Recombinant tissue plasminogen activator in the treatment of suprachoroidal hemorrhage

Nancy Kunjukunju1, Christine R Gonzales2, William S Rodden21Ochsner Medical Center, New Orleans, Louisiana; 2Retina and Vitreous Center of Southern Oregon, Ashland, Oregon, USABackground: Suprachoroidal hemorrhages are a vision-threatening complication, and poor visual outcome is correlated with increasing hemorrhage complexity. The recommended time of surgical drainage is 10–14 days after the hemorrhage begins to liquefy. We describe a case in which recombinant tissue plasminogen activator (r-tPA), alteplase, is injected within the suprachoroidal space before surgery to assist in the drainage of an organized clot prior to liquefaction. This is a report of a technique in which r-tPA is used in the intrachoroidal space to target the organized clot of suprachoroidal hemorrhage prior to drainage.Case report: A 62-year-old male presented 12 days after retinal detachment repair with sudden ocular pain and vision loss after a Valsalva maneuver. Vision was light perception only, and intraocular pressure was 43 mmHg. Diagnosed with hyphema and suprachoroidal hemorrhage, the patient underwent surgery the following day. An injection of r-tPA 100 µg was given intracamerally, and an additional dose of r-tPA 100 µg was injected into the suprachoroidal space prior to surgery. Liquified by r-tPA, the clot was expressed through the sclerotomies. Best corrected vision in the eye eight months after the drainage procedure was 20/40.Conclusion: To the author’s knowledge, this is the first reported case in which r-tPA was successfully injected in the suprachoroidal space to liquefy and drain a suprachoroidal hemorrhage prior to natural dissolution.Keywords: tPA, suprachoroidal hemorrhage, vision los

Purification and immobilization of engineered glucose dehydrogenase: A new approach to producing gluconic acid from breadwaste

Background Platform chemicals are essential to industrial processes. Used as starting materials for the manufacture of diverse products, their cheap availability and efficient sourcing are an industrial requirement. Increasing concerns about the depletion of natural resources and growing environmental consciousness have led to a focus on the economics and ecological viability of bio-based platform chemical production. Contemporary approaches include the use of immobilized enzymes that can be harnessed to produce high-value chemicals from waste. Results In this study, an engineered glucose dehydrogenase (GDH) was optimized for gluconic acid (GA) production. Sulfolobus solfataricus GDH was expressed in Escherichia coli. The Km and Vmax values for recombinant GDH were calculated as 0.87 mM and 5.91 U/mg, respectively. Recombinant GDH was immobilized on a hierarchically porous silica support (MM-SBA-15) and its activity was compared with GDH immobilized on three commercially available supports. MM-SBA-15 showed significantly higher immobilization efficiency (> 98%) than the commercial supports. After 5 cycles, GDH activity was at least 14% greater than the remaining activity on commercial supports. Glucose in bread waste hydrolysate was converted to GA by free-state and immobilized GDH. After the 10th reuse cycle on MM-SBA-15, a 22% conversion yield was observed, generating 25 gGA/gGDH. The highest GA production efficiency was 47 gGA/gGDH using free-state GDH. Conclusions This study demonstrates the feasibility of enzymatically converting BWH to GA: immobilizing GDH on MM-SBA-15 renders the enzyme more stable and permits its multiple reuse

Nampt/PBEF/visfatin serum levels: a new biomarker for retinal blood vessel occlusions

Simon Kaja,1,* Anna A Shah,1,* Shamim A Haji,1,* Krishna B Patel,1 Yuliya Naumchuk,1 Alexander Zabaneh,1 Bryan C Gerdes,1 Nancy Kunjukunju,1 Nelson R Sabates,1 Michael A Cassell,1 Ron K Lord,1 Kevin P Pikey,1 Abraham Poulose,1 Peter Koulen1,21Vision Research Center, Department of Ophthalmology, 2Department of Basic Medical Science, School of Medicine, University of Missouri – Kansas City, Kansas City, MO, USA*These authors contributed equally to this workAbstract: The main objective of the study was to quantify serum levels of nicotinamide phosphoribosyltransferase (Nampt/pre-B-Cell colony-enhancing factor 1/visfatin) in subjects with a history of retinal vascular occlusions (RVOs), disease conditions characterized by pronounced ischemia, and metabolic energy deficits. A case–control study of 18 subjects with a history of RVO as well as six healthy volunteers is presented. Serum Nampt levels were quantified using a commercially available enzyme-linked immunosorbent assay kit. Serum Nampt levels were 79% lower in patients with a history of RVO compared with that in healthy volunteers (P<0.05). There was no statistically significant difference among the types of RVOs, specifically branch retinal vein occlusions (n=7), central retinal vein occlusions (n=5), hemiretinal vein occlusions (n=3), and central retinal artery occlusions (n=3; P=0.69). Further studies are needed to establish the temporal kinetics of Nampt expression and to determine whether Nampt may represent a novel biomarker to identify at-risk populations, or whether it is a druggable target with the potential to ameliorate the long-term complications associated with the condition, ie, macular edema, macular ischemia, neovascularization, and permanent loss of vision.Keywords: Nampt, PBEF, visfatin, nicotinamide phosphoribosyltransferase, pre-B-cell colony-enhancing factor, retinal artery occlusion, retinal vein occlusion, biomarker, retina, vasculatur