48 results on '"John C. Morrison"'
Search Results
2. Electron Beam Irradiated Corneal Versus Gamma-Irradiated Scleral Patch Graft Erosion Rates in Glaucoma Drainage Device Surgery
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Ross M. Passo, Zachary B. Hoskins, Khoa D. Tran, Corrina Patzer, Beth Edmunds, John C. Morrison, Mansi Parikh, Hana L. Takusagawa, and Shandiz Tehrani
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Corneal patch graft ,Glaucoma drainage device (GDD) ,Graft erosion ,Scleral patch graft ,Tube exposure ,Ophthalmology ,RE1-994 - Abstract
Abstract Introduction Patch graft erosion and implant exposure is a known complication of glaucoma drainage device (GDD) surgery. Recently, electron beam (e-beam) irradiated corneal tissue ha s become available; however, limited data exist on the rates of erosion for e-beam irradiated corneal grafts compared to traditional scleral grafts after GDD surgery. Methods This retrospective study examines the records of 253 eyes from 225 adult subjects who underwent GDD surgery with either e-beam irradiated corneal or scleral grafts at the Casey Eye Institute by five surgeons between April 22, 2014 and October 11, 2017. Surgical procedures and the occurrence of graft erosion were determined using billing codes and verified by manual review of electronic health records. Results The average age at the time of surgery was 61.3 ± 17.5 years (n = 200) and 60.8 ± 16.8 years (n = 53) for the e-beam irradiated cornea and sclera groups, respectively. The average follow-up time post-surgery was 416 ± 345 days and 495 ± 343 days for the e-beam irradiated cornea and sclera groups, respectively. There were no statistically significant differences in sex, age, follow-up time, and glaucoma diagnosis between the groups; however, the e-beam irradiated cornea group was statistically more likely to have an Ahmed implant as compared to the sclera group. No erosion events were noted in either group. Conclusion e-Beam irradiated corneal grafts were used 3.8 times more frequently relative to scleral grafts, yet there were no cases of graft erosion in either group during the follow-up period.
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- 2019
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- View/download PDF
3. Using the Conservation Standards Framework to Address the Effects of Climate Change on Biodiversity and Ecosystem Services
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Marcia B. Brown, John C. Morrison, Terri T. Schulz, Molly S. Cross, Nicole Püschel-Hoeneisen, Varsha Suresh, and Antonieta Eguren
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biodiversity conservation ,conservation planning ,climate-smart conservation ,climate vulnerability assessment ,adaptive management ,theory of change ,Science - Abstract
Climate change has challenged biodiversity conservation practitioners and planners. In this paper, we provide scalable guidance on integrating climate change into conservation planning and adaptive management that results in the most appropriate conservation strategies. This integrated “Climate-Smart Conservation Practice” focuses on analyzing the potential impact of climate change on species, ecosystems, and ecosystem services, combined with “conventional” (non-climate) threats, and incorporating this knowledge into projects. The guidance is based on the already widely-used “Open Standards for the Practice of Conservation”, an application of systems thinking and adaptive management, which has been successfully applied to thousands of conservation projects. Our framework emphasizes a methodical analysis of climate change impacts for projects to support more productive goals and strategy development. We provide two case studies showing the applicability and flexibility of this framework. An initial key element is developing “situation models” that document both current and future threats affecting biodiversity while showing the interactions between climate and conventional threats. Guidance is also provided on how to design integrated, climate-smart goals and strategies, and detailed theories of change for selected strategies. The information and suggestions presented are intended to break down the steps to make the process more approachable, provide guidance to teams using climate change information within a systematic conservation planning process, and demonstrate how climate scientists can provide appropriate information to conservation planners.
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- 2022
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4. Risks and Benefits of Magnesium Sulfate Tocolysis in Preterm Labor (PTL)
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John C. Morrison, James A. Bofill, and John P. Elliott
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magnesium sulfate ,tocolysis ,preterm labor ,FDA ,Public aspects of medicine ,RA1-1270 - Abstract
The U.S. Food and Drug Administration issued a drug safety communication on 05/30/2013 recommending “against prolonged use of magnesium sulfate to stop preterm labor (PTL) due to bone changes in exposed babies.” In September of 2013, The American Congress of Obstetrics and Gynecologists issued Committee Opinion No. 573 “ Magnesium Sulfate Use in Obstetrics” , which supports the short term use of MgSO4 to prolong pregnancy (up to 48 hrs.) to allow for the administration of antenatal corticosteroids.” Are these pronouncements by respected organizations short sighted and will potentially result in more harm than good? The FDA safety communication focuses on bone demineralization (a few cases with fractures) with prolonged administration of MgSO4 (beyond 5–7 days). It cites 18 case reports in the Adverse Event Reporting System with an average duration of magnesium exposure of 9.6 weeks (range 8–12 wks). Other epidemiologic studies showed transient changes in bone density which resolved in the short duration of follow up. Interestingly, the report fails to acknowledge the fact that these 18 fetuses were in danger of PTD and the pregnancy was prolonged by 9.6 weeks (e.g. extending 25 weeks to 34.6 wks), thus significantly reducing mortality and morbidity. Evidence does support the efficacy of MgSO4 as a tocolytic medication. The decision to use magnesium, the dosage to administer, the duration of use, and alternative therapies are physician judgments. These decisions should be made based on a reasonable assessment of the risks of the clinical situation (PTL) and the treatments available versus the benefits of significantly prolonging pregnancy.
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- 2016
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5. The Evidence Regarding Maintenance Tocolysis
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John P. Elliott and John C. Morrison
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Gynecology and obstetrics ,RG1-991 - Abstract
Preterm delivery is a public health issue of major proportion. More than 12% of deliveries in the United States that occur at less than 37 weeks gestation preterm labor (PTL) represents the largest single reason for preterm birth (PTB). Attempts to prevent PTB have been unsuccessful. This paper of maintenance tocolytic therapy will examine the efficacy and safety of the drugs, both oral and subcutaneous, which have been utilized for prolongation of pregnancy following successful arrest of a documented episode of acute preterm labor. The evidence for oral tocolytics as maintenance therapy as well as parenteral medications for such patients is offered. Finally, the effects in the United States of the Food and Drug Administration (FDA) action on such medications are reported.
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- 2013
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6. Does Method of Placental Removal or Site of Uterine Incision Repair Alter Endometritis After Cesarean Delivery?
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Everett F. Magann, Mark K. Dodson, Robert L. Harris, Randall C. Floyd, James N. Martin, and John C. Morrison
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Gynecology and obstetrics ,RG1-991 ,Infectious and parasitic diseases ,RC109-216 - Abstract
Objective: his investigation was undertaken to evaluate the relationship between postcesarean endometritis and (1) method of placental removal and (2) site for uterine repair.
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- 1993
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7. Glaucoma: Science and Practice
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John C. Morrison, Irvin P. Pollack and John C. Morrison, Irvin P. Pollack
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- 2011
8. Electron Beam Irradiated Corneal Versus Gamma-Irradiated Scleral Patch Graft Erosion Rates in Glaucoma Drainage Device Surgery
- Author
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Shandiz Tehrani, Khoa D. Tran, Zachary B. Hoskins, Hana L. Takusagawa, Ross Passo, Corrina Patzer, Beth Edmunds, John C. Morrison, and Mansi Parikh
- Subjects
medicine.medical_specialty ,genetic structures ,Glaucoma ,03 medical and health sciences ,Glaucoma drainage device (GDD) ,0302 clinical medicine ,lcsh:Ophthalmology ,Cornea ,Corneal patch graft ,medicine ,030304 developmental biology ,Original Research ,0303 health sciences ,Graft erosion ,Scleral patch graft ,business.industry ,Surgical procedures ,medicine.disease ,Glaucoma drainage device ,eye diseases ,Tube exposure ,Surgery ,Sclera ,Ophthalmology ,medicine.anatomical_structure ,lcsh:RE1-994 ,030221 ophthalmology & optometry ,Implant ,sense organs ,Complication ,business ,Patch graft - Abstract
Introduction Patch graft erosion and implant exposure is a known complication of glaucoma drainage device (GDD) surgery. Recently, electron beam (e-beam) irradiated corneal tissue ha s become available; however, limited data exist on the rates of erosion for e-beam irradiated corneal grafts compared to traditional scleral grafts after GDD surgery. Methods This retrospective study examines the records of 253 eyes from 225 adult subjects who underwent GDD surgery with either e-beam irradiated corneal or scleral grafts at the Casey Eye Institute by five surgeons between April 22, 2014 and October 11, 2017. Surgical procedures and the occurrence of graft erosion were determined using billing codes and verified by manual review of electronic health records. Results The average age at the time of surgery was 61.3 ± 17.5 years (n = 200) and 60.8 ± 16.8 years (n = 53) for the e-beam irradiated cornea and sclera groups, respectively. The average follow-up time post-surgery was 416 ± 345 days and 495 ± 343 days for the e-beam irradiated cornea and sclera groups, respectively. There were no statistically significant differences in sex, age, follow-up time, and glaucoma diagnosis between the groups; however, the e-beam irradiated cornea group was statistically more likely to have an Ahmed implant as compared to the sclera group. No erosion events were noted in either group. Conclusion e-Beam irradiated corneal grafts were used 3.8 times more frequently relative to scleral grafts, yet there were no cases of graft erosion in either group during the follow-up period.
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- 2019
9. Early Optic Nerve Head Glial Proliferation and Jak-Stat Pathway Activation in Chronic Experimental Glaucoma
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John C. Morrison, Tiffany E. Choe, William O. Cepurna, Elaine C. Johnson, and Diana C Lozano
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0301 basic medicine ,Male ,STAT3 Transcription Factor ,Intraocular pressure ,Pathology ,medicine.medical_specialty ,genetic structures ,Optic Disk ,Optic disk ,Glaucoma ,optic nerve ,03 medical and health sciences ,Tonometry, Ocular ,0302 clinical medicine ,Rats, Inbred BN ,Glial Fibrillary Acidic Protein ,medicine ,Animals ,Intraocular Pressure ,Janus Kinases ,Microglia ,business.industry ,SOXB1 Transcription Factors ,PAX2 Transcription Factor ,JAK-STAT signaling pathway ,medicine.disease ,Immunohistochemistry ,eye diseases ,animal models ,Rats ,030104 developmental biology ,medicine.anatomical_structure ,cell proliferation ,nervous system ,Astrocytes ,Optic Nerve Injuries ,Chronic Disease ,Models, Animal ,Optic nerve ,sense organs ,business ,Neuroglia ,030217 neurology & neurosurgery ,Biomarkers ,Astrocyte ,Signal Transduction - Abstract
Purpose We previously reported increased expression of cell proliferation and Jak-Stat pathway-related genes in chronic experimental glaucoma model optic nerve heads (ONH) with early, mild injury. Here, we confirm these observations by localizing, identifying, and quantifying ONH cellular proliferation and Jak-Stat pathway activation in this model. Methods Chronic intraocular pressure (IOP) elevation was achieved via outflow pathway sclerosis. After 5 weeks, ONH longitudinal sections were immunolabeled with proliferation and cell-type markers to determine nuclear densities in the anterior (unmyelinated) and transition (partially myelinated) ONH. Nuclear pStat3 labeling was used to detect Jak-Stat pathway activation. Nuclear density differences between control ONH (uninjected) and ONH with either early or advanced injury (determined by optic nerve injury grading) were identified by ANOVA. Results Advanced injury ONH had twice the nuclear density (P < 0.0001) of controls and significantly greater astrocyte density in anterior (P = 0.0001) and transition (P = 0.006) ONH regions. An increased optic nerve injury grade positively correlated with increased microglia/macrophage density in anterior and transition ONH (P < 0.0001, both). Oligodendroglial density was unaffected. In glaucoma model ONH, 80% of anterior and 66% of transition region proliferating cells were astrocytes. Nuclear pStat3 labeling significantly increased in early injury anterior ONH, and 95% colocalized with astrocytes. Conclusions Astrocytes account for the majority of proliferating cells, contributing to a doubled nuclear density in advanced injury ONH. Jak-Stat pathway activation is apparent in the early injury glaucoma model ONH. These data confirm dramatic astrocyte cell proliferation and early Jak-Stat pathway activation in ONH injured by elevated IOP.
