Optic disc morphology and interocular symmetry in children.

PURPOSE: The purpose of the study was to obtain a pediatric reference database for optic disc parameters and interocular symmetry. To ascertain factors that modify these parameters (age, spherical equivalent [SE], and sex). METHODS: This was a cross-sectional study. 90 patients aged 5-17 years fulfilled all the inclusion criteria. After a full examination including cycloplegic refraction, all patients underwent optical coherence tomography (OCT) of the papilla using the three-dimensional (3D) scan protocol of the Topcon 3D 2000 OCT device. We provide reference values for optic disc parameters in the pediatric population. We also retrieved interocular symmetry reference values for these parameters. RESULTS: The multivariate regression analysis did not reveal variations in any of the optic disc parameters associated with age, sex, or SE (all P ≥ 0.126). The 95th percentile limit for absolute interocular differences for the cup-to-disc area ratio was 0.24. The multivariate regression analysis revealed the absence of a correlation between asymmetry of the optic disc parameters and age, sex, and the interocular difference in SE (all P ≥ 0.105). CONCLUSION: Pediatric reference databases for optic disc parameters and ranges of normality for interocular symmetry provide key diagnostic support in diseases that affect the optic nerve.

Dexamethasone intravitreal implant as an adjuvant treatment for pediatric patients with Coats' disease / Implante intravítreo de dexametasona como tratamento adjuvante em pacientes pediátricos com doença de Coats

ABSTRACT We report two cases of stage 3A unilateral Coats' disease in pediatric patients. In both cases, disease control was achieved using a dexamethasone intravitreal implant in addition to other treatments. The treatment improved visual acuity in one patient and prevented the worsening of the decline in visual acuity in the other patient during follow-up periods of 7 and 3 years, respectively. One of the patients presented an increase in intraocular pressure, which was controlled with topical antiglaucoma medication, but developed a cataract that required surgery. In conclusion, dexamethasone intravitreal implant may be a useful adjuvant treatment to consider in some pediatric cases with Coats' disease.

RESUMO Relatamos dois casos de doença de Coats em estágio 3A unilateral em pacientes pediátricos. Em ambos os casos, o controle da doença foi obtido com implante intravítreo de dexametasona, além de outros tratamentos, com melhora da acuidade visual em um caso e sem piora da visão no outro, durante um período de acompanhamento de 7 e 3 anos. Um dos casos apresentou elevação da pressão intraocular controlada com medicação antiglaucoma tópica e desenvolveu catarata que exigiu cirurgia. Em conclusão, o implante intravítreo de dexametasona pode ser um tratamento adjuvante útil a ser considerado em alguns casos pediátricos com doença de Coats.

Dexamethasone intravitreal implant as an adjuvant treatment for pediatric patients with Coats' disease.

We report two cases of stage 3A unilateral Coats' disease in pediatric patients. In both cases, disease control was achieved using a dexamethasone intravitreal implant in addition to other treatments. The treatment improved visual acuity in one patient and prevented the worsening of the decline in visual acuity in the other patient during follow-up periods of 7 and 3 years, respectively. One of the patients presented an increase in intraocular pressure, which was controlled with topical antiglaucoma medication, but developed a cataract that required surgery. In conclusion, dexamethasone intravitreal implant may be a useful adjuvant treatment to consider in some pediatric cases with Coats' disease.

Alström syndrome: Two clinical cases with two novel pathogenic variants.

PURPOSE: To report two clinical cases of Alström syndrome (AS) with novel pathogenic variant of the ALMS1 gene not previously reported. CASE DESCRIPTION: Patient 1 was a 6-year-old female presenting with poor vision. Ophthalmic examination only showed a visual field (VF) with diffusely decreased sensitivity in both eyes. At age of 15, vision and ophthalmic examination remain stable. Patient 2 was a 2-year-old male with poor vision, photophobia, and nystagmus. ERG showed a severe decrease in cone and rod responses. At age of 6, his vision is lower than 0.1 (decimal scale) and VF is severely constricted. Both of them presented with dilated cardiomyopathy in their first's months of life and patient 2 developed sensorineural deafness along with follow-up. Research genetic testing revealed two loss-of-function heterozygous genetic variants in the ALMS1 gene in both patients, so the diagnosis of AS was made. CONCLUSIONS: AS is a rare disease caused by pathogenic variants of ALMS1 gene that causes ocular manifestations in almost 100% of patients. There are many genetic variants of AMLS1 described, but novel pathogenic variants can still be found. Ophthalmologists play an important role in the diagnosis, and AS should be included in the differential diagnosis when retinal dystrophy is suspected.

Macular thickness variation and interocular symmetry by gestational age in preterm school-age children.

PURPOSE: To determine changes in macular thickness profile according to gestational age (GA) and to assess interocular symmetry in the macula of children born very preterm. METHODS: In this cross-sectional study of preterm (n = 106) and term-born (n = 49) children 5-8 years of age at time of examination, optical coherence tomography was used to measure macula thickness as described in the ETDRS study. Statistical analyses included stratified and multivariable analyses. RESULTS: Foveal minimum thickness increased with decreasing GA (P for trend, <0.001; 254.7 ± 32.8 µm for children born at 24-25 weeks and 193.2 ± 32.8 µm in term-born children). Inner and outer area thickness differed for term and preterm children, but did not vary with the degree of prematurity (inner area, 267.0 ± 11.0 µm for 24-25 weeks' GA and 305.4 ± 11.8 µm for term children [P < 0.01]; outer ring, 305.5 ± 10.4 µm in extreme preterm and 271.0 ± 10.4 µm in term children [P < 0.01]). Interocular asymmetry in preterm children was not significant for most areas; the largest interocular difference was found in the central zone (16.3 ±16.6 µm). CONCLUSIONS: In our study cohort, children born very preterm examined at school age compared to term born children had greater central thickness with decreased foveal pit, decreased inner ring, and increased thickness of the outer ring. They did not show greater interocular asymmetry.

Slow RNAPII Transcription Elongation Rate, Low Levels of RNAPII Pausing, and Elevated Histone H1 Content at Promoters Associate with Higher m6A Deposition on Nascent mRNAs.

N6-methyladenosine modification (m6A) fine-tunes RNA fate in a variety of ways, thus regulating multiple fundamental biological processes. m6A writers bind to chromatin and interact with RNA polymerase II (RNAPII) during transcription. To evaluate how the dynamics of the transcription process impact m6A deposition, we studied RNAPII elongation rates in mouse embryonic stem cells with altered chromatin configurations, due to reductions in linker histone H1 content. We found that genes transcribed at slow speed are preferentially methylated and display unique signatures at their promoter region, namely high levels of histone H1, together with marks of bivalent chromatin and low RNAPII pausing. They are also highly susceptible to m6A loss upon histone H1 reduction. These results indicate that RNAPII velocity links chromatin structure and the deposition of m6A, highlighting the intricate relationship between different regulatory layers on nascent mRNA molecules.

Signatures of genetic variation in human microRNAs point to processes of positive selection and population-specific disease risks.

The occurrence of natural variation in human microRNAs has been the focus of numerous studies during the last 20 years. Most of them have been focused on the role of specific mutations in disease, while a minor proportion seek to analyse microRNA diversity in the genomes of human populations. We analyse the latest human microRNA annotations in the light of the most updated catalogue of genetic variation provided by the 1000 Genomes Project. By means of the in silico analysis of microRNA genetic variation we show that the level of evolutionary constraint of these sequences is governed by the interplay of different factors, like their evolutionary age or genomic location. The role of mutations in the shaping of microRNA-driven regulatory interactions is emphasized with the acknowledgement that, while the whole microRNA sequence is highly conserved, the seed region shows a pattern of higher genetic diversity that appears to be caused by the dramatic frequency shifts of a fraction of human microRNAs. We highlight the participation of these microRNAs in population-specific processes by identifying that not only the seed, but also the loop, are particularly differentiated regions among human populations. The quantitative computational comparison of signatures of population differentiation showed that candidate microRNAs with the largest differences are enriched in variants implicated in gene expression levels (eQTLs), selective sweeps and pathological processes. We explore the implication of these evolutionary-driven microRNAs and their SNPs in human diseases, such as different types of cancer, and discuss their role in population-specific disease risk.

Retinal ganglion cell complex thickness at school-age, prematurity and neonatal stressors.

PURPOSE: To investigate the association between the ganglion cell complex (GCC) thickness at early school-age and prematurity and other neonatal factors. METHODS: Cross-sectional study. The sample included very preterm children with gestational age (GA) below 32 weeks or birthweight below 1500 g enrolled in a follow-up program (n = 101) and a comparison group of term-born children (n = 49). Ganglion cell complex (GCC) thickness was measured at 4-8 years using high-quality optical coherence tomography (OCT) images. Data on neonatal and postnatal features were extracted from clinical records; analyses included mixed linear models. RESULTS: Ganglion cell layer (GCL) and retinal nerve fiber layer (mRNFL) were thicker in term than in preterm born children (2.9 µm and 2.4 µm respectively, p < 0.001). Within the preterm group, lower GA was associated with a decrease in total GCL (0.7 µm per week, p < 0.001). Being small for GA was associated with further thinning in both layers (1.4 and 2.8 µm). Postnatal corticosteroids therapy and severe brain lesion were associated with thinning in the total GCL of 6 µm (p < 0.001) and 4.1 µm (p = 0.002), respectively, and shock was associated with thinning in total mRNFL of 6 µm (p < 0.001). CONCLUSIONS: Lower GA or birthweight are associated with thinning of GCC layers. When performing an OCT examination at school-age and a decrease in GCC thickness is observed, it may be relevant to ask about a history of prematurity, and further enquire about neonatal shock, postnatal corticosteroids therapy or severe brain lesion that are related to additional decrease in GCC thickness.

Contribution of Optical Coherence Tomography to the Diagnosis of Childhood-Onset Stargardt Disease in Its Early Stages.

Stargardt disease may present with alterations in optical coherence tomography before symptoms and fundus abnormalities appear. With this non-invasive test, a presumptive diagnosis can be made and genetically confirmed in the subclinical stages of the disease. [J Pediatr Ophthalmol Strabismus. 2021;58(3):e5-e8.].

Induction of TLR4/TLR2 Interaction and Heterodimer Formation by Low Endotoxic Atypical LPS.

The Toll-like receptor 4 (TLR4)/myeloid differentiation protein-2 (MD-2) complex is considered the major receptor of the innate immune system to recognize lipopolysaccharides (LPSs). However, some atypical LPSs with different lipid A and core saccharide moiety structures and compositions than the well-studied enterobacterial LPSs can induce a TLR2-dependent response in innate immune cells. Ochrobactrum intermedium, an opportunistic pathogen, presents an atypical LPS. In this study, we found that O. intermedium LPS exhibits a weak inflammatory activity compared to Escherichia coli LPS and, more importantly, is a specific TLR4/TLR2 agonist, able to signal through both receptors. Molecular docking analysis of O. intermedium LPS predicts a favorable formation of a TLR2/TLR4/MD-2 heterodimer complex, which was experimentally confirmed by fluorescence resonance energy transfer (FRET) in cells. Interestingly, the core saccharide plays an important role in this interaction. This study reveals for the first time TLR4/TLR2 heterodimerization that is induced by atypical LPS and may help to escape from recognition by the innate immune system.

Measurement of macular thickness with optical coherence tomography: impact of using a paediatric reference database and analysis of interocular symmetry.

PURPOSE: Optical coherence tomography (OCT) software is used to classify abnormality of macular thickness by colour category based on reference data from adult series. We assessed the impact of using paediatric reference thickness values for macular thickness instead of adult reference values. METHODS: Cross-sectional study. Primary and tertiary healthcare setting. Out of 140 healthy participants aged 5 to 18 years, 126 were eligible, 83% from European origin. Following a dilated eye examination and cycloplegic refraction, participants underwent macular scanning with OCT (Topcon 3D OCT-2000). Macular thickness paediatric reference values were recorded by spherical equivalent (SE) and sex, and the specific agreement between paediatric and adult reference values below or equal to percentile 5 and above percentile 95 was estimated. The absolute interocular differences for all macular parameters were determined. RESULTS: Multivariate regression analysis confirmed statistically independent positive associations between SE and average thickness, total volume, and temporal and inferior outer quadrants (all p values ≤ 0.003). The analysis also revealed higher values in males for average thickness, central thickness, and all inner macula quadrants (all p values ≤ 0.039). The use of the adult database only detected 49% of the extreme values (≤ p5 and > p95) in our paediatric sample. The 95th percentile limits for absolute interocular differences for all macular parameters ranged from 12 to 17 µm. CONCLUSIONS: OCT-based macular reference values for paediatric SE and sex improve detection of children with abnormal macular thicknesses. Interocular differences exceeding standard references for macular parameters should be considered for further examinations.

Interobserver reproducibility and interocular symmetry of the macular ganglion cell complex: assessment in healthy children using optical coherence tomography.

BACKGROUND: Assessment of interobserver reproducibility and interocular symmetry using optical coherence tomography (OCT)-based measurements of the macular ganglion cell complex (GCC) in healthy children facilitates interpretation of OCT data. We assessed the interobserver reproducibility and interocular symmetry of GCC and evaluated candidate determinants. METHODS: This was a cross-sectional study performed in a primary and tertiary health-care setting. A total of 126 healthy participants aged 5 to 18 years were eligible. GCC scans were performed by 4 operators using the Topcon 3D OCT-2000 device. Intraclass correlation coefficients (ICCs) were used to estimate reproducibility and symmetry. Cut-off points for symmetry were defined as the 95th percentile of the absolute interocular difference for 6 GCC parameters. Percentile distributions of interocular difference were generated based on age and difference in absolute interocular spherical equivalent (SE). RESULTS: The reproducibility ICC ranged from 0.96 to 0.98 for all 6 GCC parameters. Cut-off points for interocular symmetry of the superior and inferior quadrants and total macular retinal nerve fibre layer thickness (mRNFL) and macular ganglion cell layer-inner plexiform layer thickness were 3.5, 4.5, 3.0, 3.0, 2.5, and 2.5 µm respectively. A positive association was observed between the absolute interocular difference of SE and superior and total mRNFL symmetry values (p = 0.047 and p = 0.040, respectively). CONCLUSIONS: OCT measurements of GCC in healthy children show excellent reproducibility. Interocular differences in SE should be assessed when mRNFL differences exceed the 95% cut-off. These findings can contribute to establish reference values for interocular symmetry in paediatric GCC parameters.

Assessment of macular ganglion cell complex using optical coherence tomography: Impact of a paediatric reference database in clinical practice.

IMPORTANCE: Optical coherence tomography software classifies abnormality of macular ganglion cell-inner plexiform layer thickness and macular retinal nerve fibre layer thickness based on adult series. BACKGROUND: We assessed the impact of using paediatric reference macular ganglion cell complex values instead of adult reference values. DESIGN: Cross-sectional study. Primary and tertiary health-care setting. PARTICIPANTS: Out of 140 healthy participants aged 5 to 18 years, 90% were eligible. METHODS: Following a dilated eye examination and cycloplegic refraction, participants underwent optical coherence tomography ganglion cell scans (Topcon 3D OCT-2000; Topcon Corporation, Tokyo, Japan). Right eye measurements for superior, inferior, and total layer thickness and spherical equivalent were reported, together with age, sex and origin. MAIN OUTCOME MEASURES: Paediatric reference values by age and spherical equivalent were produced, and the specific agreement between paediatric and adult ganglion cell complex reference values below or equal to percentile 5 was estimated. RESULTS: The multivariate analysis confirmed a positive association between spherical equivalent and macular ganglion cell-inner plexiform layer thickness, and between age and macular retinal nerve fibre layer (five out of six regression coefficients P values were ≤ 0.03). Specific agreement was 25% for ganglion cell-inner plexiform layer thickness and > 80% for macular retinal nerve fibre layer. Adult-based software identified low ganglion cell values in one in seven children compared to paediatric reference values (0.8% vs 5.5%, P = 0.031). CONCLUSIONS AND RELEVANCE: The availability of optical coherence tomography ganglion cell complex reference values for paediatric age and spherical equivalent groups can be used to improve detection of children with low cell layer thickness.

RNA editing independently occurs at three mir-376a-1 sites and may compromise the stability of the microRNA hairpin.

RNA editing is being recognized as an important post-transcriptional mechanism that may have crucial roles in introducing genetic variation and phenotypic diversity. Despite microRNA editing recurrence, defining its biological relevance is still under extended debate. To better understand microRNA editing function and regulation we performed an exhaustive characterization of the A-to-I site-specific patterns in mir-376a-1, a mammalian microRNA which RNA editing is involved in the regulation of development and in disease. Thorough an integrative approach based on high-throughput small RNA sequencing, Sanger sequencing and computer simulations we explored mir-376a-1 editing in samples from various individuals and primate species including human placenta and macaque, gorilla, chimpanzee and human brain cortex. We observed that mir-376a-1 editing is a common phenomenon in the mature and primary microRNA molecules and it is more frequently detected in brain than in placenta. Primary mir-376a-1 is edited at three positions, -1, +4 and +44. Editing frequency estimations and in silico simulations indicated that editing was not equally recurrent along the three mir-376a-1 sites, nevertheless no epistatic interactions among them were observed. Particularly, the +4 site, located in the seed region of the mature miR-376a-5p, reached the highest editing frequency in all samples. Secondary structure predictions revealed that the +4 position was the one that conferred the highest stability to the mir-376a-1 hairpin. We suggest that molecular stability might partially explain the editing recurrence observed in certain microRNAs and that editing events conferring new functional regulatory roles in particular tissues and species could have been conserved along evolution, as it might be the case of mir-376a-1 in primate brain cortex.

Adalimumab for the treatment of refractory noninfectious paediatric uveitis.

To report the experience of our center with the use of adalimumab (ADA) for the treatment of severe refractory noninfectious paediatric uveitis. The study is a retrospective case series of all paediatric patients with refractory uveitis who were treated with ADA at the Paediatric Uveitis Unit of our center from 2008 to 2015. We present 12 patients (6 Juvenile idiopathic arthritis-associated uveitis, 4 idiopathic panuveitis, 1 early-onset sarcoidosis-associated panuveitis, and 1 intermediate uveitis), with uveitis in 19/24 eyes. Once ADA therapy was started, all the patients presented improved activity according to Standardization of Uveitis Nomenclature (SUN) criteria. Nine out of the 12 patients had structural damage before ADA could be started: cataract (n = 4), glaucoma (n = 2), cystic macular edema (n = 1), exudative retinal detachment (n = 1), and optic disk edema (n = 5). Visual acuity improved or maintained stable in 17/19 affected eyes, and only 2 eyes decreased its visual acuity because of structural damage, which was already present before ADA therapy. In our experience, ADA presents a good safety profile and is efficacious in the treatment of paediatric patients with different forms of refractory noninfectious uveitis.

MicroRNA Genetic Variation: From Population Analysis to Functional Implications of Three Allele Variants Associated with Cancer.

Nucleotide variants in microRNA regions have been associated with disease; nevertheless, few studies still have addressed the allele-dependent effect of these changes. We studied microRNA genetic variation in human populations and found that while low-frequency variants accumulate indistinctly in microRNA regions, the mature and seed regions tend to be depleted of high-frequency variants, probably as a result of purifying selection. Comparison of pairwise population fixation indexes among regions showed that the seed had higher population fixation indexes than the other regions, suggesting the existence of local adaptation in the seed region. We further performed functional studies of three microRNA variants associated with cancer (rs2910164:C > G in MIR146A, rs11614913:C > T in MIR196A2, and rs3746444:A > G in both MIR499A and MIR499B). We found differences in the expression between alleles and in the regulation of several genes involved in cancer, such as TP53, KIT, CDH1, CLH, and TERT, which may result in changes in regulatory networks related to tumorigenesis. Furthermore, luciferase-based assays showed that MIR499A could be regulating the cadherin CDH1 and the cell adhesion molecule CLH1 in an allele-dependent fashion. A better understanding of the effect of microRNA variants associated with disease could be key in our way to a more personalized medicine.

Functional Implications of Human-Specific Changes in Great Ape microRNAs.

microRNAs are crucial post-transcriptional regulators of gene expression involved in a wide range of biological processes. Although microRNAs are highly conserved among species, the functional implications of existing lineage-specific changes and their role in determining differences between humans and other great apes have not been specifically addressed. We analyzed the recent evolutionary history of 1,595 human microRNAs by looking at their intra- and inter-species variation in great apes using high-coverage sequenced genomes of 82 individuals including gorillas, orangutans, bonobos, chimpanzees and humans. We explored the strength of purifying selection among microRNA regions and found that the seed and mature regions are under similar and stronger constraint than the precursor region. We further constructed a comprehensive catalogue of microRNA species-specific nucleotide substitutions among great apes and, for the first time, investigated the biological relevance that human-specific changes in microRNAs may have had in great ape evolution. Expression and functional analyses of four microRNAs (miR-299-3p, miR-503-3p, miR-508-3p and miR-541-3p) revealed that lineage-specific nucleotide substitutions and changes in the length of these microRNAs alter their expression as well as the repertoires of target genes and regulatory networks. We suggest that the studied molecular changes could have modified crucial microRNA functions shaping phenotypes that, ultimately, became human-specific. Our work provides a frame to study the impact that regulatory changes may have in the recent evolution of our species.

Relationship between the CYP2C9 IVS8-109A>T polymorphism and high losartan hydroxylation in healthy Ecuadorian volunteers.

AIM: The CYP2C9 IVS8-109T allele was recently found to be more frequent among Swedish individuals, who have the highest losartan metabolic ratio (MR; losartan:E-3174). Thus, the influence of the CYP2C9 IVS8-109A>T polymorphism on the losartan MR was evaluated among healthy Ecuadorians. In addition, the frequency of the CYP2C9 IVS8-109A>T polymorphism was determined. RESULTS: Among CYP2C9-homozygous wild-types, those with the CYP2C9 IVS8-109T/T versus A/A genotypes had a lower MR (p < 0.05). Furthermore, the frequency of the CYP2C9 IVS8-109T variant was lower in Ecuadorians (21.4%; p < 0.001) than in populations from Sweden or Asia (ranging from 32 to 46%). CONCLUSION: In this Ecuadorian population, the CYP2C9 IVS8-109T allele was associated with an increased CYP2C9 hydroxylation capacity. Further investigation needs to be carried out in order to clarify the relevance of the SNP of CYP2C9 IVS8-109A>T on losartan hydroxylation across populations and its potential implications in CYP2C9 activity.

Cambio de actitud y comunicación persuasiva: claves para comprender los procesos de captación y conversión a sectas / No disponible

En este trabajo se considera a las sectas como un problema de salud pública. Para comprender esta idea es necesario romper con la noción clásica de que su peligrosidad viene dada por su ideología. El problema radica más bien en su organización y en las técnicas que emplean. Vistas desde esta perspectiva son fácilmente abordables por la psicología, ya que ésta posee desarrollos teóricos que nos permiten su estudio (AU)

No disponible