogramming vector with a bacteriophage φC31 attB site and used a φC31 integrase expression vector to enhance vector integration. A series of doxycycline-independent rat iPS cell lines were established. These were characterized by immunocytochemical detection of Oct4, SSEA1 and SSEA4, alkaline phosphatase staining, methylation analysis of the endogenous Oct4 promoter and RT-PCR analysis of endogenous rat pluripotency genes. We also determined the number of vector integrations and the extent to which reprogramming factor gene expression was controlled. Protocols were developed to generate embryoid bodies and rat iPS cells demonstrated as pluripotent by generating derivatives of all three embryonic germ layers in vitro, and teratoma formation in vivo. All data suggest that our rat iPS cells, generated by plasmid based reprogramming, are similar to rat ES cells. Methods of DNA transfection, protein transduction and feeder-free monolayer culture of rat iPS cells were established to enable future applications.

Staging of Macular Telangiectasia: Power-Doppler Optical Coherence Tomography and Macular Pigment Optical Density

PubMed Central

Chin, Eric K.; Kim, Dae Yu; Hunter, Allan A.; Pilli, Suman; Wilson, Machelle; Zawadzki, Robert J.; Werner, John S.; Park, Susanna S.

2013-01-01

Purpose. Two methods were used to study the stages of macular telangiectasia (MacTel): Power-Doppler optical coherence tomography (PD-OCT), which allows imaging of the retinal circulation in three dimensions, and macular pigment optical density (MPOD), which quantifies the distribution of macular carotenoids. Methods. Among 49 patients with MacTel identified, 12 eyes (6 patients) with MacTel and 7 age-matched control eyes (7 patients) were imaged with a custom-built Fourier-domain OCT instrument to acquire PD-OCT images. MPOD was measured using heterochromatic flicker photometry in 10 eyes (5 patients) with MacTel and compared with 44 age-matched control eyes (44 patients). Clinical staging of MacTel was based on best-corrected visual acuity, fundus biomicroscopy, fluorescein angiography, and OCT. Results. Stage 1 eyes (n = 2) had subtle punctate vascular signal confined to the inner portion of the outer plexiform layer (OPL) on PD-OCT. Stage 2 (n = 2) showed larger oblique vascular signal extending into deeper OPL. Stage 3 (n = 5) had disruption of outer retinal layers with abnormal vasculature extending into the outer nuclear layer. Stage 4 (n = 3) showed diffuse blurring of the retinal layers with vascular channels extending the full thickness of the retina. MPOD values in four eyes with stage 1 or 2 MacTel correlated well with age-matched controls. Six eyes with stage 3 or 4 MacTel had loss of MPOD especially at the fovea. Conclusions. PD-OCT shows penetration of the retinal capillaries into the deeper retinal layers in early stages of MacTel, with full thickness vascular proliferation in advanced disease. MPOD is commonly depleted but may appear normal in early stage MacTel. PMID:23716628

Fully Automatic Software for Retinal Thickness in Eyes With Diabetic Macular Edema From Images Acquired by Cirrus and Spectralis Systems

PubMed Central

Lee, Joo Yong; Chiu, Stephanie J.; Srinivasan, Pratul P.; Izatt, Joseph A.; Toth, Cynthia A.; Farsiu, Sina; Jaffe, Glenn J.

2013-01-01

Purpose. To determine whether a novel automatic segmentation program, the Duke Optical Coherence Tomography Retinal Analysis Program (DOCTRAP), can be applied to spectral-domain optical coherence tomography (SD-OCT) images obtained from different commercially available SD-OCT in eyes with diabetic macular edema (DME). Methods. A novel segmentation framework was used to segment the retina, inner retinal pigment epithelium, and Bruch's membrane on images from eyes with DME acquired by one of two SD-OCT systems, Spectralis or Cirrus high definition (HD)-OCT. Thickness data obtained by the DOCTRAP software were compared with those produced by Spectralis and Cirrus. Measurement agreement and its dependence were assessed using intraclass correlation (ICC). Results. A total of 40 SD-OCT scans from 20 subjects for each machine were included in the analysis. Spectralis: the mean thickness in the 1-mm central area determined by DOCTRAP and Spectralis was 463.8 ± 107.5 μm and 467.0 ± 108.1 μm, respectively (ICC, 0.999). There was also a high level agreement in surrounding areas (out to 3 mm). Cirrus: the mean thickness in the 1-mm central area was 440.8 ± 183.4 μm and 442.7 ± 182.4 μm by DOCTRAP and Cirrus, respectively (ICC, 0.999). The thickness agreement in surrounding areas (out to 3 mm) was more variable due to Cirrus segmentation errors in one subject (ICC, 0.734–0.999). After manual correction of the errors, there was a high level of thickness agreement in surrounding areas (ICC, 0.997–1.000). Conclusions. The DOCTRAP may be useful to compare retinal thicknesses in eyes with DME across OCT platforms. PMID:24084089

Are All Retinal Nerve Fiber Layer Defects on Optic Coherence Tomography Glaucomatous?

PubMed Central

Gür Güngör, Sirel; Ahmet, Akman

2017-01-01

Objectives: In this study, we investigated the patients who were referred to our clinic with a prediagnosis of glaucoma based on retinal nerve fiber layer (RNFL) defects on optic coherence tomography (OCT) but were determined to have nonglaucomatous RNLF defects upon detailed examination. Materials and Methods: The ophthalmic examination notes, OCT images, Heidelberg retinal tomography (HRT) II and fundus photographs of 357 patients were retrospectively evaluated. Final diagnoses of these patients were investigated. Results: Of the 357 patients, 216 (60.5%) were diagnosed as open angle glaucoma, 33 (9.2%) as low-tension glaucoma, 39 (10.9%) as pre-perimetric glaucoma. The ophthalmic examinations of 14 patients (3.9%) were normal and there were no RNFL defects in OCT examinations after dilatation. In 39 patients (10.9%), the ophthalmic and optic disc examinations were completely normal and no etiologic factor explaining RNFL defects was found. Twenty-two eyes of 16 patients (4.5%) were included in this study (the mean age was 53.8±11.5 years; 9 men and 7 women). After detailed questioning of the medical history and systemic and neurologic examinations, a diagnosis of ischemic optic neuropathy was made in 11 eyes (10 patients) (2.8%), optic neuritis in 3 eyes (2 patients) (0.6%), optic disc drusen in 4 eyes (2 patients) (0.6%), pseudotumor cerebri in 2 eyes (1 patient) (0.3%), and cerebral palsy in 2 eyes (1 patient) (0.3%). Conclusion: Decrease in RNFL thickness on OCT images alone may be misleading in glaucoma examination. In cases where optic disc cupping is not evident, diagnosis should not be based on OCT RNFL examinations alone, and the patient’s medical history, detailed ophthalmic examination, OCT optic disc parameters, HRT, and visual field tests should all be carefully evaluated together. PMID:29109895

Evaluation of a new method for the measurement of corneal thickness in eye bank posterior corneal lenticules using Anterior Segment Optical Coherence Tomography.

PubMed

Amato, Domenico; Lombardo, Marco; Oddone, Francesco; Nubile, Mario; Colabelli Gisoldi, Rossella A M; Villani, Carlo M; Yoo, Sonia; Parel, Jean-Marie; Pocobelli, Augusto

2011-04-01

To preliminarily evaluate the repeatability of central corneal thickness (CCT) measurements performed with Anterior Segment Optical Coherence Tomography (AS-OCT) on eye bank posterior corneal lenticules. Six donor lenticules were created with a 350 μm head microkeratome (Moria, Antony, France). All donor tissues were stored at 4°C in Eusol-C solution (Alchimia S.r.l, Ponte S. Nicolò, Italy), without the anterior cornea lamella. The CCT of each lenticule, maintained in the glass phial, was measured using a commercial AS-OCT instrument (Visante, Carl Zeiss Meditec, Dublin, California, USA) and a specially designed adaptor immediately and 4, 24 and 48 hours after dissection. Immediately after AS-OCT, CCT values were measured with the ultrasound pachymetry method used at the Eye Bank. The mean donor cornea central thickness was 647±36 μm and 660 ± 38 μm (p=0.001) as measured by AS-OCT and ultrasound, respectively; immediately after dissection, CCT values of posterior lenticules were 235 ± 43 μm and 248 ± 44 μm, respectively (p=0.001). No statistically significant changes in CCT values of donor lenticules were assessed over the 48 h period with both methods. There was a high level of agreement, evidenced by Bland-Altman analysis, between the two methods of pachymetry. AS-OCT, with the corneal tissue in the vial, was revealed to be a repeatable and reliable method for measuring posterior donor lenticule central thickness. Lenticule CCT values measured with the investigational AS-OCT method were on average 10 μm thinner than those measured with the established ultrasound method.

Q of the Earth in the 0.5-10Hz Band

DTIC Science & Technology

1981-10-16

75 23NOV76 5 3 0.0 50.ON 79.OE 0 S E.KAZ 76 9OCT76 12 31 6.6 10.7N 85.8W 85 T COSTA RICA 77 9OCT76 2 52 24.3 45.1N 153.5E 34 1 KURILES 78 9OCT76 16 2...33.2 10.ON 85.0W 58 T COSTA RICA 97 1DEC76 17 44 33.8 12.0N 90.0W 85 T CST OF CENT. AMER. 98 3DEC76 5 27 34.4 21.OS 69.0W 71 T CHILE-BOLIVIA 99...13MAR77 4 55 55.0 2.OS 58.0W 33 S BRAZIL 138 15MAR77 21 28 9.0 9.ON 83.0W 95 T COSTA RICA 139 19MAR77 10 56 6.0 43.ON 149.OE 70 I KURILES 140 4MAR77 19

Chemotherapy-Induced Depletion of OCT4-Positive Cancer Stem Cells in a Mouse Model of Malignant Testicular Cancer.

PubMed

Pierpont, Timothy M; Lyndaker, Amy M; Anderson, Claire M; Jin, Qiming; Moore, Elizabeth S; Roden, Jamie L; Braxton, Alicia; Bagepalli, Lina; Kataria, Nandita; Hu, Hilary Zhaoxu; Garness, Jason; Cook, Matthew S; Capel, Blanche; Schlafer, Donald H; Southard, Teresa; Weiss, Robert S

2017-11-14

Testicular germ cell tumors (TGCTs) are among the most responsive solid cancers to conventional chemotherapy. To elucidate the underlying mechanisms, we developed a mouse TGCT model featuring germ cell-specific Kras activation and Pten inactivation. The resulting mice developed malignant, metastatic TGCTs composed of teratoma and embryonal carcinoma, the latter of which exhibited stem cell characteristics, including expression of the pluripotency factor OCT4. Consistent with epidemiological data linking human testicular cancer risk to in utero exposures, embryonic germ cells were susceptible to malignant transformation, whereas adult germ cells underwent apoptosis in response to the same oncogenic events. Treatment of tumor-bearing mice with genotoxic chemotherapy not only prolonged survival and reduced tumor size but also selectively eliminated the OCT4-positive cancer stem cells. We conclude that the chemosensitivity of TGCTs derives from the sensitivity of their cancer stem cells to DNA-damaging chemotherapy. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Pluripotency factors in embryonic stem cells regulate differentiation into germ layers.

PubMed

Thomson, Matt; Liu, Siyuan John; Zou, Ling-Nan; Smith, Zack; Meissner, Alexander; Ramanathan, Sharad

2011-06-10

Cell fate decisions are fundamental for development, but we do not know how transcriptional networks reorganize during the transition from a pluripotent to a differentiated cell state. Here, we asked how mouse embryonic stem cells (ESCs) leave the pluripotent state and choose between germ layer fates. By analyzing the dynamics of the transcriptional circuit that maintains pluripotency, we found that Oct4 and Sox2, proteins that maintain ESC identity, also orchestrate germ layer fate selection. Oct4 suppresses neural ectodermal differentiation and promotes mesendodermal differentiation; Sox2 inhibits mesendodermal differentiation and promotes neural ectodermal differentiation. Differentiation signals continuously and asymmetrically modulate Oct4 and Sox2 protein levels, altering their binding pattern in the genome, and leading to cell fate choice. The same factors that maintain pluripotency thus also integrate external signals and control lineage selection. Our study provides a framework for understanding how complex transcription factor networks control cell fate decisions in progenitor cells. Copyright © 2011 Elsevier Inc. All rights reserved.

Surgical repair of large cyclodialysis clefts.

PubMed

Gross, Jacob B; Davis, Garvin H; Bell, Nicholas P; Feldman, Robert M; Blieden, Lauren S

2017-05-11

To describe a new surgical technique to effectively close large (>180 degrees) cyclodialysis clefts. Our method involves the use of procedures commonly associated with repair of retinal detachment and complex cataract extraction: phacoemulsification with placement of a capsular tension ring followed by pars plana vitrectomy and gas tamponade with light cryotherapy. We also used anterior segment optical coherence tomography (OCT) as a noninvasive mechanism to determine the extent of the clefts and compared those results with ultrasound biomicroscopy (UBM) and gonioscopy. This technique was used to repair large cyclodialysis clefts in 4 eyes. All 4 eyes had resolution of hypotony and improvement of visual acuity. One patient had an intraocular pressure spike requiring further surgical intervention. Anterior segment OCT imaging in all 4 patients showed a more extensive cleft than UBM or gonioscopy. This technique is effective in repairing large cyclodialysis clefts. Anterior segment OCT more accurately predicted the extent of each cleft, while UBM and gonioscopy both underestimated the size of the cleft.

Development and Application of Multifunctional Optical Coherence Tomography

NASA Astrophysics Data System (ADS)

