Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 128
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Hum Mol Genet ; 33(11): 945-957, 2024 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-38453143

RESUMEN

Inherited retinal diseases (IRDs) are a group of rare genetic eye conditions that cause blindness. Despite progress in identifying genes associated with IRDs, improvements are necessary for classifying rare autosomal dominant (AD) disorders. AD diseases are highly heterogenous, with causal variants being restricted to specific amino acid changes within certain protein domains, making AD conditions difficult to classify. Here, we aim to determine the top-performing in-silico tools for predicting the pathogenicity of AD IRD variants. We annotated variants from ClinVar and benchmarked 39 variant classifier tools on IRD genes, split by inheritance pattern. Using area-under-the-curve (AUC) analysis, we determined the top-performing tools and defined thresholds for variant pathogenicity. Top-performing tools were assessed using genome sequencing on a cohort of participants with IRDs of unknown etiology. MutScore achieved the highest accuracy within AD genes, yielding an AUC of 0.969. When filtering for AD gain-of-function and dominant negative variants, BayesDel had the highest accuracy with an AUC of 0.997. Five participants with variants in NR2E3, RHO, GUCA1A, and GUCY2D were confirmed to have dominantly inherited disease based on pedigree, phenotype, and segregation analysis. We identified two uncharacterized variants in GUCA1A (c.428T>A, p.Ile143Thr) and RHO (c.631C>G, p.His211Asp) in three participants. Our findings support using a multi-classifier approach comprised of new missense classifier tools to identify pathogenic variants in participants with AD IRDs. Our results provide a foundation for improved genetic diagnosis for people with IRDs.


Asunto(s)
Simulación por Computador , Linaje , Enfermedades de la Retina , Humanos , Enfermedades de la Retina/genética , Femenino , Masculino , Mutación , Genes Dominantes , Predisposición Genética a la Enfermedad , Biología Computacional/métodos , Fenotipo , Adulto
2.
Hum Mol Genet ; 32(12): 2005-2015, 2023 06 05.
Artículo en Inglés | MEDLINE | ID: mdl-36811936

RESUMEN

Despite increasing success in determining genetic diagnosis for patients with inherited retinal diseases (IRDs), mutations in about 30% of the IRD cases remain unclear or unsettled after targeted gene panel or whole exome sequencing. In this study, we aimed to investigate the contributions of structural variants (SVs) to settling the molecular diagnosis of IRD with whole-genome sequencing (WGS). A cohort of 755 IRD patients whose pathogenic mutations remain undefined were subjected to WGS. Four SV calling algorithms including include MANTA, DELLY, LUMPY and CNVnator were used to detect SVs throughout the genome. All SVs identified by any one of these four algorithms were included for further analysis. AnnotSV was used to annotate these SVs. SVs that overlap with known IRD-associated genes were examined with sequencing coverage, junction reads and discordant read pairs. Polymerase Chain Reaction (PCR) followed by Sanger sequencing was used to further confirm the SVs and identify the breakpoints. Segregation of the candidate pathogenic alleles with the disease was performed when possible. A total of 16 candidate pathogenic SVs were identified in 16 families, including deletions and inversions, representing 2.1% of patients with previously unsolved IRDs. Autosomal dominant, autosomal recessive and X-linked inheritance of disease-causing SVs were observed in 12 different genes. Among these, SVs in CLN3, EYS and PRPF31 were found in multiple families. Our study suggests that the contribution of SVs detected by short-read WGS is about 0.25% of our IRD patient cohort and is significantly lower than that of single nucleotide changes and small insertions and deletions.


Asunto(s)
Enfermedades de la Retina , Humanos , Enfermedades de la Retina/genética , Mutación , Secuenciación Completa del Genoma , Secuenciación del Exoma , Alelos , Glicoproteínas de Membrana/genética , Chaperonas Moleculares/genética , Proteínas del Ojo/genética
3.
Genet Med ; 26(6): 101106, 2024 06.
Artículo en Inglés | MEDLINE | ID: mdl-38420906