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- 2019
10. Individual-Specific Modeling of Rat Optic Nerve Head Biomechanics in Glaucoma
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C. Ross Ethier, Stephen A. Schwaner, Alison M. Kight, Hongli Yang, Claude F. Burgoyne, Emily Winder, Robert N. Perry, and John C. Morrison
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medicine.medical_specialty ,genetic structures ,Rat Optic Nerve ,0206 medical engineering ,Rat model ,Biomedical Engineering ,Glaucoma ,02 engineering and technology ,Retinal ganglion ,03 medical and health sciences ,Elevated intraocular pressure ,0302 clinical medicine ,Physiology (medical) ,Ophthalmology ,medicine ,business.industry ,Biomechanics ,medicine.disease ,020601 biomedical engineering ,Research Papers ,eye diseases ,Sclera ,medicine.anatomical_structure ,030221 ophthalmology & optometry ,Optic nerve ,sense organs ,business - Abstract
Glaucoma is the second leading cause of blindness worldwide and is characterized by the death of retinal ganglion cells (RGCs), the cells that send vision information to the brain. Their axons exit the eye at the optic nerve head (ONH), the main site of damage in glaucoma. The importance of biomechanics in glaucoma is indicated by the fact that elevated intraocular pressure (IOP) is a causative risk factor for the disease. However, exactly how biomechanical insult leads to RGC death is not understood. Although rat models are widely used to study glaucoma, their ONH biomechanics have not been characterized in depth. Therefore, we aimed to do so through finite element (FE) modeling. Utilizing our previously described method, we constructed and analyzed ONH models with individual-specific geometry in which the sclera was modeled as a matrix reinforced with collagen fibers. We developed eight sets of scleral material parameters based on results from our previous inverse FE study and used them to simulate the effects of elevated IOP in eight model variants of each of seven rat ONHs. Within the optic nerve, highest strains were seen inferiorly, a pattern that was consistent across model geometries and model variants. In addition, changing the collagen fiber direction to be circumferential within the peripapillary sclera resulted in more pronounced decreases in strain than changing scleral stiffness. The results from this study can be used to interpret data from rat glaucoma studies to learn more about how biomechanics affects RGC pathogenesis in glaucoma.
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- 2020
11. Focal Loss Analysis of Nerve Fiber Layer Reflectance for Glaucoma Diagnosis
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Jie Wang, Eliesa Ing, Qisheng You, Aiyin Chen, Yali Jia, John C. Morrison, Liang Liu, Ou Tan, and David Huang
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Retinal Ganglion Cells ,0301 basic medicine ,Materials science ,Optic Disk ,Population ,Biomedical Engineering ,Nerve fiber layer ,Optic disk ,Glaucoma ,Quantitative Biology - Quantitative Methods ,Standard deviation ,Article ,03 medical and health sciences ,Nerve Fibers ,0302 clinical medicine ,Optical coherence tomography ,medicine ,FOS: Electrical engineering, electronic engineering, information engineering ,Humans ,Cutoff ,Prospective Studies ,education ,focal loss analysis ,Intraocular Pressure ,Quantitative Methods (q-bio.QM) ,education.field_of_study ,optical coherence tomography ,medicine.diagnostic_test ,Image and Video Processing (eess.IV) ,Repeatability ,Electrical Engineering and Systems Science - Image and Video Processing ,medicine.disease ,Ophthalmology ,030104 developmental biology ,medicine.anatomical_structure ,glaucoma ,FOS: Biological sciences ,030221 ophthalmology & optometry ,nerve fiber layer reflectance ,Visual Fields ,Biomedical engineering - Abstract
Purpose: To evaluate nerve fiber layer (NFL) reflectance for glaucoma diagnosis. Methods: Participants were imaged with 4.5X4.5-mm volumetric disc scans using spectral-domain optical coherence tomography (OCT). The normalized NFL reflectance map was processed by an azimuthal filter to reduce directional reflectance bias due to variation of beam incidence angle. The peripapillary area of the map was divided into 160 superpixels. Average reflectance was the mean of superpixel reflectance. Low-reflectance superpixels were identified as those with NFL reflectance below the 5 percentile normative cutoff. Focal reflectance loss was measure by summing loss in low-reflectance superpixels. Results: Thirty-five normal, 30 pre-perimetric and 35 perimetric glaucoma participants were enrolled. Azimuthal filtering improved the repeatability of the normalized NFL reflectance, as measured by the pooled superpixel standard deviation (SD), from 0.73 to 0.57 dB (p, pages: 31; Tables: 6; Figures: 9
- Published
- 2020
12. Comparison of MicroRNA Expression in Aqueous Humor of Normal and Primary Open-Angle Glaucoma Patients Using PCR Arrays: A Pilot Study
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William O. Cepurna, Diana C Lozano, Kate E. Keller, Jay Ian Phillips, Julie A. Saugstad, Devin M. Gattey, Hari Jayaram, Tiffany E. Choe, Elaine C. Johnson, and John C. Morrison
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0301 basic medicine ,Regulation of gene expression ,Pathology ,medicine.medical_specialty ,microRNA ,Wnt signaling pathway ,Biology ,Molecular biology ,Reverse transcriptase ,law.invention ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,glaucoma ,law ,030221 ophthalmology & optometry ,medicine ,TaqMan ,Biomarker (medicine) ,biomarker ,KEGG ,aqueous humor ,Polymerase chain reaction - Abstract
Purpose MicroRNAs (miRNAs) are small, endogenous noncoding RNAs that have been detected in human aqueous humor (AH). Prior studies have pooled samples to obtain sufficient quantities for analysis or used next-generation sequencing. Here, we used PCR arrays with preamplification to identify and compare miRNAs from individual AH samples between patients with primary open-angle glaucoma (POAG) and normal controls. Methods AH was collected before cataract surgery from six stable, medically treated POAG patients and eight age-matched controls. Following reverse transcription and preamplification, individual patient samples were profiled on Taqman Low Density MicroRNA Array Cards. Differentially expressed miRNAs were stratified for fold changes larger than ±2 and for significance of P < 0.05. Significant Kyoto Encyclopedia of Genes and Genomes pathways influenced by the differentially expressed miRNAs were identified using the predicted target module of the miRWalk 2.0 database. Results This approach detected 181 discrete miRNAs, which were consistently expressed across all samples of both experimental groups. Significant up-regulation of miR-518d and miR-143, and significant down-regulation of miR-660, was observed in the AH of POAG patients compared with controls. These miRNAs were predicted to reduce cell proliferation and extracellular matrix remodeling, endocytosis, Wnt signaling, ubiquitin-mediated proteolysis, and adherens junction function. Conclusions This pilot study demonstrates that miRNA expression within the AH of POAG patients differs from age-matched controls. AH miRNAs exhibit potential as biomarkers of POAG, which merits further investigation in a larger case-controlled study. This technique provides a cost-effective and sensitive approach to assay miRNAs in individual patient samples without the need for pooling.
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- 2017
13. Real-time cross-sectional and en face OCT angiography guiding high-quality scan acquisition
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Yali Jia, David Huang, John C. Morrison, Shaohua Pi, Tristan T. Hormel, William O. Cepurna, Xiang Wei, and Acner Camino
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Vignetting ,medicine.diagnostic_test ,Computer science ,business.industry ,Image quality ,Graphics processing unit ,Image processing ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Article ,Refresh rate ,010309 optics ,Optics ,Optical coherence tomography ,0103 physical sciences ,Angiography ,medicine ,Computer vision ,Artificial intelligence ,0210 nano-technology ,business ,Focus (optics) - Abstract
Defocusing, vignetting, and bulk motion degrade the image quality of optical coherence tomography angiography (OCTA) more significantly than structural OCT. The assessment of focus, alignment conditions, and stability of imaging subjects in commercially available OCTA systems are currently based on OCT signal quality alone, without knowledge of OCTA signal quality. This results in low yield rates for further quantification. In this Letter, we developed a novel OCTA platform based on a graphics processing unit (GPU) for a real-time, high refresh rate, B-san-by-B-scan split-spectrum amplitude-decorrelation angiography. The GPU provides a real-time display of both cross-sectional and en face images to assist operators during scan acquisition and ensure OCTA scan quality.
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- 2019
14. Glaucoma Increases Retinal Surface Contour Variability as Measured by Optical Coherence Tomography
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Xinbo Zhang, Liang Liu, John C. Morrison, Ou Tan, and David Huang
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0301 basic medicine ,Male ,Retinal Ganglion Cells ,medicine.medical_specialty ,genetic structures ,nerve fiber layer ,Optic Disk ,Optic disk ,Nerve fiber layer ,Glaucoma ,Severity of Illness Index ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Optical coherence tomography ,Ophthalmology ,Medicine ,Humans ,Aged ,optical coherence tomography ,medicine.diagnostic_test ,Receiver operating characteristic ,business.industry ,Retinal ,Articles ,Middle Aged ,medicine.disease ,retinal surface contour variability ,eye diseases ,Visual field ,030104 developmental biology ,medicine.anatomical_structure ,chemistry ,030221 ophthalmology & optometry ,Optic nerve ,Disease Progression ,Feasibility Studies ,Visual Field Tests ,Female ,sense organs ,Visual Fields ,business ,Tomography, Optical Coherence ,Follow-Up Studies - Abstract
PURPOSE We investigated the feasibility of glaucoma detection by measuring retinal surface contour variability (RSCV) using optical coherence tomography (OCT). METHODS The peripapillary region in one eye of each participant was scanned over an 8 × 8 mm area with a swept source OCT prototype. The retinal surface contour was sampled at approximately 1.5- to 3.5-mm radius circles centered on the optic nerve head. The RSCV is defined as the average log value within a middle spatial frequency band of the Fourier transform to the elevation profile of the inner retinal surface. The spatial frequency band was optimized to distinguish glaucoma from normal. Nerve fiber layer thickness (NFLT) was sampled around a 1.7-mm radius circle. Glaucoma severity was assessed by automated static perimetry. RESULTS We enrolled 17 glaucomatous eyes and 17 healthy eyes. A great majority of the glaucoma group were in the early stage (visual field mean deviation average -2.48 ± 3.73 dB). Significant differences were found for RSCV between glaucoma and control eyes (P < 0.003) at all radii. The area under the receiver operating characteristic curve (AROC = 0.90) of RSCV was best at the 3.5-mm radius. This was not significantly better than NFLT (AROC = 0.84). With the 99% specificity, the glaucoma detection sensitivity was 53% for RSCV and 29% for NFLT (P = 0.13). CONCLUSIONS Retinal surface contour variability was significantly increased in glaucoma patients. The diagnostic accuracy of RSCV was equal to NFLT in early glaucoma. Since the RSCV detects small-scale focal damage and the average NFLT measures global damage, they provide different diagnostic information that may be synergistic.
