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POSTERIORLY INSERTED VITREOUS BASE: Preoperative Characteristics, Intraoperative Findings, and Outcomes After Vitrectomy.

Fri, 2019-03-22 23:47
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POSTERIORLY INSERTED VITREOUS BASE: Preoperative Characteristics, Intraoperative Findings, and Outcomes After Vitrectomy.

Retina. 2019 Feb 15;:

Authors: Sohn EH, Strohbehn A, Stryjewski T, Brodowska K, Flamme-Wiese MJ, Mullins RF, Eliott D

Abstract
PURPOSE: To determine the preoperative characteristics, intraoperative and postoperative complications, and outcomes of eyes with posteriorly inserted vitreous base.
METHODS: In this retrospective, observational, consecutive case series at 2 academic centers, 37 patients were studied who had posteriorly inserted vitreous base noted during vitrectomy. Posteriorly inserted vitreous base was defined as the insertion of the posterior hyaloid membrane being located posterior to the vortex veins. Fifteen eyes were analyzed in a histopathologic study of donor eyes to determine the average distance of the ora serrata from the vortex veins as this distance is uncertain.
RESULTS: Posteriorly inserted vitreous base was identified during vitrectomy in 31 eyes with rhegmatogenous retinal detachment (84%), 4 with macular hole (11%), 1 with vitreous hemorrhage, and 1 with epiretinal membrane. Adjunctive buckle was used in 24%; 54% had 360° laser. Average number of tears seen preoperatively in those with rhegmatogenous retinal detachment was 3.1. Thirty percent had new breaks identified intraoperatively. Forty-one percent had lattice degeneration; new breaks were found in 40% of eyes with lattice. Thirteen percent of rhegmatogenous retinal detachments developed proliferative vitreoretinopathy. Average distance from the ora serrata to the vortex veins was 7.6 mm.
CONCLUSION: Any eye undergoing vitrectomy may have posteriorly inserted vitreous base, but those with a high number of retinal breaks and lattice near the equator may be at highest risk. Redetachment and proliferative vitreoretinopathy still occur despite knowledge of the disorder and adjuvant treatments.

PMID: 30883531 [PubMed - as supplied by publisher]

How Much Green Does It Take to Be Orange? Determining the Cost Associated with Trauma Center Readiness.

Fri, 2019-02-22 12:36
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How Much Green Does It Take to Be Orange? Determining the Cost Associated with Trauma Center Readiness.

J Trauma Acute Care Surg. 2019 Feb 13;:

Authors: Ashley DW, Mullins RF, Dente CJ, Johns TJ, Garlow LE, Medeiros RS, Atkins EV, Solomon G, Abston D, Ferdinand CH

Abstract
BACKGROUND: Readiness Costs are real expenses incurred by trauma centers to maintain essential infrastructure to provide emergent services on a 24/7 basis. Although the components for readiness are well described in the American College of Surgeon's Resources for Optimal Care of the Injured Patient, the cost associated with each component is not well defined. We hypothesized that meeting the requirements of the 2014 Resources for Optimal Care of the Injured Patient would result in significant costs for trauma centers.
METHODS: The state trauma commission in conjunction with trauma medical directors, program managers, and financial officers of each trauma center standardized definitions for each component of trauma center readiness cost and developed a survey tool for reporting. Readiness costs were grouped into four categories: Administrative/Program Support Staff, Clinical Medical Staff, In-House Operating Room, and Education/Outreach. To verify consistent cost reporting, a financial auditor analyzed all data. Trauma center outliers were further evaluated to validate variances. All Level I/Level II trauma centers (n=16) completed the survey on 2016 data.
RESULTS: Average annual readiness cost is $10,078,506 for a Level I trauma center and $4,925,103 for Level II's. Clinical medical staff was the costliest component representing 55% of costs for Level I's and 64% for Level II's. Although education/outreach is mandated, Level I and II trauma centers only spend approximately $100,000 annually on this category (1-2%) demonstrating a lack of resources.
CONCLUSIONS: This study defines the cost associated with each component of readiness as defined in the Resources for Optimal Care of the Injured Patient manual. Average readiness cost for a Level I trauma center is $10,078,506 and $4,925,103 for a Level II. The significant cost of trauma center readiness highlights the need for additional trauma center funding to meet the requirements set forth by the American College of Surgeons.
LEVEL OF EVIDENCE: Economic & Value-based Evaluations, level III.