RESUMEN

PURPOSE: Inherited retinal diseases (IRDs) are a group of monogenic conditions that can lead to progressive blindness. Their missing heritability is still considerable, due in part to the presence of disease genes that await molecular identification. The purpose of this work was to identify novel genetic associations with IRDs. METHODS: Patients underwent a comprehensive ophthalmological evaluation using standard-of-care tests, such as detailed retinal imaging (macular optical coherence tomography and short-wavelength fundus autofluorescence) and electrophysiological testing. Exome and genome sequencing, as well as computer-assisted data analysis were used for genotyping and detection of DNA variants. A minigene-driven splicing assay was performed to validate the deleterious effects of 1 of such variants. RESULTS: We identified 8 unrelated families from Hungary, the United States, Israel, and The Netherlands with members presenting with a form of autosomal recessive and nonsyndromic retinal degeneration, predominantly described as rod-cone dystrophy but also including cases of cone/cone-rod dystrophy. Age of disease onset was very variable, with some patients experiencing first symptoms during their fourth decade of life or later. Myopia greater than 5 diopters was present in 5 of 7 cases with available refractive data, and retinal detachment was reported in 2 cases. All ascertained patients carried biallelic loss-of-function variants in UBAP1L (HGNC: 40028), a gene with unknown function and with homologies to UBAP1, encoding a protein involved in ubiquitin metabolism. One of these pathogenic variants, the intronic NM_001163692.2:c.910-7G>A substitution, was identified in 5 unrelated families. Minigene-driven splicing assays in HEK293T cells confirmed that this DNA change is responsible for the creation of a new acceptor splice site, resulting in aberrant splicing. CONCLUSION: We identified UBAP1L as a novel IRD gene. Although its function is currently unknown, UBAP1L is almost exclusively expressed in photoreceptors and the retinal pigment epithelium, hence possibly explaining the link between pathogenic variants in this gene and an ocular phenotype.


Asunto(s)
Linaje , Degeneración Retiniana , Humanos , Masculino , Femenino , Adulto , Degeneración Retiniana/genética , Persona de Mediana Edad , Mutación con Pérdida de Función , Genes Recesivos , Niño , Adolescente , Distrofias de Conos y Bastones/genética , Hungría , Adulto Joven , Predisposición Genética a la Enfermedad
4.
Gene Ther ; 29(10-11): 601-607, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-34580433

RESUMEN

Retinal damage has been associated with increased injection pressure during subretinal gene therapy delivery in various animal models, yet there are no human clinical data regarding the pressures required to initiate and propagate subretinal blebs. This study characterized the intraoperative pressure levels for subretinal gene therapy delivery across eight retinal conditions. A total of 116 patients with retinal degenerative diseases have been treated with subretinal gene therapy at OHSU-Casey Eye Institute as of June 2020; seventy patients (60.3%) were treated using a pneumatic-assisted subretinal delivery system. All retinal blebs were performed using a 41-gauge injection cannula, and use of a balanced salt solution (BSS) "pre-bleb" prior to gene therapy delivery was performed at the discretion of the surgeon. Patient age and intraoperative data for BSS and vector injections were analyzed in a masked fashion for all patients who received pneumatic-assisted subretinal gene therapy. The median age of the patients was 35 years (range 4-70). No significant differences in injection pressures were found across the eight retinal conditions. In this study, patient age was shown to affect maximum injection pressures required for bleb propagation, and the relationship between age and pressure varied based on retinal condition. These data have important implications in optimizing surgical protocols for subretinal injections.


Asunto(s)
Degeneración Retiniana , Animales , Terapia Genética/efectos adversos , Terapia Genética/métodos , Inyecciones , Retina
5.
Environ Sci Technol ; 56(21): 14923-14936, 2022 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-35594374

