Effect of cylinder power and axis changes on vision in astigmatic participants

Purpose: To ascertain the impact of altering cylinder (cyl) power and axis on vision in astigmatism.Methods: In a prospective, randomized, participant-masked, crossover clinical trial, 28 astigmatic participants were tested for the following conditions on different days: full sphero-cyl correction and undercorrection by 0.25, 0.50, and 0.75 DC while maintaining spherical equivalence. Axis was also misaligned between -30° and +30°, in 10° steps. For each configuration, monocular high- and low-contrast visual acuities (HCVA, LCVA) were measured at 6 m, and participants rated vision clarity (1-10), vision satisfaction (1-10), and vision acceptability (yes/no). Linear mixed models were used to compare visual performance in the overall group and in low, medium, and high cyl subgroups.Results: Undercorrecting cyl power affected all groups equally (P≥0.073). Undercorrection by 0.75 DC was significantly different to full cyl power for all variables (P≤0.007), while 0.25 DC undercorrection did not cause any significant decreases (P&gt;0.05). Undercorrection by 0.50 DC was significantly different to full cyl power for HCVA (P=0.006, however not clinically significant) and vision acceptability (P=0.034). Axis misalignment affected the cyl groups differently (P&lt;0.001), with the greatest impact in the high cyl group, followed by the medium then the low-cyl group. Misalignment by ±30° caused significant decreases in almost all cases (P≤0.003), while misalignments by ±10° or ±20° caused significant decreases for some cyl groups and test variables.Conclusion: Undercorrection of cyl by ≤0.50 DC while maintaining spherical equivalence has no significant effect on HCVA, LCVA, vision clarity, and vision satisfaction, while the amount of axis misalignment that can be tolerated is dependent on the cyl power. These results may have practical ophthalmic applications, such as reducing the total number of stock keeping units of toric contact lenses.</p

Visual performance of myopia control soft contact lenses in non-presbyopic myopes

Purpose: To compare the visual performance of soft contact lenses reported to reduce myopia progression.Methods: In a double-blind, randomized, crossover trial, 30 non-presbyopic myopes wore MiSight™, center-distance Proclear® Multifocal (+2.00 D add), and two prototype lenses for 1 week each. High- and low-contrast visual acuities at 6 m, and 70 and 40 cm; stereopsis at 40 cm; accommodative facility at 33 cm; and horizontal phoria at 3 m and 33 cm were measured after 1 week. Subjective performance was assessed on a numeric rating scale for vision clarity, lack of ghosting, vision stability, haloes, overall vision satisfaction, and ocular comfort. Frequency of eye-strain symptoms and willingness to purchase lenses were also reported with categorical responses. Participants reported wearing times (total and visually acceptable). Linear mixed models and chi-square tests were employed in analysis with level of significance set at 5%. Theoretical optical performance of all lenses was assessed with schematic myopic model eyes (-1.00, -3.00, and -6.00 D) by comparing the slope of the edge spread function (ESF), an indicator for optical performance/resolution and the blur patch size of the line spread function, an indicator for contrast, between the lenses.Results: Proclear Multifocal and MiSight provided the best distance acuities. However, the prototype lenses were rated significantly higher for many subjective variables, and there were no subjective variables where commercial lenses were rated significantly higher than the prototypes. Theoretical optical performance showed steeper slopes of the ESF and greater blur patch sizes of the LSP with commercial lenses, supporting the clinical findings of better visual acuities but reduced subjective performance. Participants wore prototypes longer and reported their vision acceptable for longer each day compared to MiSight. Both prototypes had the highest willingness-to-purchase rate.Conclusions: The prototypes were better tolerated by myopes compared to the commercial soft contact lenses currently used for slowing myopia progression.</p

High intake of sugars and starch, low number of meals and low roughage intake are associated with equine gastric ulcer syndrome in a Belgian cohort

Equine gastric ulcer syndrome (EGUS) is a pathological condition affecting the glandular and squamous regions of the stomach. It is characterized by non-specific clinical signs, behavioural changes or can also be found without any overt clinical manifestations. Nutritional factors such as intermittent feeding, high sugars and starch intake, large amounts of straw as forage and prolonged time without access to forage have all been associated with an increased risk of equine squamous gastric disease (ESGD). The aim of this study was to investigate which nutritional practices are commonly seen in clinical ESGD cases in Belgium. Medical records of 27 horses referred to the equine nutritional service at Ghent University (2013-2018) due to equine gastric ulcer lesions were reviewed. Twenty-one healthy horses referred for dietary evaluation during the same period were selected as control cases (CC). Dietary evaluation was performed on an individual basis. Forage/concentrate ratio on dry matter basis, forage content in the diet, total dietary sugars and starch intake per day and per meal were analysed. Retrospective descriptive and statistical analyses were performed. Significantly, higher amounts of forage intake (%DM per BW) in the CC vs. ESGD group were noted (p <= .05) with average values of 1.39 (SD +/- 0.27) and 1.27 (SD +/- 0.70) respectively. There were no significant differences for sugars and starch intake in g/kg BW/day (p = .18). However, the sugars and starch intake per meal (g/kg BW/meal) in the CC group (average value 1.06, SD +/- 0.56) was significantly (p < .001) lower than in the EGUS group (average value 1.85 SD +/- 0.78). Forage intake below the recommended absolute minimum value as well as high sugars and starch intake were most commonly associated with EGUS in the present case series. An adequate diet formulation taking into account these main nutritional factors is therefore essential to avoid gastric problems in horses

