Unilateral asymptomatic optic disc edema: do not forget sinusitis

Background: Optic disc edema is a pathological condition with various causes. Cases of optic disc swelling should be dealt with a multidisciplinary approach to rule out those causes. Unilateral optic disc edema is seen in papillitis, non-arteritic anterior ischemic optic neuropathy, retinal vein occlusion, and infection or inflammation of the contiguous sinus or orbit. Here, we report a rare case of unilateral asymptomatic optic disc edema due to posterior ethmoid sinusitis.   Case Presentation: A 53-year-old man presented for a routine 3-monthly follow-up after an uneventful cataract surgery of the right eye. All examinations were unremarkable, except for the right eye optic disc edema on fundus examination, consistent with an enlarged blind spot in the visual field test. Contrast-enhanced magnetic resonance imaging revealed mucosal thickening with muco-inflammatory exudates of the posterior ethmoidal sinus overriding the optic disc on the right side, leading to optic disc edema of the right eye. The patient was diagnosed with unilateral asymptomatic optic disc edema in the right eye due to posterior ethmoid sinusitis and referred to an otorhinolaryngologist for the management. The otorhinolaryngologist performed functional endoscopic sinus surgery and prescribed antibiotics and anti-histamines for 6 weeks. At the final examination, his visual acuity was 6/6, and the fundus examination revealed no optic disc edema. Conclusions: We reported a rare case of unilateral optic nerve edema and visual field loss with a treatable cause. Contemporary imaging provided the accurate diagnosis. Therefore, in cases of disc edema, sinusitis of the adjacent paranasal sinuses should be ruled out as a possible cause of compressive optic neuropathy or inflammation overriding the optic nerve

Headache associated with travoprost

Background: Putative adverse effects of prostaglandin analogs in patients treated for glaucoma include periocular skin darkening, herpes simplex keratitis, cystoid macular edema, iritis, and headaches. Here, we report a case of migraine headache after a travoprost administration and discuss the role of prostaglandin analogs in migraine-like headaches. Case Presentation: A 70-year-old man visited the hospital complaining of pain, redness, and sensitivity to light for 1 week associated with gradual loss of vision in the right eye after cataract surgery, which had been performed 2 years prior. After the examination, the patient was diagnosed with pseudophakic bullous keratopathy and advised to undergo optical penetrating keratoplasty of the right eye. On postoperative day 3, his intraocular pressure (IOP) was 30 mmHg at 10:00 AM in the right eye. A single dose of 0.004% travoprost was instilled in the right eye on the same day. His IOP decreased to 16 mmHg at 2:00 PM. The next day, he presented with migraine-like headache that had started within 1 h after the instillation the previous night. Unremarkable neurological examination and neuroimaging suggested that travoprost had caused the migraine. Although the headache gradually resolved, it reappeared after the administration of other prostaglandins. Trabeculectomy was performed on the right side. The IOP was controlled, and the headache was resolved. Conclusions: This case indicates a potential causal relationship between topical prostaglandin analogs and migraine-like headaches, as evidenced by symptom resolution upon discontinuation. However, large-scale studies including control groups are required to prove a causal relationship between topical prostaglandin analog administrations and headache development

Microsatellite instability and loss of heterozygosity at DNA mismatch repair gene loci occurs during hepatic carcinogenesis

DNA mismatch repair is an important mechanism involved in maintaining the fidelity of genomic DNA. Defective DNA mismatch repair is implicated in a variety of gastrointestinal and other tumors; however, its role in hepatocellular carcinoma (HCC) has not been assessed. Formalin-fixed, paraffin-embedded archival pathology tissues from 46 primary liver tumors were studied by microdissection and microsatellite analysis of extracted DNA to assess the degree of microsatellite instability, a marker of defective mismatch repair, and to determine the extent and timing of allelic loss of two DNA mismatch repair genes, human Mut S homologue-2 (hMSH2) and human Mut L homologue-1 (hMLH1), and the tumor suppressor genes adenomatous polyposis coli gene (APC), p53, and DPC4. Microsatellite instability was detected in 16 of the tumors (34.8%). Loss of heterozygosity at microsatellites linked to the DNA mismatch repair genes, hMSH2 and/or hMLH1, was found in 9 cases (19.6%), usually in association with microsatellite instability. Importantly, the pattern of allelic loss was uniform in 8 of these 9 tumors, suggesting that clonal loss had occurred. Moreover, loss at these loci also occurred in nonmalignant tissue adjacent to 4 of these tumors, where it was associated with marked allelic heterogeneity. There was relatively infrequent loss of APC, p53, or DPC4 loci that appeared unrelated to loss of hMSH2 or hMLH1 gene loci. Loss of heterozygosity at hMSH2 and/or hMLH1 gene loci, and the associated microsatellite instability in premalignant hepatic tissues suggests a possible causal role in hepatic carcinogenesis in a subset of hepatomas.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34772/1/510280114_ftp.pd

A Theoretical and Empirical Investigation of the Role of Firm Technology Investments and Sourcing Practices in Business Innovation.