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- 2016
15. Rodent retinal circulation organization and oxygen metabolism revealed by visible-light optical coherence tomography
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David Huang, William O. Cepurna, Acner Camino, Joseph M. Simonett, Xiang Wei, Shaohua Pi, Yali Jia, and John C. Morrison
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medicine.medical_specialty ,genetic structures ,01 natural sciences ,Article ,010309 optics ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Optical coherence tomography ,Vascular plexus ,Ophthalmology ,0103 physical sciences ,medicine ,Oxygen saturation (medicine) ,medicine.diagnostic_test ,business.industry ,Oxygen metabolism ,Retinal ,Blood flow ,Atomic and Molecular Physics, and Optics ,eye diseases ,chemistry ,Angiography ,030221 ophthalmology & optometry ,Optic nerve ,business ,Biotechnology - Abstract
Visible light optical coherence tomography (vis-OCT) is an emerging label-free and high-resolution 3-dimensional imaging technique that can provide retinal oximetry, angiography, and flowmetry in one modality. In this paper, we studied the organization of the arterial and venous retinal circulation in rats using vis-OCT. Arterioles were found predominantly in the superficial vascular plexus whereas veins tended to drain capillaries from the deep capillary plexus. After that, we determined the oxygen metabolic rate supported by retinal microcirculation by combining retinal vessel oxygen saturation and blood flow measurements. The ability to visualize and monitor retinal circulation organization and oxygen metabolism by vis-OCT may provide new opportunities for understanding the pathology of ocular diseases.
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- 2018
16. Automated spectroscopic retinal oximetry with visible-light optical coherence tomography
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Yali Jia, John C. Morrison, Acner Camino, David Huang, Miao Zhang, Xiang Wei, Shaohua Pi, and William O. Cepurna
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0301 basic medicine ,Reproducibility ,Materials science ,medicine.diagnostic_test ,Retinal ,01 natural sciences ,complex mixtures ,Atomic and Molecular Physics, and Optics ,Article ,Scanning laser ophthalmoscopy ,respiratory tract diseases ,010309 optics ,03 medical and health sciences ,Pulse oximetry ,chemistry.chemical_compound ,030104 developmental biology ,Optical coherence tomography ,chemistry ,In vivo ,0103 physical sciences ,medicine ,Biotechnology ,Visible spectrum ,Oxygen saturation (medicine) ,Biomedical engineering - Abstract
Accurate, quantitative assessment of retinal blood oxygen saturation (sO2 ) may provide a useful early indicator of pathophysiology in several ocular diseases. Here, with visible-light optical coherence tomography (OCT), we demonstrate an automated spectroscopic retinal oximetry algorithm to measure the sO2 within the retinal arteries (A-sO2 ) and veins (V-sO2 ) in rats by automatically detecting the vascular posterior boundary on cross-sectional structural OCT. The algorithm was validated in vitro with flow phantoms and in vivo in rats by comparing the sO2 results, respectively, to those obtained using a blood gas analyzer and pulse oximetry. We also investigated the response of oxygen extraction (A-V sO2 ), including inter-session reproducibility, at different inhaled oxygen concentrations.
- Published
- 2018
17. In Vivo Small Molecule Delivery to the Optic Nerve in a Rodent Model
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Lauren Davis, William O. Cepurna, Elaine C. Johnson, Shandiz Tehrani, R. Katherine Delf, and John C. Morrison
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0301 basic medicine ,Cytochalasin D ,genetic structures ,Phalloidin ,lcsh:Medicine ,Ophthalmologic Surgical Procedures ,Filamentous actin ,Article ,Mass Spectrometry ,Small Molecule Libraries ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,In vivo ,Optic Nerve Diseases ,medicine ,Animals ,Cytoskeleton ,lcsh:Science ,Multidisciplinary ,Chemistry ,lcsh:R ,Optic Nerve ,eye diseases ,Cell biology ,Rats ,Disease Models, Animal ,030104 developmental biology ,medicine.anatomical_structure ,Retinal ganglion cell ,Drug delivery ,Models, Animal ,030221 ophthalmology & optometry ,Optic nerve ,lcsh:Q ,sense organs ,Conjunctiva ,Chromatography, Liquid - Abstract
Small molecule delivery to the optic nerve would allow for exploration of molecular and cellular pathways involved in normal physiology and optic neuropathies such as glaucoma, and provide a tool for screening therapeutics in animal models. We report a novel surgical method for small molecule drug delivery to the optic nerve head (ONH) in a rodent model. In proof-of-principle experiments, we delivered cytochalasin D (Cyt D; a filamentous actin inhibitor) to the junction of the superior optic nerve and globe in rats to target the actin-rich astrocytic cytoskeleton of the ONH. Cyt D delivery was quantified by liquid chromatography and mass spectrometry of isolated optic nerve tissue. One day after Cyt D delivery, anterior ONH filamentous actin bundle content was significantly reduced as assessed by fluorescent-tagged phalloidin labeling, relative to sham delivery. Anterior ONH nuclear counts and axon-specific beta-3 tubulin levels, as well as peripapillary retinal ganglion cell layer nuclear counts were not significantly altered after Cyt D delivery relative to sham delivery. Lastly, the surgical delivery technique caused minimal observable axon degeneration up to 10 days post-surgery. This small molecule delivery technique provides a new approach to studying optic neuropathies in in vivo rodent models.
- Published
- 2018
18. Angiographic and structural imaging using high axial resolution fiber-based visible-light OCT
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William O. Cepurna, Acner Camino, Yali Jia, Miao Zhang, John C. Morrison, Shaohua Pi, Gangjun Liu, and David Huang
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Materials science ,genetic structures ,Capillary action ,Nerve fiber layer ,Image processing ,01 natural sciences ,Article ,010309 optics ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Optics ,Optical coherence tomography ,0103 physical sciences ,medicine ,Fiber ,Retina ,medicine.diagnostic_test ,business.industry ,Retinal ,Atomic and Molecular Physics, and Optics ,medicine.anatomical_structure ,chemistry ,030221 ophthalmology & optometry ,sense organs ,business ,Biotechnology ,Photonic-crystal fiber - Abstract
Optical coherence tomography using visible-light sources can increase the axial resolution without the need for broader spectral bandwidth. Here, a high-resolution, fiber-based, visible-light optical coherence tomography system is built and used to image normal retina in rats and blood vessels in chicken embryo. In the rat retina, accurate segmentation of retinal layer boundaries and quantification of layer thicknesses are accomplished. Furthermore, three distinct capillary plexuses in the retina and the choriocapillaris are identified and the characteristic pattern of the nerve fiber layer thickness in rats is revealed. In the chicken embryo model, the microvascular network and a venous bifurcation are examined and the ability to identify and segment large vessel walls is demonstrated.
- Published
- 2017
19. Generation of Functional Human Retinal Ganglion Cells with Target Specificity from Pluripotent Stem Cells by Chemically Defined Recapitulation of Developmental Mechanism
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Iqbal Ahmad, Shashank M. Dravid, John C. Morrison, Fang Qiu, Angie Rizzino, Pooja Teotia, Matthew J. Van Hook, and Divyan Chopra
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0301 basic medicine ,Male ,Retinal Ganglion Cells ,Time Factors ,genetic structures ,Induced Pluripotent Stem Cells ,Embryonic Development ,Embryoid body ,Biology ,Retinal ganglion ,Article ,03 medical and health sciences ,Mice ,0302 clinical medicine ,Directed differentiation ,Genes, Regulator ,Animals ,Humans ,Induced pluripotent stem cell ,Induced stem cells ,Gene Expression Regulation, Developmental ,Cell Differentiation ,Cell Biology ,Anatomy ,Embryonic stem cell ,eye diseases ,Cell biology ,Culture Media ,Electrophysiological Phenomena ,Repressor Proteins ,030104 developmental biology ,Molecular Medicine ,sense organs ,Stem cell ,030217 neurology & neurosurgery ,Developmental Biology ,Adult stem cell ,Signal Transduction - Abstract
Glaucoma is a complex group of diseases wherein a selective degeneration of retinal ganglion cells (RGCs) leads to irreversible loss of vision. A comprehensive approach to glaucomatous RGC degeneration may include stem cells to functionally replace dead neurons through transplantation and understand RGCs vulnerability using a disease in a dish stem cell model. Both approaches require the directed generation of stable, functional, and target-specific RGCs from renewable sources of cells, i.e., the embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). Here, we demonstrate a rapid and safe, stage-specific, chemically defined protocol that selectively generates RGCs across species, including human, by recapitulating the developmental mechanism. The de novo generated RGCs from pluripotent cells are similar to native RGCs at the molecular, biochemical, functional levels. They also express axon guidance molecules, and discriminate between specific and non-specific targets, and are non-tumorigenic. This article is protected by copyright. All rights reserved.