RESUMEN

Sewage treatment plants (STPs) accumulate both antibiotic and nonantibiotic antimicrobial compounds that can select for antibiotic resistant bacteria. Herein, we aimed to identify the predominant antibacterial compounds impacting E. coli from Ontario sewage sludge consisting of thousands of unknown compounds. Among the 10 extracted sludge samples, 6 extracts exerted significant growth inhibition effects in E. coli. A total of 103 compounds were tentatively detected across the 10 sludge samples by suspect screening, among which the bacterial enoyl-ACP reductase (FabI) inhibitor triclocarban was detected at the highest abundance. A hypomorphic FabI knockdown E. coli strain was highly susceptible to the sludge extracts, confirming FabI inhibitors as the primary antibacterial compounds in the sludge. Protein affinity pulldown identified triclosan as the major ligand binding to a His-tagged FabI protein from the sludge, despite the higher abundance of triclocarban in the same samples. Effect-directed analysis was used to determine the contributions of triclosan to the observed antibacterial potencies. Antibacterial effects were only detected in F17 and F18 across 20 fractions, which was consistent with the elution of triclosan and triclocarban in the same two fractions. Further, potency mass balance analysis confirmed that triclosan explained the majority (58-113%) of inhibition effects from sludge extracts. This study highlighted triclosan as the predominant antibacterial compound in sewage sludge impacting E. coli despite the co-occurrence of numerous other antibiotics and nonantibiotics.


Asunto(s)
Triclosán , Triclosán/farmacología , Triclosán/química , Enoil-ACP Reductasa (NADH)/química , Enoil-ACP Reductasa (NADH)/metabolismo , Aguas del Alcantarillado , Antibacterianos/farmacología , Escherichia coli , Ontario , Bacterias/metabolismo
6.
Mol Vis ; 27: 95-106, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33907365

RESUMEN

Purpose: Despite the extensive use of next-generation sequencing (NGS) technology to identify disease-causing genomic variations, a major gap in our understanding of Mendelian diseases is the unidentified molecular lesion in a significant portion of patients. For inherited retinal degenerations (IRDs), although currently close to 300 disease-associated genes have been identified, the mutations in approximately one-third of patients remain unknown. With mounting evidence that noncoding mutations might contribute significantly to disease burden, we aimed to systematically investigate the contributions of noncoding regions in the genome to IRDs. Methods: In this study, we focused on RPGRIP1, which has been linked to various IRD phenotypes, including Leber congenital amaurosis (LCA), retinitis pigmentosa (RP), and macular dystrophy (MD). As several noncoding mutant alleles have been reported in RPGRIP1, and we observed that the mutation carrier frequency of RPGRIP1 is higher in patient cohorts with unsolved IRDs, we hypothesized that mutations in the noncoding regions of RPGRIP1 might be a significant contributor to pathogenicity. To test this hypothesis, we performed whole-genome sequencing (WGS) for 25 patients with unassigned IRD who carry a single mutation in RPGRIP1. Results: Three noncoding variants in RPGRIP1, including a 2,890 bp deletion and two deep-intronic variants (c.2710+233G>A and c.1468-263G>C), were identified as putative second hits of RPGRIP1 in three patients with LCA. The mutant alleles were validated with direct sequencing or in vitro assays. Conclusions: The results highlight the significance of the contribution of noncoding pathogenic variants to unsolved IRD cases.


Asunto(s)
Proteínas del Citoesqueleto/genética , Mutación/genética , ARN no Traducido/genética , Degeneración Retiniana/genética , Adulto , Alelos , Preescolar , Clonación Molecular , Electrorretinografía , Femenino , Humanos , Masculino , Fenotipo , Reacción en Cadena en Tiempo Real de la Polimerasa , Retina/fisiopatología , Degeneración Retiniana/diagnóstico , Degeneración Retiniana/fisiopatología , Tomografía de Coherencia Óptica , Transfección , Agudeza Visual/fisiología , Secuenciación Completa del Genoma
7.
Exp Eye Res ; 202: 108327, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33141049

RESUMEN

PNPLA6-related disorders include several phenotypes, such as Boucher-Neuhäuser syndrome, Gordon Holmes syndrome, spastic paraplegia, photoreceptor degeneration, Oliver-McFarlane syndrome and Laurence-Moon syndrome. In this study, detailed clinical evaluations and genetic testing were performed in five (4 Chinese and 1 Caucasian/Chinese) syndromic retinal dystrophy patients. Genotype-phenotype correlations were analyzed based on review of the literatures of previously published PNPLA6-related cases. The mean age of patients and at first visit were 20.8 years (11, 12, 25, 28, 28) and 14.2 years (4, 7, 11, 24, 25), respectively. They all presented with severe chorioretinal dystrophy and profoundly decreased vision. The best corrected visual acuity (BCVA) ranged from 20/200 to 20/2000. Systemic manifestations included cerebellar ataxia, hypogonadotropic hypogonadism and hair anomalies. Six novel and three reported pathogenic variants in PNPLA6 (NM_001166111) were identified. The genotypes of the five cases are: c.3134C > T (p.Ser1045Leu) and c.3846+1G > A, c.3547C > T (p.Arg1183Trp) and c.1841+3A > G, c.3436G > A (p.Ala1146Thr) and c.2212-10A > G, c.3436G > A (p.Ala1146Thr) and c.2266C > T (p.Gln756*), c.1238_1239insC (p.Leu414Serfs*28) and c.3130A > G (p.Thr1044Ala). RT-PCR confirmed that the splicing variants indeed led to abnormal splicing. Missense variants p.Thr1044Ala, p.Ser1045Leu, p.Ala1146Thr, p.Arg1183Trp and c.3846+1G > A are located in Patatin-like phospholipase (Pat) domain. In conclusion, we report the phenotypes in five patients with PNPLA6 associated syndromic retinal dystrophy with variable systemic involvement and typical choroideremia-like fundus changes. Ocular manifestations may be the first and the only findings for years. All of our patients carried one severe deleterious variant (stop-gain or splicing variant) and one milder variant (missense variant). Retinal involvement was significantly correlated with severe deleterious variants and variants in Pat domain.


Asunto(s)
Variación Genética/genética , Fosfolipasas/genética , Distrofias Retinianas/genética , Adulto , Niño , Preescolar , Electrorretinografía , Femenino , Estudios de Asociación Genética , Técnicas de Genotipaje , Humanos , Masculino , Linaje , Reacción en Cadena en Tiempo Real de la Polimerasa , Distrofias Retinianas/diagnóstico por imagen , Distrofias Retinianas/fisiopatología , Tomografía de Coherencia Óptica , Agudeza Visual/fisiología , Adulto Joven
8.
Mol Vis ; 26: 423-433, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32565670

RESUMEN

Purpose: To evaluate the phenotypic spectrum of autosomal recessive RP1-associated retinal dystrophies and assess genotypic associations. Methods: A retrospective multicenter study was performed of patients with biallelic RP1-associated retinal dystrophies. Data including presenting symptoms and age, visual acuity, kinetic perimetry, full field electroretinogram, fundus examination, multimodal retinal imaging, and RP1 genotype were evaluated. Results: Nineteen eligible patients from 17 families were identified and ranged in age from 10 to 56 years at the most recent evaluation. Ten of the 21 unique RP1 variants identified were novel, and mutations within exon 2 accounted for nearly half of alleles across the cohort. Patients had clinical diagnoses of retinitis pigmentosa (13), cone-rod dystrophy (3), Leber congenital amaurosis (1), early-onset severe retinal dystrophy (1), and macular dystrophy (1). Macular atrophy was a common feature across the cohort. Symptom onset occurred between 4 and 30 years of age (mean 14.9 years, median 13 years), but there were clusters of onset age that correlated with the effects of RP1 mutations at a protein level. Patients with later-onset disease, including retinitis pigmentosa, had at least one missense variant in an exon 2 DCX domain. Conclusions: Biallelic RP1 mutations cause a broad spectrum of retinal disease. Exon 2 missense mutations are a significant contributor to disease and can be associated with a considerably later onset of retinitis pigmentosa than that typically associated with biallelic RP1 mutations.


Asunto(s)
Proteínas Asociadas a Microtúbulos/genética , Distrofias Retinianas/genética , Adolescente , Adulto , Alelos , Niño , Estudios de Cohortes , Distrofias de Conos y Bastones/genética , Análisis Mutacional de ADN , Electrorretinografía , Enfermedades Hereditarias del Ojo/genética , Femenino , Genotipo , Humanos , Amaurosis Congénita de Leber/genética , Degeneración Macular/genética , Masculino , Persona de Mediana Edad , Mutación , Mutación Missense , Fenotipo , Distrofias Retinianas/diagnóstico por imagen , Distrofias Retinianas/fisiopatología , Retinitis Pigmentosa/genética , Estudios Retrospectivos , Agudeza Visual
9.
Nanotechnology ; 30(2): 025203, 2019 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-30387440

