The Effects of Nitric Oxide on Choroidal Gene Expression.

Purpose: Nitric oxide (NO) is recognized as an important biological mediator that controls several physiological functions, and evidence is now emerging that this molecule may play a significant role in the postnatal control of ocular growth and myopia development. We therefore sought to understand the role that nitric oxide plays in visually-guided ocular growth in order to gain insight into the underlying mechanisms of this process. Methods: Choroids were incubated in organ culture in the presence of the NO donor, PAPA-NONOate (1.5 mM). Following RNA extraction, bulk RNA-seq was used to quantify and compare choroidal gene expression in the presence and absence of PAPA-NONOate. We used bioinformatics to identify enriched canonical pathways, predicted diseases and functions, and regulatory effects of NO in the choroid. Results: Upon treatment of normal chick choroids with the NO donor, PAPA-NONOate, we identified a total of 837 differentially expressed genes (259 upregulated genes, 578 down-regulated genes) compared with untreated controls. Among these, the top five upregulated genes were LSMEM1, STEAP4, HSPB9, and CCL19, and the top five down-regulated genes were CDCA3, SMC2, a novel gene (ENSALGALG00000050836), an uncharacterized gene (LOC107054158), and SPAG5. Bioinformatics predicted that NO treatment will activate pathways involved in cell and organismal death, necrosis, and cardiovascular system development, and inhibit pathways involved in cell proliferation, cell movement, and gene expression. Conclusions: The findings reported herein may provide insight into possible effects of NO in the choroid during visually regulated eye growth, and help to identify targeted therapies for the treatment of myopia and other ocular diseases.

Toric intraocular lens implantation vs femtosecond laser-assisted arcuate keratotomy for correction of moderate astigmatism in cataract surgery.

PURPOSE: To compare toric intraocular lens (TIOL) implantation and femtosecond laser-assisted arcuate keratotomy (FSAK) during phacoemulsification surgery in correction of moderate astigmatism. SETTING: Clinical research study. DESIGN: Prospective randomized comparison study. METHODS: Patients with age-related cataract and moderate preoperative corneal astigmatism of 1.25 to 3.0 diopters (D) were randomized into a TIOL implantation group and an FSAK group with symmetrical paired corneal arcuate keratotomies. The preoperative evaluation included corrected distance visual acuity (CDVA), corneal topography, autokeratometry, and ocular biometry. Postoperative examinations were performed at 1 month and 3 months and included CDVA and uncorrected distance visual acuity, manifest refraction, autokeratometry, and corneal topography. Vector analysis of astigmatic changes was performed using the Alpins vector method. RESULTS: This study comprised 75 eyes from 67 patients. The mean residual refractive astigmatism at 3 months was -0.63 ± 0.55 D in the TIOL group and -0.90 ± 0.53 D in the FSAK group ( P = .037) and was ≤1.00 D in 32 eyes (84%) and 25 eyes (64%), respectively. There were no statistically significant differences between the 2 groups in difference vector, angle of error, magnitude error, or correction index in the 3-month follow-up. The index of success was 0.32 ± 0.33 D in the TIOL group and 0.48 ± 0.29 D in the FSAK group ( P = .029). CONCLUSIONS: TIOL implantation showed better results in correcting moderate astigmatism. Despite this, FSAK is shown to be a safe technique for reducing astigmatism.

Meibomian Gland Changes in Open-angle Glaucoma Users Treated with Topical Medication.

SIGNIFICANCE: Glaucoma patients treated with topical hypotensive eye drops often experience changes in the ocular surface, including the lid margin and the meibomian glands. In this study, the clinical parameters of the ocular surface have been analyzed to detect the presence of meibomian gland dysfunction-related dry eye disease. PURPOSE: This study aimed to evaluate the meibomian gland dysfunction in glaucoma patients secondary to topical antiglaucomatous treatment. METHODS: A total of 131 eyes from different patients with open-angle glaucoma treated with topical medication and 92 eyes from different patients with untreated ocular hypertension were consecutively and prospectively enrolled. The structure of the meibomian glands was assessed using noncontact meibography (Keratograph 5M; Oculus, Wetzlar, Germany), and their function was evaluated by measurement of meibomian glands expressibility, the duct appearance, and the Marx line location. Moreover, tear osmolarity measurement, corneal staining score (Oxford scale), and ocular symptom assessment (Ocular Surface Disease Index questionnaire) were performed. We also compared these variables in the glaucoma group according to the presence (or not) of preservative in topical treatment. RESULTS: Meibomian gland depletion was higher in glaucoma patients with topical medication (P < .001). Furthermore, the quantity of meibomian glands and expressibility of meibum in these patients were altered compared with the control group (P < .001 in both cases). In addition, the glaucoma group presented a higher degree of corneal staining as measured with the Oxford scale (P < .001). The Marx line location score was higher (P < .001 in central Marx line and P < .003 in temporal Marx line) in patients using drugs containing preservative than in those having preservative-free treatment. Logistical regression found that Marx line central, Marx line temporal, quantity of meibum expression, and quality of meibum expression have predictive ability to detect meibomian gland dysfunction-related dry eye disease. CONCLUSIONS: Glaucoma topical treatments produce meibomian gland dysfunction altering their structure and function, and this condition can be worsened using topical treatments containing preservative.

The Relevance of a Physiological-Stage Approach Study of the Molecular and Environmental Factors Regulating Seed Germination in Wild Plants.

Germination represents the culmination of the seed developmental program and is affected by the conditions prevailing during seed maturation in the mother plant. During maturation, the dormancy condition and tolerance to dehydration are established. These characteristics are modulated by the environment to which they are subjected, having an important impact on wild species. In this work, a review was made of the molecular bases of the maturation, the processes of dormancy imposition and loss, as well as the germination process in different wild species with different life histories, and from diverse habitats. It is also specified which of these species present a certain type of management. The impact that the domestication process has had on certain characteristics of the seed is discussed, as well as the importance of determining physiological stages based on morphological characteristics, to face the complexities of the study of these species and preserve their genetic diversity and physiological responses.

Genomic characterization of three novel Desulfobacterota classes expand the metabolic and phylogenetic diversity of the phylum.

We report on the genomic characterization of three novel classes in the phylum Desulfobacterota. One class (proposed name Candidatus 'Anaeroferrophillalia') was characterized by heterotrophic growth capacity, either fermentatively or utilizing polysulfide, tetrathionate or thiosulfate as electron acceptors. In the absence of organic carbon sources, autotrophic growth via the Wood-Ljungdahl (WL) pathway and using hydrogen or Fe(II) as an electron donor is also inferred for members of the 'Anaeroferrophillalia'. The second class (proposed name Candidatus 'Anaeropigmentia') was characterized by its capacity for growth at low oxygen concentration, and the capacity to synthesize the methyl/alkyl carrier CoM, an ability that is prevalent in the archaeal but rare in the bacterial domain. Pigmentation is inferred from the capacity for carotenoid (lycopene) production. The third class (proposed name Candidatus 'Zymogenia') was characterized by fermentative heterotrophic growth capacity, broad substrate range and the adaptation of some of its members to hypersaline habitats. Analysis of the distribution pattern of all three classes showed their occurrence as rare community members in multiple habitats, with preferences for anaerobic terrestrial, freshwater and marine environments over oxygenated (e.g. pelagic ocean and agricultural land) settings. Special preference for some members of the class Candidatus 'Zymogenia' for hypersaline environments such as hypersaline microbial mats and lagoons was observed.

Saliva is a reliable and accessible source for the detection of SARS-CoV-2.

OBJECTIVES: The aim of this study was to investigate the feasibility of saliva sampling as a non-invasive and safer tool to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and to compare its reproducibility and sensitivity with nasopharyngeal swab samples (NPS). The use of sample pools was also investigated. METHODS: A total of 2107 paired samples were collected from asymptomatic healthcare and office workers in Mexico City. Sixty of these samples were also analyzed in two other independent laboratories for concordance analysis. Sample processing and analysis of virus genetic material were performed according to standard protocols described elsewhere. A pooling analysis was performed by analyzing the saliva pool and the individual pool components. RESULTS: The concordance between NPS and saliva results was 95.2% (kappa 0.727, p = 0.0001) and 97.9% without considering inconclusive results (kappa 0.852, p = 0.0001). Saliva had a lower number of inconclusive results than NPS (0.9% vs 1.9%). Furthermore, saliva showed a significantly higher concentration of both total RNA and viral copies than NPS. Comparison of our results with those of the other two laboratories showed 100% and 97% concordance. Saliva samples are stable without the use of any preservative, and a positive SARS-CoV-2 sample can be detected 5, 10, and 15 days after collection when the sample is stored at 4 °C. CONCLUSIONS: The study results indicate that saliva is as effective as NPS for the identification of SARS-CoV-2-infected asymptomatic patients. Sample pooling facilitates the analysis of a larger number of samples, with the benefit of cost reduction.

Comparison of posterior capsule opacification between Clareon CNA0T0 and Tecnis ZCB00 intraocular lenses.

INTRODUCTION: The purpose is to compare posterior capsule opacification (PCO) and its impact on vision between Clareon CNA0T0 (Alcon) and Tecnis ZCB00 intraocular lenses (IOLs) (Johnson&Johnson) 1, 6, and 12 months after implantation. METHODS: A prospective observational study was performed at the Nuestra Señora de Gracia Hospital (Zaragoza, Spain). Fifty eyes (50 patients) with Tecnis IOL (group 1) and 60 eyes (60 patients) with Clareon IOL (group 2) were enrolled. One, 6, and 12 months after age-related cataract surgery by five different surgeons, the following tests were performed: mesopic corrected distance visual acuity (CDVA), CSV1000-E test, KR-1W wavefront analyzer, OQAS II, Catquest-9SF questionnaire and mydriatic slit-lamp pictures. PCO intensity was quantified and the area of opacification was measured using ImageJ (NIH). RESULTS: Mean age was 71.20 ± 6.79 years in group 1, and 71.73 ± 8.17 years in group 2 (p = 0.72); mean axial length was 23.46 ± 1.14 and 23.53 ± 0.91 mm, respectively (p = 0.72); mean IOL power was 21.69 ± 2.26 D and 21.28 ± 2.44 D, respectively (p = 0.37). One month after surgery there were differences in intensity of PCO (0.73 ± 0.60 and 1.05 ± 0.71, respectively, p = 0.02). Six months after surgery statistical differences were found in VA with 20% CS in mydriatic conditions (0.26 ± 0.21 logMAR (20/36) and 0.18 ± 0.17 logMAR (20/30), respectively, p = 0.04). Twelve months after surgery, no differences were detected between groups. As for the evolution of PCO within the Clareon group, high order aberrations (p < 0.05) and the Strehl ratio (p = 0.02) decreased. CONCLUSION: There are no differences in slit-lamp pictures or visual function between both IOLs during the first 12 months after implantation.

The seed water content as a time-independent physiological trait during germination in wild tree species such as Ceiba aesculifolia.

Seeds constitute a key physiological stage in plants life cycle. During seed germination, there is a spatial-temporal imbibition pattern that correlates with described physiological processes. However, only the moment of testa rupture has been described as a critical, discrete stage. Could a specific relative water content (RWC) value reflect a physiological stage useful for comparisons between seed batches? We tracked seed-by-seed imbibition during germination to homogenize sampling and selected a transcriptomic approach to analyse the physiological transitions that occur in seed batches collected in different years and with contrasting phenotypic responses to a priming treatment. The seed RWC reflected the transcriptional transitions that occur during germination, regardless of imbibition time or collection year, and revealed a set of biological processes that occur in the dry seed and during early germination are associated with the phenotypic response to priming. As climate shifts, so do the timing of developmental events important for determining organismal fitness, and poses another challenge to the comprehension of molecular and physiological processes driving the interaction between organisms and environment. In this study, we demonstrate that the use of physiological traits, specific to a particular developmental stage, is a reliable time-independent approach.

Hydraulic traits vary as the result of tip-to-base conduit widening in vascular plants.

Plant hydraulic traits are essential metrics for characterizing variation in plant function, but they vary markedly with plant size and position in a plant. We explore the potential effect of conduit widening on variation in hydraulic traits along the stem. We examined three species that differ in conduit diameter at the stem base for a given height (Moringa oleifera, Casimiroa edulis, and Pinus ayacahuite). We made anatomical and hydraulic measurements at different distances from the stem tip, constructed vulnerability curves, and examined the safety-efficiency trade-off with height-standardized data. Our results showed that segment-specific hydraulic resistance varied predictably along the stem, paralleling changes in mean conduit diameter and total number of conduits. The Huber value and leaf specific conductivity also varied depending on the sampling point. Vulnerability curves were markedly less noisy with height standardization, making the vulnerability-efficiency trade-off clearer. Because conduits widen predictably along the stem, taking height and distance from the tip into account provides a way of enhancing comparability and interpretation of hydraulic traits. Our results suggest the need for rethinking hydraulic sampling for comparing plant functional differences and strategies across individuals.

Constant theoretical conductance via changes in vessel diameter and number with height growth in Moringa oleifera.

As trees grow taller, hydraulic resistance can be expected to increase, causing photosynthetic productivity to decline. Yet leaves maintain productivity over vast height increases; this maintenance of productivity suggests that leaf-specific conductance remains constant as trees grow taller. Here we test the assumption of constant leaf-specific conductance with height growth and document the stem xylem anatomical adjustments involved. We measured the scaling of total leaf area, mean vessel diameter at terminal twigs and at the stem base, and total vessel number in 139 individuals of Moringa oleifera of different heights, and estimated a whole-plant conductance index from these measurements. Whole-plant conductance and total leaf area scaled at the same rate with height. Congruently, whole-plant conductance and total leaf area scaled isometrically. Constant conductance is made possible by intricate adjustments in anatomy, with conduit diameters in terminal twigs becoming wider, lowering per-vessel resistance, with a concomitant decrease in vessel number per unit leaf area with height growth. Selection maintaining constant conductance per unit leaf area with height growth (or at least minimizing drops in conductance) is likely a potent selective pressure shaping plant hydraulics, and crucially involved in the maintenance of photosynthetic productivity per leaf area across the terrestrial landscape.

Plant height and hydraulic vulnerability to drought and cold.

Understanding how plants survive drought and cold is increasingly important as plants worldwide experience dieback with drought in moist places and grow taller with warming in cold ones. Crucial in plant climate adaptation are the diameters of water-transporting conduits. Sampling 537 species across climate zones dominated by angiosperms, we find that plant size is unambiguously the main driver of conduit diameter variation. And because taller plants have wider conduits, and wider conduits within species are more vulnerable to conduction-blocking embolisms, taller conspecifics should be more vulnerable than shorter ones, a prediction we confirm with a plantation experiment. As a result, maximum plant size should be short under drought and cold, which cause embolism, or increase if these pressures relax. That conduit diameter and embolism vulnerability are inseparably related to plant size helps explain why factors that interact with conduit diameter, such as drought or warming, are altering plant heights worldwide.

BIIDXI, the At4g32460 DUF642 gene, is involved in pectin methyl esterase regulation during Arabidopsis thaliana seed germination and plant development.