- Published
- 2016
20. Prospective risk of stillbirth and neonatal complications in twin pregnancies: systematic review and meta-analysis
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Basky Thilaganathan, John C. Morrison, Asma Khalil, Jane E. Norman, Sophie Liem, Fionnuala Breathnach, Ben W.J. Mol, Katharina Worda, Elizabeth Thom, Liesbeth Lewi, Jon Barrett, Mona M. Aboulghar, Francesca Russo, Javier Zamora, Anwar H. Nassar, Thomas J. Garite, K.S. Joseph, Kimberly Maurel, Ewoud Schuit, Dwight J. Rouse, Fiona Cheong-See, Soichiro Nakayama, Sohinee Bhattacharya, Elizabeth Asztalos, Alfredo Perales, Karien E. A. Hack, Arianne C. Lim, Vicente Serra, David Arroyo-Manzano, Selphee Tang, Julian N. Robinson, Roger B. Newman, Line Rode, C. Andrew Combs, Shakila Thangaratinam, Jodie M Dodd, RS: GROW - School for Oncology and Reproduction, RS: GROW - R4 - Reproductive and Perinatal Medicine, and MUMC+: MA Medische Staf Obstetrie Gynaecologie (9)
- Subjects
0301 basic medicine ,Pediatrics ,Neonatal intensive care unit ,Perinatal Death ,Cochrane Library ,Infant, Newborn, Diseases ,0302 clinical medicine ,Obstetrics and gynaecology ,Pregnancy ,Risk Factors ,Twins, Dizygotic ,Medicine ,Prospective Studies ,Prospective cohort study ,reproductive and urinary physiology ,Twin Pregnancy ,health care economics and organizations ,030219 obstetrics & reproductive medicine ,Obstetrics ,Incidence (epidemiology) ,Absolute risk reduction ,Obstetrics and Gynecology ,Gestational age ,Prospective risk ,General Medicine ,Stillbirth ,female genital diseases and pregnancy complications ,Meta-analysis ,Gestation ,Female ,medicine.medical_specialty ,education ,Gestational Age ,Twin-to-twin transfusion syndrome ,03 medical and health sciences ,030225 pediatrics ,Journal Article ,Humans ,Gynecology ,business.industry ,Research ,Infant, Newborn ,Twins, Monozygotic ,medicine.disease ,Confidence interval ,030104 developmental biology ,Intensive Care, Neonatal ,Pregnancy, Twin ,business - Abstract
Twin pregnancies are at increased risk of stillbirth. Uncomplicated twin pregnancies are commonly delivered earlier to prevent stillbirth; however, there is a risk of neonatal complications associated with being born prior to 39 weeks’ gestation. The optimal gestational age for delivery in twin pregnancies is unknown and likely varies by chorionicity. The present study aimed to determine the prospective risk of stillbirth in women with uncomplicated monochorionic and dichorionic twin pregnancies, and neonatal mortality risks, when delivered beyond 34 weeks of gestation. Data on twin pregnancies that reported rates of stillbirth were obtained from MEDLINE, EMBASE, and Cochrane Library. Separate analyses for risks of stillbirth and neonatal death in monochorionic and dichorionic twin pregnancies were undertaken from 34 weeks’ gestation and further and early preterm (
- Published
- 2016
21. Astrocyte Structural and Molecular Response to Elevated Intraocular Pressure Occurs Rapidly and Precedes Axonal Tubulin Rearrangement within the Optic Nerve Head in a Rat Model
- Author
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Diana C Lozano, Lauren Davis, Tiffany E. Choe, Elaine C. Johnson, William O. Cepurna, Shandiz Tehrani, Ashley Monfared, Lauren Cooper, John C. Morrison, and Joshua Cheng
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Male ,0301 basic medicine ,Macroglial Cells ,Integrins ,Intraocular pressure ,genetic structures ,lcsh:Medicine ,Biochemistry ,Axonal Transport ,Nerve Fibers ,Contractile Proteins ,0302 clinical medicine ,Animal Cells ,Tubulin ,Rats, Inbred BN ,Medicine and Health Sciences ,Medicine ,Axon ,lcsh:Science ,Cytoskeleton ,Neurons ,Multidisciplinary ,biology ,Anatomy ,Extracellular Matrix ,Enzymes ,medicine.anatomical_structure ,Optic nerve ,Cellular Types ,Cellular Structures and Organelles ,Cortactin ,Research Article ,Astrocyte ,medicine.medical_specialty ,Glial Cells ,Focal adhesion ,03 medical and health sciences ,Ocular System ,Ophthalmology ,Cell Adhesion ,Animals ,Intraocular Pressure ,Paxillin ,business.industry ,lcsh:R ,Biology and Life Sciences ,Proteins ,Optic Nerve ,Cell Biology ,Axons ,Actins ,eye diseases ,Rats ,Cytoskeletal Proteins ,Disease Models, Animal ,030104 developmental biology ,Astrocytes ,Cellular Neuroscience ,Enzymology ,biology.protein ,Axoplasmic transport ,Eyes ,Ocular Hypertension ,lcsh:Q ,sense organs ,business ,Head ,Protein Kinases ,030217 neurology & neurosurgery ,Neuroscience - Abstract
Glaucomatous axon injury occurs at the level of the optic nerve head (ONH) in response to uncontrolled intraocular pressure (IOP). The temporal response of ONH astrocytes (glial cells responsible for axonal support) to elevated IOP remains unknown. Here, we evaluate the response of actin-based astrocyte extensions and integrin-based signaling within the ONH to 8 hours of IOP elevation in a rat model. IOP elevation of 60 mm Hg was achieved under isoflurane anesthesia using anterior chamber cannulation connected to a saline reservoir. ONH astrocytic extension orientation was significantly and regionally rearranged immediately after IOP elevation (inferior ONH, 43.2° ± 13.3° with respect to the anterior-posterior axis versus 84.1° ± 1.3° in controls, p
- Published
- 2016
22. Impact of intraocular pressure on changes of blood flow in the retina, choroid, and optic nerve head in rats investigated by optical microangiography
- Author
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John C. Morrison, Elaine C. Johnson, Zhongwei Zhi, Ruikang K. Wang, and William O. Cepurna
- Subjects
Central retinal artery ,medicine.medical_specialty ,Intraocular pressure ,genetic structures ,Perfusion scanning ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,medicine.artery ,Ophthalmology ,medicine ,ocis:(170.4460) Ophthalmic optics and devices ,ocis:(170.4500) Optical coherence tomography ,030304 developmental biology ,0303 health sciences ,business.industry ,Retinal ,Blood flow ,Laser Doppler velocimetry ,Atomic and Molecular Physics, and Optics ,eye diseases ,chemistry ,Microangiography ,Ophthalmology Applications ,030221 ophthalmology & optometry ,sense organs ,ocis:(170.3880) Medical and biological imaging ,business ,Perfusion ,Biotechnology - Abstract
In this paper, we demonstrate the use of optical coherence tomography/optical microangiography (OCT/OMAG) to image and measure the effects of acute intraocular pressure (IOP) elevation on retinal, choroidal and optic nerve head (ONH) perfusion in the rat eye. In the experiments, IOP was elevated from 10 to 100 mmHg in 10 mmHg increments. At each IOP level, three-dimensional data volumes were captured using an ultrahigh sensitive (UHS) OMAG scanning protocol for 3D volumetric perfusion imaging, followed by repeated B-scans for Doppler OMAG analysis to determine blood flow velocity. Velocity and vessel diameter measurements were used to calculate blood flow in selected retinal blood vessels. Choroidal perfusion was calculated by determining the peripapillary choroidal filling at each pressure level and calculating this as a percentage of area filling at baseline (10 mmHg). ONH blood perfusion was calculated as the percentage of blood flow area over a segmented ONH area to a depth 150 microns posterior to the choroidal opening. We show that volumetric blood flow reconstructions revealed detailed 3D maps, to the capillary level, of the retinal, choroidal and ONH microvasculature, revealing retinal arterioles, capillaries and veins, the choroidal opening and a consistent presence of the central retinal artery inferior to the ONH. While OCT structural images revealed a reversible compression of the ONH and vasculature with elevated IOP, OMAG successfully documented changes in retinal, choroidal and ONH blood perfusion and allowed quantitative measurements of these changes. Starting from 30 mm Hg, retinal blood flow (RBF) diminished linearly with increasing IOP and was nearly extinguished at 100 mm Hg, with full recovery after return of IOP to baseline. Choroidal filling was unaffected until IOP reached 60 mmHg, then decreased to 20% of baseline at IOP 100 mmHg, and normalized when IOP returned to baseline. A reduction in ONH blood perfusion at higher IOP’s was also observed, but shadow from overlying retinal vessels at lower IOP’s limited precise measurements of changes in ONH capillary perfusion compared to baseline. Therefore, OCT/OMAG can be a useful tool to image and measure blood flow in the retina, choroidal and ONH of the rat eye as well as document the effects of elevated IOP on blood flow in these vascular beds.
- Published
- 2012
23. Volumetric and quantitative imaging of retinal blood flow in rats with optical microangiography
- Author
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Elaine C. Johnson, Zhongwei Zhi, Tueng T. Shen, Ruikang K. Wang, William O. Cepurna, and John C. Morrison
- Subjects
Pathology ,medicine.medical_specialty ,genetic structures ,01 natural sciences ,010309 optics ,03 medical and health sciences ,chemistry.chemical_compound ,symbols.namesake ,0302 clinical medicine ,Optical coherence tomography ,0103 physical sciences ,ocis:(170.4500) Optical coherence tomography ,Medicine ,medicine.diagnostic_test ,business.industry ,Retinal ,Blood flow ,Laser Doppler velocimetry ,Atomic and Molecular Physics, and Optics ,eye diseases ,Flow velocity ,chemistry ,Microangiography ,030221 ophthalmology & optometry ,symbols ,cardiovascular system ,Optical Coherence Tomography ,ocis:(170.3880) Medical and biological imaging ,business ,Doppler effect ,Perfusion ,Biotechnology ,Biomedical engineering - Abstract
In this paper, we present methods for 3D visualization and quantitative measurements of retinal blood flow in rats by the use of optical microangiography imaging technique (OMAG). We use ultrahigh sensitive OMAG to provide high-quality 3D RBF perfusion maps in the rat eye, from which the Doppler angle, as well as the diameters of blood vessels, are evaluated. Estimation of flow velocity (i.e. axial flow velocity) is achieved by the use of Doppler OMAG, which has its origins in phase-resolved Doppler optical coherence tomography. The measurements of the Doppler angle, vessel size, and the axial velocity lead to the quantitative assessment of the absolute flow velocity and the blood flow rate in selected retinal vessels. We demonstrate the feasibility of OMAG to provide 3D microangiograms and quantitative assessment of retinal blood flow in a rat model subjected to raised intra-ocular pressure (IOP). We show that OMAG is capable of monitoring the longitudinal response of absolute blood velocity and flow rate of retinal blood vessels to increased IOP in the rat, demonstrating its usefulness for ophthalmological research.
- Published
- 2011
24. Introduction to Special Issue on glaucomatous optic neuropathy: in vivo models and techniques
- Author
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John C. Morrison, C. Ross Ethier, and Abbott F. Clark
- Subjects
medicine.medical_specialty ,genetic structures ,business.industry ,Glaucoma ,medicine.disease ,Glaucomatous optic neuropathy ,eye diseases ,Sensory Systems ,Pathophysiology ,Article ,Cellular and Molecular Neuroscience ,Ophthalmology ,Disease Models, Animal ,In vivo ,Optic Nerve Diseases ,medicine ,Optic nerve ,Animals ,Humans ,sense organs ,business ,Neuroscience ,Intraocular Pressure - Abstract
• Animal models are essential to understand the basic pathophysiology of glaucoma and to develop improved treatments.
- Published
- 2015
25. Evaluation of the effect of elevated intraocular pressure and reduced ocular perfusion pressure on retinal capillary bed filling and total retinal blood flow in rats by OMAG/OCT
- Author
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Zhongwei Zhi, Ruikang K. Wang, Elaine C. Johnson, Hari Jayaram, John C. Morrison, and William O. Cepurna
- Subjects
medicine.medical_specialty ,Mean arterial pressure ,Intraocular pressure ,genetic structures ,Contrast Media ,Blood Pressure ,Biochemistry ,Article ,Retina ,Microcirculation ,chemistry.chemical_compound ,Imaging, Three-Dimensional ,Ophthalmology ,Pressure ,Medicine ,Animals ,Intraocular Pressure ,business.industry ,Angiography ,Retinal Vessels ,Retinal ,Cell Biology ,Anatomy ,Equipment Design ,Laser Doppler velocimetry ,eye diseases ,Capillaries ,Rats ,Perfusion ,Blood pressure ,chemistry ,Microangiography ,Regional Blood Flow ,sense organs ,Cardiology and Cardiovascular Medicine ,business ,Blood Flow Velocity ,Tomography, Optical Coherence - Abstract
Purpose To determine if retinal capillary filling is preserved in the face of acutely elevated intraocular pressure (IOP) in anesthetized rats, despite a reduction in total retinal blood flow (RBF), using optical microangiography/optical coherence tomography (OMAG/OCT). Methods OMAG provided the capability of depth-resolved imaging of the retinal microvasculature down to the capillary level. Doppler OCT was applied to measure the total RBF using an enface integration approach. The microvascular pattern, capillary density, and total RBF were monitored in vivo as the IOP was increased from 10 to 100 mm Hg in 10 mm Hg intervals and returned back to 10 mm Hg. Results In animals with mean arterial pressure (MAP) of 102 ± 4 mm Hg (n = 10), when IOP was increased from 0 to 100 mm Hg, the capillary density remained at or above 80% of baseline for the IOP up to 60 mm Hg [or ocular perfusion pressure (OPP) at 40 mm Hg]. This was then decreased, achieving 60% of baseline at IOP 70 mm Hg and OPP of 30 mm Hg. Total RBF was unaffected by moderate increases in IOP up to 30 mm Hg, beyond which total RBF decreased linearly, reaching 50% of baseline at IOP 60 mm Hg and OPP 40 mm Hg. Both capillary density and total RBF were totally extinguished at 100 mm Hg, but fully recovered when IOP returned to baseline. By comparison, a separate group of animals with lower MAP (mean = 75 ± 6 mm Hg, n = 7) demonstrated comparable decreases in both capillary filling and total RBF at IOPs that were 20 mm Hg lower than in the initial group. Both were totally extinguished at 80 mm Hg, but fully recovered when IOP returned to baseline. Relationships of both parameters to OPP were unchanged. Conclusion Retinal capillary filling and total RBF responses to IOP elevation can be monitored non-invasively by OMAG/OCT and both are influenced by OPP. Retinal capillary filling was relatively preserved down to a perfusion pressure of 40 mm Hg, despite a linear reduction in total RBF.
- Published
- 2015
26. Effectiveness of progestogens to improve perinatal outcome in twin pregnancies : an individual participant data meta-analysis
- Author
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Everett F. Magann, Elcin Cetingoz, Nicolaas P.A. Zuithoff, Y M Amin, Ewoud Schuit, John C. Morrison, Ateş Karateke, Mona M. Aboulghar, Mohamed A. Aboulghar, S. N. Caritis, Vicente Serra, Eduardo Borges da Fonseca, Christian M. Briery, Christophe Vayssière, Anneke Kwee, Arianne C. Lim, Juan Meseguer, Line Rode, Jane E. Norman, Kimberly Maurel, Rolf H.H. Groenwold, Ann Tabor, Alfredo Perales, Ihab M. Usta, K. H. Nicolaides, Ben W.J. Mol, Anwar H. Nassar, Katharina Worda, Sue Ross, Thomas J. Garite, C Cam, Dwight J. Rouse, Sarah J. Stock, Stephen Wood, Johnny Awwad, C.A. Combs, Elizabeth Thom, and K Moons
- Subjects
Cervical pessary ,Adult ,medicine.medical_specialty ,medicine.medical_treatment ,Perinatal Death ,Diseases ,Cervix Uteri ,Infant, Newborn, Diseases ,Enterocolitis, Necrotizing ,Pregnancy ,17 alpha-Hydroxyprogesterone Caproate ,medicine ,Hydroxyprogesterones ,Humans ,Twin Pregnancy ,Progesterone ,Bronchopulmonary Dysplasia ,Cerebral Hemorrhage ,Respiratory Distress Syndrome ,Respiratory Distress Syndrome, Newborn ,Progestogen ,Intravaginal ,Obstetrics ,business.industry ,Enterocolitis ,Infant, Newborn ,Obstetrics and Gynecology ,Infant ,Twin ,medicine.disease ,Newborn ,Cervical Length Measurement ,Clinical trial ,Administration, Intravaginal ,Treatment Outcome ,Premature birth ,Relative risk ,Administration ,Pregnancy, Twin ,Premature Birth ,Female ,Progestins ,business ,Necrotizing - Abstract
Background In twin pregnancies, the rates of adverse perinatal outcome and subsequent long-term morbidity are substantial, and mainly result from preterm birth (PTB). Objectives To assess the effectiveness of progestogen treatment in the prevention of neonatal morbidity or PTB in twin pregnancies using individual participant data meta-analysis (IPDMA). Search strategy We searched international scientific databases, trial registration websites, and references of identified articles. Selection criteria Randomised clinical trials (RCTs) of 17–hydroxyprogesterone caproate (17Pc) or vaginally administered natural progesterone, compared with placebo or no treatment. Data collection and analysis Investigators of identified RCTs were asked to share their IPD. The primary outcome was a composite of perinatal mortality and severe neonatal morbidity. Prespecified subgroup analyses were performed for chorionicity, cervical length, and prior spontaneous PTB. Main results Thirteen trials included 3768 women and their 7536 babies. Neither 17Pc nor vaginal progesterone reduced the incidence of adverse perinatal outcome (17Pc relative risk, RR 1.1; 95% confidence interval, 95% CI 0.97–1.4, vaginal progesterone RR 0.97; 95% CI 0.77–1.2). In a subgroup of women with a cervical length of ≤25 mm, vaginal progesterone reduced adverse perinatal outcome when cervical length was measured at randomisation (15/56 versus 22/60; RR 0.57; 95% CI 0.47–0.70) or before 24 weeks of gestation (14/52 versus 21/56; RR 0.56; 95% CI 0.42–0.75). Author's conclusions In unselected women with an uncomplicated twin gestation, treatment with progestogens (intramuscular 17Pc or vaginal natural progesterone) does not improve perinatal outcome. Vaginal progesterone may be effective in the reduction of adverse perinatal outcome in women with a cervical length of ≤25 mm; however, further research is warranted to confirm this finding.
- Published
- 2015
27. Optical Coherence Tomography Angiography of Optic Disc Perfusion in Glaucoma
- Author
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Xiaogang Wang, Rebecca L. Armour, Devin M. Gattey, Martin F. Kraus, Yali Jia, James G. Fujimoto, John C. Morrison, Eric Wei, David Huang, Beth Edmunds, Xinbo Zhang, Lori H. Lombardi, Mansi Parikh, Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology. Research Laboratory of Electronics, Kraus, Martin F., and Fujimoto, James G.
- Subjects
Male ,Retinal Ganglion Cells ,medicine.medical_specialty ,Intraocular pressure ,genetic structures ,Optic Disk ,Optic disk ,Glaucoma ,Blood Pressure ,Sensitivity and Specificity ,Article ,Ophthalmoscopy ,Imaging, Three-Dimensional ,Nerve Fibers ,Optical coherence tomography ,Ophthalmology ,Laser-Doppler Flowmetry ,Medicine ,Humans ,Fluorescein Angiography ,Intraocular Pressure ,Aged ,medicine.diagnostic_test ,business.industry ,Reproducibility of Results ,Retinal Vessels ,Middle Aged ,Fluorescein angiography ,medicine.disease ,eye diseases ,Healthy Volunteers ,Surgery ,medicine.anatomical_structure ,Cross-Sectional Studies ,Regional Blood Flow ,Angiography ,Visual Field Tests ,Female ,sense organs ,Visual Fields ,business ,Blood Flow Velocity ,Tomography, Optical Coherence ,Optic disc - Abstract
Purpose To compare optic disc perfusion between normal subjects and subjects with glaucoma using optical coherence tomography (OCT) angiography and to detect optic disc perfusion changes in glaucoma. Design Observational, cross-sectional study. Participants Twenty-four normal subjects and 11 patients with glaucoma were included. Methods One eye of each subject was scanned by a high-speed 1050-nm–wavelength swept-source OCT instrument. The split-spectrum amplitude-decorrelation angiography (SSADA) algorithm was used to compute 3-dimensional optic disc angiography. A disc flow index was computed from 4 registered scans. Confocal scanning laser ophthalmoscopy (cSLO) was used to measure disc rim area, and stereo photography was used to evaluate cup/disc (C/D) ratios. Wide-field OCT scans over the discs were used to measure retinal nerve fiber layer (NFL) thickness. Main Outcome Measures Variability was assessed by coefficient of variation (CV). Diagnostic accuracy was assessed by sensitivity and specificity. Comparisons between glaucoma and normal groups were analyzed by Wilcoxon rank-sum test. Correlations among disc flow index, structural assessments, and visual field (VF) parameters were assessed by linear regression. Results In normal discs, a dense microvascular network was visible on OCT angiography. This network was visibly attenuated in subjects with glaucoma. The intra-visit repeatability, inter-visit reproducibility, and normal population variability of the optic disc flow index were 1.2%, 4.2%, and 5.0% CV, respectively. The disc flow index was reduced by 25% in the glaucoma group (P = 0.003). Sensitivity and specificity were both 100% using an optimized cutoff. The flow index was highly correlated with VF pattern standard deviation (R[superscript 2] = 0.752, P = 0.001). These correlations were significant even after accounting for age, C/D area ratio, NFL, and rim area. Conclusions Optical coherence tomography angiography, generated by the new SSADA, repeatably measures optic disc perfusion and may be useful in the evaluation of glaucoma and glaucoma progression., National Institutes of Health (U.S.) (Grant 1R01 EY023285-01), Rosenbaum's P30EY010572, National Institutes of Health (U.S.). Clinical and Translational Science Awards (CTSA) Program (Grant UL1TR000128), Research to Prevent Blindness, Inc. (United States) (Grant R01-EY11289-26), United States. Air Force Office of Scientific Research (FA9550-10-1-0551), German Research Foundation (DFG-HO-1791/11-1), German Research Foundation (DFG-GSC80-SAOT), German Research Foundation (Training Group 1773)
- Published
- 2014
28. Risk Management in Obstetrics and Neonatal-Perinatal Medicine
- Author
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John C. Morrison, Gretchen Garbe, Jonathan K. Muraskas, Lindsay Ellsworth, and Eric Culp
- Subjects
medicine.medical_specialty ,Obstetric medicine ,business.industry ,Obstetrics ,health care facilities, manpower, and services ,education ,female genital diseases and pregnancy complications ,Maternal-fetal medicine ,Obstetrics and gynaecology ,medicine ,Neonatal perinatal medicine ,business ,reproductive and urinary physiology ,Risk management ,health care economics and organizations - Abstract
The professional liability crisis remains a common problem for obstetricians. Approximately 90% of American College of Obstetricians and Gynecologists fellows have been sued at least once and 25% have been sued four or more times. Approximately 15% of obstetricians have ceased obstetric practice because of exorbitant premiums and the prevalence of nonmeritorious claims in this field of practice. The average age at which an obstetrician/gynecologist stops providing obstetrical care is currently 48 years of age; the age at which most physicians approach the peak of judgment and experience.
- Published
- 2012
29. Uterine Contraction Monitoring, Maintenance Tocolysis, and Preterm Birth
- Author
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John P. Elliott, Stephen Jones, and John C. Morrison
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Pregnancy ,medicine.medical_specialty ,business.industry ,Obstetrics ,Terbutaline ,medicine.disease ,Maintenance therapy ,medicine ,Infusion pump ,Gestation ,business ,Regular Uterine Contraction ,Tertiary Prevention ,medicine.drug ,Full Term - Abstract
Uterine contractions occur in runs of 1-3/hr throughout pregnancy from early in the second trimester until full term usually without consequence. Regular uterine contractions are essential in every case of preterm labor (PTL) resulting in preterm delivery at
- Published
- 2012
30. Progestogens to prevent preterm birth in twin pregnancies:an individual participant data meta-analysis of randomized trials
- Author
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Steve N. Caritis, Thomas J. Garite, Julia Zachary, Anneke Kwee, Ewoud Schuit, Sarah J. Stock, Catherine Y. Spong, Everett F. Magann, Jane E. Norman, Kimberly Maurel, Karel G.M. Moons, Ben W.J. Mol, Ann Tabor, Dwight J. Rouse, Elizabeth Thom, Arianne C. Lim, Vicente Serra, Alfredo Perales, John C. Morrison, Anwar H. Nassar, Elcin Cetingoz, George R. Saade, Line Rode, Rolf H.H. Groenwold, C. Andrew Combs, Katharina Klein, Juan Meseguer, Christian M. Briery, Other departments, Obstetrics and Gynaecology, and Amsterdam Public Health
- Subjects
Adult ,medicine.medical_specialty ,Reproductive medicine ,lcsh:Gynecology and obstetrics ,law.invention ,Study Protocol ,Clinical Protocols ,Randomized controlled trial ,Pregnancy ,law ,Obstetrics and Gynaecology ,medicine ,Humans ,Adverse effect ,Twin Pregnancy ,lcsh:RG1-991 ,Randomized Controlled Trials as Topic ,Models, Statistical ,Obstetrics ,business.industry ,Individual participant data ,Infant, Newborn ,Pregnancy Outcome ,Obstetrics and Gynecology ,medicine.disease ,Pregnancy Complications ,Premature birth ,Meta-analysis ,Pregnancy, Twin ,Premature Birth ,Female ,Progestins ,business - Abstract
Background Preterm birth is the principal factor contributing to adverse outcomes in multiple pregnancies. Randomized controlled trials of progestogens to prevent preterm birth in twin pregnancies have shown no clear benefits. However, individual studies have not had sufficient power to evaluate potential benefits in women at particular high risk of early delivery (for example, women with a previous preterm birth or short cervix) or to determine adverse effects for rare outcomes such as intrauterine death. Methods/design We propose an individual participant data meta-analysis of high quality randomized, double-blind, placebo-controlled trials of progestogen treatment in women with a twin pregnancy. The primary outcome will be adverse perinatal outcome (a composite measure of perinatal mortality and significant neonatal morbidity). Missing data will be imputed within each original study, before data of the individual studies are pooled. The effects of 17-hydroxyprogesterone caproate or vaginal progesterone treatment in women with twin pregnancies will be estimated by means of a random effects log-binomial model. Analyses will be adjusted for variables used in stratified randomization as appropriate. Pre-specified subgroup analysis will be performed to explore the effect of progestogen treatment in high-risk groups. Discussion Combining individual patient data from different randomized trials has potential to provide valuable, clinically useful information regarding the benefits and potential harms of progestogens in women with twin pregnancy overall and in relevant subgroups.
- Published
- 2012
31. Current issues and perspectives in prenatal nutrition
- Author
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John P. Elliott, Baha M. Sibai, Michael W Pill, Robert A. Knuppel, and John C. Morrison
- Subjects
medicine.medical_specialty ,Pregnancy ,Prenatal nutrition ,business.industry ,Research and Reports in Neonatology ,General Engineering ,Physiology ,Intrauterine growth restriction ,Type 2 diabetes ,medicine.disease ,Preeclampsia ,Gestational diabetes ,Malnutrition ,Endocrinology ,Internal medicine ,Morning sickness ,medicine ,medicine.symptom ,business - Abstract
John C Morrison1, John Elliott2, Robert A Knuppel3, Baha Sibai4, Michael W Pill51Department of Obstetrics and Gynecology, University of Mississippi Medical Center, Jackson, MS, USA; 2Saddleback Memorial Medical Center, Women's Hospital, Laguna Hills, CA, USA; 3DuBois Regional Medical Center, DuBois, PA, USA; 4University of Cincinnati College of Medicine, Cincinnati, OH, USA; 5Gemini Healthcare, Westbrook, CT, USAAbstract: The typical American diet, characterized by energy-dense foods rich in starches, sugars, and saturated fats, and low in fruits and vegetables, is relatively unhealthy and is associated with nutritional deficiencies. Suboptimal diets for pregnant women have been associated with serious maternal medical complications (eg, iron deficiency anemia, high blood pressure, gestational diabetes, and morning sickness), as well as an increased risk of intrauterine growth restriction, birth defects, developmental delays after birth, and future chronic health problems, (eg, heart disease, type 2 diabetes, high blood pressure, and high cholesterol) during childhood, as well as later in life. Folic acid deficiency is one of the most common problems among pregnant women, and supplementation with folic acid during pregnancy has been reported to decrease the occurrence and recurrence of fetal neural tube defects. Folate supplementation beginning preconception, along with a multivitamin, at least 12 weeks prior to conception is recommended to achieve maximal risk reduction. The reported benefits of supplementing docosahexaenoic acid, an unsaturated omega-3 essential fatty acid, during pregnancy include promoting proper neurodevelopment in fetuses and infants that extends into childhood. Pregnancy is also associated with an increased susceptibility to oxidative stress, resulting from the imbalance between oxygen free radicals and the essential antioxidants that maintain homeostasis. Associated complications include preeclampsia, preterm labor, and intrauterine growth restriction. There is not enough evidence to support routine use of antioxidants, such as vitamins C and E during pregnancy, but coenzyme Q10 and lycopene are additional antioxidants under study and are yielding promising results by decreasing the occurrence of maternal complications.Keywords: prenatal nutrition, oxidative stress, coenzyme Q10, lycopene
- Published
- 2011
32. Does Method of Placental Removal or Site of Uterine Incision Repair Alter Endometritis After Cesarean Delivery?
- Author
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James N. Martin, Everett F. Magann, Robert L. Harris, Mark K. Dodson, Randall C. Floyd, and John C. Morrison
- Subjects
Gynecology ,medicine.medical_specialty ,Article Subject ,business.industry ,Obstetrics and Gynecology ,Dermatology ,medicine.disease ,lcsh:Gynecology and obstetrics ,lcsh:Infectious and parasitic diseases ,Uterine repair ,Infectious Diseases ,medicine ,lcsh:RC109-216 ,Endometritis ,Cesarean delivery ,business ,lcsh:RG1-991 ,Research Article - Abstract
Objective:his investigation was undertaken to evaluate the relationship between postcesarean endometritis and (1) method of placental removal and (2) site for uterine repair.Methods:This prospective, randomized study included 120 patients who underwent primary or repeat abdominal delivery for arrest of progress in labor, fetal distress, or breech presentation. Parturients were divided into four groups: I—spontaneous placental detachment, in situ uterine repair; II—spontaneous placental detachment, exteriorized uterine repair; III—manual placental removal, in situ uterine repair; and IV—manual placental removal, exteriorized uterine repair. Prophylactic antibiotics were not used.Results:Endometritis was significantly increased in the manual removal/exteriorized uterine repair group versus all the other groups including the spontaneous removal in situ (group I,P= 0.012), the spontaneous removal/exteriorized repair group (group II,P= 0.034), and the manual removal/in situ repair group (group III,P= 0.043). Comparison of group IV (manual removal/ exteriorized repair) with the combined groups I, II, and III (spontaneous removal/in situ repair, spontaneous removal/exteriorized repair, and manual removal/in situ repair) was significantly different (P= 0.005). Prior to delivery, use of an internal monitoring system, skill of the operating surgeon, and type of anesthesia were similar among groups.Conclusions:The findings of this investigation suggest that; when other known causes of infectious morbidity are constant, manual placental remvol in association with exteriorization for uterine repair significantly increases postcesarean endometritis.
- Published
- 1993
33. Association of Birth Weight with Polymorphisms in the IGF2, H19 and IGF2R Genes
- Author
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John C. Morrison, Erin M. Watson, James B. Hill, Everett F. Magann, Grant Somes, Julia Krushkal, and Ronald M. Adkins
- Subjects
Adult ,Male ,medicine.medical_specialty ,RNA, Untranslated ,Adolescent ,Genotype ,Birth weight ,Single-nucleotide polymorphism ,Locus (genetics) ,Biology ,Polymorphism, Single Nucleotide ,Genetic determinism ,Article ,Receptor, IGF Type 2 ,Young Adult ,Gene Frequency ,Insulin-Like Growth Factor II ,Internal medicine ,medicine ,Birth Weight ,Humans ,Allele ,Allele frequency ,Genetics ,Maternal effect ,Infant, Newborn ,female genital diseases and pregnancy complications ,Endocrinology ,Pediatrics, Perinatology and Child Health ,Female ,RNA, Long Noncoding - Abstract
There is a substantial genetic component to birth weight variation. We tested eighteen single nucleotide polymorphisms (SNPs) in the IGF2, H19, and IGF2R genes for associations with birth weight variation in 342 mother-newborn pairs (birth weight 2.1 – 4.7 Kg at term) and 527 parent-newborn trios (birth weight 2.1 – 5.1 Kg) across three localities. SNPs in the IGF2R (rs8191754; maternal genotype), IGF2 (rs3741205; newborn genotype) and in the 5' region of the H19 (rs2067051, rs2251375, and rs4929984) genes were associated with birth weight. Detailed analyses to distinguish direct maternal, direct newborn, and parent of origin effects for the most strongly associated H19 SNP (rs4929984) determined that the association of maternal genotype with newborn birth weight was due to parent of origin effects, not direct maternal effects. That SNP is located near the CTCF binding sites that influence expression of the maternally-imprinted IGF2 and paternally-imprinted H19 locus, and there are statistically significant and independent opposite effects of the same rs4929984 allele, depending on the parent from which it was inherited.
- Published
- 2010
34. Retinal Cell Responses to Elevated Intraocular Pressure: A Gene Array Comparison between the Whole Retina and Retinal Ganglion Cell Layer
- Author
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T. A. Doser, William O. Cepurna, John C. Morrison, J. A. Dyck, Elaine C. Johnson, and Ying Guo
- Subjects
Retinal Ganglion Cells ,medicine.medical_specialty ,Intraocular pressure ,genetic structures ,Glaucoma ,Giant retinal ganglion cells ,Biology ,Retina ,Immunoenzyme Techniques ,Ophthalmology ,Rats, Inbred BN ,medicine ,Animals ,RNA, Messenger ,Eye Proteins ,Intraocular Pressure ,Oligonucleotide Array Sequence Analysis ,Regulation of gene expression ,Reverse Transcriptase Polymerase Chain Reaction ,Gene Expression Profiling ,Intrinsically photosensitive retinal ganglion cells ,Articles ,medicine.disease ,Molecular biology ,eye diseases ,Rats ,Gene expression profiling ,Disease Models, Animal ,medicine.anatomical_structure ,Retinal ganglion cell ,Gene Expression Regulation ,sense organs - Abstract
To determine and compare gene expression patterns in the whole retina and retinal ganglion cell layer (RGCL) in a rodent glaucoma model.IOP was unilaterally elevated in Brown Norway rats (N = 26) by injection of hypertonic saline and monitored for 5 weeks. A cDNA microarray was used on whole retinas from one group of eyes with extensive optic nerve injury and on RGCL isolated by laser capture microdissection (LCM) from another group with comparable injury, to determine the significantly up- or downregulated genes and gene categories in both groups. Expression changes of selected genes were examined by quantitative reverse transcription-PCR (qPCR) to verify microarray results.Microarray analysis of the whole retina identified 632 genes with significantly changed expression (335 up, 297 down), associated with 9 upregulated and 3 downregulated biological processes. In contrast, the RGCL microarray yielded 3726 genes with significantly changed expression (2003 up, 1723 down), including 60% of those found in whole retina. Thirteen distinct upregulated biological processes were identified in the RGCL, dominated by protein synthesis. Among 11 downregulated processes, axon extension and dendrite morphogenesis and generation of precursor metabolism and energy were uniquely identified in the RGCL. qPCR confirmed significant changes in 6 selected messages in whole retina and 11 in RGCL. Increased Atf3, the most upregulated gene in the RGCL, was confirmed by immunohistochemistry of RGCs.Isolation of RGCL by LCM allows a more refined detection of gene response to elevated pressure and improves the potential of determining cellular mechanisms in RGCs and their supporting cells that could be targets for enhancing RGC survival.
- Published
- 2010
35. Extensive parent-of-origin genetic effects on fetal growth
- Author
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Everett F. Magann, John H Fain, Chad K. Klauser, Ronald M. Adkins, Grant W. Somes, Julia Krushkal, and John C. Morrison
- Subjects
medicine.medical_specialty ,Bioinformatics ,lcsh:Computer applications to medicine. Medical informatics ,Biochemistry ,03 medical and health sciences ,0302 clinical medicine ,Obstetrics and gynaecology ,Structural Biology ,Health science ,Fetal growth ,medicine ,Molecular Biology ,lcsh:QH301-705.5 ,030304 developmental biology ,0303 health sciences ,biology ,business.industry ,Applied Mathematics ,biology.organism_classification ,3. Good health ,Computer Science Applications ,Geography ,nervous system ,lcsh:Biology (General) ,030220 oncology & carcinogenesis ,Family medicine ,Meeting Abstract ,lcsh:R858-859.7 ,Memphis ,business - Abstract
Address: 1Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN 38163, USA, 2Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA, 3Department of Molecular Sciences, University of Tennessee Health Science Center, Memphis, TN 38163, USA, 4Department of Obstetrics and Gynecology, University of Mississippi Medical Center, Jackson, MS 39216, USA and 5Department of Obstetrics and Gynecology, Naval Medical Center at Portsmouth, VA 23708, USA
- Published
- 2009
36. Reliability and Sensitivity of the TonoLab Rebound Tonometer in Awake Brown Norway Rats
- Author
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L. Jia, Ying Guo, Elaine C. Johnson, John C. Morrison, and William O. Cepurna
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medicine.medical_specialty ,Intraocular pressure ,genetic structures ,Dark Adaptation ,Sensitivity and Specificity ,Article ,Aqueous Humor ,Tonometry, Ocular ,Ophthalmology ,Rats, Inbred BN ,Optic Nerve Diseases ,medicine ,Animals ,Intraocular Pressure ,business.industry ,BROWN NORWAY ,Reproducibility of Results ,eye diseases ,Circadian Rhythm ,Rats ,Disease Models, Animal ,Calibration ,Optic nerve ,Ocular Hypertension ,sense organs ,business - Abstract
To compare the sensitivity of the TonoLab rebound tonometer with the Tono-Pen in awake Brown Norway rats and to compare their ability to predict optic nerve damage induced by experimental IOP elevation.TonoLab and Tono-Pen tonometers were calibrated in cannulated rat eyes connected to a pressure transducer. The TonoLab was used in awake animals housed in standard lighting to measure IOP during light and dark phases. Both instruments were used to monitor chronically elevated IOP produced by episcleral vein injection of hypertonic saline. Measured IOPs were correlated with quantified optic nerve damage in injected eyes.Although they were lower than transducer and Tono-Pen measurements at all levels, TonoLab readings showed an excellent linear fit with transducer readings from 20 to 80 mm Hg (R(2) = 0.99) in cannulated eyes. In awake animals housed in standard lighting, the TonoLab documented significantly higher pressures during the dark phase (27.9 +/- 1.7 mm Hg) than during the light phase (16.7 +/- 2.3 mm Hg). With elevated IOP, correlation between TonoLab and Tono-Pen readings (R(2) = 0.86, P0.0001) was similar to that in cannulated eyes. Although both instruments provided measurements that correlated well with optic nerve injury grade, only the Tono-Pen documented significant IOP elevation in eyes with the least amount of injury (P0.05).The TonoLab is sensitive enough to be used in awake Brown Norway rats, though instrument fluctuation may limit its ability to identify significant pressure elevations in eyes with minimal optic nerve damage.
- Published
- 2009
37. NEUROTROPHIN ROLES IN RETINAL GANGLION CELL SURVIVAL: LESSONS FROM RAT GLAUCOMA MODELS
- Author
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William O. Cepurna, Elaine C. Johnson, Ying Guo, and John C. Morrison
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Retinal Ganglion Cells ,Intraocular pressure ,genetic structures ,Cell Survival ,Glaucoma ,Retinal ganglion ,Article ,Cellular and Molecular Neuroscience ,Neurotrophic factors ,medicine ,Animals ,Nerve Growth Factors ,Retina ,biology ,medicine.disease ,Sensory Systems ,eye diseases ,Rats ,Ophthalmology ,Disease Models, Animal ,medicine.anatomical_structure ,Neuroprotective Agents ,Retinal ganglion cell ,biology.protein ,Optic nerve ,sense organs ,Neuroscience ,Neurotrophin - Abstract
The neurotrophin (NT) hypothesis proposes that the obstruction of retrograde transport at the optic nerve head results in the deprivation of neurotrophic support to retinal ganglion cells (RGC) leading to apoptotic cell death in glaucoma. An important corollary to this concept is the implication that appropriate enhancement of neurotrophic support will prolong the survival of injured RGC indefinitely. This hypothesis is, perhaps, the most widely recognized theory to explain RGC loss resulting from exposure of the eye to elevated intraocular pressure (IOP). Recent studies of NT signaling using rat glaucoma models, have examined the endogenous responses of the retina to pressure exposure as well as studies designed to augment NT signaling in order to rescue RGC from apoptosis following pressure-induced injury. The examination of these studies in this review reveals a number of consistent observations and provides direction for further investigations of this hypothesis.
- Published
- 2009
38. Surgical Reduction of Dysesthetic Blebs
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Michael J. Lloyd, Matthew Giegengack, and John C. Morrison
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Male ,Intraocular pressure ,medicine.medical_specialty ,Alkylating Agents ,Visual acuity ,genetic structures ,medicine.medical_treatment ,Mitomycin ,Visual Acuity ,Glaucoma ,Aqueous humor ,Trabeculectomy ,Article ,Lens Implantation, Intraocular ,Ophthalmology ,medicine ,Humans ,Bleb (cell biology) ,Paresthesia ,Intraocular Pressure ,Aged ,Retrospective Studies ,Aged, 80 and over ,Phacoemulsification ,business.industry ,Middle Aged ,medicine.disease ,Combined Modality Therapy ,eye diseases ,Surgery ,Surgical reduction ,Female ,sense organs ,medicine.symptom ,business ,Conjunctiva ,Glaucoma, Open-Angle - Abstract
Dysesthetic blebs can complicate filtration surgery. Lubrication often reduces symptoms; however, some cases require surgical intervention. Limited conjunctivoplasty reduces the symptoms of dysesthetic blebs without sacrificing control of intraocular pressure (IOP). However, this may not sufficiently lower these blebs, particularly if the bleb is thick and dense. We describe a modified conjunctivoplasty technique that includes removal of sub-conjunctival scar tissue within the interpalpebral fissure and provide a 1-year follow-up of 13 eyes treated in this manner. All patients reported rapid, complete symptom resolution. The IOP was controlled in all 13 eyes following conjunctivoplasty; 3 required topical antiglaucoma therapy. Subconjunctival scar tissue may contribute to the formation of dysesthetic blebs owing to its thickness and by encouraging local dissection of aqueous humor. Our report demonstrates that removal of this tissue does not compromise IOP control when performed with conjunctivoplasty.
- Published
- 2008
39. Comparison of Anterior Segment Structures in Two Rat Glaucoma Models: An Ultrasound Biomicroscopic Study
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William O. Cepurna, John Danias, Thomas W. Mittag, L. Jia, John C. Morrison, Elaine C. Johnson, Nikolaos Nissirios, and R.A. Chanis
- Subjects
Male ,medicine.medical_specialty ,Intraocular pressure ,genetic structures ,Ultrasound biomicroscopy ,Microscopy, Acoustic ,Glaucoma ,Ocular hypertension ,Scleral spur ,Article ,Tonometry, Ocular ,Ciliary body ,Anterior Eye Segment ,Ophthalmology ,Rats, Inbred BN ,medicine ,Animals ,Rats, Wistar ,Intraocular Pressure ,business.industry ,medicine.disease ,eye diseases ,Hypertonic saline ,Rats ,Disease Models, Animal ,medicine.anatomical_structure ,Optic nerve ,Female ,Ocular Hypertension ,sense organs ,business - Abstract
Purpose—Optic nerve disease in chronic IOP elevation rat glaucoma models develops at different rates. This study was undertaken to investigate whether anterior chamber (AC) changes develop in two popular models in vivo and whether the changes are related to IOP. Methods—Ten female Wistar rats and 12 male Brown-Norway rats were subjected to episcleral vein cauterization (EVC) and hypertonic saline episcleral vein sclerosis (HSEVS), respectively. Contralateral untreated eyes served as controls. IOP was recorded for a period of 5 to 6 weeks, and with the rats under anesthesia, the eyes were imaged with an ultrasound biomicroscope. Measurements of the AC depth (ACD), trabecular–iris angle (TIA), iris thickness at the thickest point near the pupillary margin (IT), angle opening distance (AOD; at 200 μm from the scleral spur), and ciliary body area (CBA) were compared between control eyes of the two strains and between experimental and control eyes within each strain. The differences were correlated with IOP history. Results—Eyes subjected to EVC demonstrated greater increases in IOP than eyes subjected to HSEVS. Between rat strains, control eyes differed significantly in all the parameters studied, except for ACD. No difference was detected between experimental and control eyes in the EVC group. In contrast, experimental eyes in the HSEVS group had ~71% larger ACDs and ~32% smaller CBAs than did the contralateral control eyes (P < 0.001). ACD and CBA correlated well (R 2 = 0.80 and 0.51, respectively) with IOP in the HSEVS group. Two of the experimental eyes in this group showed the presence of ultrasound-scattering material in the AC. Conclusions—Despite apparently higher IOP exposure, eyes in the EVC rat model of glaucoma do not undergo changes in the AC. In contrast, eyes subjected to HSEVS display deepening of the AC and reduction in size of the ciliary body within 5 to 6 weeks. These changes correlate to IOP exposure and may be the result of specific changes induced by the experimental intervention. These models are likely to rely on different mechanisms of pressure elevation and cannot be used interchangeably. Rat models of glaucoma that involve chronic elevation of IOP are often used to study the retinal and optic nerve pathophysiology of the disease 1 as well as for screening potential neuroprotective agents. 2 These models presumably rely on occlusion of the outflow pathways
- Published
- 2008
40. Global Changes in Optic Nerve Head Gene Expression after Exposure to Elevated Intraocular Pressure in a Rat Glaucoma Model
- Author
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John C. Morrison, Elaine C. Johnson, Thomas A. Doser, William O. Cepurna, and L. Jia
- Subjects
Ribosomal Proteins ,Pathology ,medicine.medical_specialty ,genetic structures ,Genes, MHC Class II ,Optic Disk ,Optic disk ,Ocular hypertension ,Glaucoma ,Nerve fiber ,Biology ,Retinal ganglion ,Polymerase Chain Reaction ,Article ,Immunoenzyme Techniques ,Transforming Growth Factor beta ,Rats, Inbred BN ,Optic Nerve Diseases ,medicine ,Animals ,RNA, Messenger ,Intraocular Pressure ,Cell Proliferation ,Oligonucleotide Array Sequence Analysis ,Gene Expression Profiling ,Nerve injury ,medicine.disease ,Lipids ,eye diseases ,Extracellular Matrix ,Rats ,Up-Regulation ,Disease Models, Animal ,medicine.anatomical_structure ,nervous system ,Gene Expression Regulation ,Optic nerve ,sense organs ,Microglia ,medicine.symptom ,Lysosomes ,Optic disc - Abstract