PMID: 30768564 [PubMed - as supplied by publisher]

PyMINEr Finds Gene and Autocrine-Paracrine Networks from Human Islet scRNA-Seq.

Fri, 2019-02-15 11:26
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PyMINEr Finds Gene and Autocrine-Paracrine Networks from Human Islet scRNA-Seq.

Cell Rep. 2019 Feb 12;26(7):1951-1964.e8

Authors: Tyler SR, Rotti PG, Sun X, Yi Y, Xie W, Winter MC, Flamme-Wiese MJ, Tucker BA, Mullins RF, Norris AW, Engelhardt JF

Abstract
Toolsets available for in-depth analysis of scRNA-seq datasets by biologists with little informatics experience is limited. Here, we describe an informatics tool (PyMINEr) that fully automates cell type identification, cell type-specific pathway analyses, graph theory-based analysis of gene regulation, and detection of autocrine-paracrine signaling networks in silico. We applied PyMINEr to interrogate human pancreatic islet scRNA-seq datasets and discovered several features of co-expression graphs, including concordance of scRNA-seq-graph structure with both protein-protein interactions and 3D genomic architecture, association of high-connectivity and low-expression genes with cell type enrichment, and potential for the graph structure to clarify potential etiologies of enigmatic disease-associated variants. We further created a consensus co-expression network and autocrine-paracrine signaling networks within and across islet cell types from seven datasets. PyMINEr correctly identified changes in BMP-WNT signaling associated with cystic fibrosis pancreatic acinar cell loss. This proof-of-principle study demonstrates that the PyMINEr framework will be a valuable resource for scRNA-seq analyses.

PMID: 30759402 [PubMed - in process]

CRISPR-Cas9 genome engineering: Treating inherited retinal degeneration.

Fri, 2019-02-15 11:26
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CRISPR-Cas9 genome engineering: Treating inherited retinal degeneration.

Prog Retin Eye Res. 2018 07;65:28-49

Authors: Burnight ER, Giacalone JC, Cooke JA, Thompson JR, Bohrer LR, Chirco KR, Drack AV, Fingert JH, Worthington KS, Wiley LA, Mullins RF, Stone EM, Tucker BA

Abstract
Gene correction is a valuable strategy for treating inherited retinal degenerative diseases, a major cause of irreversible blindness worldwide. Single gene defects cause the majority of these retinal dystrophies. Gene augmentation holds great promise if delivered early in the course of the disease, however, many patients carry mutations in genes too large to be packaged into adeno-associated viral vectors and some, when overexpressed via heterologous promoters, induce retinal toxicity. In addition to the aforementioned challenges, some patients have sustained significant photoreceptor cell loss at the time of diagnosis, rendering gene replacement therapy insufficient to treat the disease. These patients will require cell replacement to restore useful vision. Fortunately, the advent of induced pluripotent stem cell and CRISPR-Cas9 gene editing technologies affords researchers and clinicians a powerful means by which to develop strategies to treat patients with inherited retinal dystrophies. In this review we will discuss the current developments in CRISPR-Cas9 gene editing in vivo in animal models and in vitro in patient-derived cells to study and treat inherited retinal degenerative diseases.

PMID: 29578069 [PubMed - indexed for MEDLINE]

Generation of an immortalized human choroid endothelial cell line (iChEC-1) using an endothelial cell specific promoter.