BACKGROUND: DUF642 proteins constitute a highly conserved family of proteins that are associated with the cell wall and are specific to spermatophytes. Transcriptome studies have suggested that members of this family are involved in seed development and germination processes. Previous in vitro studies have revealed that At4g32460- and At5g11420-encoded proteins interact with the catalytic domain of pectin methyl esterase 3 (AtPME3, which is encoded by At3g14310). PMEs play an important role in plant development, including seed germination. The aim of this study was to evaluate the function of the DUF642 gene At4g32460 during seed germination and plant development and to determine its relation to PME activity regulation. RESULTS: Our results indicated that the DUF642 proteins encoded by At4g32460 and At5g11420 could be positive regulators of PME activity during several developmental processes. Transgenic lines overexpressing these proteins showed increased PME activity during seed germination, and improved seed germination performance. In plants expressing At4g32460 antisense RNA, PME activity was decreased in the leaves, and the siliques were very short and contained no seeds. This phenotype was also present in the SALK_142260 and SALK_054867 lines for At4g32460. CONCLUSIONS: Our results suggested that the DUF642 family contributes to the complexity of the methylesterification process by participating in the fine regulation of pectin status during plant development.

Effects of burial and storage on germination and seed reserves of 18 tree species in a tropical deciduous forest in Mexico.

The changes in germination and seed reserve composition that occur while seeds are stored in the laboratory or buried in the soil are important for understanding the potential and ecological longevity of seeds as well as seed-bank dynamics. Both germination and seed-bank dynamics depend on water availability. We studied 18 tree species, including those with permeable or impermeable seeds, from a tropical deciduous forest in Mexico. We measured seed germination in a growth chamber after (1) dispersal, (2) laboratory storage, (3) seed burial at two field sites and directly in the field, and (4) two rainy seasons. Lipids, nitrogen, and nonstructural carbohydrates were quantified after dispersal and after laboratory or field storage. Sixteen species were viable after three periods of laboratory storage (~3 years). Eleven species were viable after two burial periods in the field (~2 years). Nitrogen concentration decreased after storage and burial in 11 species. Species lipid concentration had a negative relationship with species water content at dispersal and after one burial period, whereas nonstructural carbohydrates showed the opposite trend. Potential and ecological longevities were similar in impermeable seeds. Most of the species studied can form persistent seed banks consisting mainly of species with impermeable seeds that can remain in the soil without degrading their viability. Germination in the field is staggered following natural precipitation pulses as a strategy to stagger seedling recruitment, which may insure against unfavorable conditions.

Seed reserve composition in 19 tree species of a tropical deciduous forest in Mexico and its relationship to seed germination and seedling growth.

BACKGROUND AND AIMS: The size and composition of seed reserves may reflect the ecological strategy and evolutionary history of a species and also temporal variation in resource availability. The seed mass and composition of seed reserves of 19 co-existing tree species were studied, and we examined how they varied among species in relation to germination and seedling growth rates, as well as between two years with contrasting precipitation (652 and 384 mm). METHODS: Seeds were collected from a tropical deciduous forest in the northwest of Mexico (Chamela Biological Station). The seed dry mass, with and without the seed coat, and the concentrations of lipids, nitrogen and non-structural carbohydrates for the seed minus seed coat were determined. The anatomical localization of these reserves was examined using histochemical analysis. The germination capacity, rate and lag time were determined. The correlations among these variables, and their relationship to previously reported seedling relative growth rates, were evaluated with and without phylogenetic consideration. KEY RESULTS: There were interannual differences in seed mass and reserve composition. Seed was significantly heavier after the drier year in five species. Nitrogen concentration was positively correlated with seed coat fraction, and was significantly higher after the drier year in 12 species. The rate and lag time of germination were negatively correlated with each other. These trait correlations were also supported for phylogenetic independent contrasts. Principal component analysis supported these correlations, and indicated a negative association of seedling relative growth rate with seed size, and a positive association of germination rate with nitrogen and lipid concentrations. CONCLUSIONS: Nitrogen concentration tended to be higher after the drier year and, while interannual variations in seed size and reserve composition were not sufficient to affect interspecific correlations among seed and seedling traits, some of the reserves were related to germination variables and seedling relative growth rate.