Zhi, Zhongwei

Microcirculation refers to the functions of capillaries and the neighboring lymphatic vessels. It plays a vital role in the pathophysiology of disorders in many clinical areas including cardiology, dermatology, neurology and ophthalmology, and so forth. It is crucial to develop imaging technologies that can provide both qualitative and quantitative information as to how microcirculation responds to certain injury and/or disease, and its treatment. Optical coherence tomography (OCT) is a non-invasive optical imaging technique for high-resolution cross-sectional imaging of specimens, with many applications in clinical medicine. Current state-of-the-art OCT systems operate in the Fourier domain, using either a broadband light source with a spectrometer, known as spectral domain OCT (SDOCT), or a rapidly tunable laser, known as swept source OCT (SSOCT). The current Fourier domain OCT systems have dramatically improvement in sensitivity, resolution and speed compared to time domain OCT. In addition to the improvement in the OCT system hardware, different methods for functional measurements of tissue beds have been developed and demonstrated. This includes but not limited to, i) Phase-resolved Doppler OCT for quantifying the blood flow, ii) OCT angiography for visualization of microvasculature, iii) Polarization sensitive OCT for measuring the intrinsic optical property/ birefringence of tissue, iv) spectroscopic OCT for measuring blood oxygenation, etc. Functional OCT can provide important clinical information that is not available in the typical intensity based structural OCT images. Among these functional OCT modalities, Doppler OCT and OCT angiography attract great interests as they show high capability for in vivo study of microvascular pathology. By analyzing the Doppler effect of a flowing particle on light frequency, Doppler OCT allows the quantification of the blood flow speed and blood flow rate. The most popular approach for Doppler OCT is achieved through analysis of the phase term in complex OCT signal which termed as Phase-resolved Doppler OCT. However, as limited by the phase noise and motion, Phase-resolved Doppler OCT can only be applied for relative large blood vessels, such as arterioles and venules. On the other hand, in order to visualize the microcirculation network, a number of strategies to enable better contrast of microvasculature components, which we termed OCT angiography, have been introduced during recent years. As a variation of Fourier domain OCT, optical microangiography (OMAG) is one of earliest proposed OCT angiography technique which is capable of generating 3D images of dynamic blood perfusion distribution within microcirculatory tissue beds. The OMAG algorithm works by separating the static and moving elements by high pass filtering on complex valued interferometric data after Fourier transform. Based on the conventional OMAG algorithm, we further developed ultra-high sensitive OMAG (UHS-OMAG) by switching the high-pass filtering from fast scan direction (adjacent A-lines within one B-frame) to slow scan direction (adjacent B-frames), which has a dramatically improved performance for capillary network imaging and analysis. Apart from the microvascular study with current available functional OCT for, visualization of the lymphatic system (lymph nodes and lymphatic vessels) plays a significant role in assessing patients with various malignancies and lymphedema. However, there is a lack of label-free and noninvasive method for lymphangiography. Hence, a cutting edge research to investigate the capability of OCT as a tool for non-invasive and label-free lymphangiography would be highly desired. The objective of my thesis is to develop a multiple-functional SDOCT system to image the microcirculation and quantify the several important parameters of microcirculation within microcirculatory tissue beds, and further apply it for pre-clinical research applications. The multifunctional OCT system provides modalities including structural OCT, OCT angiography, Doppler OCT and Optical lymphangiography, for multi-parametric study of tissue microstructure, blood vessel morphology, blood flow and lymphatic vessel all together. The thesis mainly focus on two parts: first, development of multi-functional OCT/optical microangiography (OMAG) system and methods for volumetric imaging of microvasculature and quantitative measurement of blood flow, and its application for pathological research in ophthalmology on rodent eye models; second, development of ultra-high resolution OCT system and algorithm for simultaneous label free imaging of blood and lymphatic vessel, and its application in wound healing study on mouse ear flap model. Objectives of my research are achieved through the following specific aims: Aim 1: Improve the sensitivity of OMAG for microvasculature imaging; perform volumetric and quantitative imaging of vasculature with combined OMAG and Phase-resolved Doppler OCT for in vivo study of vascular physiology. Aim 2: Develop high speed high resolution OCT system and method for rodent eye imaging. Apply the combined OMAG and Phase-resolved Doppler OCT approach to investigate the impact of elevated intraocular pressure on retinal, choroidal and optic nerve head blood flow in rat eye model, which aids to the better understanding of the mechanism and development of glaucoma. Aim 3: Apply the developed OCT system and ultra-high sensitive OMAG algorithm for noninvasive imaging of retinal morphology and microvasculature in obese mice, which may play an important role in early diagnosis of Diabetic retinopathy. Aim 4: Developing an ultra-high resolution SDOCT system using broadband Supercontinuum light source to achieve ultra-high resolution microvasculature imaging of biological tissue. Aim 5: Develop methods for simultaneous label free optical imaging of blood and lymphatic vessel and demonstrate its capability by monitoring the blood and lymph response to wound healing on mouse ear pinna model.

A transfected cell model for the renal toxin transporter, rOCT2.

PubMed

Pan, B F; Sweet, D H; Pritchard, J B; Chen, R; Nelson, J A

1999-02-01

A cDNA for the organic cation transporter (rOCT2) of the rat kidney was inserted into the retroviral plasmid pLXSN. This plasmid was used to stably transfect NIH3T3 cells. The transfected cell line exhibited an enhanced rate of tetraethylammonium (TEA) uptake and efflux compared to wild-type NIH3T3 cells. Uptake of TEA by the transfected cells was markedly reduced upon incubation at 4 degrees C. When the extracellular pH was lowered from 8.1 to 5.9, uptake was also reduced, suggesting inhibition of rOCT2 by extracellular protons. The apparent K(m) for TEA in the transfected cells was 141 microM. The classical organic cation transport inhibitors, cyanine 863 and cimetidine, produced noncompetitive inhibition with apparent Ki values of 0.81 and 198 microM, respectively. Daunomycin, vinblastine, and the deoxyadenosine analogs, 2'-deoxytubercidin and 2-chlorodeoxyadenosine, did not appear to be substrates for rOCT2. However, the anticancer drug, cisplatin, competitively inhibited TEA uptake by rOCT2 with an apparent Ki value of 925 microM, suggesting that rOCT2 may play a role in its renal secretion. In summary, transfected NIH3T3 cells provide a facile system by which this and other organic ion transporters can be studied.

Ex vivo imaging of human thyroid pathology using integrated optical coherence tomography and optical coherence microscopy

NASA Astrophysics Data System (ADS)

Zhou, Chao; Wang, Yihong; Aguirre, Aaron D.; Tsai, Tsung-Han; Cohen, David W.; Connolly, James L.; Fujimoto, James G.

2010-01-01

We evaluate the feasibility of optical coherence tomography (OCT) and optical coherence microscopy (OCM) for imaging of benign and malignant thyroid lesions ex vivo using intrinsic optical contrast. 34 thyroid gland specimens are imaged from 17 patients, covering a spectrum of pathology ranging from normal thyroid to benign disease/neoplasms (multinodular colloid goiter, Hashimoto's thyroiditis, and follicular adenoma) and malignant thyroid tumors (papillary carcinoma and medullary carcinoma). Imaging is performed using an integrated OCT and OCM system, with <4 μm axial resolution (OCT and OCM), and 14 μm (OCT) and <2 μm (OCM) transverse resolution. The system allows seamless switching between low and high magnifications in a way similar to traditional microscopy. Good correspondence is observed between optical images and histological sections. Characteristic features that suggest malignant lesions, such as complex papillary architecture, microfollicules, psammomatous calcifications, or replacement of normal follicular architecture with sheets/nests of tumor cells, can be identified from OCT and OCM images and are clearly differentiable from normal or benign thyroid tissues. With further development of needle-based imaging probes, OCT and OCM could be promising techniques to use for the screening of thyroid nodules and to improve the diagnostic specificity of fine needle aspiration evaluation.

Optical coherence tomography based imaging of dental demineralisation and cavity restoration in 840 nm and 1310 nm wavelength regions

NASA Astrophysics Data System (ADS)

Damodaran, Vani; Rao, Suresh Ranga; Vasa, Nilesh J.

2016-08-01

In this paper, a study of in-house built optical coherence tomography (OCT) system with a wavelength of 840 nm for imaging of dental caries, progress in demineralisation and cavity restoration is presented. The caries when imaged with the 840 nm OCT system showed minute demineralisation in the order of 5 μm. The OCT system was also proposed to study the growth of lesion and this was demonstrated by artificially inducing caries with a demineralisation solution of pH 4.8. The progress of carious lesion to a depth of about 50-60 μm after 60 hours of demineralisation was clearly observed with the 840 nm OCT system. The tooth samples were subjected to accelerated demineralisation condition at pH of approximately 2.3 to study the adverse effects and the onset of cavity formation was clearly observed. The restoration of cavity was also studied by employing different restorative materials (filled and unfilled). In the case of restoration without filler material (unfilled), the restoration boundaries were clearly observed. Overall, results were comparable with that of the widely used 1310 nm OCT system. In the case of restoration with filler material, the 1310 nm OCT imaging displayed better imaging capacity due to lower scattering than 840 nm imaging.

High definition live 3D-OCT in vivo: design and evaluation of a 4D OCT engine with 1 GVoxel/s.

PubMed

Wieser, Wolfgang; Draxinger, Wolfgang; Klein, Thomas; Karpf, Sebastian; Pfeiffer, Tom; Huber, Robert

2014-09-01

We present a 1300 nm OCT system for volumetric real-time live OCT acquisition and visualization at 1 billion volume elements per second. All technological challenges and problems associated with such high scanning speed are discussed in detail as well as the solutions. In one configuration, the system acquires, processes and visualizes 26 volumes per second where each volume consists of 320 x 320 depth scans and each depth scan has 400 usable pixels. This is the fastest real-time OCT to date in terms of voxel rate. A 51 Hz volume rate is realized with half the frame number. In both configurations the speed can be sustained indefinitely. The OCT system uses a 1310 nm Fourier domain mode locked (FDML) laser operated at 3.2 MHz sweep rate. Data acquisition is performed with two dedicated digitizer cards, each running at 2.5 GS/s, hosted in a single desktop computer. Live real-time data processing and visualization are realized with custom developed software on an NVidia GTX 690 dual graphics processing unit (GPU) card. To evaluate potential future applications of such a system, we present volumetric videos captured at 26 and 51 Hz of planktonic crustaceans and skin.

DETECTION OF NONEXUDATIVE CHOROIDAL NEOVASCULARIZATION IN AGE-RELATED MACULAR DEGENERATION WITH OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

PubMed

Palejwala, Neal V; Jia, Yali; Gao, Simon S; Liu, Liang; Flaxel, Christina J; Hwang, Thomas S; Lauer, Andreas K; Wilson, David J; Huang, David; Bailey, Steven T

2015-11-01

To evaluate eyes with age-related macular degeneration and high-risk characteristics for choroidal neovascularization (CNV) with optical coherence tomographic (OCT) angiography to determine whether earlier detection of CNV is possible. Eyes with drusen, pigmentary changes, and with CNV in the fellow eye were scanned with a 70-kHz spectral domain OCT system (Optovue RTVue-XR Avanti). The split-spectrum amplitude-decorrelation angiography (SSADA) algorithm was used to distinguish blood flow from static tissue. Two masked graders reviewed scans for CNV, defined as flow in the outer retinal/sub-RPE slab. Choroidal neovascularization flow area repeatability and between-grader reproducibility were calculated. Of 32 eyes, 2 (6%) were found to have Type 1 CNV with OCT angiography. The lesions were not associated with leakage on fluorescein angiography or fluid on OCT. One case was followed for 8 months without treatment, and the CNV flow area enlarged slightly without fluid buildup on OCT or vision loss. Between-grader reproducibility of the CNV flow area was 9.4% (coefficient of variation) and within-visit repeatability was 5.2% (pooled coefficient of variation). Optical coherence tomographic angiography can detect the presence of nonexudative CNV, lesions difficult to identify with fluorescein angiography and OCT. Further study is needed to understand the significance and natural history of these lesions.

High definition live 3D-OCT in vivo: design and evaluation of a 4D OCT engine with 1 GVoxel/s

PubMed Central

Wieser, Wolfgang; Draxinger, Wolfgang; Klein, Thomas; Karpf, Sebastian; Pfeiffer, Tom; Huber, Robert

2014-01-01

We present a 1300 nm OCT system for volumetric real-time live OCT acquisition and visualization at 1 billion volume elements per second. All technological challenges and problems associated with such high scanning speed are discussed in detail as well as the solutions. In one configuration, the system acquires, processes and visualizes 26 volumes per second where each volume consists of 320 x 320 depth scans and each depth scan has 400 usable pixels. This is the fastest real-time OCT to date in terms of voxel rate. A 51 Hz volume rate is realized with half the frame number. In both configurations the speed can be sustained indefinitely. The OCT system uses a 1310 nm Fourier domain mode locked (FDML) laser operated at 3.2 MHz sweep rate. Data acquisition is performed with two dedicated digitizer cards, each running at 2.5 GS/s, hosted in a single desktop computer. Live real-time data processing and visualization are realized with custom developed software on an NVidia GTX 690 dual graphics processing unit (GPU) card. To evaluate potential future applications of such a system, we present volumetric videos captured at 26 and 51 Hz of planktonic crustaceans and skin. PMID:25401010

The octamer-binding proteins form multi-protein--DNA complexes with the HSV alpha TIF regulatory protein.

PubMed Central

Kristie, T M; LeBowitz, J H; Sharp, P A

1989-01-01

The herpes simplex virus transactivator, alpha TIF, stimulates transcription of the alpha/immediate early genes via a cis-acting site containing an octamer element and a conserved flanking sequence. The alpha TIF protein, produced in a baculovirus expression system, nucleates the formation of at least two DNA--protein complexes on this regulatory element. Both of these complexes contain the ubiquitous Oct-1 protein, whose POU domain alone is sufficient to allow assembly of the alpha TIF-dependent complexes. A second member of the POU domain family, the lymphoid specific Oct-2 protein, can also be assembled into similar complexes at high concentrations of alpha TIF protein. These complexes contain at least two cellular proteins in addition to Oct-1. One of these proteins is present in both insect and HeLa cells and probably recognizes sequences in the cis element. The second cellular protein, only present in HeLa cells, probably binds by protein-protein interactions. Images PMID:2556266

The octamer-binding proteins form multi-protein--DNA complexes with the HSV alpha TIF regulatory protein.

PubMed

Kristie, T M; LeBowitz, J H; Sharp, P A

1989-12-20

The herpes simplex virus transactivator, alpha TIF, stimulates transcription of the alpha/immediate early genes via a cis-acting site containing an octamer element and a conserved flanking sequence. The alpha TIF protein, produced in a baculovirus expression system, nucleates the formation of at least two DNA--protein complexes on this regulatory element. Both of these complexes contain the ubiquitous Oct-1 protein, whose POU domain alone is sufficient to allow assembly of the alpha TIF-dependent complexes. A second member of the POU domain family, the lymphoid specific Oct-2 protein, can also be assembled into similar complexes at high concentrations of alpha TIF protein. These complexes contain at least two cellular proteins in addition to Oct-1. One of these proteins is present in both insect and HeLa cells and probably recognizes sequences in the cis element. The second cellular protein, only present in HeLa cells, probably binds by protein-protein interactions.

Nondestructive analysis of automotive paints with spectral domain optical coherence tomography.

PubMed

Dong, Yue; Lawman, Samuel; Zheng, Yalin; Williams, Dominic; Zhang, Jinke; Shen, Yao-Chun

2016-05-01

We have demonstrated for the first time, to our knowledge, the use of optical coherence tomography (OCT) as an analytical tool for nondestructively characterizing the individual paint layer thickness of multiple layered automotive paints. A graph-based segmentation method was used for automatic analysis of the thickness distribution for the top layers of solid color paints. The thicknesses measured with OCT were in good agreement with the optical microscope and ultrasonic techniques that are the current standard in the automobile industry. Because of its high axial resolution (5.5 μm), the OCT technique was shown to be able to resolve the thickness of individual paint layers down to 11 μm. With its high lateral resolution (12.4 μm), the OCT system was also able to measure the cross-sectional area of the aluminum flakes in a metallic automotive paint. The range of values measured was 300-1850  μm². In summary, the proposed OCT is a noncontact, high-resolution technique that has the potential for inclusion as part of the quality assurance process in automobile coating.

Eco-friendly films prepared from plantain flour/PCL blends under reactive extrusion conditions using zirconium octanoate as a catalyst.

PubMed

Gutiérrez, Tomy J; Alvarez, Vera A

2017-12-15

Plantain flour (Musa ssp., group AAB, sub-group clone Harton)/poly(ε-caprolactone) (PCL) blends, containing glycerol as a plasticizer, were prepared by reactive extrusion (REx) in a twin-screw extruder using zirconium octanoate (Zr(Oct) 4 ) as a catalyst, followed by thermo-compression molding for film development. The films were then characterized in terms of their: infrared (FTIR) spectra, water solubility, thermogravimetric (TGA) curves, differential scanning calorimetry (DSC) thermograms, and X-ray diffraction (XDR) diffractograms, as well as their microstructural, mechanical and antimicrobial properties in order to (1) compare the effects of PCLs with two different molecular weights (M w ) on the characteristics of the plantain flour/PCL blends, and (2) determine whether using Zr(Oct) 4 in the production of active composite polymer materials improves their properties. The plantain flour/PCL blends were all developed successfully. The higher M w PCL gave more hydrophobic and thermally stable films with improved mechanical properties. The addition of the Zr(Oct) 4 catalyst to the plantain flour/PCL blends also resulted in films with similar characteristics to those described above, due to the cross-linking of the polymers. In addition, the films containing the catalyst showed antimicrobial activity against Escherichia coli O157:H7 and Staphylococcus aureus indicating a dual effect of Zr(Oct) 4 , and making it an attractive alternative for the development of active films. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hypoxia-Mediated Epigenetic Regulation of Stemness in Brain Tumor Cells.

PubMed

Prasad, Pankaj; Mittal, Shivani Arora; Chongtham, Jonita; Mohanty, Sujata; Srivastava, Tapasya

2017-06-01

Activation of pluripotency regulatory circuit is an important event in solid tumor progression and the hypoxic microenvironment is known to enhance the stemness feature of some cells. The distinct population of cancer stem cells (CSCs)/tumor initiating cells exist in a niche and augment invasion, metastasis, and drug resistance. Previously, studies have reported global hypomethylation and site-specific aberrant methylation in gliomas along with other epigenetic modifications as important contributors to genomic instability during glioma progression. Here, we have demonstrated the role of hypoxia-mediated epigenetic modifications in regulating expression of core pluripotency factors, OCT4 and NANOG, in glioma cells. We observe hypoxia-mediated induction of demethylases, ten-eleven-translocation (TET) 1 and 3, but not TET2 in our cell-line model. Immunoprecipitation studies reveal active demethylation and direct binding of TET1 and 3 at the Oct4 and Nanog regulatory regions. Tet1 and 3 silencing assays further confirmed induction of the pluripotency pathway involving Oct4, Nanog, and Stat3, by these paralogues, although with varying degrees. Knockdown of Tet1 and Tet3 inhibited the formation of neurospheres in hypoxic conditions. We observed independent roles of TET1 and TET3 in differentially regulating pluripotency and differentiation associated genes in hypoxia. Overall, this study demonstrates an active demethylation in hypoxia by TET1 and 3 as a mechanism of Oct4 and Nanog overexpression thus contributing to the formation of CSCs in gliomas. Stem Cells 2017;35:1468-1478. © 2017 AlphaMed Press.

Acquisition cancer stemness, mesenchymal transdifferentiation, and chemoresistance properties by chronic exposure of oral epithelial cells to arecoline.

PubMed

Wang, Tung Yuan; Peng, Chih-Yu; Lee, Shiuan-Shinn; Chou, Ming-Yung; Yu, Cheng-Chia; Chang, Yu-Chao

2016-12-20

Oral squamous cell carcinoma (OSCC), one of the most deadliest malignancies in the world, is caused primarily by areca nut chewing in Southeast Asia. The mechanisms by which areca nut participates in OSCC tumorigenesis are not well understood. In this study, we investigated the effects of low dose long-term arecoline (10 μg/mL, 90-days), a major areca nut alkaloid, on enhancement cancer stemness of human oral epithelial (OE) cells. OE cells with chronic arecoline exposure resulted in increased ALDH1 population, CD44 positivity, stemness-related transcription factors (Oct4, Nanog, and Sox2), epithelial-mesenchymal transdifferentiation (EMT) traits, chemoresistance, migration/invasiveness/anchorage independent growth and in vivo tumor growth as compared to their untreated controls. Mechanistically, ectopic miR-145 over-expression in chronic arecoline-exposed OE (AOE) cells inhibited the cancer stemness and xenografic. In AOE cells, luciferase reporter assays further revealed that miR-145 directly targets the 3' UTR regions of Oct4 and Sox2 and overexpression of Sox2/Oct4 effectively reversed miR-145-regulated cancer stemness-associated phenomenas. Additionally, clinical results further revealed that Sox2 and Oct4 expression was inversely correlated with miR-145 in the tissues of areca quid chewing-associated OSCC patients. This study hence attempts to provide novel insight into areca nut-induced oral carcinogenesis and new intervention for the treatment of OSCC patients, especially in areca nut users.

Multimodal ophthalmic imaging using handheld spectrally encoded coherence tomography and reflectometry (SECTR)

NASA Astrophysics Data System (ADS)

Leeburg, Kelsey C.; El-Haddad, Mohamed T.; Malone, Joseph D.; Terrones, Benjamin D.; Tao, Yuankai K.

2018-02-01

Scanning laser ophthalmoscopy (SLO) provides high-speed, noninvasive en face imaging of the retinal fundus. Optical coherence tomography (OCT) is the current "gold-standard" for ophthalmic diagnostic imaging and enables depth-resolved visualization of ophthalmic structures and image-based surrogate biomarkers of disease. We present a compact optical and mechanical design for handheld spectrally encoded coherence tomography and reflectometry (SECTR) for multimodality en face spectrally encoded reflectometry (SER) and cross-sectional OCT imaging. We custom-designed a double-pass telecentric scan lens, which halves the size of 4-f optical relays and allowed us to reduce the footprint of our SECTR scan-head by a factor of >2.7x (volume) over our previous design. The double-pass scan lens was optimized for diffraction-limited performance over a +/-10° scan field. SECTR optics and optomechanics were combined in a compact rapid-prototyped enclosure with dimensions 87 x 141.8 x 137 mm (w x h x d). SECTR was implemented using a custom-built 400 kHz 1050 nm swept-source. OCT and SER were simultaneously digitized on dual input channels of a 4 GS/s digitizer at 1.4 GS/s per channel. In vivo human en face SER and cross-sectional OCT images were acquired at 350 fps. OCT volumes of 1000 B-scans were acquired in 2.86 s. We believe clinical translation of our compact handheld design will benefit point-of-care ophthalmic diagnostics in patients who are unable to be imaged on conventional slit-lamp based systems, such as infants and the bedridden. When combined with multi-volumetric registration methods, handheld SECTR will have advantages in motion-artifact free imaging over existing handheld technologies.

Optical Coherence Tomography Scan Circle Location and Mean Retinal Nerve Fiber Layer Measurement Variability

PubMed Central

Gabriele, Michelle L.; Ishikawa, Hiroshi; Wollstein, Gadi; Bilonick, Richard A.; Townsend, Kelly A.; Kagemann, Larry; Wojtkowski, Maciej; Srinivasan, Vivek J.; Fujimoto, James G.; Duker, Jay S.; Schuman, Joel S.

2009-01-01

PURPOSE To investigate the effect on optical coherence tomography (OCT) retinal nerve fiber layer (RNFL) thickness measurements of varying the standard 3.4-mm-diameter circle location. METHODS The optic nerve head (ONH) region of 17 eyes of 17 healthy subjects was imaged with high-speed, ultrahigh-resolution OCT (hsUHR-OCT; 501 × 180 axial scans covering a 6 × 6-mm area; scan time, 3.84 seconds) for a comprehensive sampling. This method allows for systematic simulation of the variable circle placement effect. RNFL thickness was measured on this three-dimensional dataset by using a custom-designed software program. RNFL thickness was resampled along a 3.4-mm-diameter circle centered on the ONH, then along 3.4-mm circles shifted horizontally (x-shift), vertically (y-shift) and diagonally up to ±500 µm (at 100-µm intervals). Linear mixed-effects models were used to determine RNFL thickness as a function of the scan circle shift. A model for the distance between the two thickest measurements along the RNFL thickness circular profile (peak distance) was also calculated. RESULTS RNFL thickness tended to decrease with both positive and negative x- and y-shifts. The range of shifts that caused a decrease greater than the variability inherent to the commercial device was greater in both nasal and temporal quadrants than in the superior and inferior ones. The model for peak distance demonstrated that as the scan moves nasally, the RNFL peak distance increases, and as the circle moves temporally, the distance decreases. Vertical shifts had a minimal effect on peak distance. CONCLUSIONS The location of the OCT scan circle affects RNFL thickness measurements. Accurate registration of OCT scans is essential for measurement reproducibility and longitudinal examination (ClinicalTrials.gov number, NCT00286637). PMID:18515577

Optical coherence tomography in optic pit maculopathy managed with vitrectomy-laser-gas.

PubMed

García-Arumí, José; Guraya, Borja Corcóstegui; Espax, Ana Boixadera; Castillo, Vicente Martínez; Ramsay, Laura Sararols; Motta, R Max

2004-10-01

Optic disc pit (ODP) maculopathy has a poor visual prognosis if left to its natural course. Several therapeutic approaches have been attempted. The cases of 11 patients evaluated with optical coherence tomography (OCT) and treated with vitrectomy-laser-gas and their functional and anatomical outcomes are presented. Retrospective interventional consecutive case series, including 11 eyes with ODP maculopathy. Pre- and postoperative best-corrected visual acuity (BCVA), OCT and angiography were recorded. All patients underwent pars plana vitrectomy, posterior hyaloid dissection peripapillary diode laser prior to retinal reapplication and C(3)F(8) 15% injection. Mean preoperative BCVA was 20/126. Median preoperative BCVA was 1.0 LogMAR (range 1.3-0.4) . Eighty-two per cent of patients gained 2 or more Snellen lines of vision (mean 4.4 lines gained). Mean final BCVA was 20/32, and median final BCVA was 20/30 in Snellen VA and 0.2 in LogMAR (range 0.7-0) Preoperative OCT in all but one case confirmed the bilaminar structure of the macular detachment. Postoperative OCT helped in monitoring reabsorption of the macular detachment, which was achieved in all cases after an average of 6.5 months post-surgery. BCVA increased progressively as the subretinal fluid was reabsorbed (P=0.006). Mean duration of postoperative follow-up was 15 months. Recurrence was observed in two cases. In our series, the vitrectomy-laser-gas procedure for ODP maculopathy improved vision and achieved satisfactory anatomic results in all 11 cases. OCT was useful in the diagnosis and follow-up of this pathology. However, the low incidence of this entity makes it difficult to obtain series large enough to determine the efficacy of the vitrectomy-laser-gas procedure and other treatment modalities and be able to suggest a procedure of choice.

Human forniceal region is the stem cell-rich zone of the conjunctival epithelium.

PubMed

Harun, Mohd Hairul Nizam; Sepian, Siti Norzalehawati; Chua, Kien-Hui; Ropilah, Abd Rahman; Abd Ghafar, Norzana; Che-Hamzah, Jemaima; Bt Hj Idrus, Ruszymah; Annuar, Faridah Hanom

2013-03-01

The anterior surface of the eye is covered by several physically contiguous but histologically distinguishable epithelia overlying the cornea, limbus, bulbar conjunctiva, fornix conjunctiva, and palpebral conjunctiva. The self-renewing nature of the conjunctival epithelia makes their long-term survival ultimately dependent on small populations of stem cells. Hence, the objective of this study was to investigate the expression of the stem cell genes Sox2, OCT4, NANOG, Rex1, NES, and ABCG2 in cultured human conjunctival epithelium from different conjunctival zones, namely, the bulbar, palpebral and fornix zones. Three samples were taken from patients with primary pterygium and cataract (age range 56-66 years) who presented to our eye clinic at the UKM Medical Centre. The eye was examined with slit lamp to ensure there was no underlying ocular surface diseases and glaucoma. Conjunctival tissue was taken from patients who underwent a standard cataract or pterygium operation as a primary procedure. Tissues were digested, cultured, and propagated until an adequate number of cells was obtained. Total RNA was extracted and subjected to expression analysis of conjunctival epithelium genes (KRT4, KRT13, KRT19) and stem cell genes (Sox2, OCT4, NANOG, Rex1, NES, ABCG2) by reverse transcriptase-PCR and 2% agarose gel electrophoresis. The expression of Sox2, OCT4, and NANOG genes were detected in the fornical cells, while bulbar cells only expressed Sox2 and palpebral cells only expressed OCT4. Based on these results, the human forniceal region expresses a higher number of stem cell genes than the palpebral and bulbar conjunctiva.

4D microscope-integrated OCT improves accuracy of ophthalmic surgical maneuvers

NASA Astrophysics Data System (ADS)

Carrasco-Zevallos, Oscar; Keller, Brenton; Viehland, Christian; Shen, Liangbo; Todorich, Bozho; Shieh, Christine; Kuo, Anthony; Toth, Cynthia; Izatt, Joseph A.

2016-03-01

Ophthalmic surgeons manipulate micron-scale tissues using stereopsis through an operating microscope and instrument shadowing for depth perception. While ophthalmic microsurgery has benefitted from rapid advances in instrumentation and techniques, the basic principles of the stereo operating microscope have not changed since the 1930's. Optical Coherence Tomography (OCT) has revolutionized ophthalmic imaging and is now the gold standard for preoperative and postoperative evaluation of most retinal and many corneal procedures. We and others have developed initial microscope-integrated OCT (MIOCT) systems for concurrent OCT and operating microscope imaging, but these are limited to 2D real-time imaging and require offline post-processing for 3D rendering and visualization. Our previously presented 4D MIOCT system can record and display the 3D surgical field stereoscopically through the microscope oculars using a dual-channel heads-up display (HUD) at up to 10 micron-scale volumes per second. In this work, we show that 4D MIOCT guidance improves the accuracy of depth-based microsurgical maneuvers (with statistical significance) in mock surgery trials in a wet lab environment. Additionally, 4D MIOCT was successfully performed in 38/45 (84%) posterior and 14/14 (100%) anterior eye human surgeries, and revealed previously unrecognized lesions that were invisible through the operating microscope. These lesions, such as residual and potentially damaging retinal deformation during pathologic membrane peeling, were visualized in real-time by the surgeon. Our integrated system provides an enhanced 4D surgical visualization platform that can improve current ophthalmic surgical practice and may help develop and refine future microsurgical techniques.

Transport of biguanides by human organic cation transporter OCT2.

PubMed

Sogame, Yoshihisa; Kitamura, Atsushi; Yabuki, Masashi; Komuro, Setsuko; Takano, Mikihisa

2013-06-01

Biguanides have the severe side effect of lactic acidosis. Although both metformin and phenformin are biguanide derivatives, there is a difference in the frequency at which they induce lactic acidosis. However, the reasons for the difference are not clear. Metformin has been reported to be mainly excreted into urine by human organic cation transporter 2 (hOCT2). The present study was designed to investigate the renal transport of metformin and phenformin, focusing on hOCT2, using hOCT2-expressing oocytes. Both biguanides were found to be good substrates for hOCT2. However, phenformin exhibited a higher affinity and transport activity than metformin. The Km values for metformin and phenformin were 235 and 37.4 μM, with CL(int) (V(max)/K(m)) values of 71.9×10⁻³ μL/min per oocyte and 209×10⁻³ μL/min per oocyte, respectively. This is the first report that has compared the transport profiles of these biguanides in hOCT2-expressing oocytes. The results suggest that plasma concentration of phenformin in subjects carrying hOCT2 variant may be higher compared to reference subjects, as reported in metformin. In addition, the relationship between plasma concentration of these biguanides and blood lactate level as well as the possible reasons for the difference in the associated frequency of occurrence of lactic acidosis are discussed. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Characterization of transparent dentin in attrited teeth using optical coherence tomography.

PubMed

Mandurah, Mona M; Sadr, Alireza; Bakhsh, Turki A; Shimada, Yasushi; Sumi, Yasunori; Tagami, Junji

2015-05-01

Attrition and wear of tooth surface occur with aging and result in loss of enamel, with exposure and histological changes in dentin. Dealing with attrited teeth and restoration of the lost tissue are clinically challenging. The main objective of this study is to characterize the exposed transparent dentin in the occlusal surface of attrited teeth by optical coherence tomography (OCT). Naturally attrited, extracted human teeth with occlusal-transparent dentin were investigated in comparison to sound and carious teeth. The teeth were subjected to OCT imaging and then cross-sectioned and polished. OCT B-scans were compared to light microscopy images of the same cross section. In OCT images, some changes were evident at the transparent dentin in attrited teeth. An OCT attenuation coefficient parameter (μ t) was derived based on the Beer-Lambert law as a function of backscatter signal slope. The mean values of μ t were 1.05 ± 0.3, 2.23 ± 0.4, and 0.61 ± 0.27 mm(-1) for sound, carious, and transparent dentins, respectively. One-way ANOVA with Tukey's post-hoc showed a significant difference between groups (p < 0.05). Physiological changes in transparent dentin that involve deposition of mineral casts in the dentinal tubules lead to lower attenuation of OCT signal. OCT has a potential role to detect transparent dentin on the surface of attrited teeth and can be used in the future as a clinical adjunct tool.

Real-time data processing for in-line monitoring of a pharmaceutical coating process by optical coherence tomography

NASA Astrophysics Data System (ADS)

Markl, Daniel; Ziegler, Jakob; Hannesschläger, Günther; Sacher, Stephan; Buchsbaum, Andreas; Leitner, Michael; Khinast, Johannes G.

