α-Crystallin chaperone mimetic drugs inhibit lens γ-crystallin aggregation: Potential role for cataract prevention.

Γ-Crystallins play a major role in age-related lens transparency. Their destabilization by mutations and physical chemical insults are associated with cataract formation. Therefore, drugs that increase their stability should have anticataract properties.

An Anatomic Study of the Proximal Tibial Epiphysis With Relevance to Percutaneous Epiphysiodesis Using Transphyseal Screws (PETS).

Background: Percutaneous epiphysiodesis using transphyseal screws (PETS) is a common procedure to correct lower extremity limb-length discrepancies in the pediatric population. A potential complication of this procedure is development of tibial valgus deformity, which may occur secondary to decreased screw purchase in the thinner medial proximal tibial epiphysis. The thickness of the proximal tibial epiphysis has not yet been well quantified, which was the aim of this study.

An anatomic and 3D study of the development of the proximal humeral physis.

Purpose: During maturation, the ossification centers of the proximal humerus form a characteristic pattern consisting of a metaphyseal peak and corresponding epiphyseal valley. The surface topographies of the metaphyseal peak and epiphyseal valley are not well described and may have variation with age and structural importance to the pathogenesis of proximal humeral epiphysiolysis.

Methods: High-resolution 3-dimensional surface scans of 24 cadaveric proximal humeral epiphyses and metaphyses in specimens aged 3 to 18 years were obtained.

Intra-articular injection receipt within 3 months prior to primary total knee arthroplasty is associated with increased periprosthetic joint infection risk.

Purpose: This systematic review and meta-analysis analyzed the influence of pre-operative intra-articular injections (IAI) on periprosthetic joint infection (PJI) rates after primary total knee arthroplasty (TKA).

Methods: Studies published between January 1st, 2000 and May 1st, 2021 evaluating PJI rates among TKA patients with and without IAI were identified from PubMed, Cochrane Library, MEDLINE, EBSCO Host, and Google Scholar. The pooled effect of IAI on PJI risk was calculated utilizing Mantel-Haenszel (M-H) models.

How do pre-operative intra-articular injections impact periprosthetic joint infection risk following primary total hip arthroplasty? A systematic review and meta-analysis.

Introduction: Although intra-articular injections (IAIs) serve as the first-line non-surgical management for severe osteoarthritis (OA), recent analyses have suggested they are associated with an increased infection risk following primary total hip arthroplasty (THA). Therefore, our systematic review and meta-analysis explored the relationship between IAIs and periprosthetic joint infection (PJI) following THA reported in the current literature.

Methods: Five online databases were queried for analyses published from January 1st, 2000-May 1st, 2021 reporting on PJI rates between patients undergoing primary THA who did and did not preoperatively receive an IAI.

An anatomical study defining the safe range of angles in percutaneous iliosacral and transsacral screw fixation.

Percutaneous iliosacral screw fixation and transsacral fixation are challenging procedures requiring extensive knowledge of sacral anatomy to avoid damaging nearby neurovascular structures. Greater knowledge of anatomical screw trajectory and size allowances would be helpful to guide surgical placement. An anatomical study of 40 cadaveric sacra in specimens ages 18-65 was performed.

Periprosthetic joint infection rates across primary total hip arthroplasty surgical approaches: a systematic review and meta-analysis of 653,633 procedures.

Introduction: Evidence demonstrates comparable clinical outcomes across the various surgical approaches to primary total hip arthroplasty (THA). However, high-quality contemporary data regarding periprosthetic joint infection (PJI) risk between direct anterior approach (DAA) and other (THA) approaches is lacking. This systematic review and meta-analysis evaluated PJI rates reported in the literature between the DAA and other approaches.

Melanopsin tristability for sustained and broadband phototransduction.

Mammals rely upon three ocular photoreceptors to sense light: rods, cones, and intrinsically photosensitive retinal ganglion cells (ipRGCs). Rods and cones resolve details in the visual scene. Conversely, ipRGCs integrate over time and space, primarily to support "non-image" vision.

Adaptation to steady light by intrinsically photosensitive retinal ganglion cells.

Intrinsically photosensitive retinal ganglion cells (ipRGCs) are recently discovered photoreceptors in the mammalian eye. These photoreceptors mediate primarily nonimage visual functions, such as pupillary light reflex and circadian photoentrainment, which are generally expected to respond to the absolute light intensity. The classical rod and cone photoreceptors, on the other hand, mediate image vision by signaling contrast, accomplished by adaptation to light.

Melanopsin-positive intrinsically photosensitive retinal ganglion cells: from form to function.

Melanopsin imparts an intrinsic photosensitivity to a subclass of retinal ganglion cells (ipRGCs). Generally thought of as irradiance detectors, ipRGCs target numerous brain regions involved in non-image-forming vision. ipRGCs integrate their intrinsic, melanopsin-mediated light information with rod/cone signals relayed via synaptic connections to influence light-dependent behaviors.

Tracer coupling of intrinsically photosensitive retinal ganglion cells to amacrine cells in the mouse retina.

Intrinsically photosensitive retinal ganglion cells (ipRGCs) are a subtype of ganglion cell in the mammalian retina that expresses the photopigment melanopsin and drives non-image-forming visual functions. Three morphological subtypes of ipRGCs (M1, M2, and M3) have been described based on their dendritic stratifications in the inner plexiform layer (IPL), but the question of their potential interactions via electrical coupling remains unsettled. In this study, we have addressed this question in the mouse retina by, injecting the tracer Neurobiotin into ipRGCs that had been genetically labelled with the fluorescent protein, tdTomato.

Intrinsically photosensitive retinal ganglion cells.

Life on earth is subject to alternating cycles of day and night imposed by the rotation of the earth. Consequently, living things have evolved photodetective systems to synchronize their physiology and behavior with the external light-dark cycle. This form of photodetection is unlike the familiar "image vision," in that the basic information is light or darkness over time, independent of spatial patterns.

Photon capture and signalling by melanopsin retinal ganglion cells.

A subset of retinal ganglion cells has recently been discovered to be intrinsically photosensitive, with melanopsin as the pigment. These cells project primarily to brain centres for non-image-forming visual functions such as the pupillary light reflex and circadian photoentrainment. How well they signal intrinsic light absorption to drive behaviour remains unclear.

Non-image-forming ocular photoreception in vertebrates.

It has been accepted for a hundred years or more that rods and cones are the only photoreceptive cells in the retina. The light signals generated in rods and cones, after processing by downstream retinal neurons (bipolar, horizontal, amacrine and ganglion cells), are transmitted to the brain via the axons of the ganglion cells for further analysis. In the past few years, however, convincing evidence has rapidly emerged indicating that a small subset of retinal ganglion cells in mammals is also intrinsically photosensitive.

Sodium currents in subthalamic nucleus neurons from Nav1.6-null mice.

In some central neurons, including cerebellar Purkinje neurons and subthalamic nucleus (STN) neurons, TTX-sensitive sodium channels show unusual gating behavior whereby some channels open transiently during recovery from inactivation. This "resurgent" sodium current is effectively activated immediately after action potential-like waveforms. Earlier work using Purkinje neurons suggested that the great majority of resurgent current originates from Na(v)1.

Subthreshold sodium currents and pacemaking of subthalamic neurons: modulation by slow inactivation.

Neurons of the subthalamic nucleus (STN) are spontaneously active. By voltage clamping dissociated rat STN neurons with their own firing patterns, we found that pacemaking is driven by two kinds of subthreshold sodium current: a steady-state "persistent" sodium current and a dynamic "resurgent" sodium current, which promotes rapid firing by flowing immediately after a spike. These currents are strongly regulated by a process of slow inactivation that is active at physiological firing frequencies.