The core thesis of my dissertation is that the information technology and sourcing practices of firms affect how innovative those firms are in the long run. In the first chapter of my dissertation I develop a theoretical model of firm-level innovation that asserts that firms can exploit strategic, organizational and technological levers to encourage innovation. The model I build leverages findings from prior management and MIS research. I then utilize the Interpretive Systems View of Organizations (Daft & Weick, 1984) to understand how information technology and firm sourcing practices specifically might affect firm-level innovation and define a research agenda that proposes a set of research questions to guide this area of inquiry. In the second chapter I explore a subset of the research questions defined in Chapter 1 by exploring how IT investments affect a firm’s ability to innovate. I develop hypotheses suggesting both direct and indirect (through increasing returns to R&D investment) effects of IT investment on innovative output in high-tech firms. I test my hypotheses on an unbalanced panel of large US high-tech firms from 1998 - 2003 with patent, financial and IT investment data compiled from the US Patents & Trademarks Office, COMPUSTAT and Informationweek surveys. I find strong support for the direct effects of IT investment on innovative output but not for a positive indirect effect. These findings contribute to the existing literature on the business value of information systems by identifying another significant way in which IT investments add value to firms. In the third chapter I evaluate whether externally-facing IT investments and different types of sourcing practices are associated with higher levels of innovation in high-tech firms. I test my hypotheses on an unbalanced panel of large US high-tech firms from 2003 - 2007 with patent, financial, sourcing and IT investment data compiled from the US Patents & Trademarks Office, COMPUSTAT and Informationweek surveys. I find support for customer-facing IT investments being associated with higher innovative output but not supplier-facing IT investments. Additionally I find that business process outsourcing is associated with higher levels of firm innovation while IT outsourcing is not.PHDBusiness AdministrationUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/95962/1/scherian_1.pd

IT Enabled Innovation: A Theoretical and Empirical Investigation of the Role of Information Technology and Outsourcing in Business Innovation

In this paper I present a summary of my dissertation in which I study the relationship between information technology, outsourcing and innovation. I propose to do this in three distinct, but related, papers. The first paper will be a theoretical essay that reviews and synthesizes relevant literature from information systems, economics, public policy and management research. This paper will develop a model of innovation in firms and will propose research questions and hypotheses, grounded in relevant management theories, relating IT and outsourcing to innovation. The second paper will focus on the relationship between IT investments and innovation in firms. The third paper will specifically study the relationship between engaging in outsourcing and innovation in firms Both empirical papers will test their hypotheses on unbalanced panel data sets of large US-based firms using patent counts as the measure of innovative output

Orthoptic parameters and asthenopic symptoms analysis after 3D viewing at varying distances

AIM: To analyse visual modifications such as amplitude of accommodation, near point of convergence(NPC)reopsis and near phoria associated with asthenopic symptoms after 3D viewing at varying distances.METHODS: A prospective study. Thirty young adults were randomly selected. Each individual was exposed to 3D viewing thrice in a day for a fixed distance and the distance was varied on three consecutive days. Same video of equal duration and different screen sizes were used for every distance. Cyclic 3D mode of K-multimedia(KM)player was used for projecting the 3D video. Different variables like stereopsis, amplitude of accommodation, near point of accommodation, near phoria and asthenopic symptoms were recorded immediately after 3D video viewing. Stereopsis was measured with “Toegepast Natuurwetenschappelijk Onderzoek” or “Netherlands Organisation for Applied Scientific Research”(TNO test), amplitude of accommodation and NPC were measured using RAF ruler, near phoria was measured using prism bar and a closed ended sample questionnaire was used to know the occurrence of asthenopic symptoms. Statistical analyses were performed using descriptive statistics, paired t-test etc. Qualitative data was analyzed using Chi-square test.RESULTS: For every distance of 40 cm, 3 m and 6 m, amplitude of accommodation was significantly reduced by 0.66 D, 1.12 D and 1.44 D. NPC got significantly receded by 0.63 cm, 0.93 cm and 1.23 cm, and the near phoria was significantly increased by 0.87, and 2.2 prism dioptres(PD)base-in respectively. It was found that most of the subjects got pain around the eyes, headache and irritation for each viewing distance. This study also revealed that 3D video viewing in theaters may increase the symptoms of headache, watering and irritation. Symptoms like headache, watering, fatigue, irritation and nausea may increase considerably at home environment and symptoms such as headache and watering may cause significant discomfort by 3D viewing using a laptop.CONCLUSION: There was a significant difference in amplitude of accommodation, NPC, near phoria and asthenopic symptoms before and after viewing a 3D video and also at three viewing distances. There was a predominant occurrence of asthenopic symptoms after 3D video viewing at different distances