Influence of zonular tension on molecular transport in the porcine ocular lens.

Introduction: Accommodation is the process of changing the ocular lens' refractive power and focal distance. This process involves application of biomechanical forces on the lens by the surrounding musculature. Previous studies have demonstrated that the lens epithelium demonstrates mechanotransduction and that tension influences its chemical activity.

Torsion-Induced Traumatic Optic Neuropathy (TITON): A Physiologically Relevant Animal Model of Traumatic Optic Neuropathy.

Traumatic optic neuropathy (TON) is a common cause of irreversible blindness following head injury. TON is characterized by axon damage in the optic nerve followed by retinal ganglion cell death in the days and weeks following injury. At present, no therapeutic or surgical approach has been found to offer any benefit beyond observation alone.

An technique to measure resistance to compression and kinking of endotracheal tubes.

Background: During intraoperative care, ventilatory parameters including peak inflating pressure (PIP) and exhaled tidal volumes are continuously monitored to assess changes in respiratory resistance and compliance. Changes in these parameters, such as an increase in PIP or a decrease in the exhaled tidal volume, may indicate various pathologic processes that may require immediate attention to prevent inadequate ventilation resulting in hypoxemia or hypercarbia. A kinked endotracheal tube (ETT) may mimic other pathologic processes including bronchospasm, mainstem intubation, or ventilator malfunction.

Automated Compression Testing of the Ocular Lens.

The biomechanical properties of the ocular lens are essential to its function as a variable power optical element. These properties change dramatically with age in the human lens, resulting in a loss of near vision called presbyopia. However, the mechanisms of these changes remain unknown.

A method for generating zonular tension in the murine eye by embedding and compressing the globe in a hydrogel.

The ocular lens is the primary organ within the eye responsible for accommodation. During accommodation, the lens is subject to biomechanical forces. We previously demonstrated that stretching the porcine lens can increase lens epithelial cell proliferation.

Taxonomic insights from floral scents of western North American sessile-flowered Trillium.

Premise: Chemical composition of floral volatiles can be an important complement to morphological characters in describing and identifying species. Four of the five species of western sessile-flowered Trillium are challenging to distinguish morphologically due to wide intraspecific variation and overlapping characters among taxa. Characterizing their floral volatile compositions could aid future taxonomic, ecological, and evolutionary studies of Trillium and related taxa.

Association of Nicotine Cessation Time on the Incidence of Recurrent Incisional Hernia Repair and Postoperative Surgical Site Occurrences.

Background: Nicotine products are believed to be associated with a higher incidence of incisional hernia (IH) recurrence and postoperative complications after IH repair.

Methods: A retrospective analysis of the Abdominal Core Health Quality Collaborative (ACHQC) database was performed. Outcomes included risk of IH recurrence, 30-day surgical site infection (SSI), and 30-day surgical site occurrence (SSO).

GC/MS analysis of hypoxic volatile metabolic markers in the MDA-MB-231 breast cancer cell line.

Hypoxia in disease describes persistent low oxygen conditions, observed in a range of pathologies, including cancer. In the discovery of biomarkers in biological models, pathophysiological traits present a source of translatable metabolic products for the diagnosis of disease in humans. Part of the metabolome is represented by its volatile, gaseous fraction; the volatilome.

The complexity of biological disturbance agents, fuels heterogeneity, and fire in coniferous forests of the western United States.

Forest biological disturbance agents (BDAs) are insects, pathogens, and parasitic plants that affect tree decline, mortality, and forest ecosystems processes. BDAs are commonly thought to increase the likelihood and severity of fire by converting live standing trees to more flammable, dead and downed fuel. However, recent research indicates that BDAs do not necessarily increase, and can reduce, the likelihood or severity of fire.

Too hot, too cold, or just right: Can wildfire restore dry forests of the interior Pacific Northwest?

As contemporary wildfire activity intensifies across the western United States, there is increasing recognition that a variety of forest management activities are necessary to restore ecosystem function and reduce wildfire hazard in dry forests. However, the pace and scale of current, active forest management is insufficient to address restoration needs. Managed wildfire and landscape-scale prescribed burns hold potential to achieve broad-scale goals but may not achieve desired outcomes where fire severity is too high or too low.

Orbital fat swelling: A biomechanical theory and supporting model for spaceflight-associated neuro-ocular syndrome (SANS).

Spaceflight-Associated Neuro-ocular Syndrome (SANS) is a descriptor of several ocular and visual signs and symptoms which commonly afflicts those exposed to microgravity. We propose a new theory for the driving force leading to the development of Spaceflight-Associated Neuro-ocular Syndrome which is described a finite element model of the eye and orbit. Our simulations suggest that the anteriorly directed force produced by orbital fat swelling is a unifying explanatory mechanism for Spaceflight-Associated Neuro-ocular Syndrome, as well as producing a larger effect than that generated by elevation in intracranial pressure.

Oxidative stress in the brain and retina after traumatic injury.

The brain and the retina share many physiological similarities, which allows the retina to serve as a model of CNS disease and disorder. In instances of trauma, the eye can even indicate damage to the brain abnormalities observed such as irregularities in pupillary reflexes in suspected traumatic brain injury (TBI) patients. Elevation of reactive oxygen species (ROS) has been observed in neurodegenerative disorders and in both traumatic optic neuropathy (TON) and in TBI.

Validity of aerosolization detection with an air quality indicator in noncontact tonometry using corneal phantoms.

PrÉcis: Using a controlled experimental design with corneal phantoms, this study provides evidence of the lack of validity of a static air quality indicator, previously used to characterize aerosolization during dynamic noncontact tonometry.

Purpose: To evaluate the accuracy of aerosol concentrations reported by an air quality indicator (AQI) following an air puff from a noncontact tonometer using non-aerosolizing corneal phantoms.

Methods: Three rubber corneal phantoms of different stiffnesses were used to represent varying intraocular pressure (IOP) values.

Arvcf Dependent Adherens Junction Stability is Required to Prevent Age-Related Cortical Cataracts.

The etiology of age-related cortical cataracts is not well understood but is speculated to be related to alterations in cell adhesion and/or the changing mechanical stresses occurring in the lens with time. The role of cell adhesion in maintaining lens transparency with age is difficult to assess because of the developmental and physiological roles that well-characterized adhesion proteins have in the lens. This report demonstrates that Arvcf, a member of the p120-catenin subfamily of catenins that bind to the juxtamembrane domain of cadherins, is an essential fiber cell protein that preserves lens transparency with age in mice.

A Review of Lens Biomechanical Contributions to Presbyopia.

Presbyopia-the progressive loss of near focus with age-is primarily a result of changes in lens biomechanics. In particular, the shape of the ocular lens in the absence of zonular tension changes significantly throughout adulthood. Contributors to this change in shape are changes in lens biomechanical properties, continuous volumetric growth lens, and possibly remodeling of the lens capsule.

Tunable alginate hydrogels as injectable drug delivery vehicles for optic neuropathy.

Many disease pathologies, particularly in the eye, are induced by oxidative stress. In particular, injury to the optic nerve (ON), or optic neuropathy, is one of the most common causes of vision loss. Traumatic optic neuropathy (TON) occurs when the ON is damaged following blunt or penetrating trauma to either the head or eye.

The Shape of Corneal Deformation Alters Air Puff-Induced Loading.

To determine the dynamic modification of the load exerted on the eye during air-puff testing by accounting for the deformation of the cornea. The effect of corneal load alteration with surface shape () was characterized as an additional component of the load produced during the concave phase where the fluid outflow tangential to the corneal surface creates backward pressure. Concave phase duration ( ), maximum value ( ), and the area under -time curve ( ) are calculated for 26 keratoconic (KCN), 102 normal (NRL), and 29 ocular hypertensive (OHT) subjects.

The Roles of Vitreous Biomechanics in Ocular Disease, Biomolecule Transport, and Pharmacokinetics.

Purpose: The biomechanical properties of the vitreous humor and replication of these properties to develop substitutes for the vitreous humor have rapidly become topics of interest over the last two decades. In particular, the behavior of the vitreous humor as a viscoelastic tissue has been investigated to identify its role in a variety of processes related to biotransport, aging, and age-related pathologies of the vitreoretinal interface.

Methods: A thorough search and review of peer-reviewed publications discussing the biomechanical properties of the vitreous humor in both human and animal specimens was conducted.

Hydrodynamic Interaction Between Tear Film and Air Puff From Noncontact Tonometry.

Purpose: The purpose of this study was to investigate the mechanism of potential droplet formation in response to air puff deformation with two noncontact tonometers (NCTs).

Methods: Twenty healthy volunteers were examined using two NCTs, Ocular Response Analyzer and Corvis ST, and two contact tonometers, iCare and Tono-Pen. High-speed videos of the tear film response were captured with at spatial resolution of 20 microns/pixel at 2400 fps.

Biological Preparation and Mechanical Technique for Determining Viscoelastic Properties of Zonular Fibers.

Elasticity is essential to the function of tissues such as blood vessels, muscles, and lungs. This property is derived mostly from the extracellular matrix (ECM), the protein meshwork that binds cells and tissues together. How the elastic properties of an ECM network relate to its composition, and whether the relaxation properties of the ECM play a physiological role, are questions that have yet to be fully addressed.

An Ecological Perspective on Living with Fire in Ponderosa Pine Forests of Oregon and Washington: Resistance, Gone but not Forgotten.

Wildland fires (WLF) have become more frequent, larger, and severe with greater impacts to society and ecosystems and dramatic increases in firefighting costs. Forests throughout the range of ponderosa pine in Oregon and Washington are jeopardized by the interaction of anomalously dense forest structure, a warming and drying climate, and an expanding human population. These forests evolved with frequent interacting disturbances including low-severity surface fires, droughts, and biological disturbance agents (BDAs).

Biomarkers and heterogeneous fibroblast phenotype associated with incisional hernia.

Development of incisional hernia (IH) is multifactorial but inflammation and abdominal wall ECM (extracellular matrix) disorganization are key pathological events. We investigated if the differential expression of fibroblast biomarkers reflects the cellular milieu and the dysregulated ECM in IH tissues. Expression of fibroblast biomarkers, including connective tissue growth factor, alpha-smooth muscle actin (α-SMA), CD34 (cluster of differentiation 34), cadherin-11 and fibroblast specific protein 1 (FSP1), was examined by histology and immunofluorescence in the hernial-fascial ring/neck tissue (HRT) and hernia sack tissue (HST) harvested from the patients undergoing hernia surgery and compared with normal fascia (FT) and peritoneum (PT) harvested from brain-dead healthy subjects undergoing organ procurement for transplantation.

The Anaerobic Fungi: Challenges and Opportunities for Industrial Lignocellulosic Biofuel Production.

Lignocellulose is a promising feedstock for biofuel production as a renewable, carbohydrate-rich and globally abundant source of biomass. However, challenges faced include environmental and/or financial costs associated with typical lignocellulose pretreatments needed to overcome the natural recalcitrance of the material before conversion to biofuel. Anaerobic fungi are a group of underexplored microorganisms belonging to the early diverging phylum Neocallimastigomycota and are native to the intricately evolved digestive system of mammalian herbivores.

Cytoreduction with hyperthermic intra peritoneal and intra thoracic chemotherapy for metastatic Sertoli-Leydig cell tumor of the ovary.

Sertoli Leydig cell tumor (SLCT) is a rare sex-cord stromal tumor of the ovary that generally has a benign course. Here, we report an unusual case of recurrent, metastatic SLCT and its unique management with a combination of cytoreductive surgery, hyperthermic intraperitoneal chemotherapy, hyperthermic intrathoracic chemotherapy, and systemic chemotherapy.