2014-05-01

Coating of tablets is a widely applied unit operation in the pharmaceutical industry. Thickness and uniformity of the coating layer are crucial for efficacy as well as for compliance. Not only due to different initiatives it is thus essential to monitor and control the coating process in-line. Optical coherence tomography (OCT) was already shown in previous works to be a suitable candidate for in-line monitoring of coating processes. However, to utilize the full potential of the OCT technology an automatic evaluation of the OCT measurements is essential. The automatic evaluation is currently implemented in MATLAB and includes several steps: (1) extraction of features of each A-scan, (2) classification of Ascan measurements based on their features, (3) detection of interfaces (air/coating and coating/tablet core), (4) correction of distortions due to the curvature of the bi-convex tablets and the oblique orientation of the tablets, and (5) determining the coating thickness. The algorithm is tested on OCT data acquired by moving the sensor head of the OCT system across a static tablet bed. The coating thickness variations of single tablets (i.e., intra-tablet coating variability) can additionally be analyzed as OCT allows the measurement of the coating thickness on multiple displaced positions on one single tablet. Specifically, the information about those parameters emphasizes the high capability of the OCT technology to improve process understanding and to assure a high product quality.

Peri-strut low-intensity areas in optical coherence tomography correlate with peri-strut inflammation and neointimal proliferation: an in-vivo correlation study in the familial hypercholesterolemic coronary swine model of in-stent restenosis.

PubMed

Tellez, Armando; Afari, Maxwell E; Buszman, Piotr P; Seifert, Paul; Cheng, Yanping; Milewski, Krzysztof; McGregor, Jennifer C; Garza, Javier A; Roberts, Mary B; Yi, Geng Hua; Kaluza, Greg L; Granada, Juan F

2014-11-01

Peri-strut low-intensity area (PLI) is a common imaging finding during the evaluation of in-stent neointima using optical coherence tomography (OCT). We aimed to determine the biological significance of PLI by comparing in-vivo OCT images with the corresponding histological sections obtained from the familial hypercholesterolemic swine model of coronary stenosis. A total of 26 coronary vessels of nine familial hypercholesterolemic swine were injured with 30% balloon overstretch and then immediately followed by everolimus eluting or bare metal stent placement at 20% overstretch. At 30 days, all stented vessels were subjected to in-vivo OCT analysis and were harvested for histological evaluation. For OCT analysis, stent cross-sections (three per stent) were categorized into presence (PLI+) or absence (PLI-) of PLI. In histology, inflammation and fibrin deposition were scored semiquantitatively from 0 (none) to 3 (severe). PLI was found in 64.9% of stent sections. Peri-strut inflammation was more frequently observed in OCT sections PLI (+) compared with PLI (-) (56.0 vs. 7.4%, P=0.01). In contrast, peri-strut fibrin deposits was similar in both groups (PLI+=58.0% vs. PLI-=59.3%, P=0.94). Histological neointimal thickness was significantly higher in PLI (+) sections (mean±SE: 0.68±0.06 vs. 0.34±0.02 mm; P<0.01), yielding a higher percent area stenosis compared with PLI (-) (mean±SE: 59.0±4.4 vs. 34.1±2.2%, P<0.01). The PLI diagnostic sensitivity and specificity for inflammation were 80 and 76.1%, respectively (>56% PLI, area under the curve=0.86, P<0.01), whereas for fibrin deposition, the sensitivity and specificity were 42.2 and 76.1%, respectively (area under the curve=0.56, P=NS). Area under the receiver operating characteristic curve was significantly higher for identifying inflammation than fibrin (0.86 vs. 0.56, P<0.01). The severity of PLI correlated with the neointimal thickness when assessed by OCT (R=0.79, P<0.001). The presence of PLI in OCT correlates with neointimal thickness and appears to have a diagnostic value in the recognition of peri-strut inflammation, therefore possibly serving as a surrogate for in-vivo assessment of stent efficacy.

Tunable optical coherence tomography in the infrared range using visible photons

NASA Astrophysics Data System (ADS)

Paterova, Anna V.; Yang, Hongzhi; An, Chengwu; Kalashnikov, Dmitry A.; Krivitsky, Leonid A.

2018-04-01

Optical coherence tomography (OCT) is an appealing technique for bio-imaging, medicine, and material analysis. For many applications, OCT in mid- and far-infrared (IR) leads to significantly more accurate results. Reported mid-IR OCT systems require light sources and photodetectors which operate in mid-IR range. These devices are expensive and need cryogenic cooling. Here, we report a proof-of-concept demonstration of a wavelength tunable IR OCT technique with detection of only visible range photons. Our method is based on the nonlinear interference of frequency correlated photon pairs. The nonlinear crystal, introduced in the Michelson-type interferometer, generates photon pairs with one photon in the visible and another in the IR range. The intensity of detected visible photons depends on the phase and loss of IR photons, which interact with the sample under study. This enables us to characterize sample properties and perform imaging in the IR range by detecting visible photons. The technique possesses broad wavelength tunability and yields a fair axial and lateral resolution, which can be tailored to the specific application. The work contributes to the development of versatile 3D imaging and material characterization systems working in a broad range of IR wavelengths, which do not require the use of IR-range light sources and photodetectors.

Micromotor endoscope catheter for in vivo, ultrahigh-resolution optical coherence tomography

NASA Astrophysics Data System (ADS)

Herz, P. R.; Chen, Y.; Aguirre, A. D.; Schneider, K.; Hsiung, P.; Fujimoto, J. G.; Madden, K.; Schmitt, J.; Goodnow, J.; Petersen, C.

2004-10-01

A distally actuated, rotational-scanning micromotor endoscope catheter probe is demonstrated for ultrahigh-resolution in vivo endoscopic optical coherence tomography (OCT) imaging. The probe permits focus adjustment for visualization of tissue morphology at varying depths with improved transverse resolution compared with standard OCT imaging probes. The distal actuation avoids nonuniform scanning motion artifacts that are present with other probe designs and can permit a wider range of imaging speeds. Ultrahigh-resolution endoscopic imaging is demonstrated in a rabbit with <4-µm axial resolution by use of a femtosecond Crforsterite laser light source. The micromotor endoscope catheter probe promises to improve OCT imaging performance in future endoscopic imaging applications.

Super-achromatic microprobe for ultrahigh-resolution endoscopic OCT imaging at 800 nm (Conference Presentation)

NASA Astrophysics Data System (ADS)

Yuan, Wu; Alemohammad, Milad; Yu, Xiaoyun; Yu, Shaoyong; Li, Xingde

2016-03-01

In this paper, we report a super-achromatic microprobe made with fiber-optic ball lens to enable ultrahigh-resolution endoscopic OCT imaging. An axial resolution of ~2.4 µm (in air) can be achieved with a 7-fs Ti:Sapphire laser. The microprobe has minimal astigmatism which affords a high transverse resolution of ~5.6 µm. The miniaturized microprobe has an outer diameter of ~520 µm including the encasing metal guard and can be used to image small luminal organs. The performance of the ultrahigh-resolution OCT microprobe was demonstrated by imaging rat esophagus, guinea pig esophagus, and mouse rectum in vivo.

Intraretinal Correlates of Reticular Pseudodrusen Revealed by Autofluorescence and En Face OCT.

PubMed

Paavo, Maarjaliis; Lee, Winston; Merriam, John; Bearelly, Srilaxmi; Tsang, Stephen; Chang, Stanley; Sparrow, Janet R

2017-09-01

We sought to determine whether information revealed from the reflectance, autofluorescence, and absorption properties of RPE cells situated posterior to reticular pseudodrusen (RPD) could provide insight into the origins and structure of RPD. RPD were studied qualitatively by near-infrared fundus autofluorescence (NIR-AF), short-wavelength fundus autofluorescence (SW-AF), and infrared reflectance (IR-R) images, and the presentation was compared to horizontal and en face spectral domain optical coherence tomographic (SD-OCT) images. Images were acquired from 23 patients (39 eyes) diagnosed with RPD (mean age 80.7 ± 7.1 [SD]; 16 female; 4 Hispanics, 19 non-Hispanic whites). In SW-AF, NIR-AF, and IR-R images, fundus RPD were recognized as interlacing networks of small scale variations in IR-R and fluorescence (SW-AF, NIR-AF) intensities. Darkened foci of RPD colocalized in SW-AF and NIR-AF images, and in SD-OCT images corresponded to disturbances of the interdigitation (IZ) and ellipsoid (EZ) zones and to more pronounced hyperreflective lesions traversing photoreceptor-attributable bands in SD-OCT images. Qualitative assessment of the outer nuclear layer (ONL) revealed thinning as RPD extended radially from the outer to inner retina. In en face OCT, hyperreflective areas in the EZ band correlated topographically with hyporeflective foci at the level of the RPE. The hyperreflective lesions corresponding to RPD in SD-OCT scans are likely indicative of degenerating photoreceptor cells. The darkened foci at positions of RPD in NIR-AF and en face OCT images indicate changes in the RPE monolayer with the reduced NIR-AF and en face OCT signal suggesting a reduction in melanin that could be accounted for by RPE thinning.

Additive diagnostic role of imaging in glaucoma: optical coherence tomography and retinal nerve fiber layer photography.

PubMed

Kim, Ko Eun; Kim, Seok Hwan; Oh, Sohee; Jeoung, Jin Wook; Suh, Min Hee; Seo, Je Hyun; Kim, Martha; Park, Ki Ho; Kim, Dong Myung

2014-11-20

To investigate the additive diagnostic role of spectral-domain optical coherence tomography (SD-OCT) and red-free retinal nerve fiber layer photography (RNFLP) in making clinical glaucoma diagnosis. Four diagnostic combination sets, including the most recent image from each measurement of 196 glaucoma eyes (including the 44 preperimetric glaucoma eyes) and 101 healthy eyes, were prepared: (1) stereo disc photography and Humphrey visual field (SH), (2) SH and SD-OCT (SHO), (3) SH and RNFLP (SHR), and (4) SHR and SD-OCT (SHRO). Each randomly sorted set was serially presented at 1-month intervals to five glaucoma specialists who were asked to evaluate them in a subjective and independent manner. The specialists' glaucoma-diagnostic performances based on the sets were then compared. For each specialist, adding SD-OCT to SH or SHR increased the glaucoma-diagnostic sensitivity but not to a level of statistical significance. For one specialist, adding RNFLP to SH significantly increased the sensitivity. Each specialist showed a high level of specificity regardless of the diagnostic set. The overall sensitivity of all specialists' assessments was significantly increased by adding RNFLP or the combination of SD-OCT and RNFLP to SH (P < 0.001); however, adding SD-OCT to SH or SHR did not significantly increase the sensitivity. A similar relationship was noted also for the preperimetric glaucoma subgroup. In contrast to RNFLP, SD-OCT did not significantly enhance the diagnostic accuracy of detecting glaucoma or even of preperimetric glaucoma. Our results suggest that, at least for glaucoma specialists, the additive diagnostic role of OCT is limited. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

[Sensitivity and specificity of optical coherence tomography in diagnosing polypoidal choroidal vasculopathy].

PubMed

Zhang, Yi; Yao, Jing; Wang, Xiao-Hua; Zhao, Lin; Wang, Li-Jun; Wang, Jian-Ming; Zhou, Ai-Yi

2016-02-20

To establish the diagnostic criteria for polypoidal choroidal vasculopathy (PCV) based on spectral-domain optical coherence tomography (SD OCT) by evaluating the sensitivity and specificity of SD OCT in differentiating PCV from wet age-related macular degeneration (wAMD). The clinical data were reviewed for 62 patients (63 eyes) with the initial diagnosis of PCV or wAMD between August, 2012 and June, 2016. Twenty-four patients (25 eyes) were diagnosed to have PCV and 38 (38 eyes) had wAMD based on findings by fundus photography, fluorescein angiography (FFA) and indocyanine green angiography (ICGA). Among the 6 features of SD OCT, namely a sharp RPED peak, double-layer sign, multiple RPED, an RPED notch, a hyporeflective lumen representing polyps, and hyperreflective intraretinal hard exudates, findings of the first two features and at least one of the other features sufficed the diagnosis of PCV; in the absence of the first two features, the diagnosis of PCV was also made when at least 3 of the other features were present simultaneously. The sensitivity and specificity of SD OCT-based diagnosis were estimated by comparison with the gold standard ICGA-based diagnosis. In the 25 eyes with an established diagnosis of PCV, 23 eyes (92.0%) met the diagnostic criteria based on SD OCT findings; in the 38 eyes with the diagnosis of wAMD, only 4 eyes (10.5%) met the criteria. The sensitivity and specificity of SD OCT-based diagnosis of PCV was 92.0% and 89.5%, respectively. s We established the diagnostic criteria for PCV based on SD OCT findings with a high sensitivity and specificity. SD OCT shows a strong capacity for differentiating PCV from wAMD.

Non-invasive intraoperative optical coherence tomography of the resection cavity during surgery of intrinsic brain tumors

NASA Astrophysics Data System (ADS)

Giese, A.; Böhringer, H. J.; Leppert, J.; Kantelhardt, S. R.; Lankenau, E.; Koch, P.; Birngruber, R.; Hüttmann, G.

2006-02-01

Optical coherence tomography (OCT) is a non-invasive imaging technique with a micrometer resolution. It allows non-contact / non-invasive analysis of central nervous system tissues with a penetration depth of 1-3,5 mm reaching a spatial resolution of approximately 4-15 μm. We have adapted spectral-domain OCT (SD-OCT) and time-domain OCT (TD-OCT) for intraoperative detection of residual tumor during brain tumor surgery. Human brain tumor tissue and areas of the resection cavity were analyzed during the resection of gliomas using this new technology. The site of analysis was registered using a neuronavigation system and biopsies were taken and submitted to routine histology. We have used post image acquisition processing to compensate for movements of the brain and to realign A-scan images for calculation of a light attenuation factor. OCT imaging of normal cortex and white matter showed a typical light attenuation profile. Tumor tissue depending on the cellularity of the specimen showed a loss of the normal light attenuation profile resulting in altered light attenuation coefficients compared to normal brain. Based on this parameter and the microstructure of the tumor tissue, which was entirely absent in normal tissue, OCT analysis allowed the discrimination of normal brain tissue, invaded brain, solid tumor tissue, and necrosis. Following macroscopically complete resections OCT analysis of the resection cavity displayed the typical microstructure and light attenuation profile of tumor tissue in some specimens, which in routine histology contained microscopic residual tumor tissue. We have demonstrated that this technology may be applied to the intraoperative detection of residual tumor during resection of human gliomas.

Effect of treatment with depot somatostatin analogue octreotide on primary hyperparathyroidism (PHP) in multiple endocrine neoplasia type 1 (MEN1) patients.

PubMed

Faggiano, Antongiulio; Tavares, Lidice Brandao; Tauchmanova, Libuse; Milone, Francesco; Mansueto, Gelsomina; Ramundo, Valeria; De Caro, Maria Laura Del Basso; Lombardi, Gaetano; De Rosa, Gaetano; Colao, Annamaria

2008-11-01

In patients with multiple endocrine neoplasia type 1 (MEN1), expression of somatostatin receptor (SST) in parathyroid adenomas and effectiveness of therapy with somatostatin analogues on primary hyperparathyroidism (PHP) have been scarcely investigated. To evaluate the effects of depot long acting octreotide (OCT-LAR) in patients with MEN1-related PHP. Eight patients with a genetically confirmed MEN1, presenting both PHP and duodeno-pancreatic neuroendocrine tumours (NET), were enrolled. The initial treatment was OCT-LAR 30 mg every 4 weeks. This therapy was established to stabilize the duodeno-pancreatic NET before to perform parathyroidectomy for PHP. Before OCT-LAR therapy, a SST scintigraphy was performed in all patients. SST subtype 2A immunohistochemistry was performed on parathyroid tumour samples from three patients undergone parathyroidectomy after OCT-LAR therapy. Serum concentrations of PTH, calcium and phosphorus as well as the 24-h urine calcium : creatinine ratio and the renal threshold phosphate concentration were evaluated before and after OCT-LAR. After OCT-LAR therapy, hypercalcaemia and hypercalciuria normalized in 75% and 62.5% of patients, respectively, and serum phosphorus and renal threshold phosphate significantly increased. Serum PTH concentrations significantly decreased in all patients and normalized in two of them. SST subtype 2A immunostaining was found in all parathyroid adenomas investigated, while SST scintigraphy showed a positive parathyroid tumour uptake in three of eight patients (37.5%). Six months of OCT-LAR therapy controlled hypercalcaemia and hypercalciuria in two-thirds of patients with MEN1-related PHP. Direct OCT-LAR effects mediated by binding to SST expression on parathyroid tumour cells are likely the main mechanism to explain the activity of this compound on calcium and phosphorus abnormalities in MEN1 PHP.

A feedback loop comprising PRMT7 and miR-24-2 interplays with Oct4, Nanog, Klf4 and c-Myc to regulate stemness

PubMed Central

Lee, Sung-Hun; Chen, Tsai-Yu; Dhar, Shilpa S.; Gu, Bingnan; Chen, Kaifu; Kim, Young Zoon; Li, Wei; Lee, Min Gyu

2016-01-01

Self-renewal and pluripotency are two fundamental characteristics of embryonic stem cells (ESCs) and are controlled by diverse regulatory factors, including pluripotent factors, epigenetic regulators and microRNAs (miRNAs). Although histone methyltransferases are key epigenetic regulators, whether and how a histone methyltransferase forms a network with miRNAs and the core pluripotent factor system to regulate ESC stemness is little known. Here, we show that the protein arginine methyltransferase 7 (PRMT7) is a pluripotent factor essential for the stemness of mouse ESCs. PRMT7 repressed the miR-24-2 gene encoding miR-24-3p and miR-24-2-5p by upregulating the levels of symmetrically dimethylated H4R3. Notably, miR-24-3p targeted the 3′ untranslated regions (UTRs) of the major pluripotent factors Oct4, Nanog, Klf4 and c-Myc, whereas miR-24-2-5p silenced Klf4 and c-Myc expression. miR-24-3p and miR-24-2-5p also targeted the 3′UTR of their repressor gene Prmt7. miR-24-3p and miR-24-2-5p induced mouse ESC differentiation, and their anti-sense inhibitors substantially reversed spontaneous differentiation of PRMT7-depleted mouse ESCs. Oct4, Nanog, Klf4 and c-Myc positively regulated Prmt7 expression. These findings define miR-24-3p and miR-24-2-5p as new anti-pluripotent miRNAs and also reveal a novel epigenetic stemness-regulatory mechanism in which a double-negative feedback loop consisting of PRMT7 and miR-24-3p/miR24-2-5p interplays with Oct4, Nanog, Klf4 and c-Myc to control ESC stemness. PMID:27625395

A feedback loop comprising PRMT7 and miR-24-2 interplays with Oct4, Nanog, Klf4 and c-Myc to regulate stemness.

PubMed

Lee, Sung-Hun; Chen, Tsai-Yu; Dhar, Shilpa S; Gu, Bingnan; Chen, Kaifu; Kim, Young Zoon; Li, Wei; Lee, Min Gyu

2016-12-15

Self-renewal and pluripotency are two fundamental characteristics of embryonic stem cells (ESCs) and are controlled by diverse regulatory factors, including pluripotent factors, epigenetic regulators and microRNAs (miRNAs). Although histone methyltransferases are key epigenetic regulators, whether and how a histone methyltransferase forms a network with miRNAs and the core pluripotent factor system to regulate ESC stemness is little known. Here, we show that the protein arginine methyltransferase 7 (PRMT7) is a pluripotent factor essential for the stemness of mouse ESCs. PRMT7 repressed the miR-24-2 gene encoding miR-24-3p and miR-24-2-5p by upregulating the levels of symmetrically dimethylated H4R3. Notably, miR-24-3p targeted the 3' untranslated regions (UTRs) of the major pluripotent factors Oct4, Nanog, Klf4 and c-Myc, whereas miR-24-2-5p silenced Klf4 and c-Myc expression. miR-24-3p and miR-24-2-5p also targeted the 3'UTR of their repressor gene Prmt7 miR-24-3p and miR-24-2-5p induced mouse ESC differentiation, and their anti-sense inhibitors substantially reversed spontaneous differentiation of PRMT7-depleted mouse ESCs. Oct4, Nanog, Klf4 and c-Myc positively regulated Prmt7 expression. These findings define miR-24-3p and miR-24-2-5p as new anti-pluripotent miRNAs and also reveal a novel epigenetic stemness-regulatory mechanism in which a double-negative feedback loop consisting of PRMT7 and miR-24-3p/miR24-2-5p interplays with Oct4, Nanog, Klf4 and c-Myc to control ESC stemness. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

Spectral domain optical coherence tomography and fundus autofluorescence findings in cytomegalovirus retinitis in HIV-infected patients.

PubMed

Yashiro, Shigeko; Nishijima, Takeshi; Yamamoto, Yuuka; Sekine, Yumi; Yoshida-Hata, Natsuyo; Iida, Tomohiro; Oka, Shinichi

2018-05-01

To assess the usefulness of spectral domain optical coherence tomography (SD-OCT) and fundus autofluorescence (FAF) findings in cytomegalovirus (CMV) retinitis. Observational case series. Thirteen eyes of 11 human immunodeficiency virus (HIV)-positive patients with CMV retinitis underwent full ophthalmologic examinations, SD-OCT, and 4 eyes of 4 patients underwent FAF. FAF images included short-wavelength autofluorescence (SW-AF) and near-infrared autofluorescence (IR-AF). CMV retinitis was classified into proposed categories of acute, subacute, remission, and recurrent; the acute stage was further subdivided into initial, early, and late stages. In the initial stage, vertical structural disruption of all retinal layers was observed by SD-OCT, and FAF showed hyperautofluorescence on SW-AF and hypoautofluorescence on IR-AF. In the early stage, SD-OCT showed significant retinal thickening; cells and debris from the retinal surface to the vitreous; enlarged vessels with/without thickened vessel walls; and highly complicated serous retinal detachment. In the late to subacute stage, features observed included rhegmatogenous retinal detachment with shrinking posterior hyaloid membrane and waving from the ellipsoid zone to the retinal pigment epithelium. In remission, FAF findings were hypoautofluorescence on SW-AF and hyperautofluorescence on IR-AF. Although the number of examined eyes was limited, SD-OCT and FAF provide new information in various stages of CMV retinitis in patients with HIV infection that is not obtainable by conventional examination and which may be of great benefit when screening for the initial stage of CMV retinitis.

Development of a high-speed VCSEL OCT system for real-time imaging of conscious patients larynx using a hand-held probe (Conference Presentation)

NASA Astrophysics Data System (ADS)

Rangarajan, Swathi; Chou, Li-Dek; Coughlan, Carolyn; Sharma, Giriraj; Wong, Brian J. F.; Ramalingam, Tirunelveli S.

2016-02-01

Fourier domain optical coherence tomography (FD-OCT) is a noninvasive imaging modality that has previously been used to image the human larynx. However, differences in anatomical geometry and short imaging range of conventional OCT limits its application in a clinical setting. In order to address this issue, we have developed a gradient-index (GRIN) lens rod-based hand-held probe in conjunction with a long imaging range 200 kHz Vertical-Cavity Surface Emitting Lasers (VCSEL) swept-source optical coherence tomography (SS-OCT) system for high speed real-time imaging of the human larynx in an office setting. This hand-held probe is designed to have a long and dynamically tunable working distance to accommodate the differences in anatomical geometry of human test subjects. A nominal working distance (~6 cm) of the probe is selected to have a lateral resolution <100 um within a depth of focus of 6.4 mm, which covers more than half of the 12 mm imaging range of the VCSEL laser. The maximum lateral scanning range of the probe at 6 cm working distance is approximately 8.4 mm, and imaging an area of 8.5 mm by 8.5 mm is accomplished within a second. Using the above system, we will demonstrate real-time cross-sectional OCT imaging of larynx during phonation in vivo in human and ex-vivo in pig vocal folds.

Mitigation of enamel erosion using commercial toothpastes evaluated with optical coherence tomography

NASA Astrophysics Data System (ADS)

Cassimiro-Silva, Patricia Fernandes; Maia, Ana Marly Araújo; Monteiro, Gabriela Queiroz de Melo; Gomes, Anderson S. L.

2016-03-01

The aim of this study was to evaluate the efficacy of commercial toothpastes containing sodium fluoride (NaF), stannous fluoride (SnF2), or casein phosphopeptides (CPP)-amorphous calcium phosphate (ACP)/NaF regarding their potential to inhibit enamel erosion. Twenty-eight 4×4 mm enamel specimens were randomly allocated into 4 groups (n=7): negative control; Pronamel (NaF); Pro Health (SnF2/NaF); Mi Paste Plus (CPP-ACP/NaF). Erosive cycles with 0.5% citric acid, 5 times, 3 minutes/day for 7 days were performed. After the first and last cycle of each day, toothpaste slurries were applied for 2 min. The quantitative analysis was accomplished using Contact Profilometry and Optical Coherence Tomography (OCT), complemented by roughness and qualitative scanning electron microscopy (SEM) analysis. OCT and Profilometry analysis showed similar effectiveness in measuring the reduction of mineral loss. A significant increase in the mean roughness values was observed on eroded surface and also on treated surface as revealed by scanning electron microscopy. The use of SnF2/NaF toothpaste was the most effective method for reducing mineral loss. As quantitative methods, OCT and Contact Profilometry showed no statistical differences. OCT, which was used for this purpose for the first time, has the advantage of being noninvasive, and therefore have the potential for clinical application.

Dual-wavelength multifrequency photothermal wave imaging combined with optical coherence tomography for macrophage and lipid detection in atherosclerotic plaques using gold nanoparticles

PubMed Central

Wang, Tianyi; Jacob Mancuso, J.; Sapozhnikova, Veronika; Dwelle, Jordan; Ma, Li L.; Willsey, Brian; Shams Kazmi, S. M.; Qiu, Jinze; Li, Xiankai; Asmis, Reto; Johnston, Keith P.; Feldman, Marc D.

2012-01-01

Abstract. The objective of this study was to assess the ability of combined photothermal wave (PTW) imaging and optical coherence tomography (OCT) to detect, and further characterize the distribution of macrophages (having taken up plasmonic gold nanorose as a contrast agent) and lipid deposits in atherosclerotic plaques. Aortas with atherosclerotic plaques were harvested from nine male New Zealand white rabbits divided into nanorose- and saline-injected groups and were imaged by dual-wavelength (800 and 1210 nm) multifrequency (0.1, 1 and 4 Hz) PTW imaging in combination with OCT. Amplitude PTW images suggest that lateral and depth distribution of nanorose-loaded macrophages (confirmed by two-photon luminescence microscopy and RAM-11 macrophage stain) and lipid deposits can be identified at selected modulation frequencies. Radiometric temperature increase and modulation amplitude of superficial nanoroses in response to 4 Hz laser irradiation (800 nm) were significantly higher than native plaque (P<0.001). Amplitude PTW images (4 Hz) were merged into a coregistered OCT image, suggesting that superficial nanorose-loaded macrophages are distributed at shoulders on the upstream side of atherosclerotic plaques (P<0.001) at edges of lipid deposits. Results suggest that combined PTW-OCT imaging can simultaneously reveal plaque structure and composition, permitting characterization of nanorose-loaded macrophages and lipid deposits in atherosclerotic plaques. PMID:22502567

Is high pressure postdilation safe in bioresorbable vascular scaffolds? Optical coherence tomography observations after noncompliant balloons inflated at more than 24 atmospheres.

PubMed

Fabris, Enrico; Caiazzo, Gianluca; Kilic, Ismail Dogu; Serdoz, Roberta; Secco, Gioel Gabrio; Sinagra, Gianfranco; Lee, Renick; Foin, Nicolas; Di Mario, Carlo

2016-04-01

Optical coherence tomography (OCT) was used to investigate integrity and expansion of bioresorbable drug-eluting scaffolds (BVS) after high-pressure postdilation (HPPD). Because of concerns about the risk of BVS damage, postdilation was not recommended and applied in the existing randomized studies and most registries. Recent real world data suggest incomplete BVS expansion cause higher rates of thrombosis. In vivo confirmation of the safety of high pressure postdilation is of paramount importance. Data from final OCT examination of consecutive implanted BVS, postdilated with noncompliant (NC) balloons at pressure ≥24 atm were analyzed. The following stent performance indices were assessed with OCT: mean and minimal lumen and scaffold area, residual area stenosis (RAS), incomplete strut apposition (ISA), tissue prolapse, eccentricity index (EI), symmetry index (SI), strut fractures, and edge dissections. Twenty-two BVS postdilated at high pressure were analyzed. The average maximal postdilation balloon inflation (maxPD) was 28 ± 3 atm. High pressure OPN NC Balloon (SIS Medical AG, Winterthur Switzerland) was used in 41% of postdilations with a maximal PD of 30 ± 4.7 atm. Final mean and minimal lumen area were 6.8 ± 1.4 and 5.5 ± 1.4 mm(2) , respectively. OCT showed low percentage of RAS (16 ± 9.6%), and low percentage of ISA (1.8 ± 2.4%). Mean EI was 0.86 ± 0.02 and SI 0.35 ± 0.14. OCT analysis showed one edge dissection and no scaffold fractures. BVS deployment optimization using HPPD does not cause BVS disruption and is associated with a good BVS expansion, low rate of strut malapposition and edge dissections. © 2015 Wiley Periodicals, Inc.

Tri-band optical coherence tomography for lipid and vessel spectroscopic imaging

NASA Astrophysics Data System (ADS)

Yu, Luoqin; Kang, Jiqiang; Wang, Xie; Wei, Xiaoming; Chan, Kin-Tak; Lee, Nikki P.; Wong, Kenneth K. Y.

2016-03-01

Optical coherence tomography (OCT) has been utilized for various functional imaging applications. One of its highlights comes from spectroscopic imaging, which can simultaneously obtain both morphologic and spectroscopic information. Assisting diagnosis and therapeutic intervention of coronary artery disease is one of the major directions in spectroscopic OCT applications. Previously Tanaka et al. have developed a spectral domain OCT (SDOCT) to image lipid distribution within blood vessel [1]. In the meantime, Fleming et al. have demonstrated optical frequency domain imaging (OFDI) by a 1.3-μm swept source and quadratic discriminant analysis model [2]. However, these systems suffered from burdensome computation as the optical properties' variation was calculated from a single-band illumination that provided limited contrast. On the other hand, multi-band OCT facilitates contrast enhancement with separated wavelength bands, which further offers an easier way to distinguish different materials. Federici and Dubois [3] and Tsai and Chan [4] have demonstrated tri-band OCT systems to further enhance the image contrast. However, these previous work provided under-explored functional properties. Our group has reported a dual-band OCT system based on parametrically amplified Fourier domain mode-locked (FDML) laser with time multiplexing scheme [5] and a dual-band FDML laser OCT system with wavelength-division multiplexing [6]. Fiber optical parametric amplifier (OPA) can be ideally incorporated in multi-band spectroscopic OCT system as it has a broad amplification window and offers an additional output range at idler band, which is phase matched with the signal band. The sweeping ranges can thus overcome traditional wavelength bands that are limited by intra-cavity amplifiers in FDML lasers. Here, we combines the dual-band FDML laser together with fiber OPA, which consequently renders a simultaneous tri-band output at 1.3, 1.5, and 1.6 μm, for intravascular applications. Lipid and blood vessel distribution can be subsequently visualized with the tri-band OCT system by ex vivo experiments using porcine artery model with artificial lipid plaques.

Assessment of simulated lesions on primary teeth with near-infrared imaging

NASA Astrophysics Data System (ADS)

Tam, Wilson; Lee, Robert C.; Lin, Brent; Simon, Jacob C.; Fried, Daniel

2016-02-01

Previous studies have demonstrated that the structural changes on enamel due to demineralization and remineralization can be exploited through optical imaging methods such as QLF, thermal and NIR imaging. The purpose of this study is to investigate whether PS-OCT and NIR reflectance imaging can be utilized to assess lesion structure in artificial enamel lesions on the smooth surfaces of primary teeth exposed to fluoride. The smooth coronal surfaces of primary teeth (n=25) were divided into 4 windows: sound, demineralization, demineralization with remineralization and APF with demineralization. Windows were treated with either acidulated phosphate fluoride (APF) for 1 minute, a demineralization solution for 4 days, and/or an acidic remineralization solution for 12 days. The samples were imaged using PS-OCT, QLF and NIR reflectance at 1400-1700 nm wavelengths. This study demonstrated that both PS-OCT and NIR reflectance imaging were suitable for assessing lesion structure in the smooth surfaces of primary dentition.

Assessment of simulated lesions on primary teeth with near-infrared imaging.

PubMed

Tam, Wilson; Lee, Robert C; Lin, Brent; Simon, Jacob C; Fried, Daniel

2016-02-13

Previous studies have demonstrated that the structural changes on enamel due to demineralization and remineralization can be exploited through optical imaging methods such as QLF, thermal and NIR imaging. The purpose of this study is to investigate whether PS-OCT and NIR reflectance imaging can be utilized to assess lesion structure in artificial enamel lesions on the smooth surfaces of primary teeth exposed to fluoride. The smooth coronal surfaces of primary teeth (n=25) were divided into 4 windows: sound, demineralization, demineralization with remineralization and APF with demineralization. Windows were treated with either acidulated phosphate fluoride (APF) for 1 minute, a demineralization solution for 4 days, and/or an acidic remineralization solution for 12 days. The samples were imaged using PS-OCT, QLF and NIR reflectance at 1400-1700 nm wavelengths. This study demonstrated that both PS-OCT and NIR reflectance imaging were suitable for assessing lesion structure in the smooth surfaces of primary dentition.

JEMRMS Small Satellite Deployment Observation

NASA Image and Video Library

2012-10-04

ISS033-E-009334 (4 Oct. 2012) --- Several tiny satellites are featured in this image photographed by an Expedition 33 crew member on the International Space Station. The satellites were released outside the Kibo laboratory using a Small Satellite Orbital Deployer attached to the Japanese module’s robotic arm on Oct. 4, 2012. Japan Aerospace Exploration Agency astronaut Aki Hoshide, flight engineer, set up the satellite deployment gear inside the lab and placed it in the Kibo airlock. The Japanese robotic arm then grappled the deployment system and its satellites from the airlock for deployment.

JEMRMS Small Satellite Deployment Observation

NASA Image and Video Library

2012-10-04

ISS033-E-009458 (4 Oct. 2012) --- Several tiny satellites are featured in this image photographed by an Expedition 33 crew member on the International Space Station. The satellites were released outside the Kibo laboratory using a Small Satellite Orbital Deployer attached to the Japanese module’s robotic arm on Oct. 4, 2012. Japan Aerospace Exploration Agency astronaut Aki Hoshide, flight engineer, set up the satellite deployment gear inside the lab and placed it in the Kibo airlock. The Japanese robotic arm then grappled the deployment system and its satellites from the airlock for deployment.

SSOD on JEM RMS

NASA Image and Video Library

2012-10-04

ISS033-E-009269 (4 Oct. 2012) --- A Small Satellite Orbital Deployer (SSOD) attached to the Japanese module’s robotic arm is featured in this image photographed by an Expedition 33 crew member on the International Space Station. Several tiny satellites were released outside the Kibo laboratory using the SSOD on Oct. 4, 2012. Japan Aerospace Exploration Agency astronaut Aki Hoshide, flight engineer, set up the satellite deployment gear inside the lab and placed it in the Kibo airlock. The Japanese robotic arm then grappled the deployment system and its satellites from the airlock for deployment.

Assessment of a new biomimetic scaffold and its effects on bone formation by OCT

NASA Astrophysics Data System (ADS)

Yang, Ying; Aydin, Halil M.; Piskin, Erhan; El Haj, Alicia J.

2009-02-01

The ultimate target of bone tissue engineering is to generate functional load bearing bone. By nature, the porous volume in the trabecular bone is occupied by osseous medulla. The natural bone matrix consists of hydroxyapatite (HA) crystals precipitated along the collagen type I fibres. The mineral phase renders bone strength while collagen provides flexibility. Without mineral component, bone is very flexible and can not bear loads, whereas it is brittle in the case of mineral phase without the collagen presence. In this study, we designed and prepared a new type of scaffold which mimics the features of natural bone. The scaffold consists of three different components, a biphasic polymeric base composed of two different biodegradable polymers prepared by using dual porogen approach and bioactive agents, i.e., collagen and HA particles which are distributed throughout the matrix only in the pore surfaces. Interaction of the bioactive scaffolds possessing very high porosity and interconnected pore structures with cells were investigated in a prolonged culture period by using an osteoblastic cell line. The mineral HA particles have a slight different refractive index from the other elements such as polymeric scaffolds and cell/matrix in a tissue engineering constructs, exhibiting brighter images in OCT. Thus, OCT renders a convenient means to assess the morphology and architecture of the blank biomimetic scaffolds. This study also takes a close observation of OCT images for the cultured cell-scaffold constructs in order to assess neo-formed minerals and matrix. The OCT assessments have been compared with the results from confocal and SEM analysis.

In vivo μOCT imaging of the airways(Conference Presentation)

NASA Astrophysics Data System (ADS)

Leung, Hui Min; Yonker, Lael M.; Mou, Hongmei; Som, Avira; Hurley, Bryan P.; Tearney, Guillermo J.

2017-04-01

Chronic dysregulated influx of neutrophil into the airway increases neutrophil burden and augments the inflammatory processes often observed in diseases such as cystic fibrosis. The quantification of neutrophil influx is often accomplished with the use of destructive tests such as imaging cytometry and myeloperoxidase assay. However, those methods are unable to capture information about the cascade of events that precede trans-epithelium migration. In this work, we employed a high resolution micro-optical coherence tomography (µOCT) technology to perform real time imaging of neutrophil activity across airway epithelial cells grown on the underside of Transwell permeable supports. This inverted configuration allows the creation of an air-liquid interface at the apical side of the cells. The µOCT imaging technology, based on the principles of spectral-domain OCT, has a lateral and axial resolution of 2 and 1.3µm, respectively. In addition, it has an axial range of approximately 300µm and is capable of recording cross-sectional images at 40 fps. By raster scanning the illumination beam, the behavior of the neutrophils across a 3D volume can be recorded over time. Thus, this imaging modality is capable of resolving individual neutrophils and, potentially, capturing the cascading events involving neutrophil tethering, subsequent adhesion to activated epithelial cells and the ultimate passage through the epithelial cells to the air space on the apical side. As a result, not only can the amount of neutrophil migration be quantified, how neutrophils behave, organize and interact with the epithelial cells and each other can also be more closely analyzed by µOCT imaging.

Massively parallel simulator of optical coherence tomography of inhomogeneous turbid media.

PubMed

Malektaji, Siavash; Lima, Ivan T; Escobar I, Mauricio R; Sherif, Sherif S

2017-10-01

An accurate and practical simulator for Optical Coherence Tomography (OCT) could be an important tool to study the underlying physical phenomena in OCT such as multiple light scattering. Recently, many researchers have investigated simulation of OCT of turbid media, e.g., tissue, using Monte Carlo methods. The main drawback of these earlier simulators is the long computational time required to produce accurate results. We developed a massively parallel simulator of OCT of inhomogeneous turbid media that obtains both Class I diffusive reflectivity, due to ballistic and quasi-ballistic scattered photons, and Class II diffusive reflectivity due to multiply scattered photons. This Monte Carlo-based simulator is implemented on graphic processing units (GPUs), using the Compute Unified Device Architecture (CUDA) platform and programming model, to exploit the parallel nature of propagation of photons in tissue. It models an arbitrary shaped sample medium as a tetrahedron-based mesh and uses an advanced importance sampling scheme. This new simulator speeds up simulations of OCT of inhomogeneous turbid media by about two orders of magnitude. To demonstrate this result, we have compared the computation times of our new parallel simulator and its serial counterpart using two samples of inhomogeneous turbid media. We have shown that our parallel implementation reduced simulation time of OCT of the first sample medium from 407 min to 92 min by using a single GPU card, to 12 min by using 8 GPU cards and to 7 min by using 16 GPU cards. For the second sample medium, the OCT simulation time was reduced from 209 h to 35.6 h by using a single GPU card, and to 4.65 h by using 8 GPU cards, and to only 2 h by using 16 GPU cards. Therefore our new parallel simulator is considerably more practical to use than its central processing unit (CPU)-based counterpart. Our new parallel OCT simulator could be a practical tool to study the different physical phenomena underlying OCT, or to design OCT systems with improved performance. Copyright © 2017 Elsevier B.V. All rights reserved.

KLF4 Nuclear Export Requires ERK Activation and Initiates Exit from Naive Pluripotency.

PubMed

Dhaliwal, Navroop K; Miri, Kamelia; Davidson, Scott; Tamim El Jarkass, Hala; Mitchell, Jennifer A

2018-04-10

Cooperative action of a transcription factor complex containing OCT4, SOX2, NANOG, and KLF4 maintains the naive pluripotent state; however, less is known about the mechanisms that disrupt this complex, initiating exit from pluripotency. We show that, as embryonic stem cells (ESCs) exit pluripotency, KLF4 protein is exported from the nucleus causing rapid decline in Nanog and Klf4 transcription; as a result, KLF4 is the first pluripotency transcription factor removed from transcription-associated complexes during differentiation. KLF4 nuclear export requires ERK activation, and phosphorylation of KLF4 by ERK initiates interaction of KLF4 with nuclear export factor XPO1, leading to KLF4 export. Mutation of the ERK phosphorylation site in KLF4 (S132) blocks KLF4 nuclear export, the decline in Nanog, Klf4, and Sox2 mRNA, and differentiation. These findings demonstrate that relocalization of KLF4 to the cytoplasm is a critical first step in exit from the naive pluripotent state and initiation of ESC differentiation. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

The functional performance of microencapsulated human pancreatic islet-derived precursor cells.

PubMed

Montanucci, Pia; Pennoni, Ilaria; Pescara, Teresa; Blasi, Paolo; Bistoni, Giovanni; Basta, Giuseppe; Calafiore, Riccardo

2011-12-01

We have examined long-term cultured, human islet-derived stem/precursor cells (hIPC). Whole human islets (HI) were obtained by multi-enzymatic digestion of cadaveric donor pancreases, plated on tissue flasks, and allowed to adhere and expand for several in vitro passages, in order to obtain hIPC. We detected specific stem cell markers (Oct-4, Sox-2, Nanog, ABCG2, Klf-4, CD117) in both intact HI and hIPC. Moreover, hIPC while retaining the expression of Glut-2, Pdx-1, CK-19, and ICA-512, started re-expressing Ngn3, thereby indicating acquisition of a specific pancreatic islet beta cell-oriented phenotype identity. The intrinsic plasticity of hIPC was documented by their ability to differentiate into various germ layer-derived cell phenotypes (ie, osteocytic, adipocytic and neural), including endocrine cells associated with insulin secretory capacity. To render hIPC suitable for transplantation we have enveloped them within our highly purified, alginate-based microcapsules. Upon intraperitoneal graft in NOD/SCID mice we have observed that the microcapsules acted as three-dimensional niches favouring post-transplant hIPC differentiation and acquisition of beta cell-like functional competence. Copyright © 2011 Elsevier Ltd. All rights reserved.

Comparison of Central Corneal Thickness Between Fourier-Domain OCT, Very High-Frequency Digital Ultrasound, and Scheimpflug Imaging Systems.

PubMed

Yap, Timothy E; Archer, Timothy J; Gobbe, Marine; Reinstein, Dan Z

2016-02-01

To compare corneal thickness measurements between three imaging systems. In this retrospective study of 81 virgin and 58 post-laser refractive surgery corneas, central and minimum corneal thickness were measured using optical coherence tomography (OCT), very high-frequency digital ultrasound (VHF digital ultrasound), and a Scheimpflug imaging system. Agreement between methods was analyzed using mean differences (bias) (OCT - VHF digital ultrasound, OCT - Scheimpflug, VHF digital ultrasound - Scheimpflug) and Bland-Altman analysis with 95% limits of agreement (LoA). Virgin cornea mean central corneal thickness was 508.3 ± 33.2 µm (range: 434 to 588 µm) for OCT, 512.7 ± 32.2 µm (range: 440 to 587 µm) for VHF digital ultrasound, and 530.2 ± 32.6 µm (range: 463 to 612 µm) for Scheimpflug imaging. OCT and VHF digital ultrasound showed the closest agreement with a bias of -4.37 µm, 95% LoA ±12.6 µm. Least agreement was between OCT and Scheimpflug imaging with a bias of -21.9 µm, 95% LoA ±20.7 µm. Bias between VHF digital ultrasound and Scheimpflug imaging was -17.5 µm, 95% LoA ±19.0 µm. In post-laser refractive surgery corneas, mean central corneal thickness was 417.9 ± 47.1 µm (range: 342 to 557 µm) for OCT, 426.3 ± 47.1 µm (range: 363 to 563 µm) for VHF digital ultrasound, and 437.0 ± 48.5 µm (range: 359 to 571 µm) for Scheimpflug imaging. Closest agreement was between OCT and VHF digital ultrasound with a bias of -8.45 µm, 95% LoA ±13.2 µm. Least agreement was between OCT and Scheimpflug imaging with a bias of -19.2 µm, 95% LoA ±19.2 µm. Bias between VHF digital ultrasound and Scheimpflug imaging was -10.7 µm, 95% LoA ±20.0 µm. No relationship was observed between difference in central corneal thickness measurements and mean central corneal thickness. Results were similar for minimum corneal thickness. Central and minimum corneal thickness was measured thinnest by OCT and thickest by Scheimpflug imaging in both groups. A clinically significant bias existed between Scheimpflug imaging and the other two modalities. Copyright 2016, SLACK Incorporated.

