A simple active fluid model unites cytokinesis, cell crawling, and axonal outgrowth.

While the structural organization and molecular biology of neurons are well characterized, the physical process of axonal elongation remains elusive. The classic view posited elongation occurs through the deposition of cytoskeletal elements in the growth cone at the tip of a stationary array of microtubules. Yet, recent studies reveal axonal microtubules and docked organelles flow forward in bulk in the elongating axons of , chick sensory, rat hippocampal, and neurons.

Temporary Keratoprosthesis and Primary Corneal Graft for Ocular Trauma: A Systematic Review and Meta-Analysis.

Purpose: When severe retinal and corneal injury occur together, a temporary keratoprosthesis (TKP) is often a last resort to allow posterior segment visualization to enable vitreoretinal surgery, followed by a penetrating keratoplasty (PKP) which can restore corneal clarity in a single operation. We aimed to assess visual outcomes following combined PKP and vitreoretinal surgery with the use of a TKP for cases of ocular trauma.

Design: A systematic literature review was performed following PRISMA guidelines (PROSPERO registration number: CRD42023423518).

PKA Activity-Driven Modulation of Bidirectional Long-Distance transport of Lysosomal vesicles During Synapse Maintenance.

The bidirectional long-distance transport of organelles is crucial for cell body-synapse communication. However, the mechanisms by which this transport is modulated for synapse formation, maintenance, and plasticity are not fully understood. Here, we demonstrate through quantitative analyses that maintaining sensory neuron-motor neuron synapses in the gill-siphon withdrawal reflex is linked to a sustained reduction in the retrograde transport of lysosomal vesicles in sensory neurons.

A simple active fluid model unites cytokinesis, cell crawling, and axonal outgrowth.

Axonal outgrowth, cell crawling, and cytokinesis utilize actomyosin, microtubule-based motors, cytoskeletal dynamics, and substrate adhesions to produce traction forces and bulk cellular motion. While it has long been appreciated that growth cones resemble crawling cells and that the mechanisms that drive cytokinesis help power cell crawling, they are typically viewed as unique processes. To better understand the relationship between these modes of motility, here, we developed a unified active fluid model of cytokinesis, amoeboid migration, mesenchymal migration, neuronal migration, and axonal outgrowth in terms of cytoskeletal flow, adhesions, viscosity, and force generation.

The Risk of Sympathetic Ophthalmia Associated with Open-Globe Injury Management Strategies: A Meta-analysis.

Topic: Sympathetic ophthalmia (SO) is a sight-threatening granulomatous panuveitis caused by a sensitizing event. Primary enucleation or primary evisceration, versus primary repair, as a risk management strategy after open-globe injury (OGI) remains controversial.

Clinical Relevance: This systematic review was conducted to report the incidence of SO after primary repair compared with that of after primary enucleation or primary evisceration.

The Use of Preoperative Prophylactic Systemic Antibiotics for the Prevention of Endopthalmitis in Open Globe Injuries: A Meta-Analysis.

Topic: This study reports the effect of systemic prophylactic antibiotics (and their route) on the risk of endophthalmitis after open globe injury (OGI).

Clinical Relevance: Endophthalmitis is a major complication of OGI; it can lead to rapid sight loss in the affected eye. The administration of systemic antibiotic prophylaxis is common practice in some health care systems, although there is no consensus on their use.

Applying a Military Teleophthalmology Mobile App in a Noncombat Emergent Care Setting.

Introduction: Teleophthalmology has a natural role in the military due to the inherent organization of its medical system, which provides care to patients in remote locations around the world. Improving access to ophthalmic care enhances force readiness because ocular trauma and disease can cause vision impairment or blindness and can occur anywhere service members are located. Recently, a secure, Health Insurance Portability and Accountability Act-compliant mobile phone application (app) for teleophthalmology called Forward Operating Base Expert Telemedicine Resource Utilizing Mobile Application for Trauma (FOXTROT) was beta tested in Afghanistan and demonstrated that this solution can improve and extend ophthalmic care in a deployed environment.

Live Imaging and Quantitative Analysis of Organelle Transport in Sensory Neurons of Aplysia Californica.

Axonal transport moves proteins, RNAs, and organelles between the soma and synapses to support synaptic function and activity-dependent changes in synaptic strength. This transport is impaired in several neurodegenerative disorders such as Alzheimer's disease. Thus, it is critical to understand the regulation and underlying mechanisms of the transport process.

Needle decompression of the eye! Emergent management of a vision threatening surgical complication.

Acute angle-closure glaucoma (AACG) is a medical emergency that can cause permanent visual deficits without prompt recognition. From 2006 to 2011, nearly 12 million visits to emergency departments (ED) in the United States were ophthalmologic in nature, making it crucial for emergency physicians to be familiar with the diagnosis and treatment of ophthalmologic emergencies. AACG can be precipitated by several mechanisms including pupillary block, anticholinergic medications, and sympathomimetic medications.

Effectiveness of the Ophthalmological Training Component of the STOMP (Simulation Training for Operational Medical Providers) Curriculum.

Introduction: Simulation has been used in medicine to train clinicians to manage a variety of clinical scenarios. A key adaptation of the use of simulation in military healthcare occurred in 2015 with the development of the STOMP (Simulation Training for Operational Medical Providers) curriculum, a specific curriculum designed for the intern (PGY-1) trained physicians being sent into the military to practice primary care. Despite showing the curriculum's influence on self-perceived comfort scores, no study has determined whether simulation is an effective means of improving general medical officer (GMO) physicians' skills compared to other traditional styles of education.

Military Teleophthalmology in Afghanistan Using Mobile Phone Application.

Importance: The coronavirus disease 2019 pandemic has highlighted the need to expand telemedicine solutions.

Objective: To beta test a secure teleophthalmology mobile app at military treatment facilities in Afghanistan.

Design, Setting, And Participants: This prospective case series included 16 military treatment facilities at diverse roles of care including forward operating bases in Afghanistan and 1 location outside of Afghanistan.

Dynein-mediated microtubule translocation powering neurite outgrowth in chick and neurons requires microtubule assembly.

Previously, we have shown that bulk microtubule (MT) movement correlates with neurite elongation, and blocking either dynein activity or MT assembly inhibits both processes. However, whether the contributions of MT dynamics and dynein activity to neurite elongation are separate or interdependent is unclear. Here, we investigated the underlying mechanism by testing the roles of dynein and MT assembly in neurite elongation of and chick neurites using time-lapse imaging, fluorescent speckle microscopy, super-resolution imaging and biophysical analysis.

Diplopia and Strabismus After Corneal Refractive Surgery.

Introduction: Diplopia and strabismus are known complications after corneal refractive surgery (CRS). Within the U.S.

Synapse Formation Activates a Transcriptional Program for Persistent Enhancement in the Bi-directional Transport of Mitochondria.

Mechanisms that regulate the bi-directional transport of mitochondria in neurons for maintaining functional synaptic connections are poorly understood. Here, we show that in the pre-synaptic sensory neurons of the Aplysia gill withdrawal reflex, the formation of functional synapses leads to persistent enhancement in the flux of bi-directional mitochondrial transport. In the absence of a functional synapse, activation of cAMP signaling is sufficient to enhance bi-directional transport in sensory neurons.

Acute Onset Esotropia From Excessive Smartphone Use in a Teenager.

Acute acquired comitant esotropia secondary to smart-phone use is a newly described phenomenon. This case report describes a boy with acute acquired comitant esotropia due to prolonged smartphone use who had improvement in binocular function after cessation of near work for several weeks. [J Pediatr Ophthalmol Strabismus.

An Integrated Cytoskeletal Model of Neurite Outgrowth.

Neurite outgrowth underlies the wiring of the nervous system during development and regeneration. Despite a significant body of research, the underlying cytoskeletal mechanics of growth and guidance are not fully understood, and the relative contributions of individual cytoskeletal processes to neurite growth are controversial. Here, we review the structural organization and biophysical properties of neurons to make a semi-quantitative comparison of the relative contributions of different processes to neurite growth.

Modeling the Axon as an Active Partner with the Growth Cone in Axonal Elongation.

Forces generated by the growth cone are vital for the proper development of the axon and thus brain function. Although recent experiments show that forces are generated along the axon, it is unknown whether the axon plays a direct role in controlling growth cone advance. Here, we use analytic and finite element modeling of microtubule dynamics and the activity of the molecular motors myosin and dynein to investigate mechanical force balance along the length of the axon and its effects on axonal outgrowth.

Neurite elongation is highly correlated with bulk forward translocation of microtubules.

During the development of the nervous system and regeneration following injury, microtubules (MTs) are required for neurite elongation. Whether this elongation occurs primarily through tubulin assembly at the tip of the axon, the transport of individual MTs, or because MTs translocate forward in bulk is unclear. Using fluorescent speckle microscopy (FSM), differential interference contrast (DIC), and phase contrast microscopy, we tracked the movement of MTs, phase dense material, and docked mitochondria in chick sensory and Aplysia bag cell neurons growing rapidly on physiological substrates.

Non-Cell-Autonomous Regulation of Retrograde Motoneuronal Axonal Transport in an SBMA Mouse Model.

Defects in axonal transport are seen in motoneuronal diseases, but how that impairment comes about is not well understood. In spinal bulbar muscular atrophy (SBMA), a disorder linked to a CAG/polyglutamine repeat expansion in the androgen receptor (AR) gene, the disease-causing AR disrupts axonal transport by acting in both a cell-autonomous fashion in the motoneurons themselves, and in a non-cell-autonomous fashion in muscle. The non-cell-autonomous mechanism is suggested by data from a unique "myogenic" transgenic (TG) mouse model in which an AR transgene expressed exclusively in skeletal muscle fibers triggers an androgen-dependent SBMA phenotype, including defects in retrograde transport.

Penetrating Orbital Injury From a Needlefish.

Orbital penetrating injuries are an unfortunately common occurrence; however, those from marine animals are rare. Injuries from marine animals can be quite profound and there are no known reports of complete visual recovery after an orbital penetrating injury. Complications range from secondary infection to a carotid-cavernous fistula, which can complicate the management of these patients.

Slipping the knot: a comparison of knots used in adjustable suture strabismus surgery.

Purpose: To evaluate the frictional force created by different knots used in adjustable suture strabismus surgery.

Methods: To allow the simulation of strabismus surgery suture tying methods a model using 6-0 polyglactin 910 suture was created. Three different knots were evaluated: (1) the sliding noose knot with a double wrap of suture, (2) the cinch knot with a single throw on both sides of the pole suture, (2) and a single-throw square knot.

Automated measurement of fast mitochondrial transport in neurons.

There is growing recognition that fast mitochondrial transport in neurons is disrupted in multiple neurological diseases and psychiatric disorders. However, a major constraint in identifying novel therapeutics based on mitochondrial transport is that the large-scale analysis of fast transport is time consuming. Here we describe methodologies for the automated analysis of fast mitochondrial transport from data acquired using a robotic microscope.

Plication augmentation of the modified Hummelsheim procedure for treatment of large-angle esotropia due to abducens nerve palsy and type 1 Duane syndrome.

Background: Multiple procedures have been described to treat a large-angle esodeviation with an associated abduction deficit. We report a plication augmentation of the Hummelsheim procedure for the management of esotropia and severe abduction deficit due to abducens nerve palsy or type 1 Duane syndrome.

Methods: The medical records of patients operated on using the plication augmentation Hummelsheim procedure at two tertiary centers were retrospectively reviewed.