Fri, 2018-12-28 02:03
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Generation of an immortalized human choroid endothelial cell line (iChEC-1) using an endothelial cell specific promoter.

Microvasc Res. 2018 Dec 17;:

Authors: Giacalone JC, Miller MJ, Workalemahu G, Reutzel AJ, Ochoa D, Scott Whitmore S, Stone EM, Tucker BA, Mullins RF

Abstract
Age-related macular degeneration (AMD) is a common cause of blindness worldwide. While recent studies have revealed that the loss of choroidal endothelial cells (ChECs) is critical to the disease pathogenesis of dry AMD, in vitro studies are needed to fully elucidate the disease mechanism. However, these studies remain hindered due to the lack of publically available human ChEC lines. To address this need, ChECs were harvested form donor tissue and enriched for by using magnetic cell separation using anti-CD31 conjugated microbeads. Next, lenti-viral vectors with endothelial-specific promoters driving genes necessary for immortalization, CDH5p-hTERT and CDH5p TAg, were generated. Stable integration of both gene cassettes allowed cells to maintain their proliferative state and yielded an immortalized cell line (iChEC-1). Immunocytochemical analysis of iChEC-1 confirmed the expression of important ChEC markers such as CA4, a marker of choriocapillaris endothelial cells, CDH5, and CD34, pan-endothelial cell markers. qRT-PCR analysis of expanded clones from iChEC-1 further showed that the line maintained expression of other important endothelial markers, vWF, PECAM1, and PLVAP, similar to primary cells. Functional responses were characterized by tube-forming assays and repopulation of decellularized choroid with the immortalized cell line. In conclusion, the iChEC-1 line presents a suitable immortalized human ChEC line for future in vitro studies of AMD.

PMID: 30571950 [PubMed - as supplied by publisher]

Correlation of Optical Coherence Tomography and Retinal Histology in Normal and Pro23His Retinal Degeneration Pig.

Thu, 2018-12-13 21:28
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Correlation of Optical Coherence Tomography and Retinal Histology in Normal and Pro23His Retinal Degeneration Pig.

Transl Vis Sci Technol. 2018 Nov;7(6):18

Authors: Cheng J, Sohn EH, Jiao C, Adler KL, Kaalberg EE, Russell SR, Mullins RF, Stone EM, Tucker BA, Han IC

Abstract
Purpose: We correlate optical coherence tomography (OCT) retinal layer thickness measurements with histology in wild-type and retinal degenerative pigs.
Methods: OCT scans were obtained using the Bioptigen Envisu R2200. In normal pigs, three eyes were imaged in vivo, and three eyes were imaged after enucleation. In the Pro23His retinal degeneration pigs (P23H), one eye was imaged in vivo and four eyes were imaged after enucleation. All eyes were fixed in 4% paraformaldehyde and processed for histology. Corresponding retinal locations on OCT and histology were identified using anatomic landmarks (optic nerve, retinal vessels, visual streak). Individual retinal layer thicknesses were measured by two independent, masked graders, and intraclass correlation coefficients were used to determine agreement. OCT and histologic retinal thickness measurements were averaged and compared.
Results: OCT and histologic measurements correlated highly in normal and diseased eyes (R 2 = 0.91 and 0.92, respectively), and scans performed in vivo and ex vivo did not differ significantly. Despite good overall correlation, certain individual retinal layers (e.g., retinal nerve fiber layer [NFL], inner [INL] and outer [ONL] nuclear layers) appeared thicker on OCT compared to histology, while other layers (e.g., retinal pigment epithelium) appeared thinner. No statistically significant difference was found between OCT and histology for any retinal layer thickness measurement.
Conclusions: Retinal layer thickness measurements correlate well with histology in pig eyes, but differences in individual retinal layers may be seen.
Translational Relevance: OCT may be used in pigs to measure retinal thicknesses with good overall correlation to histologic measurements.

PMID: 30519502 [PubMed]