Intracapsular accommodation mechanism in terms of lens curvature gradient.

The intracapsular accommodation mechanism (IAM) may be understood as an increase in the lens equivalent refractive index as the eye accommodates. Our goal was to evaluate the existence of an IAM by analysing observed changes in the inner curvature gradient of the lens. To this end, we fitted a gradient index and curvature lens model to published experimental data on external and nucleus geometry changes during accommodation.

Melatonin as a Mediator of the Gut Microbiota-Host Interaction: Implications for Health and Disease.

In recent years, the role played by melatonin on the gut microbiota has gained increasingly greater attention. Additionally, the gut microbiota has been proposed as an alternative source of melatonin, suggesting that this antioxidant indoleamine could act as a sort of messenger between the gut microbiota and the host. This review analyses the available scientific literature about possible mechanisms involved in this mediating role, highlighting its antioxidant effects and influence on this interaction.

Effects of long-term individual housing of middle-aged female on spatial learning and memory in the Barnes maze task.

Introduction: Prolonged social isolation is a form of passive chronic stress that has consequences on human and animal behavior. The present study was undertaken to elucidate whether the long-term isolation would precipitate age-related changes in anxiety and spatial learning and memory in degus.

Methods: We investigated the effects of long-term social isolation on anxiety levels in the light-dark test, and spatial orientation abilities in the Barnes maze.

Guide of management of alterations in mineral and bone metabolism during gestation and lactation.

Objective: To provide practical recommendations for the management of mineral and bone metabolism alterations in pregnancy and lactation.

Participants: Members of the Working Group on Osteoporosis and Mineral Metabolism of the Spanish Society of Endocrinology and Nutrition.

Methods: Recommendations were formulated according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system to describe both the strength of recommendations and the quality of evidence.

Mitochondrial Dysfunction and Oxidative Stress in Rheumatoid Arthritis.

Control of excessive mitochondrial oxidative stress could provide new targets for both preventive and therapeutic interventions in the treatment of chronic inflammation or any pathology that develops under an inflammatory scenario, such as rheumatoid arthritis (RA). Increasing evidence has demonstrated the role of mitochondrial alterations in autoimmune diseases mainly due to the interplay between metabolism and innate immunity, but also in the modulation of inflammatory response of resident cells, such as synoviocytes. Thus, mitochondrial dysfunction derived from several danger signals could activate tricarboxylic acid (TCA) disruption, thereby favoring a vicious cycle of oxidative/mitochondrial stress.

Catastrophe optics theory unveils the localised wave aberration features that generate ghost images.

Monocular polyplopia (ghost or multiple images) is a serious visual impediment for some people who report seeing two (diplopia), three (triplopia) or even more images. Polyplopia is expected to appear if the point spread function (PSF) has multiple intensity cores (a dense concentration of a large portion of the radiant flux contained in the PSF) relatively separated from each other, each of which contributes to a distinct image. We present a theory that assigns these multiple PSF cores to specific features of aberrated wavefronts, thereby accounting optically for the perceptual phenomenon of monocular polyplopia.

The medium-term consequences of a COVID-19 lockdown on lifestyle among Spanish older people with hypertension, pulmonary disease, cardiovascular disease, musculoskeletal disease, depression, and cancer.

Objectives: This study investigated the associations of chronic diseases with changes in lifestyle and health behaviours in older people following the coronavirus disease 2019 (COVID-19) lockdown in Spain and compared the differences in changes over time.

Methods: 1,092 participants (80.3±5.

Effect of depression on mortality in type 2 diabetes mellitus after 8 years of follow-up. The DIADEMA study.

Aim: To assess the effect of depression on all-cause mortality in patients with type 2 diabetes mellitus (T2DM) followed up during 8 years in primary care in Spain.

Methods: Depression was diagnosed according to MINI 5.0.

How important is current physical fitness for future quality of life? Results from an 8-year longitudinal study on older adults.

Introduction: A vast amount of research has focused on the effects of physical fitness (PF) on mortality, with little research evaluating the effects of PF on future expected health related quality of life (HRQoL).

Aim: To evaluate how current PF influences future HRQoL measured in a prospective 8-year study in older adults.

Methods: A total of 617 (157 males) older adults (>65y) participated in the study.

Autophagy Activation by Resveratrol Reduces Severity of Experimental Rheumatoid Arthritis.

Scope: Previous work reported that dietary supplementation with resveratrol lowers synovial hyperplasia, inflammatory and oxidative damage in an antigen-induced arthritis (AIA) model. Here, it is investigated whether resveratrol can regulate the abnormal synovial proliferation by inducing autophagy and controlling the associated inflammatory response.

Methods And Results: Animals treated with resveratrol 8 weeks before AIA induction show the highest significant signal for microtubule-associated protein 1 light chain 3 by confocal microscopy.

Aberrations and accommodation.

Modern methods of measuring the refractive state of the eye include wavefront sensors which make it possible to monitor both static and dynamic changes of the ocular wavefront while the eye observes a target positioned at different distances away from the eye. In addition to monitoring the ocular aberrations, wavefront refraction methods allow measurement of the accommodative response while viewing with the eye's habitual chromatic and monochromatic aberrations present, with these aberrations removed, and with specific aberrations added or removed. A large number of experiments describing the effects of accommodation on aberrations and vice versa are reviewed, pointing out the implications for fundamental questions related to the mechanism of accommodation.

