Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 84
Filtrar
1.
Science ; : eado5143, 2024 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-38963875

RESUMEN

The 2024 moment magnitude (Mw) 7.5 Noto Peninsula (Japan) earthquake caused devastation to communities and was generated by a complex rupture process. Using space geodetic and seismic observations, we show that the event deformed the peninsula with a peak uplift reaching 5 m at the west coast. Shallow slip exceeded 10 m on an offshore fault. Peak stress drop was greater than 10 MPa. This devastating event began with a slow rupture propagation lasting 15-20 s near its hypocenter, where seismic swarms had surged since 2020 due to lower-crust fluid supply. The slow start was accompanied by intense high-frequency seismic radiation. These observations suggest a distinct coseismic slip mode reflecting high heterogeneity in fault properties within a fluid-rich fault zone.

2.
Am J Ophthalmol ; 265: 117-126, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38701877

RESUMEN

PURPOSE: To compare the quality of images of gratings placed in a model eye viewed through an extended depth of focus (EDoF) intraocular lens (IOL) to that of diffractive bifocal IOL or monofocal IOL. DESIGN: Experimental laboratory investigation. METHODS: Nondiffractive wavefront shaping EDoF (CNAET0, Alcon Laboratories), echelette-designed EDoF (ZXR00V, Johnson & Johnson Vision), diffractive bifocal IOL with low power addition (SV25T, Alcon Laboratories), or monofocal IOL (CNA0T0, Alcon Laboratories) was placed in a fluid-filled model eye. A United States Air Force Resolution Grating Target was glued to the posterior surface of the model eye and viewed through a flat or a wide-angle contact lens. The contrast of the gratings viewed through the EDoF or multifocal IOLs was compared to that through the monofocal IOL. A wavefront analyzer was used to measure the spherical power of the central 4.5 mm optics of the EDoF, multifocal, and monofocal IOLs. The distribution of the dioptric power and the dioptric power map were compared. RESULTS: The gratings observed through the flat contact lens with CNAET0, ZXR00V, or SV25T were slightly blurred when viewed through the multifocal optics. The blurred area was in the circumferential area of CNAET0, the central area of SV25T, and the peripheral area of ZXR00V. The mean contrast was 0.258 ± 0.020 for CNAET0, 0.227 ± 0.025 for ZXR00V, and 0.221 ± 0.020 for SV25T for the 16.0 cyc/mm grating. The contrast was significantly lower for ZXR00V (P = .004) and SV25T (P = .004) than 0.303 ± 0.015 for CNA0T0 but the differences were not significant for CNAET0. For the wide-angle contact lens, the contrast for CNAET0 was 0.182 ± 0.009, for ZXR00V was 0.162 ± 0.011, and for SV25T was 0.163 ± 0.007 for the 16.0 cyc/mm grating, and none was significantly different from 0.188 ± 0.012 for CNA0T0. The dioptric variations of CNAET0 indicated a ring-shaped area of higher power corresponding to the circumferential blurred zone observed through the flat contact lens. CONCLUSIONS: The wavefront shaping and echelette-designed EDoF-IOLs reduce the contrast of the grating more than the monofocal IOL when viewed through the flat contact lens. The degree of reduction depended on the design of the extended-focus optics. The difference was less through the wide-angle contact lens.

