Faculty Research
Permanent URI for this collection
Browse
Recent Submissions
Item Optimization of the Oertli CataRhex 3 (R) phacoemulsification machine(2019) Stutz, Lance A.; Heczko, Joshua B.; Bird, Brian A.; Thomson, Rhett S.; Bernhisel, Ashlie A.; Barlow, William R.; Zaugg, Brian; Olson, Randall J.; Pettey, Jeff H.The aim of this study was to determine optimal bottle height, vacuum, aspiration rate, and power settings of the Oertli CataRhex 3 (R) phacoemulsification machine. Methods: Porcine lens nuclei were hardened with formalin and cut into 2.0 mm cubes. Lens cubes were emulsified using the easyTip (R) 2.2 mm at 30 degrees. Fragment removal time (efficiency) and fragment bounces off the tip (chatter) were measured. Settings tested included bottle height of 60, 80, 100 and 120 cmItem The effect of increasing power when grooving using phacoemulsification(2019) Thomson, Rhett S.; Bird, Brian A.; Stutz, Lance A.; Heczko, Joshua B.; Bernhisel, Ashlie A.; Barlow, William R.; Zaugg, Brian; Olson, Randall J.; Pettey, Jeff H.To determine optimal power settings on the Centurion Vision System during the grooving step in cataract surgery. Methods: Intact porcine lenses hardened by formalin and placed in a chamber designed to simulate the anterior chamber of the eye were used to test longitudinal power at 40%, 70%, and 100% and torsional power at 0%. Flow rate was set at 40 mL/min. Vacuum was set at 400 mmHg, intraocular pressure was set at 50 mmHg, and a balanced phacoemulsification tip with a 20 degree tip and a 30 degree bevel was used. Efficiency (time to groove the lens in half) was determined. Results: Increasing longitudinal power from 40% to 70% increased efficiency by 28% (P< 0.05), and by 32% (P<0.05) when increasing longitudinal power from 40% to 100%. There was no statistically significant increase in efficiency from 70% to 100%. Conclusion: For the tested variables, a longitudinal power of 70% was determined to be most efficient during the grooving step of cataract surgery for equivalent 3-4+ nuclei. Further increases in power demonstrated no statistically significant improvement in efficiency.Item Generation of electrophysiologically functional cardiomyocytes from mouse induced pluripotent stem cells(2016) Wang, Hongran; Xi, Yutao; Zheng, Yi; Wang, Xiaohong; Cooney, Austin J.Induced pluripotent stem (iPS) cells can efficiently differentiate into the three germ layers similar to those formed by differentiated embryonic stem(ES) cells. This provides a new source of cells in which to establish preclinical allogeneic transplantation models. Our iPS cells were generated from mouse embryonic fibroblasts (MEFs) transfected with the Yamanaka factors, the four transcription factors (Oct4, Sox2, Klf4 and c-Myc), without antibiotic selection or MEF feeders. After the formation of embryoid bodies (EBs), iPS cells spontaneously differentiated into Flk1-positive cardiac progenitors and cardiomyocytes expressing cardiac-specific markers such as alpha sarcomeric actinin (alpha-actinin), cardiac alpha myosin heavy chain (alpha-MHC), cardiac troponin T (cTnT), and connexin 43 (CX43), as well as cardiac transcription factors Nk2 homebox 5 (Nkx2.5) and gata binding protein 4 (gata4). The electrophysiological activity of iPS cell-derived cardiomyocytes (iPS-CMs) was detected in beating cell clusters with optical mapping and RH237 a voltage-sensitive dye, and in single contracting cells with patch-clamp technology. Incompletely differentiated iPS cells formed teratomas when transplanted into a severe combined immunodeficiency (SCID) mouse model of myocardial infarction. Our results show that somatic cells can be reprogrammed into pluripotent stem cells, which in turn spontaneously differentiate into electrophysiologically functional mature cardiomyocytes expressing cardiac-specific makers, and that these cells can potentially be used to repair myocardial infarction (MI) in the future. (C) 2016 University of Texas at Austin Dell Medical School. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Item Gastric and Duodenal Pseudomelanosis: An Extended Unusual Finding in a Patient with End Stage Kidney Disease(2016) Qureshi, Noor U. A.; Younus, Muhammad F.; Alavi, Kourosh; Sheikh, Muhammad Y.Gastric and duodenal pseudomelanosis is a rare endoscopic mucosal finding, characterized by the accumulation of iron in macrophages of the lamina propria of the stomach and duodenum. The clinical significance and long term sequelae have not been clarified yet. However, this benign condition is associated with a variety of clinical conditions, such as essential hypertension, chronic renal failure, diabetes mellitus, long term intake of iron supplements, and furosemide. Duodenal pseudomelanosis appears to be more common than gastric pseudomelanosis given the fact that a few cases of gastric pseudomelanosis have been reported in the literature so far. We report a case of 88-year-old lady with ESRD who is maintained on hemodialysis and presented with abdominal pain. An upper GI endoscopy showed discoloration of the antrum of the stomach and most portion of her duodenum. Histopathology report confirmed the presence of iron laden macrophages in the lamina propria of both stomach and duodenum.Item An Unusual Case of Left Atrial Mural Thrombus following Aortic Valve Replacement(2019) Taha, Mohamed E.; Eljack, Ammar; Ibrahim, Hisham; Roongsritong, ChanwitThe left atrial thrombus is a well-known complication of atrial fibrillation and rheumatic mitral valve disease and carries a high risk for systemic thromboembolism. They are generally dissolved after a certain period of optimal anticoagulation. A large thrombus, on the other hand, may persist even with adequate anticoagulation. The surgical removal of a thrombus theoretically poses some risk of systemic embolization, making its management a clinical dilemma. Furthermore, a refractory thrombus is uncommon. Thus, an evidence-based guideline in selecting the optimal therapy is needed. We report a case of a 74-year-old male with atrial fibrillation and a history of unprovoked pulmonary embolism who was incidentally found to have a massive left atrial thrombus shortly after discontinuing warfarin about 4 months following bioprosthetic aortic valve replacement. The thrombus was refractory to anticoagulation posing a clinical management dilemma. This case is interesting in terms of presentation and the approach to diagnosis and treatment.