The Coding Region of the HCV Genome Contains a Network of Regulatory RNA Structures.

RNA is a versatile macromolecule that accommodates functional information in primary sequence and secondary and tertiary structure. We use a combination of chemical probing, RNA structure modeling, comparative sequence analysis, and functional assays to examine the role of RNA structure in the hepatitis C virus (HCV) genome. We describe a set of conserved but functionally diverse structural RNA motifs that occur in multiple coding regions of the HCV genome, and we demonstrate that conformational changes in these motifs influence specific stages in the virus' life cycle. Our study shows that these types of structures can pervade a genome, where they play specific mechanistic and regulatory roles, constituting a "code within the code" for controlling biological processes.

Difficulties of nasocutaneous fistula repair, following lacrimal outflow system malignancy resection.

PURPOSE: To evaluate the incidence of nasocutaneous fistula (NCF) development, following en bloc resection of lacrimal outflow system malignancies (LOSM), and describe the methods of surgical repair. METHODS: Retrospective review of all patients who underwent resection of LOSM with reconstruction and post-treatment protocol at the University of Miami between 1997 and 2021. RESULTS: Of the 23 included patients, 10 (43%) developed postoperative NCF. All NCFs developed within one year of surgical resection or completion of radiation therapy. NCF was seen more frequently in patients who underwent adjuvant radiation therapy and those who had reconstruction of the orbital wall with titanium implants. All patients underwent at least one revisional surgery to close the NCF, including local flap transposition (9/10), paramedian forehead flap (5/10), pericranial flap (1/10), nasoseptal flap (2/10), and microvascular free flap (1/10). Local tissue transfer, pericranial, paramedian, and nasoseptal forehead flaps failed in most cases. Two patients had long-term closure; one patient who underwent a paramedian flap and a second who underwent a radial forearm free flap, suggesting that well-vascularized flaps may be the most viable option for repair. CONCLUSIONS: NCF is a known complication, following en bloc resection of lacrimal outflow system malignancies. Risk factors for formation may include adjuvant radiation therapy and use of titanium implants for reconstruction. Surgeons should consider utilizing robust vascular-pedicled flaps or microvascular free flaps for repair of NCF in this clinical scenario.

Orbital Vascular Malformations: Relationship Between Enophthalmos and Clinically Apparent Distensibility with Valsalva.

PURPOSE: Determining the hemodynamic characteristics of an orbital vascular malformation is a critical step in management. The purpose of this study is to assess the relationship between enophthalmos and clinically apparent distensibility of orbital vascular malformations, to optimize imaging and treatment. METHODS: In this cross-sectional cohort study consecutive patients at a single institution were screened for study entry. Data extracted included age, sex, Hertel measurements, presence or absence of distensibility during the Valsalva maneuver, whether lesions were primarily venous or lymphatic based on imaging, and location of the lesion relative to the globe. Enophthalmos was defined as ≥ 2 mm difference from the opposite side. Parametric and nonparametric statistics were used, and linear regression was performed to examine factors predictive of Hertel measurement. RESULTS: Twenty-nine patients met the inclusion criteria. Relative enophthalmos ≥2 mm was significantly associated with distensibility ( p = 0.03; odds ratio = 5.33). Distensibility and venous dominant morphology were the 2 most important factors associated with enophthalmos on regression analysis. The relative position of the lesion anterior or posterior to the globe did not have a significant bearing on baseline enophthalmos. CONCLUSIONS: The presence of enophthalmos increases the likelihood that an orbital vascular malformation is distensible. This group of patients was also more likely to be characterized by venous dominant malformations. Baseline clinical enophthalmos may serve as a useful surrogate marker for distensibility and venous dominance, which may be useful in guiding the selection of appropriate imaging.

Low-grade fibromyxoid sarcoma of the orbit.

A 70-year-old male presented with diplopia and painless proptosis of the left eye for 5 months. Examination showed 6 mm of axial proptosis and restriction of supraduction, abduction and adduction, and mild limitation of infraduction of the left eye. Magnetic resonance imaging demonstrated a large, moderately well-circumscribed intraconal mass in the left lateral orbit, and excisional biopsy was performed. Histopathologic features of mixed fibrous and myxoid areas in a whorl-like pattern and immunohistochemical staining for MUC4 confirmed the diagnosis of low-grade fibromyxoid sarcoma (LGFMS). Next-generation sequencing revealed genetic fusion of EWSR1-CREB3L1. LGFMS is an extremely rare neoplasm with only two prior documented cases of orbital involvement. Here, we report the third case of orbital LGFMS.

Ocular Perfusion Following Orbital Apex Exenteration.

A 68-year-old man with a history of type 2 diabetes mellitus and kidney transplantation on chronic immunosuppression presented with right-sided proptosis and vision loss. He was hospitalized 4 months prior for invasive sinus aspergillosis. MRI revealed abnormal enhancement in the right orbital apex, inferior medial right orbit, anterior cranial fossa floor, and anterior aspect of the falx cerebri. The patient was successfully managed with extensive sinus surgery, bifrontal craniotomy with resection of dura, cribriform plate resection, and a right orbital apex exenteration. The globe and anterior orbital structures were preserved to cover the large surgical sinodural-orbital defect and avoid complex reconstructive surgery. Orbital perfusion was maintained by exploiting the robust anastomoses between branches of external carotid and ophthalmic artery.

A Natural History of Silent Brain Syndrome over 36 Years: A case report.

A 34-year-old Caucasian male who underwent a ventricular shunt at age 21 presented with bilateral enophthalmos, poor eyelid-globe apposition and exposure keratopathy characteristic of silent brain syndrome. Progressive enophthalmos and corneal decompensation were documented in serial photographs and radiographic studies over 36 years. Over this period, no sequelae of shunt over-drainage were observed. A lumbar puncture at the last follow-up measured CSF opening pressure to be within the normal range. Additional systemic findings included pneumosinus dilatans, loss of adipose tissue in the temporalis fossa and atrophy of the dorsal interossei of the hand. Surgical interventions to preserve ocular function included insertion of orbital floor wedge and sheet implants, sheet orbital roof implants, and retroplacement of canthal tendons. This report chronicles the long-term clinical course of a patient with silent brain syndrome. The systemic changes suggest factors beyond low intracranial pressure may contribute to the pathogenesis of the condition in our patient.

Predicted group II intron lineages E and F comprise catalytically active ribozymes.

Group II introns are self-splicing, retrotransposable ribozymes that contribute to gene expression and evolution in most organisms. The ongoing identification of new group II introns and recent bioinformatic analyses have suggested that there are novel lineages, which include the group IIE and IIF introns. Because the function and biochemical activity of group IIE and IIF introns have never been experimentally tested and because these introns appear to have features that distinguish them from other introns, we set out to determine if they were indeed self-splicing, catalytically active RNA molecules. To this end, we transcribed and studied a set of diverse group IIE and IIF introns, quantitatively characterizing their in vitro self-splicing reactivity, ionic requirements, and reaction products. In addition, we used mutational analysis to determine the relative role of the EBS-IBS 1 and 2 recognition elements during splicing by these introns. We show that group IIE and IIF introns are indeed distinct active intron families, with different reactivities and structures. We show that the group IIE introns self-splice exclusively through the hydrolytic pathway, while group IIF introns can also catalyze transesterifications. Intriguingly, we observe one group IIF intron that forms circular intron. Finally, despite an apparent EBS2-IBS2 duplex in the sequences of these introns, we find that this interaction plays no role during self-splicing in vitro. It is now clear that the group IIE and IIF introns are functional ribozymes, with distinctive properties that may be useful for biotechnological applications, and which may contribute to the biology of host organisms.

Hepatitis C virus RNA replication and virus particle assembly require specific dimerization of the NS4A protein transmembrane domain.

Hepatitis C virus (HCV) NS4A is a single-pass transmembrane (TM) protein essential for viral replication and particle assembly. The sequence of the NS4A TM domain is highly conserved, suggesting that it may be important for protein-protein interactions. To test this hypothesis, we measured the potential dimerization of the NS4A TM domain in a well-characterized two-hybrid TM protein interaction system. The NS4A TM domain exhibited a strong homotypic interaction that was comparable in affinity to glycophorin A, a well-studied human blood group antigen that forms TM homodimers. Several mutations predicted to cluster on a common surface of the NS4A TM helix caused significant reductions in dimerization, suggesting that these residues form an interface for NS4A dimerization. Mutations in the NS4A TM domain were further examined in the JFH-1 genotype 2a replicon system; importantly, all mutations that destabilized NS4A dimers also caused defects in RNA replication and/or virus assembly. Computational modeling of NS4A TM interactions suggests a right-handed dimeric interaction of helices with an interface that is consistent with the mutational effects. Furthermore, defects in NS4A oligomerization and virus particle assembly of two mutants were rescued by NS4A A15S, a TM mutation recently identified through forward genetics as a cell culture-adaptive mutation. Together, these data provide the first example of a functionally important TM dimer interface within an HCV nonstructural protein and reveal a fundamental role of the NS4A TM domain in coordinating HCV RNA replication and virus particle assembly.

The linker region of NS3 plays a critical role in the replication and infectivity of hepatitis C virus.

Hepatitis C virus (HCV) NS3-4A is required for viral replication and assembly. We establish that virus assembly is sensitive to mutations in the linker region between the helicase and protease domains of NS3-4A. However, we find that the protease cleavage, RNA binding, and unwinding rates of NS3 are minimally affected in vitro. Thus, we conclude that the NS3 linker is critical for mediating protein-protein interactions and dynamic control rather than for modulating the enzymatic functions of NS3-4A.

Life-threatening periocular pseudomonal necrotizing fasciitis in an immunocompetent infant.

Purpose: Necrotizing fasciitis, a severe soft tissue bacterial infection, is uncommon in the periocular region due to its rich blood supply. This report highlights a rare case in an immunocompetent infant. Observations: A 10-month-old immunocompetent female exhibited fever, irritability, and right eyelid swelling post-fall. Despite initial treatment with cephalexin for presumed cellulitis, her condition rapidly deteriorated, suggesting necrotizing fasciitis. She stabilized after receiving broad-spectrum intravenous antibiotics and aggressive surgical debridement but later required orbital exenteration due to extensive tissue necrosis. Conclusions and Importance: Periocular necrotizing fasciitis is exceedingly rare, particularly in immunocompetent individuals. Prompt diagnosis and treatment are critical to mitigate morbidity and mortality.

Subcutaneous tocilizumab for active thyroid eye disease refractory to orbital radiation and systemic steroids in tobacco smokers.

PURPOSE: Tocilizumab (TCZ) through intravenous infusion has been shown to effectively treat active thyroid eye disease (TED) refractory to systemic steroids. TCZ is also available as a self-administered subcutaneous injection, but data demonstrating the efficacy of this formulation are limited. This study investigated the efficacy and safety of subcutaneous TCZ (SC-TCZ) for the treatment of active, moderate-to-severe TED in smokers. MATERIALS AND METHODS: This retrospective clinical case series evaluated the clinical outcomes and adverse effects of SC-TCZ when taken for a minimum of 4 months by patients with moderate-to-severe TED and a current or recent history of cigarette smoking. RESULTS: Three patients received SC-TCZ every 1-2 weeks (4.6-11.2 mg/kg/month). The average pre-to-posttreatment clinical activity score reduction was 5.4, and proptosis was reduced by an average of 2.0 mm. No serious adverse effects were reported. CONCLUSION: SC-TCZ may be a useful and effective therapy for treating challenging cases of inflammatory TED and offers a safe alternative to office or hospital-based infusions. Further studies are needed to better understand optimal dosing regimens and relative efficacy compared to monthly TCZ infusions and other immunotherapies.

Clinicopathologic Correlations of Retrocorneal Membranes Associated With Endothelial Corneal Graft Failure.

PURPOSE: To provide clinicopathologic correlations for retrocorneal membranes associated with Descemet stripping automated endothelial keratoplasty (DSAEK) failure. DESIGN: Retrospective case series. METHODS: The specimens and medical records of the patients diagnosed with clinically significant retrocorneal membranes associated with DSAEK failure at the Bascom Palmer Eye Institute or the University of Miami Veterans Hospital between October 2015 and March 2020 were reviewed for demographics, clinical presentation, comorbidities, and surgeries performed. Histopathologic analysis was performed on hematoxylin-eosin and periodic acid-Schiff sections. Immunohistochemical studies were performed for smooth muscle actin (α-SMA), pancytokeratin, and CK7. Immunofluorescence was performed for vimentin, N-cadherin, ROCK1, RhoA, ZEB1, and Snail. RESULTS: A total of 7 patients (3 male and 4 female) were identified to have a clinically significant retrocorneal membranes at the time of graft failure. The average age at the time of first DSAEK was 70 years (range: 55-85 years). All patients were pseudophakic and had a glaucoma drainage device in place; 1 had a history of failed DSAEK. Ranging from 0 to 47 months after surgery, a variably thick retrocorneal fibrous membrane was observed, eventually leading to graft failure. Four patients underwent subsequent penetrating keratoplasty and 3 underwent repeat DSAEK. On histopathologic evaluation, a pigmented fibrocellular tissue was identified along the posterior margin of the corneas and DSAEK buttons in all cases. Further characterization with immunohistochemistry and immunofluorescence demonstrated membranes to be negative for pancytokeratin and positive for α-SMA, vimentin, CK7, N-cadherin, ZEB1, Snail, ROCK1, and RhoA. CONCLUSIONS: Fibrocellular retrocorneal membrane proliferation may be associated with DSAEK failure in patients with previous glaucoma drainage device surgery. Our results demonstrate myofibroblastic differentiation and a lack of epithelial differentiation. Positivity for markers of an endothelial-to-mesenchymal transition indicates possible endothelial origin and could be the hallmark for future targeted pharmacotherapy.

Primary evisceration for neonatal endogenous endophthalmitis: A report of two cases.

PURPOSE: To present two cases of neonatal endophthalmitis with poor prognosis that were managed with primary evisceration. OBSERVATIONS: Case 1 is a 27-weeks' gestation neonate who developed Pseudomonas aeruginosa endophthalmitis complicated by globe rupture. Case 2 describes a 34-weeks' gestation neonate with Serratia marcescens endophthalmitis. Both patients had poor prognosis and thus underwent primary evisceration with good long-term cosmetic outcomes at 15 years and 17 months, respectively. CONCLUSIONS AND IMPORTANCE: Primary evisceration should be considered in neonates with endophthalmitis with a poor prognosis and can result in good long-term cosmesis.

UV-Photokeratitis Associated with Germicidal Lamps Purchased during the COVID-19 Pandemic.

PURPOSE: To report photokeratitis caused by the improper use of germicidal lamps purchased during the COVID-19 pandemic. METHODS: Case series. RESULTS: Seven patients presented with acute ocular surface pain after exposure to UV-emitting germicidal lamps. Visual acuity was 20/30 or better in 13 of 14 eyes (93%). Anterior segment examination revealed varying degrees of conjunctival injection and diffusely distributed punctate epithelial erosions (PEEs) in every patient. No intraocular inflammation was identified across the cohort and all fundus examinations were normal. Treatment varied by provider and included artificial tears alone or in combination with antibiotic ointments and/or topical steroids. Five patients were followed via telehealth, one patient returned for an in-office visit, and one patient was lost to follow-up. Five of six patients endorsed complete resolution of symptoms within 2-3 days. CONCLUSIONS: Patients should follow manufacturer recommendations when using UV-emitting germicidal lamps and avoid direct exposure to the ocular surface.

Laser Resurfacing for the Management of Periorbital Scarring.

Laser (light amplification by the stimulated emission of radiation) skin resurfacing is currently one of the most widely adopted technologies in facial rejuvenation. While most often used for aesthetic purposes, lasers also have applications in the management of scars. Since the introduction of the CO2 laser for skin rejuvenation in the 1990s, the last three decades have seen significant growth in the number of laser devices available to the physician. More recently, promising alternatives to light-based resurfacing technologies have emerged that include radiofrequency and intense focused ultrasound. To help the physician navigate the most current laser technologies as they apply to periocular scars, this review discusses the available treatment modalities, pre-treatment assessment of periorbital scars, treatment selection, and reported outcomes and complications. The recommendations described herein are based on published literature and the authors' experience in an academic oculoplastics practice.

Complications after cosmetic periocular filler: prevention and management.

Soft tissue fillers are a mainstay in contemporary, minimally invasive facial rejuvenation procedures owing to timely results and minimal recovery period. Although associated with a low complication rate, soft tissue fillers are not without risk. Complications range from mild superficial skin irregularities to granuloma formation to vascular occlusion leading to skin necrosis or even blindness. Fillers vary in composition, elasticity, hydrophilicity and duration of effect that is tailored to specific cosmetic indications. Selecting the right product for the desired effect can cut down on unwanted outcomes. Severe adverse events can be avoided with safe injection technique, early recognition of symptoms and a thorough knowledge of the local anatomy. This review outlines several complications all providers should recognize and discusses strategies for their prevention and management.

Periorbital Silicone Granulomatosis 30 Years after Acupuncture.

Silicone-based compounds are commonly used in many medical applications, such as coatings for needles and syringes. Foreign body granulomas are a well-recognized complication of silicone exposure; however, they may be challenging to identify without a clear history. A 61-year-old female patient without prior history of periocular injections, filler, or surgery presented to our oculoplastic clinic with multiple periocular lesions. The patient subsequently underwent excisional biopsy of two prominent lesions, which were identified as granulomas on pathology. Further questioning revealed the cause to be facial acupuncture performed decades prior, and a subsequent targeted exam identified additional lesions at other needling sites. A third lesion was subsequently excised, and there was no recurrence at the last follow-up 3 months postsurgery. Acupuncture is an increasingly common but underrecognized source of silicone exposure and can present up to several decades after exposure as a chronic granulomatous response in a characteristic multifocal pattern.

A Multinational Comparison of Anti-Vascular Endothelial Growth Factor Use: The United States, the United Kingdom, and Asia-Pacific.

PURPOSE: A comparison of anti-vascular endothelial growth factor (anti-VEGF) medication use across multiple countries. CLINICAL RELEVANCE: Anti-VEGF medication use is now considered first-line treatment for numerous retinal diseases globally. Exploring medication choices, costs within each healthcare system, policy challenges, emerging treatments, and patient access all provide insight into a newly recognized and major public health issue. METHODS: All data presented in this review are available through the published English literature in PubMed, non-peer-reviewed trade publications, and reported surveys. The following search terms were used: anti-VEGF OR bevacizumab OR ranibizumab OR aflibercept OR pegaptanib OR conbercept AND trends OR survey OR cost OR patterns OR preference. Countries with large populations and available data included the United States, United Kingdom, China, India, Korea, Singapore, and Australia. Population and economic statistics were obtained from published reports from the World Bank, World Health Organization, and Commonwealth Fund. RESULTS: Anti-VEGF medication use and costs are significant aspects of patient and healthcare system expenditures in each nation and may have an especially large potential economic burden in India and China. Bevacizumab use comprises the majority of anti-VEGF medication use in the United States and Singapore, although aflibercept use is growing rapidly. Paradoxically, data demonstrate that there is a significant trend in medication choice toward ranibizumab and aflibercept among practice settings outside of the United States, such as the United Kingdom, China, South Korea, and Australia. The price of anti-VEGF medications ranged from US $30 (ziv-aflibercept) to US $1950 (ranibizumab and aflibercept). Ranibizumab's price ranged from US $240 in India to US $1950 in the United States. Conbercept in China costs approximately US $1150 per dose. CONCLUSIONS: Outside of the United States, many nations are using a majority of more expensive anti-VEGF medications, which may lead to increased costs and decreased access. Increasing the availability of safely compounded anti-VEGF medications will likely improve access, create patient/provider choice, and decrease relative healthcare costs for the growing burden of retinal diseases globally.

Punctal Plug Granuloma After Blepharoplasty.

This case report discusses a diagnosis of foreign body granuloma resulting from a punctal plug in a patient aged 66 years with chronic dry eye and a history of blepharoplasty.