3.
ACS Phys Chem Au ; 4(1): 85-93, 2024 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-38283787

RESUMEN

Nanosecond resolved fluorescence correlation spectroscopy (ns-FCS) based on two-color fluorescence detection is a powerful strategy for investigating the fast dynamics of biological macromolecules labeled with donor and acceptor fluorophores. The standard methods of ns-FCS use two single-photon avalanche diodes (SPADs) for the detection of single-color signals (four SPADs for two-color signals) to eliminate the afterpulse artifacts of SPAD at the expense of the efficiency of utilizing photon data in the calculation of correlograms. Herein, we demonstrated that hybrid photodetectors (HPDs) enable the recording of fluorescence photons in ns-FCS based on the minimal system using two HPDs for the detection of two-color signals. However, HPD exhibited afterpulses at a yield with respect to the rate of photodetection (<10-4) much lower than that of SPADs (∼10-2), which could still hamper correlation measurements. We demonstrated that the simple subtraction procedure could eliminate afterpulse artifacts. While the quantum efficiency of photodetection for HPDs is lower than that for high-performance SPADs, the developed system can be practically used for two-color ns-FCS in a time domain longer than a few nanoseconds. The fast chain dynamics of the B domain of protein A in the unfolded state was observed using the new method.

4.
Eye (Lond) ; 38(2): 266-273, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-37524830

RESUMEN

OBJECTIVES: To investigate the relationship between the shape of the optic nerve head (ONH) margin detected by optical coherence tomography (OCT) and the clinical characteristics of glaucomatous eyes with papillomacular retinoschisis (PMRS). METHODS: The medical record of patients with a PMRS in a glaucomatous eye were reviewed. The eyes were placed into two groups determined by the shape of the ONH margin in the OCT images; eyes with an externally oblique ONH margin (Group 1) and eyes with an internally oblique ONH margin (Group 2). We compared the clinical characteristics of the PMRS of these two groups. RESULTS: We studied 31 eyes of 29 patients with PMRS and glaucoma with 24 eyes in Group 1 and 7 eyes in Group 2. The optic nerve fibre layer schisis on the lamina cribrosa (LC), beta zone, and gamma zone, and found that the LC defects were detected significantly more frequently in Group 1 than in Group 2 eyes (P < 0.05). A retinal nerve fibre schisis was observed around the ONH significantly more frequently in Group 2 than in Group 1 eyes (P < 0.01). CONCLUSION: The cases of glaucoma-associated PMRS could be classified into two groups according to the obliquity of the ONH. They had differences in the findings of OCT and FA. The possibility that the mechanism of PMRS development is different in both groups is suggested.


Asunto(s)
Glaucoma , Disco Óptico , Retinosquisis , Humanos , Tomografía de Coherencia Óptica/métodos , Retinosquisis/diagnóstico por imagen , Glaucoma/diagnóstico , Presión Intraocular
5.
Can J Exp Psychol ; 2023 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-37917423

RESUMEN

Performing a cognitive task prior to making a recognition judgment increases the probability of old responses, which is known as the revelation effect. The criterion shift account (Niewiadomski & Hockley, 2001) proposes that occupation of working memory causes the revelation effect. However, we proposed that working memory does not cause it. Two experiments were conducted to disconfirm the relationship between working memory and the revelation effect and to consider an alternative explanation that metacognition causes the effect. In Experiment 1, the revelation effect was caused by a finger movement task, which puts little or no load on working memory. In Experiment 2, a metacognitive instruction that a cognitive task would make subsequent recognition easier induced a conservative criterion shift. The finding that a simple motor task caused the revelation effect in Experiment 1 disconfirms the relationship between working memory and the revelation effect and extends the boundaries of the occurrence of the effect. The findings in Experiment 2 suggest that metacognition may be related to the occurrence of the revelation effect. This study implies a paradoxical aspect of human cognition in that metacognition, which usually makes cognition more effective and rational, may also cause an irrational phenomenon, the revelation effect. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

6.
Nat Commun ; 14(1): 4960, 2023 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-37620307

RESUMEN

Primary tumor cells metastasize to a distant preferred organ. However, the most decisive host factors that determine the precise locations of metastases in cancer patients remain unknown. We have demonstrated that post-translational citrullination of fibrinogen creates a metastatic niche in the vulnerable spots. Pulmonary endothelial cells mediate the citrullination of fibrinogen, changing its conformation, surface charge, and binding properties with serum amyloid A proteins (SAAs), to make it a host tissue-derived metastatic pathogen. The human-specific SAAs-citrullinated fibrinogen (CitFbg) complex recruits cancer cells to form a protein-metastatic cell aggregation in humanized SAA cluster mice. Furthermore, a CitFbg peptide works as a competitive inhibitor to block the homing of metastatic cells into the SAAs-CitFbg sites. The potential metastatic sites in the lungs of patients are clearly visualized by our specific antibody for CitFbg. Thus, CitFbg deposition displays metastatic risks for cancer patients, and the citrullinated peptide is a new type of metastasis inhibitor.