Implications of Vitamin D in Multiple Sclerosis and Other Neurodegenerative Processes: Bibliometric Analysis and Systematic Review.

In recent years, numerous investigations focused on the pleiotropic actions of vitamin D have been carried out. These actions include the participation of this molecule in neurophysiological and neuropathological processes. As a consequence, abundant scientific literature on the role of this vitamin in neurodegenerative entities has emerged, even concerning clinical studies.

The effect of spherical aberration on visual performance and refractive state for stimuli and tasks typical of night viewing.

Purpose: The aim of this work was to examine the impact of Seidel spherical aberration (SA) on optimum refractive state for detecting and discriminating small bright lights on a dark background.

Methods: An adaptive-optics system was used to correct ocular aberrations of cyclopleged eyes and then systematically introduce five levels of Seidel SA for a 7-mm diameter pupil: 0,±0.18, and±0.

There is more to accommodation of the eye than simply minimizing retinal blur.

Eyes of children and young adults change their optical power to focus nearby objects at the retina. But does accommodation function by trial and error to minimize blur and maximize contrast as is generally accepted? Three experiments in monocular and monochromatic vision were performed under two conditions while aberrations were being corrected. In the first condition, feedback was available to the eye from both optical vergence and optical blur.

Interrelationships Among Gut Microbiota and Host: Paradigms, Role in Neurodegenerative Diseases and Future Prospects.

Background & Objective: Advances in the knowledge of the microbiota and concepts related to it have triggered a wake-up call in biomedicine. The development in various scientific areas has enabled a better and broader approach to everything concerning the set of families of microorganisms that coexist with an individual and are able to function as one or more organs in its body. Among the aforementioned scientific areas, those worth mentioning are the advances/progress in biotechnological resources and, in particular, molecular biology and related areas.

Human eyes do not need monochromatic aberrations for dynamic accommodation.

Purpose: To determine if human accommodation uses the eye's own monochromatic aberrations to track dynamic accommodative stimuli.

Methods: Wavefront aberrations were measured while subjects monocularly viewed a monochromatic Maltese cross moving sinusoidally around 2D of accommodative demand with 1D amplitude at 0.2 Hz.

Dynamic accommodation without feedback does not respond to isolated blur cues.

The aim of this study was to determine whether dynamic accommodation responds to isolated blur cues without feedback, and without changes in the distance of the object. Nine healthy subjects aged 21-40years were recruited. Four different aberration patterns were used as stimuli to induce blur with (1) the eye's natural, uncorrected, optical aberrations, (2) all aberrations corrected, (3) spherical aberration only, or (4) astigmatism only.

A New Frailty Score for Experimental Animals Based on the Clinical Phenotype: Inactivity as a Model of Frailty.

The development of animal models to study human frailty is important to test interventions to be translated to the clinical practice. The aim of this work was to develop a score for frailty in experimental animals based in the human frailty phenotype. We also tested the effect of physical inactivity in the development of frailty as determined by our score.

Prevalence of vertebral fracture and densitometric osteoporosis in Spanish adult men: The Camargo Cohort Study.

The aim of this study was to assess the prevalence of densitometric osteoporosis and vertebral fractures in Spanish men aged ≥50 years, and to study how the relationship between them may change depending on how osteoporosis is diagnosed. A community-based population of 1003 men aged ≥50 years was studied. Bone mineral density (BMD) was measured by DXA at the lumbar spine, femoral neck and total hip.

Ocular Straylight with Different Multifocal Contact Lenses.

Purpose: Multifocal contact lenses have been growing in popularity as a modality to correct presbyopic eyes, although visual side effects such as disability glare have been reported. The objective of this study was to investigate the effect of multifocal contact lenses on disability glare by means of ocular straylight.

Methods: A prospective randomized, comparative study was performed that included 16 subjects free of ocular pathology.

CathepsinKCre mediated deletion of βcatenin results in dramatic loss of bone mass by targeting both osteoclasts and osteoblastic cells.

It is well established that activation of Wnt/βcatenin signaling in the osteoblast lineage leads to an increase in bone mass through a dual mechanism: increased osteoblastogenesis and decreased osteoclastogenesis. However, the effect of this pathway on the osteoclast lineage has been less explored. Here, we aimed to examine the effects of Wnt/βcatenin signaling in mature osteoclasts by generating mice lacking βcatenin in CathepsinK-expressing cells (Ctnnb1;CtsKCre mice).

Lipopolysaccharide Binding Protein and Oxidative Stress in a Multiple Sclerosis Model.

Recent findings in experimental autoimmune encephalomyelitis (EAE) suggest that altering certain bacterial populations present in the gut may lead to a proinflammatory condition, that could result in the development of multiple sclerosis (MS). Also, Reactive Oxygen Species seem to be involved in the course of MS. In this study, it has been aimed to relate all these variables starting from an analysis of the lipopolysaccharide (LPS) and LPS-binding protein (LBP) with the determination of parameters related to oxidative stress in the blood, brain and spinal cord.

Optical Characterization Method for Tilted or Decentered Intraocular Lenses.

Purpose: To test and validate a method for measuring the optical quality and optical power of monofocal intraocular lenses (IOLs) in the presence of a tilt or a decentration as well as its optical power.

Methods: The experimental system consists of an artificial eye (wet-cell) and a commercial aberrometer with a Shack-Hartmann sensor. Optical image quality parameters such as point spread function (PSF), modulation transfer function (MTF), and the simulations of the retinal image of an extended object are computed from the in vitro wavefront data of an IOL.