Atmospheric Electricity and Tethered Aerostats, Volume 2

DTIC Science & Technology

1976-05-11

vs Altitude (Non- conducting or Conducting Tethers...Effect of Corona Charge Plume 15 3.1 Tether Current vs Balloon Altitude , BJ+3 - 25 Sep 73 20 3.2 Tether Current vs Balloon Altitude , Baldy - 17 Oct 73 21...3.3 Tether Current vs Balloon Altitude , Baldy - 31 Oct 73 22 3.4 Tether Current vs Balloon Altitude , Baldy - 2 Nov 73 23 3.5 Tether Current vs

Echo the Bat and the Pigeon Adventure

NASA Technical Reports Server (NTRS)

Butcher, Ginger

2000-01-01

A multimedia, CD ROM to teach 2nd graders about remote sensing was created and developed into a web site. Distribution was expanded for Grades K-4 or 5-8. The idea was to have a story introduction, interactive story and a teacher's website. Interactive Multimedia Adventures in Grade School Education using Remote Sensing (I.M.A.G.E.R.S.) was created. The lessons are easy to use, readily available and aligned with national standards. This resource combines hands-on activities with an interactive web site

Satellite Eyes First Major Atlantic Hurricane in 3 Years: Gonzalo

NASA Image and Video Library

2014-10-15

Hurricane Gonzalo has made the jump to major hurricane status and on Oct. 15 was a Category 4 storm on the Saffir-Simpson Hurricane Scale. NOAA's GOES-East satellite provided imagery of the storm. According to the National Hurricane Center, Gonzalo is the first category 4 hurricane in the Atlantic basin since Ophelia in 2011. NOAA's GOES-East satellite provides visible and infrared images of weather from its orbit in a fixed position over the Earth. On Oct. 15 at 15:15 UTC (11:15 a.m. EDT) GOES saw Gonzalo had tightly wrapped bands of thunderstorms spiraling into the center of its circulation. The eye of the storm was obscured by high clouds in the image. NOAA aircraft data and microwave images clearly show concentric eyewalls, with the inner radius of maximum winds now only about 4-5 nautical miles from the center. NOAA manages the GOES satellites, while NASA/NOAA's GOES Project at NASA's Goddard Space Flight Center in Greenbelt, Maryland created the image. The NASA/NOAA GOES Project creates images and animations from GOES data. At 11 a.m. EDT on Oct. 15, Gonzalo's maximum sustained winds increased to near 130 mph (215 kph) and the National Hurricane Center (NHC) noted that fluctuations in intensity are expected over the next couple of days. Gonzalo's cloud-covered eye was located near latitude 23.5 north and longitude 68.0 west, about 640 miles (1,025 km) south-southwest of Bermuda. Gonzalo is moving toward the northwest near 12 mph (19 kph). The minimum central pressure recently reported by an air force reconnaissance aircraft was 949 millibars. Tropical storm conditions are possible in Bermuda by late Thursday night, Oct. 16, and hurricane conditions are possible over Bermuda on Friday Oct. 16. Ocean swells however, will be felt over a much larger area, reached the U.S. east coast on Oct. 16. Large swells generated by Gonzalo are affecting portions of the Virgin Islands, the northern coasts of Puerto Rico and the Dominican Republic and portions of the Bahamas. Swells will reach much of the east coast of the United States and Bermuda on Thursday. By late Oct. 16, Gonzalo is expected to turn to the northeast and the center is expected to approach Bermuda sometime on Oct. 17. Credit: NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Variations in retinal nerve fiber layer measurements on optical coherence tomography after implantation of trifocal intraocular lens.

PubMed

García-Bella, Javier; Martínez de la Casa, José M; Talavero González, Paula; Fernández-Vigo, José I; Valcarce Rial, Laura; García-Feijóo, Julián

2018-01-01

To establish the changes produced after implantation of a trifocal intraocular lens (IOL) on retinal nerve fiber layer measurements performed with Fourier-domain optical coherence tomography (OCT). This prospective study included 100 eyes of 50 patients with bilateral cataract in surgical range, no other associated ocular involvement, refractive errors between +5 and -5 spherical diopters, and less than 1.5 D of corneal astigmatism. The eyes were operated by phacoemulsification with implantation of 2 different trifocal IOLs (FineVision and AT LISA tri 839MP) in randomized equal groups. Cirrus OCT and Spectralis OCT were performed before surgery and 3 months later. Both analyzed the thickness of the nerve fiber layer and thickness divided by quadrants (6 in case of Spectralis and 4 in case of Cirrus HD). The mean age of patients was 67.5 ± 5.8 years. The global nerve fiber layer thickness measured with Spectralis OCT was 96.77 μm before surgery and 99.55 μm after. With Cirrus OCT, the global thickness was 85.29 μm before surgery and 89.77 μm after. Statistically significant differences in global thickness measurements between preimplantation and postimplantation of the IOL were found with both OCT in the 2 groups. Statistically significant differences were also found in temporal and superior quadrants. The implantation of a diffractive trifocal IOL alters the results of the optic nerve fiber layer on Fourier-domain OCT in these patients, which should be taken into account in the posterior study of these patients.

In vivo layer visualization of rat olfactory bulb by a swept source optical coherence tomography and its confirmation through electrocoagulation and anatomy

PubMed Central

Watanabe, Hideyuki; Rajagopalan, Uma Maheswari; Nakamichi, Yu; Igarashi, Kei M.; Madjarova, Violeta Dimitrova; Kadono, Hirofumi; Tanifuji, Manabu

2011-01-01

Here, we report in vivo 3-D visualization of the layered organization of a rat olfactory bulb (OB) by a swept source optical coherence tomography (SS-OCT). The SS-OCT operates at a wavelength of 1334 nm with respective theoretical depth and lateral resolutions of 6.7 μm and 15.4 μm in air and hence it is possible to get a 3D structural map of OB in vivo at the micron level resolution with millimeter-scale imaging depth. Up until now, with methods such as MRI, confocal microscopy, OB depth structure in vivo had not been clearly visualized as these do not satisfy the criterion of simultaneously providing micron-scale spatial resolution and imaging up to a few millimeter in depth. In order to confirm the OB’s layered organization revealed by SS-OCT, we introduced the technique of electrocoagulation to make landmarks across the layered structure. To our knowledge this is such a first study that combines electrocoagulation and OCT in vivo of rat OB. Our results confirmed the layered organization of OB, and moreover the layers were clearly identified by electrocoagulation landmarks both in the OCT structural and anatomical slice images. We expect such a combined study is beneficial for both OCT and neuroscience fields. PMID:21833364

Different foveal schisis patterns in each retinal layer in eyes with hereditary juvenile retinoschisis evaluated by en-face optical coherence tomography.

PubMed

Yoshida-Uemura, Tomoyo; Katagiri, Satoshi; Yokoi, Tadashi; Nishina, Sachiko; Azuma, Noriyuki

2017-04-01

To analyze the structures of schisis in eyes with hereditary juvenile retinoschisis using en-face optical coherence tomography (OCT) imaging. In this retrospective observational study, we reviewed the medical records of patients with hereditary juvenile retinoschisis who underwent comprehensive ophthalmic examinations including swept-source OCT. OCT images were obtained from 16 eyes of nine boys (mean age ± standard deviation, 10.6 ± 4.0 years). The horizontal OCT images at the fovea showed inner nuclear layer (INL) schisis in one eye (6.3 %), ganglion cell layer (GCL) and INL schisis in 12 eyes (75.0 %), INL and outer plexiform layer (OPL) schisis in two eyes (12.5 %), and GCL, INL, and OPL schisis in one eye (6.3 %). En-face OCT images showed characteristic schisis patterns in each retinal layer, which were represented by multiple hyporeflective holes in the parafoveal region in the GCL, a spoke-like pattern in the foveal region, a reticular pattern in the parafoveal region in the INL, and multiple hyporeflective polygonal cavities with partitions in the OPL. Our results using en-face OCT imaging clarified different patterns of schisis formation among the GCL, INL, and OPL, which lead to further recognition of structure in hereditary juvenile retinoschisis.

Stem cell isolation by a morphology-based selection method in postnatal mouse ovary.

PubMed

Parvari, Soraya; Abbasi, Mehdi; Abbasi, Niloufar; Malek, Valliollah Gerayeli; Amidi, Fardin; Aval, Fereydoon Sargolzaei; Roudkenar, Mehryar Habibi; Izadyar, Fariburz

2015-06-19

An increasing body of evidence has emerged regarding the existence and function of spermatogonial stem cells (SSCs); however, their female counterparts are the subject of extensive debate. Theoretically, ovarian germ stem cells (GSCs) have to reside in the murine ovary to support and replenish the follicle pool during the reproductive life span. Recently, various methods have been recruited to isolate and describe aspects of ovarian GSCs, but newer and more convenient strategies in isolation are still growing. Herein, a morphology-based method was used to isolate GSCs. A cell suspension of mouse neonatal ovaries was cultured. Colonies of GSCs were harvested mechanically and cultivated on mouse embryonic fibroblasts (MEF). Alkaline phosphatase activity was assessed to verify stemness features of cells in colonies. Expression of germ and stem cell specific genes (Oct-4, Nanog, Fragilis, C-kit, Dazl, and Mvh) was analyzed by reverse transcription-polymerase chain reaction (RT-PCR). Immunofluorescence of Oct4, Dazl, Mvh, and SSEA-1 was also performed. Small colonies without a clear border appeared during the first 4 days of culture, and the size of colonies increased rapidly. Cells in colonies were positive for alkaline phosphatase activity. Reverse transcription-polymerase chain reaction showed that Oct-4, Fragilis, C-kit, Nanog, Mvh, and Dazl were expressed in colony-forming cells. Immunofluorescence revealed a positive signal for Oct4, Dazl, Mvh, and SSEA-1 in colonies as well. The applicability of morphological selection for isolation of GSCs was verified. This method is easier and more economical than other techniques. The availability of ovarian stem cells can motivate further studies in development of oocyte and cell-based therapies.

Stem cell isolation by a morphology-based selection method in postnatal mouse ovary

PubMed Central

Parvari, Soraya; Abbasi, Niloufar; Malek, Valliollah Gerayeli; Amidi, Fardin; Aval, Fereydoon Sargolzaei; Roudkenar, Mehryar Habibi; Izadyar, Fariburz

2015-01-01

Introduction An increasing body of evidence has emerged regarding the existence and function of spermatogonial stem cells (SSCs); however, their female counterparts are the subject of extensive debate. Theoretically, ovarian germ stem cells (GSCs) have to reside in the murine ovary to support and replenish the follicle pool during the reproductive life span. Recently, various methods have been recruited to isolate and describe aspects of ovarian GSCs, but newer and more convenient strategies in isolation are still growing. Herein, a morphology-based method was used to isolate GSCs. Material and methods A cell suspension of mouse neonatal ovaries was cultured. Colonies of GSCs were harvested mechanically and cultivated on mouse embryonic fibroblasts (MEF). Alkaline phosphatase activity was assessed to verify stemness features of cells in colonies. Expression of germ and stem cell specific genes (Oct-4, Nanog, Fragilis, C-kit, Dazl, and Mvh) was analyzed by reverse transcription-polymerase chain reaction (RT-PCR). Immunofluorescence of Oct4, Dazl, Mvh, and SSEA-1 was also performed. Results Small colonies without a clear border appeared during the first 4 days of culture, and the size of colonies increased rapidly. Cells in colonies were positive for alkaline phosphatase activity. Reverse transcription-polymerase chain reaction showed that Oct-4, Fragilis, C-kit, Nanog, Mvh, and Dazl were expressed in colony-forming cells. Immunofluorescence revealed a positive signal for Oct4, Dazl, Mvh, and SSEA-1 in colonies as well. Conclusions The applicability of morphological selection for isolation of GSCs was verified. This method is easier and more economical than other techniques. The availability of ovarian stem cells can motivate further studies in development of oocyte and cell-based therapies. PMID:26170863

Peripheral mRNA expression of pluripotency markers in bipolar disorder and the effect of long-term lithium treatment.

PubMed

Ferensztajn-Rochowiak, Ewa; Tarnowski, Maciej; Samochowiec, Jerzy; Michalak, Michal; Ratajczak, Mariusz Z; Rybakowski, Janusz K

2016-10-01

The aim was to evaluate the peripheral mRNA expression of pluripotency master transcriptional factors such as octamer-binding transcription factor 4 (Oct4), sex-determining region Y-box 2 (Sox2) and homeobox protein Nanog, in patients with bipolar disorder (BD), and the effect of long-term lithium treatment. Fifteen BD patients (aged 53±7years) not treated with lithium, with duration of illness>10years, 15 BD patients (aged 55±6years) treated with lithium for 8-40 years (mean 16years) and 15 control subjects (aged 50±5years) were included. Assessment of the mRNA levels of pluripotency markers (Oct-4, Sox 2 and Nanog) was performed, using the Real-time quantitative reverse transcription PCR (RQ-PCR) procedure, and the number of CD34+ very small embryonic-like stem cells (VSELs) was measured by flow cytometric analysis. In those BD patients not treated with lithium the expression of all three pluripotency genes was significantly higher than that in the control subjects. Oct-4, Sox2 and Nanog also positively correlated with the number of CD34+ VSELs/[ul] in this group. In the lithium-treated patients the mRNA levels of Nanog were significantly higher than in the control individuals and correlated with the number and % of CD34+ VSELs. The overexpression of the pluripotency master transcriptional factors in patients with a long duration of BD not treated with lithium, may contribute to the pathogenesis of the illness and make them potential biological markers of BD. Long-term lithium treatment may attenuate these excessive regenerative processes, especially in relation to the transcription factors Oct-4 and Sox2. Copyright © 2016. Published by Elsevier Urban & Partner Sp. z o.o.

Micromotor endoscope catheter for in vivo, ultrahigh-resolution optical coherence tomography.

PubMed

Herz, P R; Chen, Y; Aguirre, A D; Schneider, K; Hsiung, P; Fujimoto, J G; Madden, K; Schmitt, J; Goodnow, J; Petersen, C

2004-10-01

A distally actuated, rotational-scanning micromotor endoscope catheter probe is demonstrated for ultrahigh-resolution in vivo endoscopic optical coherence tomography (OCT) imaging. The probe permits focus adjustment for visualization of tissue morphology at varying depths with improved transverse resolution compared with standard OCT imaging probes. The distal actuation avoids nonuniform scanning motion artifacts that are present with other probe designs and can permit a wider range of imaging speeds. Ultrahigh-resolution endoscopic imaging is demonstrated in a rabbit with <4-microm axial resolution by use of a femtosecond Cr:forsterite laser light source. The micromotor endoscope catheter probe promises to improve OCT imaging performance in future endoscopic imaging applications.

Detection of vesicant-induced upper airway mucosa damage in the hamster cheek pouch model using optical coherence tomography.

PubMed

Hammer-Wilson, Marie J; Nguyen, Vi; Jung, Woong-Gyu; Ahn, Yehchen; Chen, Zhongping; Wilder-Smith, Petra

2010-01-01

Hamster cheek pouches were exposed to 2-chloroethyl ethyl sulfide [CEES, half-mustard gas (HMG)] at a concentration of 0.4, 2.0, or 5.0 mg/ml for 1 or 5 min. Twenty-four hours post-HMG exposure, tissue damage was assessed by both stereomicrography and optical coherence tomography (OCT). Damage that was not visible on gross visual examination was apparent in the OCT images. Tissue changes were found to be dependent on both HMG concentration and exposure time. The submucosal and muscle layers of the cheek pouch tissue showed the greatest amount of structural alteration. Routine light microscope histology was performed to confirm the OCT observations.

A genetic and developmental pathway from STAT3 to the OCT4–NANOG circuit is essential for maintenance of ICM lineages in vivo

PubMed Central

Do, Dang Vinh; Ueda, Jun; Messerschmidt, Daniel M.; Lorthongpanich, Chanchao; Zhou, Yi; Feng, Bo; Guo, Guoji; Lin, Peiyu J.; Hossain, Md Zakir; Zhang, Wenjun; Moh, Akira; Wu, Qiang; Robson, Paul; Ng, Huck Hui; Poellinger, Lorenz; Knowles, Barbara B.; Solter, Davor; Fu, Xin-Yuan

2013-01-01

Although it is known that OCT4–NANOG are required for maintenance of pluripotent cells in vitro, the upstream signals that regulate this circuit during early development in vivo have not been identified. Here we demonstrate, for the first time, signal transducers and activators of transcription 3 (STAT3)-dependent regulation of the OCT4–NANOG circuitry necessary to maintain the pluripotent inner cell mass (ICM), the source of in vitro-derived embryonic stem cells (ESCs). We show that STAT3 is highly expressed in mouse oocytes and becomes phosphorylated and translocates to the nucleus in the four-cell and later stage embryos. Using leukemia inhibitory factor (Lif)-null embryos, we found that STAT3 phosphorylation is dependent on LIF in four-cell stage embryos. In blastocysts, interleukin 6 (IL-6) acts in an autocrine fashion to ensure STAT3 phosphorylation, mediated by janus kinase 1 (JAK1), a LIF- and IL-6-dependent kinase. Using genetically engineered mouse strains to eliminate Stat3 in oocytes and embryos, we firmly establish that STAT3 is essential for maintenance of ICM lineages but not for ICM and trophectoderm formation. Indeed, STAT3 directly binds to the Oct4 and Nanog distal enhancers, modulating their expression to maintain pluripotency of mouse embryonic and induced pluripotent stem cells. These results provide a novel genetic model of cell fate determination operating through STAT3 in the preimplantation embryo and pluripotent stem cells in vivo. PMID:23788624

YKL-40 is differentially expressed in human embryonic stem cells and in cell progeny of the three germ layers.

PubMed

Brøchner, Christian B; Johansen, Julia S; Larsen, Lars A; Bak, Mads; Mikkelsen, Hanne B; Byskov, Anne Grete; Andersen, Claus Yding; Møllgård, Kjeld

2012-03-01

The secreted glycoprotein YKL-40 participates in cell differentiation, inflammation, and cancer progression. High YKL-40 expression is reported during early human development, but its functions are unknown. Six human embryonic stem cell (hESC) lines were cultured in an atmosphere of low or high oxygen tension, in culture medium with or without basic fibroblast growth factor, and on feeder layers comprising mouse embryonic fibroblasts or human foreskin fibroblasts to evaluate whether hESCs and their progeny produced YKL-40 and to characterize YKL-40 expression during differentiation. Secreted YKL-40 protein and YKL-40 mRNA expression were measured by enzyme-linked immunosorbent assay (ELISA) and quantitative RT-PCR. Serial-sectioned colonies were stained for YKL-40 protein and for pluripotent hESC (OCT4, NANOG) and germ layer (HNF-3β, PDX1, CD34, p63, nestin, PAX6) markers. Double-labeling showed YKL-40 expression in OCT4-positive hESCs, PAX6-positive neuroectodermal cells, and HNF-3β-positive endodermal cells. The differentiating progeny showed strong YKL-40 expression. Abrupt transition between YKL-40 and OCT4-positive hESCs and YKL-40-positive ecto- and neuroectodermal lineages was observed within the same epithelial-like layer. YKL-40-positive cells within deeper layers lacked contact with OCT4-positive cells. YKL-40 may be important in initial cell differentiation from hESCs toward ectoderm and neuroectoderm, with retained epithelial morphology, whereas later differentiation into endoderm and mesoderm involves a transition into the deeper layers of the colony.

Alkaline phosphatase and OCT-3/4 as useful markers for predicting susceptibility of human deciduous teeth-derived dental pulp cells to reprogramming factor-induced iPS cells.

PubMed

Inada, Emi; Saitoh, Issei; Kubota, Naoko; Soda, Miki; Matsueda, Kazunari; Murakami, Tomoya; Sawami, Tadashi; Kagoshima, Akiko; Yamasaki, Youichi; Sato, Masahiro

2017-11-01

The aim of the present study was to prove that primary cells enriched with stem cells are more easily reprogrammed to generate induced pluripotent stem (iPS) cells than those with scarce numbers of stem cells. We surveyed the alkaline phosphatase (ALP) activity in five primarily-isolated human deciduous teeth-derived dental pulp cells (HDDPC) with cytochemical staining to examine the possible presence of stem cells. Next, the expression of stemness-specific factors, such as OCT(Octumer-binding transcription factor)3/4, NANOG, SOX2(SRY (sex determining region Y)-box 2), CD90, muscle segment homeodomain homeobox (MSX) 1, and MSX2, was assessed with a reverse transcription polymerase chain reaction method. Finally, these isolated HDDPC were transfected with plasmids carrying genes coding Yamanaka factors to determine whether these cells could be reprogrammed to generate iPS cells. Of the five primarily-isolated HDDPC, two (HDDPC-1 and -5) exhibited higher degrees of ALP activity. OCT-3/4 expression was also prominent in those two lines. Furthermore, these two lines proliferated faster than the other three lines. The transfection of HDDPC with Yamanaka factors resulted in the generation of iPS cells from HDDPC-1 and -5. The number of cells with the stemness property of HDDPC differs among individuals, which suggests that HDDPC showing an increased expression of both ALP and OCT-3/4 can be more easily reprogrammed to generate iPS cells after the forced expression of reprogramming factors. © 2016 John Wiley & Sons Australia, Ltd.

Isolation, identification and multipotential differentiation of mouse adipose tissue-derived stem cells.

PubMed

Taha, Masoumeh Fakhr; Hedayati, Vahideh

2010-08-01

Bone marrow and adipose tissue have provided two suitable sources of mesenchymal stem cells. Although previous studies have confirmed close similarities between bone marrow-derived stem cells (BM-MSCs) and adipose tissue-derived stem cells (ADSCs), the molecular phenotype of ADSCs is still poorly identified. In the present study, mouse ADSCs were isolated from the inguinal fat pad of 12-14 weeks old mice. Freshly isolated and three passaged ADSCs were analyzed for the expression of OCT4, Sca-1, c-kit and CD34 by RT-PCR. Three passaged ADSCs were analyzed by flow cytometry for the presence of CD11b, CD45, CD31, CD29 and CD44. Moreover, cardiogenic, adipogenic and neurogenic differentiation of ADSCs were induced in vitro. Freshly isolated ADSCs showed the expression of OCT4, Sca-1, c-kit and CD34, and two days cultured ADSCs were positively immunostained with anti-OCT4 monoclonal antibody. After three passages, the expression of OCT4, c-kit and CD34 eliminated, while the expression of Sca-1 showed a striking enhancement. These cells were identified positive for CD29 and CD44 markers, and they showed the lack of CD45 and CD31 expression. Three passaged ADSCs were differentiated to adipocyte-, cardiomyocyte- and neuron-like cells that were identified based on the positive staining with Sudan black, anti-cardiac troponin I antibody and anti-map-2 antibody, respectively. In conclusion, adipose tissue contains a stem cell population that seems to be a good multipotential cell candidate for the future cell replacement therapy. Copyright 2010 Elsevier Ltd. All rights reserved.

Age-Related Differences in Longitudinal Structural Change by Spectral-Domain Optical Coherence Tomography in Early Experimental Glaucoma

PubMed Central

Yang, Hongli; He, Lin; Gardiner, Stuart K.; Reynaud, Juan; Williams, Galen; Hardin, Christy; Strouthidis, Nicholas G.; Downs, J. Crawford; Fortune, Brad; Burgoyne, Claude F.

2014-01-01

Purpose. To characterize age-related differences in the magnitude of spectral-domain optical coherence tomography (SD-OCT) structural change in early experimental glaucoma (EG). Methods. Both eyes from four young (1.4–2.6 years) and four old (18.6–21.9 years) rhesus monkeys were imaged at least three times at baseline, and then every 2 weeks after laser-induced, chronic, unilateral IOP elevation until the onset of EG (confocal scanning laser tomographic surface change confirmed twice). Two to 20 weeks after EG onset, animals were euthanized and optic nerve axon counts for all eyes were performed. Masked operators delineated retinal and ONH landmarks in 40 radial B-scans from each eye and imaging session to quantify change from baseline in five SD-OCT neural and connective tissue parameters. The effects of EG, age, and EG × age interactions on the magnitude, rate (magnitude per postlaser time), and IOP responsiveness (magnitude per cumulative IOP insult) of postlaser parameter change were individually assessed using general estimating equation models. Results. Presac SD-OCT RNFLT and minimum rim width change and postmortem axon loss was not significantly different in old compared with young EG eyes. The rate of change and IOP responsiveness of the parameters anterior lamina cribrosa surface depth relative to Bruch's membrane opening (BMO) and BMO depth relative to peripheral Bruch's membrane were significantly lower (P < 0.05) in the old compared with the young EG eyes. Conclusions. At similar postlaser times, levels of cumulative IOP insult and axonal damage, SD-OCT–detected ONH connective tissue structural change is greater in young compared with old monkey EG eyes. PMID:25190652

Optical Coherence Tomography Evaluation in the Multicenter Uveitis Steroid Treatment (MUST) Trial

PubMed Central

Domalpally, Amitha; Altaweel, Michael M.; Kempen, John H.; Myers, Dawn; Davis, Janet L; Foster, C Stephen; Latkany, Paul; Srivastava, Sunil K.; Stawell, Richard J.; Holbrook, Janet T.

2013-01-01

Purpose To describe the evaluation of optical coherence tomography (OCT) scans in the Muliticenter Uveitis Steroid Treatment (MUST) trial and report baseline OCT features of enrolled participants. Methods Time domain OCTs acquired by certified photographers using a standardized scan protocol were evaluated at a Reading Center. Accuracy of retinal thickness data was confirmed with quality evaluation and caliper measurement of centerpoint thickness (CPT) was performed when unreliable. Morphological evaluation included cysts, subretinal fluid,epiretinal membranes (ERMs),and vitreomacular traction. Results Of the 453 OCTs evaluated, automated retinal thickness was accurate in 69.5% of scans, caliper measurement was performed in 26%,and 4% were ungradable. Intraclass correlation was 0.98 for reproducibility of caliper measurement. Macular edema (centerpoint thickness ≥ 240um) was present in 36%. Cysts were present in 36.6% of scans and ERMs in 27.8%, predominantly central. Intergrader agreement ranged from 78 − 82% for morphological features. Conclusion Retinal thickness data can be retrieved in a majority of OCT scans in clinical trial submissions for uveitis studies. Small cysts and ERMs involving the center are common in intermediate and posterior/panuveitis requiring systemic corticosteroid therapy. PMID:23163490

Optical Coherence Tomography for Brain Imaging

NASA Astrophysics Data System (ADS)

Liu, Gangjun; Chen, Zhongping

Recently, there has been growing interest in using OCT for brain imaging. A feasibility study of OCT for guiding deep brain probes has found that OCT can differentiate the white matter and gray matter because the white matter tends to have a higher peak reflectivity and steeper attenuation rate compared to gray matter. In vivo 3D visualization of the layered organization of a rat olfactory bulb with OCT has been demonstrated. OCT has been used for single myelin fiber imaging in living rodents without labeling. The refractive index in the rat somatosensory cortex has also been measured with OCT. In addition, functional extension of OCT, such as Doppler-OCT (D-OCT), polarization sensitive-OCT (PS-OCT), and phase-resolved-OCT (PR-OCT), can image and quantify physiological parameters in addition to the morphological structure image. Based on the scattering changes during neural activity, OCT has been used to measure the functional activation in neuronal tissues. PS-OCT, which combines polarization sensitive detection with OCT to determine tissue birefringence, has been used for the localization of nerve fiber bundles and the mapping of micrometer-scale fiber pathways in the brain. D-OCT, also named optical Doppler tomography (ODT), combines the Doppler principle with OCT to obtain high resolution tomographic images of moving constituents in highly scattering biological tissues. D-OCT has been successfully used to image cortical blood flow and map the blood vessel network for brain research. In this chapter, the principle and technology of OCT and D-OCT are reviewed and examples of potential applications are described.

Generation of urine-derived induced pluripotent stem cells from a patient with phenylketonuria

PubMed Central

Qi, Zijuan; Cui, Yazhou; Shi, Liang; Luan, Jing; Zhou, Xiaoyan; Han, Jinxiang

2018-01-01

Summary The aim of the study was to establish an induced pluripotent stem cell line from urine-derived cells (UiPSCs) from a patient with phenylketonuria (PKU) in order to provide a useful research tool with which to examine the pathology of this rare genetic metabolic disease. Urine-derived epithelial cells (UCs) from a 15-year-old male patient with PKU were isolated and reprogrammed with integration-free episomal vectors carrying an OCT4, SOX2, KLF4, and miR-302-367 cluster. PKU-UiPSCs were verified as correct using alkaline phosphatase staining. Pluripotency markers were detected with real-time PCR and flow cytometry. Promoter methylation in two pluripotent genes, NANOG and OCT4, was analyzed using bisulphite sequencing. An embryoid body (EB) formation assay was also performed. An induced pluripotent stem cell line (iPSC) was generated from epithelial cells in urine from a patient with PKU. This cell line had increased expression of stem cell biomarkers, it efficiently formed EBs, it stained positive for alkaline phosphatase (ALP), and it had a marked decrease in promoter methylation in the NANOG and OCT4 genes. The PKU-UiPSCs created here had typical characteristics and are suitable for further differentiation.

Flexible Ablators: Applications and Arcjet Testing

NASA Technical Reports Server (NTRS)

Arnold, James O.; Venkatapathy, Ethiraj; Beck, Robin A S.; Mcguire, Kathy; Prabhu, Dinesh K.; Gorbunov, Sergey

2011-01-01

Flexible ablators were conceived in 2009 to meet the technology pull for large, human Mars Exploration Class, 23 m diameter hypersonic inflatable aerodynamic decelerators. As described elsewhere, they have been recently undergoing initial technical readiness (TRL) advancement by NASA. The performance limits of flexible ablators in terms of maximum heat rates, pressure and shear remain to be defined. Further, it is hoped that this emerging technology will vastly expand the capability of future NASA missions involving atmospheric entry systems. This paper considers four topics of relevance to flexible ablators: (1) Their potential applications to near/far term human and robotic missions (2) Brief consideration of the balance between heat shield diameter, flexible ablator performance limits, entry vehicle controllability and aft-body shear layer impingement of interest to designers of very large entry vehicles, (3) The approach for developing bonding processes of flexible ablators for use on rigid entry bodies and (4) Design of large arcjet test articles that will enable the testing of flexible ablators in flight-like, combined environments (heat flux, pressure, shear and structural tensile loading). Based on a review of thermal protection system performance requirements for future entry vehicles, it is concluded that flexible ablators have broad applications to conventional, rigid entry body systems and are enabling to large deployable (both inflatable and mechanical) heat shields. Because of the game-changing nature of flexible ablators, it appears that NASA's Office of the Chief Technologist (OCT) will fund a focused, 3-year TRL advancement of the new materials capable of performance in heat fluxes in the range of 200-600 W/sq. cm. This support will enable the manufacture and use of the large-scale arcjet test designs that will be a key element of this OCT funded activity.

JPRS Report, East Asia: Southeast Asia.

DTIC Science & Technology

1991-11-20

namese Embassy in Kuala Lumpur this month to help Malaysian investors interested in entering our markets , as Malaysia has done through its consulate...in Increase of Imports [KOMPAS 10 Oct] 4 Metal Corrosion Expense 1 Percent of GNP [KOMPAS 9 Oct] 5 MALAYSIA ECONOMIC Vietnamese Officials... markets . The 15 projects are scheduled for the 1991-1992 to 1994-1995 fiscal years and do not include four mega- projects that were rescheduled two

The Basicity of Unsaturated Hydrocarbons as probed by H-Bond Acceptor Ability. Bifurcated N–H+⋯π Hydrogen Bonding

PubMed Central

Stoyanov, Evgenii S.; Stoyanova, Irina V.; Reed, Christopher A.

2009-01-01

The competitive substitution of the anion in contact ion pairs of the type [Oct3NH+]B(C6F5)4− by unsaturated hydrocarbons L in accordance with the equilibrium Oct3NH+⋯Anion− + nL ↔ [Oct3NH+⋯Ln]Anion− has been studied in CCl4 solution. On the basis of equilibrium constants K and shifts of νNH to low frequency, it is established that complexed Oct3NH+⋯Ln cations with n = 1 and 2 are formed, having unidentate and bifurcated N–H+⋯π hydrogen bonds, respectively. Bifurcated H-bonds to unsaturated hydrocarbons have not been observed previously. The unsaturated hydro-carbons studied include benzene and methylbenzenes, fused-ring aromatics, alkenes, conjugated dienes, and alkynes. From the magnitude of the red shifts in N-H stretching frequencies, ΔνNH, a new scale for ranking the π-basicity of unsaturated hydrocarbons is proposed: fused-ring aromatics ≤ benzene < toluene < xylene < mesitylene < durene < conjugated dienes ∼ 1-alkynes < pentamethylbenzene < hexamethyl-benzene < internal alkynes ∼ cyclo-alkenes < 1-methylcycloalkenes. This scale is relevant to the discussion of π complexes for incipient protonation reactions and to understanding N–H+⋯π hydrogen bonding in proteins and molecular crystals. PMID:18637650