Asunto(s)
Células Endoteliales , Hemostáticos , Humanos , Animales , Ratones , Proteína Amiloide A Sérica , Causalidad , Fibrinógeno
7.
Sci Rep ; 13(1): 8530, 2023 05 26.
Artículo en Inglés | MEDLINE | ID: mdl-37237029

RESUMEN

The purpose of this study is to show the characteristics of person misidentifications, that is, experiences in which persons are misidentified as known persons. A total of 121 participants were asked how many times they misidentified persons in the last year and details of a recent person misidentification were recorded through a traditional questionnaire. Additionally, they answered questions in a diary method questionnaire, about the details of person misidentification each time they experienced it, during the two-week survey period. The questionnaires revealed that the participants misidentified both known and unknown persons as familiar persons approximately six (traditional questionnaire) or 19 (diary method) times a year on average, regardless of whether they expected the persons to be there. They were more likely to misidentify a person as a familiar than as a less familiar person. It was also shown that the similarity of the faces of the person actually seen and the person they were mistaken for was not as high as the similarities of build and clothing. This study is expected to provide suggestions for models of person identification and enhance the research on errors.


Asunto(s)
Reconocimiento de Identidad , Humanos , Encuestas y Cuestionarios
8.
Sci Adv ; 8(22): eabn5626, 2022 06 03.
Artículo en Inglés | MEDLINE | ID: mdl-35658044

RESUMEN

Dynamic chromatin behavior plays a critical role in various genome functions. However, it remains unclear how chromatin behavior changes during interphase, where the nucleus enlarges and genomic DNA doubles. While the previously reported chromatin movements varied during interphase when measured using a minute or longer time scale, we unveil that local chromatin motion captured by single-nucleosome imaging/tracking on a second time scale remained steady throughout G1, S, and G2 phases in live human cells. This motion mode appeared to change beyond this time scale. A defined genomic region also behaved similarly. Combined with Brownian dynamics modeling, our results suggest that this steady-state chromatin motion was mainly driven by thermal fluctuations. Steady-state motion temporarily increased following a DNA damage response. Our findings support the viscoelastic properties of chromatin. We propose that the observed steady-state chromatin motion allows cells to conduct housekeeping functions, such as transcription and DNA replication, under similar environments during interphase.


Asunto(s)
Cromatina , Nucleosomas , Núcleo Celular , Cromatina/genética , Replicación del ADN , Humanos , Interfase
9.
Sci Rep ; 12(1): 7179, 2022 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-35504923

RESUMEN

The slip history of short-term slow slip event (SSE) is typically inferred from daily Global Positioning System (GPS) data, which, however, cannot image the sub-daily processes, leaving the underlying mechanisms of SSEs elusive. To address the temporal resolution issue, we attempted to employ the kinematic subdaily GPS analysis, which has never been applied to SSE studies because its signal-to-noise ratio has been believed too low. By carefully post-processing sub-daily positions to remove non-tectonic position fluctuation, our 30-min kinematic data clearly exhibits the transient motion of a few mm during one Cascadia SSE. A spatiotemporal slip image by inverting the 30-min data exhibits a multi-stage evolution; it consists of an isotropic growth of SSE followed by an along-strike migration and termination within the rheologically controlled down-dip width. This transition at the slip growth mode is similar to the rupture growth of regular earthquakes, implying the presence of common mechanical factors behind the two distinct slip phenomena. The comparison with a slip inversion of the daily GPS demonstrates the current performance and limitation of the subdaily data in the SSE detection and imaging. Better understanding of the non-tectonic noise in the kinematic GPS analysis will further improve the temporal resolution of SSE.

10.
Jpn J Ophthalmol ; 65(6): 786-796, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34505174

RESUMEN

PURPOSE: To determine factors significantly correlated with the failure of macular reattachment by pars plana vitrectomy (PPV) without laser photocoagulation of the optic disc margin to treat optic disc pit (ODP) maculopathy. DESIGN: Retrospective, interventional case series. METHODS: We reviewed the medical records of 35 consecutive patients with ODP maculopathy who underwent PPV without laser photocoagulation. PPV with the creation of a posterior vitreous detachment (PVD) was performed in 34 eyes. An epiretinal membrane and internal limiting membrane present in the other eye with a PVD were removed. Patients were followed for 12-193 months (mean 58 months) after surgery. The main outcome measures were the postoperative rate of retinal reattachment and best-corrected visual acuity. The preoperative clinical characteristics of the successful cases were compared to those of the unsuccessful cases. RESULTS: A complete retinal reattachment was attained in 31 of 35 eyes and it required about one year. The 4 other eyes that did not achieve a macular reattachment after the primary PPV underwent additional therapies. The factors that were significantly associated with a failure of a retinal reattachment after primary PPV were the presence of a retinal detachment connected to the optic disc (P < 0.001) and the presence of preoperative headaches (P = 0.030). CONCLUSIONS: Clinicians should be aware that the presence of a preoperative macular detachment connected to the optic disc margin and preoperative headaches are indicators for an unsuccessful outcome of PPV without laser photocoagulation in eyes with ODP maculopathy.


Asunto(s)
Degeneración Macular , Disco Óptico , Desprendimiento de Retina , Estudios de Seguimiento , Humanos , Coagulación con Láser , Rayos Láser , Desprendimiento de Retina/diagnóstico , Desprendimiento de Retina/cirugía , Estudios Retrospectivos , Factores de Riesgo , Tomografía de Coherencia Óptica , Agudeza Visual , Vitrectomía
11.
Nucleic Acids Res ; 49(15): 8642-8664, 2021 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-34352099

RESUMEN

Architectural DNA-binding proteins (ADBPs) are abundant constituents of eukaryotic or bacterial chromosomes that bind DNA promiscuously and function in diverse DNA reactions. They generate large conformational changes in DNA upon binding yet can slide along DNA when searching for functional binding sites. Here we investigate the mechanism by which ADBPs diffuse on DNA by single-molecule analyses of mutant proteins rationally chosen to distinguish between rotation-coupled diffusion and DNA surface sliding after transient unbinding from the groove(s). The properties of yeast Nhp6A mutant proteins, combined with molecular dynamics simulations, suggest Nhp6A switches between two binding modes: a static state, in which the HMGB domain is bound within the minor groove with the DNA highly bent, and a mobile state, where the protein is traveling along the DNA surface by means of its flexible N-terminal basic arm. The behaviors of Fis mutants, a bacterial nucleoid-associated helix-turn-helix dimer, are best explained by mobile proteins unbinding from the major groove and diffusing along the DNA surface. Nhp6A, Fis, and bacterial HU are all near exclusively associated with the chromosome, as packaged within the bacterial nucleoid, and can be modeled by three diffusion modes where HU exhibits the fastest and Fis the slowest diffusion.


Asunto(s)
Proteínas de Unión al ADN/genética , ADN/genética , Proteínas HMGN/genética , Proteínas Mutantes/genética , Proteínas de Saccharomyces cerevisiae/genética , Cromosomas Bacterianos/genética , Proteínas Mitocondriales/genética , Simulación de Dinámica Molecular , Unión Proteica/genética , Saccharomyces cerevisiae/genética , Imagen Individual de Molécula
12.
Nagoya J Med Sci ; 83(2): 277-286, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-34239176

RESUMEN

Distribution of radiation by C-arm cone-beam computed tomography (CBCT) in the angiographic suite and effectiveness of protection devices were assessed. CBCT image of a human phantom was obtained by a rotation of 220 degrees during 8 seconds of exposure. One hundred and twelve dosimeters were placed at different positions around the beam entry site, and color maps of dose distributions were drawn for horizontal and vertical planes. The measurements showed the highest radiation dose over 600 µGy by a single CBCT image acquisition at a distance of 60 cm from the beam entry site and a height of 90 cm from the floor. The color maps demonstrated the dose distribution to be more intense at the bilateral directions of the phantom. With the use of a ceiling-mounted transparent lead-acryl screen and a table-suspended lead curtain, the doses were reduced by 45-92 % at a direction of 210 degrees and a distance of 120 cm.


Asunto(s)
Tomografía Computarizada de Haz Cónico , Humanos , Fantasmas de Imagen , Dosis de Radiación , Dispersión de Radiación
13.
Curr Opin Struct Biol ; 71: 123-135, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34303931

RESUMEN

Chromatin in eukaryotic cells is a negatively charged long polymer consisting of DNA, histones, and various associated proteins. With its highly charged and heterogeneous nature, chromatin structure varies greatly depending on various factors (e.g. chemical modifications and protein enrichment) and the surrounding environment (e.g. cations): from a 10-nm fiber, a folded 30-nm fiber, to chromatin condensates/droplets. Recent advanced imaging has observed that chromatin exhibits a dynamic liquid-like behavior and undergoes structural variations within the cell. Current computational modeling has made it possible to reconstruct the liquid-like chromatin in the cell by dealing with a number of nucleosomes on multiscale levels and has become a powerful technique to inspect the molecular mechanisms giving rise to the observed behavior, which imaging methods cannot do on their own. Based on new findings from both imaging and modeling studies, we discuss the dynamic aspect of chromatin in living cells and its functional relevance.


Asunto(s)
Cromatina , Nucleosomas , Simulación por Computador , ADN , Histonas/genética
14.
Am J Ophthalmol Case Rep ; 22: 101029, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33665476

RESUMEN

It is known that the retinal detachments (RDs) associated with a morning glory disc anomaly (MGDA) usually appear from around the disc anomaly and complications by peripheral fibrovascular proliferation and tractional RD are very rare. We report our findings in an eye with MGDA that had a tractional RD, massive exudation from a peripheral temporal fibrovascular proliferation and vasculatures stretched by this proliferation and by a contraction of the hyaloidal membrane. The RD was successfully treated by vitrectomy and encircling buckling surgery.

15.
Life Sci Alliance ; 4(4)2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33536240

RESUMEN

Liquid droplets formed inside the cell by liquid-liquid phase separation maintain membrane-less condensates/bodies (or compartments). These droplets are important for concentrating certain molecules and facilitating spatiotemporal regulation of cellular functions. 1,6-hexanediol (1,6-HD), an aliphatic alcohol, inhibits weak hydrophobic protein-protein/protein-RNA interactions required for the droplet formation (droplet melting activity) and is used here to elucidate the formation process of cytoplasmic/nuclear condensates/bodies. However, the effect of 1,6-HD on chromatin in living cells remains unclear. We found that 1,6-HD drastically suppresses chromatin motion and hyper-condenses chromatin in human cells by using live-cell single-nucleosome imaging, which detects changes in the state of chromatin. These effects were enhanced in a dose-dependent manner. Chromatin was "frozen" by 5%, or higher, concentrations of 1,6-HD. 1,6-HD greatly facilitated cation-dependent chromatin condensation in vitro. This 1,6-HD action is distinct from its melting activity of liquid droplets. Alcohols, such as 1,6-HD, appear to remove water molecules around chromatin and locally condense chromatin. Therefore, liquid droplet results obtained using 1,6-HD should be carefully interpreted or reconsidered when these droplets are associated with chromatin.


Asunto(s)
Cromatina/efectos de los fármacos , Cromatina/metabolismo , Glicoles/farmacología , Núcleo Celular/efectos de los fármacos , Núcleo Celular/genética , Núcleo Celular/metabolismo , Células Cultivadas , Cromatina/genética , Proteínas de Unión al ADN , Relación Dosis-Respuesta a Droga , Técnica del Anticuerpo Fluorescente , Humanos
16.
Jpn J Ophthalmol ; 65(4): 569-580, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33496889

RESUMEN

PURPOSE: To compare the quality of images viewed through an extended depth of focus (EDF) intraocular lens (IOL) to that through multifocal or monofocal IOL. STUDY DESIGN: Experimental study METHODS: EDF IOL (Symfony®, ZXR00V, Johnson & Johnson Vision), diffractive multifocal (ZLB00, + 3.25D or ZMB00, + 4.0D), or monofocal (ZCB00V) IOL with a spherical power of + 20.0 diopter (D) was placed in a fluid-filled model eye with corneal aberrations similar to those of human eyes. A United States Air Force Resolution Grating Target was glued to the posterior surface of the model eye and viewed through a flat contact lens, a 60D or 128D wide-angle non-contact lens (Resight®) or wide-angle contact lens (MiniQuad®). The contrast of the grating images recorded with the EDF and multifocal IOLs were compared to those through the monofocal IOL. RESULTS: The grating images viewed through the flat contact lens were slightly blurred when viewed through the EDF IOL but clearer than those through the multifocal IOLs with very blurred images in the periphery. The contrast of the images viewed through the EDF and multifocal IOLs through the flat contact lens was significantly lower than through the monofocal IOL (P < 0.02). The contrast of the images viewed through the EDF IOL with 60D or 128D wide-angle non-contact lens was significantly lower than through the monofocal IOL (P < 0.05) but not with wide-angle contact lens. CONCLUSION: Our results suggest that vitreous surgeons can accomplish a clearer view during vitrectomy in EDF IOL-implanted eyes with a wide-angle viewing contact lens and a flat contact lens than in multifocal IOL-implanted eyes.


Asunto(s)
Lentes Intraoculares , Lentes Intraoculares Multifocales , Facoemulsificación , Sensibilidad de Contraste , Humanos , Implantación de Lentes Intraoculares , Diseño de Prótesis , Vitrectomía
17.
Sci Rep ; 10(1): 13697, 2020 08 13.
Artículo en Inglés | MEDLINE | ID: mdl-32792545

RESUMEN

Characterization of the target search dynamics of DNA-binding proteins along DNA has been hampered by the time resolution of a standard single-molecule fluorescence microscopy. Here, we achieved the time resolution of 0.5 ms in the fluorescence microscopy measurements by optimizing the fluorescence excitation based on critical angle illumination and by utilizing the time delay integration mode of the electron-multiplying charge coupled device. We characterized the target search dynamics of the tumor suppressor p53 along nonspecific DNA at physiological salt concentrations. We identified a short-lived encounter intermediate before the formation of the long-lived p53-DNA complex. Both the jumps and the one-dimensional diffusion of p53 along DNA were accelerated at higher salt concentrations, suggesting the rotation-uncoupled movement of p53 along DNA grooves and conformational changes in the p53/DNA complex. This method can be used to clarify the unresolved dynamics of DNA-binding proteins previously hidden by time averaging.


Asunto(s)
ADN/metabolismo , Imagen Individual de Molécula/métodos , Proteína p53 Supresora de Tumor/metabolismo , Sitios de Unión , Humanos , Microscopía Fluorescente , Unión Proteica , Sales (Química)/química
18.
Curr Opin Cell Biol ; 64: 77-89, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32283330

RESUMEN

Eukaryotic chromatin is a negatively charged polymer consisting of genomic DNA, histones, and various nonhistone proteins. Because of its highly charged character, the structure of chromatin varies greatly depending on the surrounding environment (i.e. cations etc.): from an extended 10-nm fiber, to a folded 30-nm fiber, to chromatin condensates/liquid-droplets. Over the last ten years, newly developed technologies have drastically shifted our view on chromatin from a static regular structure to a more irregular and dynamic one, locally like a fluid. Since no single imaging (or genomics) method can tell us everything and beautiful images (or models) can fool our minds, comprehensive analyses based on many technical approaches are important to capture actual chromatin organization inside the cell. Here we critically discuss our current view on chromatin and methodology used to support the view.


Asunto(s)
Cromatina/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Supervivencia Celular , Cromatina/química , ADN/genética , Histonas/metabolismo , Humanos , Nucleosomas/metabolismo
19.
Ophthalmic Res ; 63(6): 572-579, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32135544

RESUMEN

OBJECTIVE: To determine the vascular density of the anterior segment (AS) of the eye from optical coherence tomography angiography (OCTA) images and slit-lamp photographs. METHODS: A swept-source OCTA (Plex Elite 9000; Carl Zeiss) device modified with a +10-diopter lens was used to record the vasculature of the AS. Twenty eyes, including 4 eyes of 4 healthy subjects and 16 eyes of 12 patients scheduled for cataract surgery or combined vitrectomy and cataract surgery, were studied. The slit-lamp photographs of the AS were acquired concurrently with the AS-OCTA images. The vascular density was measured preoperatively and postoperatively in the nasal, temporal, superior, and inferior quadrants after binarization with ImageJ software. RESULTS: Acceptable AS-OCTA images were obtained of 65% (superior), 80% (nasal), 70% (inferior), and 80% (temporal) of the eyes. The percentage of acceptable images was significantly lower in the superior quadrant among the AS-OCTA images than among the AS photographs (100%; p = 0.004). The vascular density determined by AS-OCTA was higher than that determined in the AS photographs in all quadrants (p = 0.011 to <0.001). The AS-OCTA B-mode images showed that vascular flow was identified mainly between the conjunctiva and sclera but not in the ciliary body. The vascular density increased significantly after cataract surgery in the superior quadrant, which was significantly correlated with the location of the surgical incision (p = 0.03). CONCLUSION: AS-OCTA can obtain images with higher vascular density of the conjunctiva and sclera than slit-lamp photographs, and AS-OCTA images can show a postoperative increase in vascular density.


Asunto(s)
Segmento Anterior del Ojo/diagnóstico por imagen , Angiografía con Fluoresceína/métodos , Densidad Microvascular , Vasos Retinianos/diagnóstico por imagen , Microscopía con Lámpara de Hendidura/métodos , Tomografía de Coherencia Óptica/métodos , Estudios Transversales , Femenino , Fondo de Ojo , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
20.
Int J Mol Sci ; 21(3)2020 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-32033163

RESUMEN

Interactions between DNA and DNA-binding proteins play an important role in many essential cellular processes. A key function of the DNA-binding protein p53 is to search for and bind to target sites incorporated in genomic DNA, which triggers transcriptional regulation. How do p53 molecules achieve "rapid" and "accurate" target search in living cells? The search dynamics of p53 were expected to include 3D diffusion in solution, 1D diffusion along DNA, and intersegmental transfer between two different DNA strands. Single-molecule fluorescence microscopy enabled the tracking of p53 molecules on DNA and the characterization of these dynamics quantitatively. Recent intensive single-molecule studies of p53 succeeded in revealing each of these search dynamics. Here, we review these studies and discuss the target search mechanisms of p53.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , ADN/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Animales , Sitios de Unión/fisiología , Humanos , Unión Proteica/fisiología , Transcripción Genética/fisiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA