Spinal cord injury significantly alters the properties of reticulospinal neurons: delayed repolarization mediated by potassium channels.

After rostral spinal cord injury (SCI) of lampreys, the descending axons of injured (axotomized) reticulospinal (RS) neurons regenerate and locomotor function gradually recovers. Our previous studies indicated that relative to uninjured lamprey RS neurons, injured RS neurons display several dramatic changes in their biophysical properties, called the "injury phenotype." In the present study, at the onset of applied depolarizing current pulses for membrane potentials below as well as above threshold for action potentials (APs), injured RS neurons displayed a transient depolarization consisting of an initial depolarizing component followed by a delayed repolarizing component.

A physics-based digital twin for model predictive control of autonomous unmanned aerial vehicle landing.

This paper proposes a two-level, data-driven, digital twin concept for the autonomous landing of aircraft, under some assumptions. It features a digital twin instance (DTI) for model predictive control (MPC); and an innovative, real-time, digital twin prototype for fluid-structure interaction and flight dynamics to inform it. The latter digital twin is based on the linearization about a pre-designed glideslope trajectory of a high-fidelity, viscous, nonlinear computational model for flight dynamics; and its projection onto a low-dimensional approximation subspace to achieve real-time performance, while maintaining accuracy.

Spinal Cord Injury Significantly Alters the Properties of Reticulospinal Neurons: I. Biophysical Properties, Firing Patterns, Excitability, and Synaptic Inputs.

Following spinal cord injury (SCI) for larval lampreys, descending axons of reticulospinal (RS) neurons regenerate, and locomotor function gradually recovers. In the present study, the electrophysiological properties of uninjured (left)-injured (right) pairs of large, identified RS neurons were compared following rostral, right spinal cord hemi-transections (HTs). First, changes in firing patterns of injured RS neurons began in as little as 2-3 days following injury, these changes were maximal at ~2-3 weeks (wks), and by 12-16 wks normal firing patterns were restored for the majority of neurons.

Modeling of lamprey reticulospinal neurons: multiple distinct parameter sets yield realistic simulations.

For the lamprey and other vertebrates, reticulospinal (RS) neurons project descending axons to the spinal cord and activate motor networks to initiate locomotion and other behaviors. In the present study, a biophysically detailed computer model of lamprey RS neurons was constructed consisting of three compartments: dendritic, somatic, and axon initial segment (AIS). All compartments included passive channels.

Follow the nevus: the cost-utility of monitoring for growth of choroidal nevi.

Aim: To develop a model to evaluate the cost-utility of choroidal nevi monitoring recommendations with varying clinical risk factors.

Methods: A Markov model was created to evaluate the cost-utility in cost per quality-adjusted life-year ($/QALY) for monitoring patients with choroidal nevus. This probabilistic model was applied both to a hypothetically monitored and unmonitored group of patients beginning at different ages and with varying clinical risk factors of the nevus.

Restoration of the Topological Organization of the Trigeminal System Following Trigeminal Nerve Root Injury in the Lamprey.

Two issues were examined regarding the trigeminal system in larval lampreys: (1) for normal animals, double labeling was used to confirm that the trigeminal system has a topological organization; (2) following trigeminal nerve root transections, double labeling was used to test whether the topological organization of the trigeminal system is restored. First, for normal animals, Alexa 488 dextran amine applied to the medial oral hood (anterior head) labeled trigeminal motoneurons (MNs) in the ventromedial part of the trigeminal motor nuclei (nVm) and axons of trigeminal sensory neurons (SNs) in the ventromedial part of the trigeminal descending tracts (dV). Also, Texas red dextran amine (TRDA) applied to the lateral oral hood labeled trigeminal MNs in the dorsolateral nVm and sensory axons in the dorsolateral dV.

Genomic discovery of ion channel genes in the central nervous system of the lamprey Petromyzon marinus.