Rapid Analysis of Listeria monocytogenes Cell Wall Teichoic Acid Carbohydrates by ESI-MS/MS

We report the application of electrospray ionization (ESI) mass spectrometry for compositional characterization of wall teichoic acids (WTA), a major component of Gram-positive bacterial cell walls. Tandem mass spectrometry (ESI-MS/MS) of purified and chemically hydrolyzed monomeric WTA components provided sufficient information to identify WTA monomers and their specific carbohydrate constituents. A lithium matrix was used for ionization of uncharged WTA monomers, and successfully applied to analyze the WTA molecules of four Listeria strains differing in carbohydrate substitution on a conserved polyribitol-phosphate backbone structure. Carbohydrate residues such as N-acetylglucosamine or rhamnose linked to the WTA could directly be identified by ESI-MS/MS, circumventing the need for quantitative analysis by gas chromatography. The presence of a terminal N-acetylglucosamine residue tethered to the ribitol was confirmed using fluorescently labeled wheat-germ agglutinin. In conclusion, the mass spectrometry method described here will greatly facilitate compositional analysis and characterization of teichoic acids and similar macromolecules from diverse bacterial species, and represents a significant advance in the identification of serovar-specific carbohydrates and sugar molecules on bacteria

Activation of Hypoxia Inducible Factor 1 Is a General Phenomenon in Infections with Human Pathogens

Background: Hypoxia inducible factor (HIF)-1 is the key transcriptional factor involved in the adaptation process of cells and organisms to hypoxia. Recent findings suggest that HIF-1 plays also a crucial role in inflammatory and infectious diseases. Methodology/Principal Findings: Using patient skin biopsies, cell culture and murine infection models, HIF-1 activation was determined by immunohistochemistry, immunoblotting and reporter gene assays and was linked to cellular oxygen consumption. The course of a S. aureus peritonitis was determined upon pharmacological HIF-1 inhibition. Activation of HIF-1 was detectable (i) in all ex vivo in biopsies of patients suffering from skin infections, (ii) in vitro using cell culture infection models and (iii) in vivo using murine intravenous and peritoneal S. aureus infection models. HIF-1 activation by human pathogens was induced by oxygen-dependent mechanisms. Small colony variants (SCVs) of S. aureus known to cause chronic infections did not result in cellular hypoxia nor in HIF-1 activation. Pharmaceutical inhibition of HIF-1 activation resulted in increased survival rates of mice suffering from a S. aureus peritonitis. Conclusions/Significance: Activation of HIF-1 is a general phenomenon in infections with human pathogenic bacteria, viruses, fungi and protozoa. HIF-1-regulated pathways might be an attractive target to modulate the course of life-threatening infections

c-di-AMP Is a New Second Messenger in Staphylococcus aureus with a Role in Controlling Cell Size and Envelope Stress.

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Relationship between Expression of the Family of M Proteins and Lipoteichoic Acid to Hydrophobicity and Biofilm Formation in Streptococcus pyogenes

Background: Hydrophobicity is an important attribute of bacteria that contributes to adhesion and biofilm formation. Hydrophobicity of Streptococcus pyogenes is primarily due to lipoteichoic acid (LTA) on the streptococcal surface but the mechanism(s) whereby LTA is retained on the surface is poorly understood. In this study, we sought to determine whether members of the M protein family consisting of Emm (M protein), Mrp (M-related protein), Enn (an M-like protein), and the streptococcal protective antigen (Spa) are involved in anchoring LTA in a manner that contributes to hydrophobicity of the streptococci and its ability to form biofilms. Methodology/Principal Findings: Isogenic mutants defective in expression of emm, mrp, enn, and/or spa genes of eight different serotypes and their parental strains were tested for differences in LTA bound to surface proteins, LTA released into the culture media, and membrane-bound LTA. The effect of these mutations on the ability of streptococci to form a hydrophobic surface and to generate biofilms was also investigated. A recombinant strain overexpressing Emm1 was also engineered and similarly tested. The serotypes tested ranged from those that express only a single M protein gene to those that express two or three members of the M protein family. Overexpression of Emm1 led to enhanced hydrophobicity an