Glaucoma is the second leading cause of blindness worldwide, affecting approximately 60 million people.1 Although many risk factors are associated with glaucoma, IOP is the most widely recognized, and lowering IOP is the goal of current glaucoma therapies. When IOP is experimentally elevated in nonhuman primates, the pattern of optic nerve head (ONH) cupping, optic nerve axon degeneration, and selective loss of retinal ganglion cells replicates the pathologic features of human glaucoma. Clinically, human glaucomatous optic neuropathy is characterized by optic disc cupping and a pattern of visual field loss.2 Cupping results from the loss of optic nerve axons and posterior bowing and remodeling of the support structures of the ONH.3,4 Often, these changes are most pronounced in the superior and inferior parts of the nerve head. The most characteristic visual field defect is the arcuate scotoma, which arches above or below central fixation and follows the pathways of the nerve fiber bundles as they converge on the superior and inferior poles of the ONH.2,5,6 Regional variation in laminar structure suggests less support and protection for axons, possibly explaining the apparent increased susceptibility of axons that pass through the superior and inferior ONH. In the face of increased or fluctuating IOP, movement of the lamina may result in preferential mechanical injury to neural tissues in these regions.7 In addition, because the vascular supply to the ONH tissue lies within the laminar beams, this pattern could result in regionally compromised blood flow.8 Current experimental evidence supporting either of these mechanisms is limited, and the cellular events that connect the regional pattern of glaucomatous optic nerve damage with the known structural anatomy of the ONH are still largely unknown. Regardless of mechanism, the variation in the structure of the ONH provides the only anatomic correlation with the characteristic pattern of glaucomatous optic nerve axon loss. The apparent vulnerability of the ONH to pressure-induced axonal injury has led many investigators to examine changes in the composition of glaucomatous human and experimental monkey ONH tissues. These ONHs are characterized by axon loss, gliotic scaring, increased expression of matrix metalloproteinases, and abnormal deposition of extracellular matrix (ECM) materials, including collagens, tropoelastin, tenascin, and proteoglycans.9–20 In the rat, glaucoma can be modeled by sclerosing aqueous outflow pathways to produce a sustained elevation of IOP.21 In this model, pressure causes a selective loss of retinal ganglion cells and a characteristic pattern of axon degeneration that begins in the superior quadrant of the optic nerve.21,22 In addition, immunohistochemical studies of ONH reveal that pressure-induced injury is accompanied by deposition of collagens and other ECM components, similar to that in human glaucoma.23 This deposition of ECM is preceded by a loss of gap junctional connexin 43 immunolabeling and evidence of astrocytic proliferation.24 By immunohistochemical analysis, the initial evidence of ECM deposition coincided with a decrease in ONH labeling for neurotrophins and astrocytic GFAP.24 Although the ONH is recognized as the likely site of initial injury in human glaucoma and in experimental IOP elevation glaucoma models, very little is known about the changes in gene expression that accompany this injury. In this study, we used microarray analysis to identify the genes and functional gene classes most altered in expression in the rat ONH after exposure to experimentally elevated pressure that results in extensive and ongoing optic nerve degeneration. Then, we used real-time quantitative (q)PCR to verify selected changes in gene expression initially identified by microarray analysis and to examine several genes not included on the arrays. To expand this study, we included qPCR analyses of ONHs from eyes with focal regions of degeneration in optic nerve cross-sections. Focal injury occurs in eyes with more mild pressure elevations or those of shorter duration and probably reflects earlier responses to pressure-induced nerve injury. We compared injury in these ONHs to those in ONHs with more extensive injury due to elevated IOP and to those after optic nerve transection, to evaluate ONH responses to simple loss of axons. The expansion of the qPCR study to nerves with focal injuries allows us to explore the potential of discovering, by future microarray analyses, unique or more dramatic alterations in gene expression that occur early in the injury process. To our knowledge, this is the first genome-wide analysis of expression changes in the ONH in response to elevated IOP.
- Published
- 2007
41. Haplotypes of the imprinted insulin gene are associated with size for gestational age and umbilical cord IGF-II levels
- Author
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Grant Somes, Julia Krushkal, Chad K. Klauser, Ronald M. Adkins, John C. Morrison, John N. Fain, and Everett F. Magann
- Subjects
Insulin Gene ,medicine.medical_specialty ,business.industry ,Applied Mathematics ,Haplotype ,Gestational age ,Bioinformatics ,Umbilical cord ,Biochemistry ,Computer Science Applications ,Endocrinology ,medicine.anatomical_structure ,Text mining ,Structural Biology ,Internal medicine ,Poster Presentation ,medicine ,DNA microarray ,business ,Molecular Biology - Published
- 2008
42. Glaucoma : Science and Practice
- Author
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John C. Morrison, Irvin P. Pollack, John C. Morrison, and Irvin P. Pollack
- Subjects
- Glaucoma
- Abstract
Refresh and update your knowledge on all new therapeutic techniques!Rapid advances in identifying the epidemiology, physiology, and genetics of glaucoma have led to dramatic developments in diagnostic and therapeutic techniques. This new text offers you concise coverage of every major clinical breakthrough, as well as the basic science needed to thoroughly understand all manifestations of the disease. It is written by a'who's who'of international experts, who share their tips and techniques in every information-filled chapter.Benefit from these special features: Key discussions of the pathophysiology of the disease, as well as the pharmacologic mechanisms of different drugs and their efficacy Valuable diagnostic decision diagrams that lead to quick and accurate decisions Helpful pearls, pitfalls, and special considerations that offer guidance in specific situations and show how to avoid problems and complications Nearly 300 superb, full-color illustrations that depict the distinguishing features of each entity Inclusion of such cutting-edge material as'neuroprotection', and several other new topics Whether you are an experienced practitioner needing a quick review or a resident learning a topic for the first time, Glaucoma: Science and Practice is packed with essential clinical and scientific information. Here is the timely, current, and practical resource you need to understand the complexities of glaucoma and provide optimal patient care.
- Published
- 2003
43. Infectious Necrosis With Dehiscence of the Uterine Repair Complicating Cesarean Delivery: A Review.
- Author
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Michel E Rivlin, C S Carroll, and John C Morrison
- Published
- 2004
- Full Text
- View/download PDF
44. The Impact of Leiomyomas on Pregnancy.
- Author
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Roberts, William E., Fulp, Kari S., MD, John C. Morrison, and Martin, James N.
- Published
- 1999
- Full Text
- View/download PDF
45. Elevated Intraocular Pressure and Optic Nerve Injury Models in the Rat.
- Author
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John C Morrison
- Published
- 2005
- Full Text
- View/download PDF
46. Induction of autophagy in rats upon overexpression of wild-type and mutant optineurin gene
- Author
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Tara T. Nguyen, Xiang X. Shen, John C. Morrison, Beatrice Y.J.T. Yue, Elaine C. Johnson, Hongyu Ying, Sanja S. Turturro, and Ruth Zelkha
- Subjects
Male ,Retinal Ganglion Cells ,Proteasome Endopeptidase Complex ,Recombinant Fusion Proteins ,Mutant ,Green Fluorescent Proteins ,Biology ,Retinal ganglion ,Adeno-associated type 2 viral (AAV2) vectors ,Green fluorescent protein ,Cell Line ,03 medical and health sciences ,0302 clinical medicine ,Downregulation and upregulation ,Transcription Factor TFIIIA ,Autophagy ,Animals ,Intraocular Pressure ,030304 developmental biology ,Optineurin ,Sirolimus ,0303 health sciences ,Wild type ,Glaucoma ,Cell Biology ,Amyotrophic lateral sclerosis ,Molecular biology ,Cell biology ,PSMB5 ,Rats ,Amino Acid Substitution ,030221 ophthalmology & optometry ,E50K mutation ,Rat ,Ubiquitin-proteasome pathway (UPP) ,Microtubule-Associated Proteins ,Research Article - Abstract
Background Optineurin is a gene associated with normal tension glaucoma and amyotrophic lateral sclerosis. It has been reported previously that in cultured RGC5 cells, the turnover of endogenous optineurin involves mainly the ubiquitin-proteasome pathway (UPP). When optineurin is upregulated or mutated, the UPP function is compromised as evidenced by a decreased proteasome β5 subunit (PSMB5) level and autophagy is induced for clearance of the optineurin protein. Results Adeno-associated type 2 viral (AAV2) vectors for green fluorescence protein (GFP) only, GFP-tagged wild-type and Glu50Lys (E50K) mutated optineurin were intravitreally injected into rats for expression in retinal ganglion cells (RGCs). Following intravitreal injections, eyes that received optineurin vectors exhibited retinal thinning, as well as RGC and axonal loss compared to GFP controls. By immunostaining and Western blotting, the level of PSMB5 and autophagic substrate degradation marker p62 was reduced, and the level of autophagic marker microtubule associated protein 1 light chain 3 (LC3) was enhanced. The UPP impairment and autophagy induction evidently occurred in vivo as in vitro. The optineurin level, RGC and axonal counts, and apoptosis in AAV2-E50K-GFP-injected rat eyes were averted to closer to normal limits after treatment with rapamycin, an autophagic enhancer. Conclusions The UPP function was reduced and autophagy was induced when wild-type and E50K optineurin was overexpressed in rat eyes. This study validates the in vitro findings, confirming that UPP impairment and autophagy induction also occur in vivo. In addition, rapamycin is demonstrated to clear the accumulated mutant optineurin. This agent may potentially be useful for rescuing of the adverse optineurin phenotypes in vivo.
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47. Astrocyte Structural and Molecular Response to Elevated Intraocular Pressure Occurs Rapidly and Precedes Axonal Tubulin Rearrangement within the Optic Nerve Head in a Rat Model.
- Author
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Shandiz Tehrani, Lauren Davis, William O Cepurna, Tiffany E Choe, Diana C Lozano, Ashley Monfared, Lauren Cooper, Joshua Cheng, Elaine C Johnson, and John C Morrison
- Subjects
Medicine ,Science - Abstract
Glaucomatous axon injury occurs at the level of the optic nerve head (ONH) in response to uncontrolled intraocular pressure (IOP). The temporal response of ONH astrocytes (glial cells responsible for axonal support) to elevated IOP remains unknown. Here, we evaluate the response of actin-based astrocyte extensions and integrin-based signaling within the ONH to 8 hours of IOP elevation in a rat model. IOP elevation of 60 mm Hg was achieved under isoflurane anesthesia using anterior chamber cannulation connected to a saline reservoir. ONH astrocytic extension orientation was significantly and regionally rearranged immediately after IOP elevation (inferior ONH, 43.2° ± 13.3° with respect to the anterior-posterior axis versus 84.1° ± 1.3° in controls, p
- Published
- 2016
- Full Text
- View/download PDF
48. Saving the World's Terrestrial Megafauna.
- Author
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Ripple WJ, Chapron G, López-Bao JV, Durant SM, Macdonald DW, Lindsey PA, Bennett EL, Beschta RL, Bruskotter JT, Campos-Arceiz A, Corlett RT, Darimont CT, Dickman AJ, Dirzo R, Dublin HT, Estes JA, Everatt KT, Galetti M, Goswami VR, Hayward MW, Hedges S, Hoffmann M, Hunter LTB, Kerley GIH, Letnic M, Levi T, Maisels F, Morrison JC, Nelson MP, Newsome TM, Painter L, Pringle RM, Sandom CJ, Terborgh J, Treves A, Van Valkenburgh B, Vucetich JA, Wirsing AJ, Wallach AD, Wolf C, Woodroffe R, Young H, and Zhang L
- Published
- 2016
- Full Text
- View/download PDF
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