The lamprey is a popular animal model for a number of types of neurobiology studies, including organization and operation of locomotor and respiratory systems, behavioral recovery following spinal cord injury (SCI), cellular and synaptic neurophysiology, comparative neuroanatomy, neuropharmacology, and neurodevelopment. Yet relatively little work has been done on the molecular underpinnings of nervous system function in lamprey. This is due in part to a paucity of gene information for some of the most fundamental proteins involved in neural activity: ion channels.

Reversal of cilioretinal artery occlusion with intra-arterial tissue plasminogen activator.

Purpose: To present the reversal of a cilioretinal artery occlusion with the use of intra-arterial tissue plasminogen activator.

Observations: A monocular 74 year old male presented with a cilioretinal artery occlusion. Treatment with intra-arterial tissue plasminogen activator 7 hours after the onset of symptoms led to a complete restoration of vision.

Elimination of Left-Right Reciprocal Coupling in the Adult Lamprey Spinal Cord Abolishes the Generation of Locomotor Activity.

The contribution of left-right reciprocal coupling between spinal locomotor networks to the generation of locomotor activity was tested in adult lampreys. Muscle recordings were made from normal animals as well as from experimental animals with rostral midline (ML) spinal lesions (~13%→35% body length, BL), before and after spinal transections (T) at 35% BL. Importantly, in the present study actual locomotor movements and muscle burst activity, as well as other motor activity, were initiated in whole animals by descending brain-spinal pathways in response to sensory stimulation of the anterior head.

Comparison of Regional vs. General Anesthesia for Surgical Repair of Open-Globe Injuries at a University Referral Center.

Purpose: This study compares the clinical features and physician selection of either Regional Anesthesia (peribulbar or retrobulbar block) with Monitored Anesthesia Care (RA-MAC) or General Anesthesia (GA) for open globe injury repair.

Design: A non-randomized, comparative, retrospective case series at a University Referral Center.

Participants: All adult repairable open globe injuries receiving primary repair between January 1st, 2004 and December 31st, 2014 (11 years).

Culture-Positive Endophthalmitis After Open Globe Injuries With and Without Retained Intraocular Foreign Bodies.

Background And Objective: To report the visual and anatomical outcomes and microbiologic spectrum of culture-positive endophthalmitis in open globe injuries (OGIs) with or without intraocular foreign bodies (IOFBs).

Patients And Methods: A retrospective, interventional case series of OGIs (n = 718) treated between 2004 and 2015. Patients underwent a management protocol for OGI, including systemic broad-spectrum antibiotics, on presentation.

Regulation of axonal regeneration following spinal cord injury in the lamprey.

Following rostral spinal cord injury (SCI) in larval lampreys, injured descending brain neurons, particularly reticulospinal (RS) neurons, regenerate their axons, and locomotor behavior recovers in a few weeks. However, axonal regeneration of descending brain neurons is mostly limited to relatively short distances, but the mechanisms for incomplete axonal regeneration are unclear. First, lampreys with rostral SCI exhibited greater axonal regeneration of descending brain neurons, including RS neurons, as well as more rapid recovery of locomotor muscle activity right below the lesion site, compared with animals with caudal SCI.

Retinal Detachment in a Combined Case of Stickler Syndrome and X-Linked Retinoschisis.

A 12-year-old boy presented with a total rhegmatogenous retinal detachment and a giant retinal tear in the right eye. Clinical examination, optical coherence tomography, and fundus images showed an optically empty vitreous, lattice degeneration, and retinoschisis of the macula. Genetic testing revealed mutations in the COL2A1 and RS1 genes, confirming a dual diagnosis of Stickler syndrome and X-linked retinoschisis, respectively.

Descending propriospinal neurons mediate restoration of locomotor function following spinal cord injury.

Unlabelled: Following spinal cord injury (SCI) in the lamprey, there is virtually complete recovery of locomotion within a few weeks, but interestingly, axonal regeneration of reticulospinal (RS) neurons is mostly limited to short distances caudal to the injury site. To explain this situation, we hypothesize that descending propriospinal (PS) neurons relay descending drive from RS neurons to indirectly activate spinal central pattern generators (CPGs). In the present study, the contributions of PS neurons to locomotor recovery were tested in the lamprey following SCI.

AIMING FOR THE BULL'S EYE: The Cost-Utility of Screening for Hydroxychloroquine Retinopathy.

Background: Throughout medicine, the cost of various treatments has been increasingly studied with the result that certain management guidelines might be reevaluated in their context. Cost-utility is a term referring to the expense of preventing the loss of quality of life, quantified in dollars per quality-adjusted life year. In 2002, the American Academy of Ophthalmology published hydroxychloroquine screening recommendations which were revised in 2011.

In Vivo Porcine Model of Venous Air Embolism During Pars Plana Vitrectomy.

Purpose: Venous air embolism (VAE) during pars plana vitrectomy (PPV) can occur owing to improper positioning of the infusion cannula in the suprachoroidal space and may lead to sudden compromise of cardiac circulation and death. This was an in vivo demonstration of fatal VAE during PPV to show that air can travel from the suprachoroidal space into the central circulation.

Design: Experimental in vivo surgical study on porcine eyes.

Similarities and Differences for Swimming in Larval and Adult Lampreys.

The spinal locomotor networks controlling swimming behavior in larval and adult lampreys may have some important differences. As an initial step in comparing the locomotor systems in lampreys, in larval animals the relative timing of locomotor movements and muscle burst activity were determined and compared to those previously published for adults. In addition, the kinematics for free swimming in larval and adult lampreys was compared in detail for the first time.

Ocular surface disease and dacryoadenitis in aging C57BL/6 mice.

Dry eye in humans displays increased prevalence in the aged and in women. Here, we investigated the ocular surfaces and lacrimal glands of aged mice of both sexes. We surveyed three different ages [young, middle-aged (6 to 9 months), and elderly] by investigating severity markers of dry eye disease (DED).

Epidemiology of Ocular Surface Squamous Neoplasia in a Veterans Affairs Population.

Purpose: To evaluate the epidemiology of ocular surface squamous neoplasia (OSSN) and its associated risk factors in a South Florida Veterans Affairs Hospital population.

Methods: Retrospective case-control study. Twenty-eight confirmed cases of OSSN from 24,179 veterans who received care at the Miami Veterans Affairs Healthcare System and affiliated satellite eye clinics between March 1, 2007, and March 1, 2012.

Long-term Supplementation With n-6 and n-3 PUFAs Improves Moderate-to-Severe Keratoconjunctivitis Sicca: A Randomized Double-Blind Clinical Trial.

Purpose: Supplementation with gamma-linolenic acid (GLA) and omega-3 (n-3) polyunsaturated fatty acids (PUFAs) has been found to decrease the production of disease-relevant inflammatory mediators that are implicated in the pathogenesis of chronic dry eye. This study evaluated the effect of a supplement containing both GLA and n-3 PUFAs on signs and symptoms of moderate-to-severe keratoconjunctivitis sicca in postmenopausal patients.

Methods: This multicenter, double-masked placebo-controlled clinical trial enrolled 38 patients (both eyes) with tear dysfunction who were randomized to supplemental GLA + n-3 PUFAs or placebo for 6 months.

Biodegradable PLGA-Based Drug Delivery Systems for Modulating Ocular Surface Disease under Experimental Murine Dry Eye.

Objective: Continuous drug delivery to the ocular surface remains difficult due to the rapid tear clearance of topically applied agents. The purpose of this study was to evaluate biodegradable and biocompatible drug delivery systems on the ocular surface using poly-lactic-co-glycolic acid (PLGA) based polymers.

Methods: Fluorescein-labeled albumin and doxycycline were individually encapsulated into a PLGA-based matrix using a water-oil-water double emulsion method.