RESUMEN

We demonstrate single- and double-gate synaptic operations of a thin-film transistor (TFT) with double-gate stack consisting of an Al-top-gate/SiO x /TaO x /n-IGZO on a SiO2/n+-Si-bottom-gate substrate. This synaptic TFT exhibits a tunable drain current, mimicking synaptic weight modulation in the biological synapse, upon repeatedly applying gate and drain voltages. The drain current modulation features are analog, voltage-polarity dependently reversible, and strong with a dynamic range of multiple orders of magnitude (∼104). These features occur as a consequence of the changes in mobility of the IGZO channel, gate insulator capacitance, and threshold voltage. The drain current modulation responsive to the timing of the voltage application emulates synaptic potentiation, depression, paired-pulse facilitation, and memory transition behaviors depending on the voltage pulse amplitude, width, repetition number, and interval between pulses. The synaptic motions can be realized also by a double-gate operation that separately tunes the channel conductance by top-gate biasing and senses it by bottom-gate biasing. It provides the modulated synaptic weight with a wide level of synaptic weight through the read condition using a bottom-gate stack without read-disturbance. These results verify the potential application of TaO x /IGZO TFT with single- and double-gate operations to artificial synaptic devices.

10.
BMC Ophthalmol ; 19(1): 246, 2019 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-31810438

RESUMEN

BACKGROUND: Alström syndrome (AS) is a rare monogenic disorder characterized by progressive multi-organ pathology including retinal degeneration, hearing impairment and type 2 diabetes. Here we present clinical features in two siblings diagnosed with Alström syndrome associated with two novel changes in ALMS1. CASE PRESENTATION: Two siblings originally diagnosed as having achromatopsia presented with mild light sensitivity, nonspecific otitis media, and mild developmental delay during the first decade of life with a relatively stable ocular appearance during second decade, late onset of nystagmus and dyschromatopsia (after 20 years) and preserved vision during the third decade of life. One sibling had late onset hearing loss and both siblings had symmetric high myopia, normal stature, and ptosis. Clinical findings revealed structural and functional tests consistent with a cone-rod dystrophy. Novel variants c.9894dupC (p.S3298 fs) and c.10769delC (p.T3590 fs) in ALMS1 gene were found. CONCLUSIONS: Two North American siblings who presented with a mild clinical phenotype of Alström syndrome were found to have novel mutations in ALMS1. These two frame-shift mutations segregated with the disease phenotype lending evidence to their pathogenicity.


Asunto(s)
Síndrome de Alstrom/genética , Proteínas de Ciclo Celular/genética , Mutación , Degeneración Retiniana/etiología , Adulto , Humanos , Masculino , Hermanos , Adulto Joven
11.
Adv Exp Med Biol ; 1185: 407-411, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31884646

RESUMEN

The targeted development of neuroprotective therapies for retinitis pigmentosa (RP) depends upon a better understanding of the mechanisms of photoreceptor cell death. Nucleotide metabolite-associated photoreceptor cell death is an emerging area of research that is important in multiple models of RP, yet the exact pathophysiology remains to be elucidated. One common pathway of photoreceptor cell death in RP is cGMP dysregulation, which is underscored by its potential to be relevant in up to 30% of patients with RP. Optimizing tools for detecting and quantifying nucleotide metabolites in the retina is vital to expanding this area of research. Immunohistochemistry is useful for localizing abnormally high levels of cGMP in a cell-specific manner, while enzyme-linked immunosorbent assay and liquid chromatography-mass spectrometry are quantitative and more sensitive. These techniques can form the basis for more sophisticated experiments to elucidate upstream events in photoreceptor cell death, which will hopefully lead to the development of novel therapies for patients with RP.


Asunto(s)
Muerte Celular , GMP Cíclico/metabolismo , Células Fotorreceptoras/patología , Retinitis Pigmentosa/patología , Animales , Modelos Animales de Enfermedad , Humanos , Retina/citología , Retina/patología
12.
Nanotechnology ; 29(29): 295201, 2018 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-29714170

RESUMEN

We report a variety of synaptic behaviors in a thin-film transistor (TFT) with a metal-oxide-semiconductor gate stack that has a Pt/HfO x /n-type indium-gallium-zinc oxide (n-IGZO) structure. The three-terminal synaptic TFT exhibits a tunable synaptic weight with a drain current modulation upon repeated application of gate and drain voltages. The synaptic weight modulation is analog, voltage-polarity dependent reversible, and strong with a dynamic range of multiple orders of magnitude (>104). This modulation process emulates biological synaptic potentiation, depression, excitatory-postsynaptic current, paired-pulse facilitation, and short-term to long-term memory transition behaviors as a result of repeated pulsing with respect to the pulse amplitude, width, repetition number, and the interval between pulses. These synaptic behaviors are interpreted based on the changes in the capacitance of the Pt/HfO x /n-IGZO gate stack, the channel mobility, and the threshold voltage that result from the redistribution of oxygen ions by the applied gate voltage. These results demonstrate the potential of this structure for three-terminal synaptic transistor using the gate stack composed of the HfO x gate insulator and the IGZO channel layer.

13.
Nanotechnology ; 29(26): 265204, 2018 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-29633723

RESUMEN

A crossbar array of Pt/CeO2/Pt memristors exhibited the synaptic characteristics such as analog, reversible, and strong resistance change with a ratio of ∼103, corresponding to wide dynamic range of synaptic weight modulation as potentiation and depression with respect to the voltage polarity. In addition, it presented timing-dependent responses such as paired-pulse facilitation and the short-term to long-term memory transition by increasing amplitude, width, and repetition number of voltage pulse and reducing the interval time between pulses. The memory loss with a time was fitted with a stretched exponential relaxation model, revealing the relation of memory stability with the input stimuli strength. The resistance change was further enhanced but its stability got worse as increasing measurement temperature, indicating that the resistance was changed as a result of voltage- and temperature-dependent electrical charging and discharging to alter the energy barrier for charge transport. These detailed synaptic characteristics demonstrated the potential of crossbar array of Pt/CeO2/Pt memristors as artificial synapses in highly connected neuron-synapse network.

14.
Retina ; 38(9): 1725-1730, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29160785

RESUMEN

PURPOSE: We report a novel finding on spectral domain optical coherence tomography in patients with choroideremia, which we describe as scleral pits (SCPs). METHODS: Cross-sectional observational case series of 36 patients with choroideremia, who underwent ophthalmic examination and multimodal imaging, including optical coherence tomography of the macula. Optical coherence tomography images were reviewed for SCP, which were defined as discrete tracts of hyporeflectivity that traverse the sclera with or without the involvement of Bruch membrane, retinal pigment epithelium, and retina. Unpaired two-tailed t-test with Welch correction was used for statistical analysis. RESULTS: Of the 36 patients, 19 had SCP in at least one eye. Scleral pits were confined to areas of advanced chorioretinal degeneration and never involved the foveola. Type 1 SCP affected only the sclera, whereas Type 2 SCP also involved the Bruch membrane and the retinal pigment epithelium. Type 3 SCP additionally had a full-thickness retinal defect. Patients with SCP were significantly older (51 ± 2 vs. 33 ± 4 years; P < 0.05) and had lower best-corrected visual acuity (20/160 vs. 20/30 or 0.9 ± 0.2 vs. 0.2 ± 0.07 logarithm of the minimum angle of resolution; P < 0.05) than patients without SCP. Patients with SCP had a greater myopic refractive error compared with patients without SCP (-2.6 ± 0.5 vs. -0.3 ± 0.5D; P < 0.05), but there was no significant correlation between the number of SCPs with refraction. Short posterior ciliary arteries were observed to enter the eye through one Type 3 SCP. CONCLUSION: Scleral pits are, to the best of our knowledge, a novel optical coherence tomography finding in advanced choroideremia that likely represents the abnormal juxtaposition of penetrating short posterior ciliary arteries with the retina.


Asunto(s)
Anomalías Múltiples/terapia , Coroides/irrigación sanguínea , Coroideremia/terapia , Labio Leporino/terapia , Fisura del Paladar/terapia , Quistes/terapia , Terapia Genética/métodos , Labio/anomalías , Epitelio Pigmentado de la Retina/patología , Esclerótica/anomalías , Anomalías Múltiples/diagnóstico , Anomalías Múltiples/fisiopatología , Adulto , Anciano , Lámina Basal de la Coroides/patología , Coroideremia/diagnóstico , Coroideremia/fisiopatología , Labio Leporino/diagnóstico , Labio Leporino/fisiopatología , Fisura del Paladar/diagnóstico , Fisura del Paladar/fisiopatología , Estudios Transversales , Quistes/diagnóstico , Quistes/fisiopatología , Femenino , Angiografía con Fluoresceína/métodos , Estudios de Seguimiento , Humanos , Labio/fisiopatología , Masculino , Persona de Mediana Edad , Tomografía de Coherencia Óptica/métodos , Agudeza Visual
15.
Nanotechnology ; 28(22): 225201, 2017 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-28488590

RESUMEN

A synaptic transistor emulating the biological synaptic motion is demonstrated using the memcapacitance characteristics in a Pt/HfOx/n-indium-gallium-zinc-oxide (IGZO) memcapacitor. First, the metal-oxide-semiconductor (MOS) capacitor with Pt/HfOx/n-IGZO structure exhibits analog, polarity-dependent, and reversible memcapacitance in capacitance-voltage (C-V), capacitance-time (C-t), and voltage-pulse measurements. When a positive voltage is applied repeatedly to the Pt electrode, the accumulation capacitance increases gradually and sequentially. The depletion capacitance also increases consequently. The capacitances are restored by repeatedly applying a negative voltage, confirming the reversible memcapacitance. The analog and reversible memcapacitance emulates the potentiation and depression synaptic motions. The synaptic thin-film transistor (TFT) with this memcapacitor also shows the synaptic motion with gradually increasing drain current by repeatedly applying the positive gate and drain voltages and reversibly decreasing one by applying the negative voltages, representing synaptic weight modulation. The reversible and analog conductance change in the transistor at both the voltage sweep and pulse operations is obtained through the memcapacitance and threshold voltage shift at the same time. These results demonstrate the synaptic transistor operations with a MOS memcapacitor gate stack consisting of Pt/HfOx/n-IGZO.

16.
Retina ; 37(6): 1104-1119, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27755372

RESUMEN

PURPOSE: To determine whether ultra-wide-field fundus autofluorescence (UWFFAF) findings in acute zonal occult outer retinopathy correlated well with perimetry, optical coherence tomography, and electroretinography findings. METHODS: Retrospective observational study on 16 eyes of 10 subjects with AZOOR seen at a single referral center from October 2012 to March 2015 who had UWFFAF performed. Chi-square analysis was performed to compare categorical variables, and Mann-Whitney U test used for comparisons of nonparametric continuous variables. RESULTS: All eyes examined within 3 months of symptom onset (five of the five eyes) had diffusely hyperautofluorescent areas on UWFFAF. The remaining eyes contained hypoautofluorescent lesions with hyperautofluorescent borders. In 11/16 (68.8%) eyes, UWFFAF showed the full extent of lesions that would not have been possible with standard fundus autofluorescence centered on the fovea. There were 3 patterns of spread: centrifugal spread (7/16, 43.8%), centripetal spread (5/16, 31.3%), and centrifugal + centripetal spread (4/16, 25.0%). The UWFFAF lesions corresponded well with perimetric, optical coherence tomography, and electroretinography abnormalities. CONCLUSION: The UWFFAF along with optical coherence tomography can be useful in the evaluation and monitoring of acute zonal occult outer retinopathy patients.


Asunto(s)
Angiografía con Fluoresceína/métodos , Fóvea Central/patología , Escotoma/diagnóstico , Tomografía de Coherencia Óptica/métodos , Campos Visuales , Adolescente , Adulto , Anciano , Electrorretinografía , Femenino , Fondo de Ojo , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Escotoma/fisiopatología , Agudeza Visual , Síndromes de Puntos Blancos , Adulto Joven
18.
Retina ; 37(10): 1956-1966, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28145975

RESUMEN

PURPOSE: Congenital achromatopsia is an autosomal recessive disease causing substantial reduction or complete absence of cone function. Although believed to be a relatively stationary disorder, questions remain regarding the stability of cone structure over time. In this study, the authors sought to assess the repeatability of and examine longitudinal changes in measurements of central cone structure in patients with achromatopsia. METHODS: Forty-one subjects with CNGB3-associated achromatopsia were imaged over a period of between 6 and 26 months using optical coherence tomography and adaptive optics scanning light ophthalmoscopy. Outer nuclear layer (ONL) thickness, ellipsoid zone (EZ) disruption, and peak foveal cone density were assessed. RESULTS: ONL thickness increased slightly compared with baseline (0.184 µm/month, P = 0.02). The EZ grade remained unchanged for 34/41 subjects. Peak foveal cone density did not significantly change over time (mean change 1% per 6 months, P = 0.126). CONCLUSION: Foveal cone structure showed little or no change in this group of subjects with CNGB3-associated achromatopsia. Over the time scales investigated (6-26 months), achromatopsia seems to be a structurally stable condition, although longer-term follow-up is needed. These data will be useful in assessing foveal cone structure after therapeutic intervention.


Asunto(s)
Defectos de la Visión Cromática/genética , Canales Catiónicos Regulados por Nucleótidos Cíclicos/genética , ADN/genética , Fóvea Central/patología , Mutación , Células Fotorreceptoras Retinianas Conos/patología , Agudeza Visual , Adolescente , Adulto , Niño , Defectos de la Visión Cromática/diagnóstico , Defectos de la Visión Cromática/fisiopatología , Canales Catiónicos Regulados por Nucleótidos Cíclicos/metabolismo , Análisis Mutacional de ADN , Electrorretinografía , Femenino , Fóvea Central/fisiopatología , Humanos , Estudios Longitudinales , Masculino , Oftalmoscopía/métodos , Células Fotorreceptoras Retinianas Conos/fisiología , Tomografía de Coherencia Óptica/métodos , Adulto Joven
19.
Retina ; 36(12): 2339-2347, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27336230

RESUMEN

PURPOSE: To demonstrate the clinical utility of optical coherence tomography (OCT) angiography (OCT-A) in inherited retinal dystrophies complicated by choroidal neovascularization (CNV). METHODS: Optical coherence tomography angiography and structural OCT were performed using a 70-kHz spectral domain OCT system using the split-spectrum amplitude-decorrelation angiography algorithm. Semiautomated image processing software was used to segment and measure the CNV. RESULTS: Four participants were enrolled to study the following inherited retinal dystrophies complicated by CNV: choroideremia, EFEMP1-related retinopathy, Best vitelliform dystrophy, and adult-onset vitelliform dystrophy. Interpretation of fluorescein angiography was difficult because of abnormal retinal architecture but suggested the presence of CNV. Structural OCT revealed subretinal or subretinal pigment epithelium fibrovascular tissue, within which flow signal was observed on OCT-A. The CNV morphology varied from dense capillary networks in active lesions to asymptomatic large caliber loops. Baseline CNV vessel areas ranged from 0.07 mm to 0.98 mm. After treatment with intravitreal bevacizumab, the CNV in choroideremia decreased in the vessel area then rebounded, whereas the one in EFEMP1-related retinopathy remained largely unchanged. CONCLUSION: Optical coherence tomography angiography enables morphologic characterization and quantification of CNV in patients with retinal dystrophies despite distorted retinal architecture, can assess response to treatment, and may facilitate differentiation between active and regressed lesions.


Asunto(s)
Neovascularización Coroidal/diagnóstico por imagen , Angiografía con Fluoresceína , Distrofias Retinianas/diagnóstico por imagen , Tomografía de Coherencia Óptica/métodos , Adolescente , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Distrofias Retinianas/complicaciones , Agudeza Visual
20.
J Calif Dent Assoc ; 44(2): 85-92, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26930751

RESUMEN

As medical technology advances in the area of cancer therapeutics, dental practitioners will encounter patients with active cancer or a history of cancer. Typically, these patients may have had or are undergoing therapies such as surgery, radiation, chemotherapy or a combination of therapies. These patients may present with multiple side effects that dental practitioners can manage or prevent. We discuss some of these concerns and provide management strategies.


Asunto(s)
Enfermedades de la Boca/prevención & control , Neoplasias de la Boca/terapia , Osteonecrosis de los Maxilares Asociada a Difosfonatos/prevención & control , Candidiasis Bucal/prevención & control , Humanos , Terapia Neoadyuvante/efectos adversos , Osteorradionecrosis/prevención & control , Estomatitis/prevención & control , Xerostomía/prevención & control
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA