667 resultados para cornea opacity
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Purpose: Proper delineation of ocular anatomy in 3D imaging is a big challenge, particularly when developing treatment plans for ocular diseases. Magnetic Resonance Imaging (MRI) is nowadays utilized in clinical practice for the diagnosis confirmation and treatment planning of retinoblastoma in infants, where it serves as a source of information, complementary to the Fundus or Ultrasound imaging. Here we present a framework to fully automatically segment the eye anatomy in the MRI based on 3D Active Shape Models (ASM), we validate the results and present a proof of concept to automatically segment pathological eyes. Material and Methods: Manual and automatic segmentation were performed on 24 images of healthy children eyes (3.29±2.15 years). Imaging was performed using a 3T MRI scanner. The ASM comprises the lens, the vitreous humor, the sclera and the cornea. The model was fitted by first automatically detecting the position of the eye center, the lens and the optic nerve, then aligning the model and fitting it to the patient. We validated our segmentation method using a leave-one-out cross validation. The segmentation results were evaluated by measuring the overlap using the Dice Similarity Coefficient (DSC) and the mean distance error. Results: We obtained a DSC of 94.90±2.12% for the sclera and the cornea, 94.72±1.89% for the vitreous humor and 85.16±4.91% for the lens. The mean distance error was 0.26±0.09mm. The entire process took 14s on average per eye. Conclusion: We provide a reliable and accurate tool that enables clinicians to automatically segment the sclera, the cornea, the vitreous humor and the lens using MRI. We additionally present a proof of concept for fully automatically segmenting pathological eyes. This tool reduces the time needed for eye shape delineation and thus can help clinicians when planning eye treatment and confirming the extent of the tumor.
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PURPOSE Contamination with bacteria and/or fungi is a serious complication in organ-cultured corneas. Hence, antibiotic and antifungal agents are added to the culture medium. The concentration of different antimicrobial and antifungal additives to the media over time has so far not been investigated in detail and is the aim of this study. METHODS Nine human fresh corneoscleral discs were stored in corneal culture medium consisting of 2% fetal bovine serum and minimal essential medium. In addition, the culture medium contained 1200 μg/mL penicillin G, 25 μg/mL amphotericin B, 120 μg/mL streptomycin, and 100 μg/mL voriconazole. The concentration of amphotericin B used was 10 times higher than in clinical routine to facilitate its detection. The cultures were kept at 37°C for 28 days. At days 0, 7, 14, 21, and 28, samples of the culture medium were harvested for analysis of antimicrobial concentrations by liquid chromatography and electrospray ionization tandem mass spectrometry. RESULTS During corneal storage, the concentration of all antibiotics and antifungal agents declined significantly. By day 28, penicillin G was reduced to 14% of the original concentration. Amphotericin B and streptomycin retained approximately 60% of the original concentration to the end of the experiment and voriconazole maintained stable concentrations after an initial decline to approximately 80% at 7 days. CONCLUSIONS Throughout the entire storage period, the concentrations of penicillin G, streptomycin, and voriconazole exceeded the minimum inhibitory concentrations of all common contaminants, obviating the need for a change of the medium for antimicrobial reasons. Based on the minimum inhibitory concentrations and our findings, the initial concentration of amphotericin B should be raised to 5 μg/mL.
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PURPOSE To describe the clinical outcome of corneal cross-linking (CXL) in a young child with keratoconus. METHODS This is a case report of a young girl with keratoconus with ophthalmologic findings and 3-year follow-up. Follow-up visits included visual acuity measurement, retinoscopy, corneal tomography, and topography. RESULTS A girl with Down syndrome was diagnosed with bilateral keratoconus and relative amblyopia at the age of 4 years. The best-corrected near visual acuity was 20/100 binocularly. Corneal tomography showed the following parameters: OD K(max) 47.2 diopters (D), thinnest location 442 μm; OS K(max) 49.6 D, thinnest location 432 μm. Three months later, the keratoconus in the left eye progressed (K(max) 50.2 D, thinnest location 424 μm), and CXL was performed. One year later, CXL was necessary also in the right eye because of progression. The girl was most recently reexamined at the age of 7 years. The corrected near visual acuity was 20/80 in both eyes. The corneal curvature slightly flattened, and the corneal thickness stabilized (OD K(max) 46.8 D, thinnest location 389 μm; OS K(max) 49.4 D, thinnest location 360 μm). CONCLUSIONS Onset of keratoconus can occur in early childhood, especially in patients with Down syndrome. In this case, CXL was performed at 4 and 5 years of age without complications and stopped further keratoconus progression.
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PURPOSE To determine whether the scleral stroma is affected as much as the corneal stroma in keratoconus. SETTING University Eye Clinic, Bern, Switzerland. DESIGN Comparative case-control study. METHODS Eyes with keratoconus (keratoconus group) and eyes of age-, sex-, and axial length-matched controls (control group) were analyzed. Corneal videokeratometry and pachymetry were performed using a Scheimpflug tomographer (Pentacam). For measurements of the peripheral cornea and the anterior sclera, a spectral-domain anterior segment optical coherence tomography device (Spectralis) was used. RESULTS The study group comprised 51 eyes and the control group, 50 eyes. The mean central corneal thickness in the keratoconus group was statistically significantly lower than in the control group (447.8 μm ± 57.8 [SD] versus 550.5 ± 35.5 μm) (P < .0001). No significant difference in the mean anterior scleral thickness was found between the keratoconus group and the control group (479.1 ± 43.7 μm versus 474.2 ± 43.0 μm) (P =.57). CONCLUSION Although corneal thinning was observed in keratoconus patients, the anterior scleral stroma thickness in these patients seemed to be similar to that in healthy control eyes.
Lung Pattern Classification for Interstitial Lung Diseases Using a Deep Convolutional Neural Network
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Automated tissue characterization is one of the most crucial components of a computer aided diagnosis (CAD) system for interstitial lung diseases (ILDs). Although much research has been conducted in this field, the problem remains challenging. Deep learning techniques have recently achieved impressive results in a variety of computer vision problems, raising expectations that they might be applied in other domains, such as medical image analysis. In this paper, we propose and evaluate a convolutional neural network (CNN), designed for the classification of ILD patterns. The proposed network consists of 5 convolutional layers with 2×2 kernels and LeakyReLU activations, followed by average pooling with size equal to the size of the final feature maps and three dense layers. The last dense layer has 7 outputs, equivalent to the classes considered: healthy, ground glass opacity (GGO), micronodules, consolidation, reticulation, honeycombing and a combination of GGO/reticulation. To train and evaluate the CNN, we used a dataset of 14696 image patches, derived by 120 CT scans from different scanners and hospitals. To the best of our knowledge, this is the first deep CNN designed for the specific problem. A comparative analysis proved the effectiveness of the proposed CNN against previous methods in a challenging dataset. The classification performance (~85.5%) demonstrated the potential of CNNs in analyzing lung patterns. Future work includes, extending the CNN to three-dimensional data provided by CT volume scans and integrating the proposed method into a CAD system that aims to provide differential diagnosis for ILDs as a supportive tool for radiologists.
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15-Lipoxygenase 2 (15-LOX2) is a recently cloned human lipoxygenase that shows tissue-restricted expression in prostate, lung, skin, and cornea. The protein level and enzymatic activity of 15-LOX2 have been shown to be down-regulated in prostate cancers compared with normal and benign prostate tissues. We report the cloning and functional characterization of 15-LOX2 and its three splice variants (termed 15-LOX2sv-a, 15-LOX2sv-b, and 15-LOX2sv-c) from primary prostate epithelial (NHP) cells. Western blotting with multiple NHP cell strains and prostate cancer (PCa) cell lines reveals that the expression of 15-LOX2 is lost in all PCa cell lines, accompanied by decreased enzymatic activity. 15-LOX2 is expressed at multiple subcellular locations, including cytoplasm, cytoskeleton, cell-cell border, and nucleus. Surprisingly, the three splice variants of 15-LOX2 are mostly excluded from the nucleus. To elucidate the relationship between nuclear localization, enzymatic activity, and tumor suppressive functions, we established PCa cell clones stably expressing 15-LOX2 or 15-LOX2sv-b. The 15-LOX2 clones express 15-LOX2 in the nuclei and possess robust enzymatic activity, whereas 15-LOX2sv-b clones show neither nuclear protein localization nor arachidonic acid-metabolizing activity. Interestingly, both 15-LOX2- and 15-LOX2sv-b-stable clones proliferate much slower in vitro when compared with control clones. When orthotopically implanted in nude mouse prostate, both 15-LOX2 and 15-LOX2sv-b suppress PC3 tumor growth in vivo. Finally, cultured NHP cells lose the expression of putative stem/progenitor cell markers, slow down in proliferation, and enter senescence. Several pieces of evidence implicate 15-LOX2 plays a role in replicative senescence of NHP cells: (1) promoter activity and the mRNA and protein levels of 15-LOX2 and its splice variants are upregulated in serially passaged NHP cells, which precede replicative senescence and occur in a cell-autonomous manner; (2) PCa cells stably expressing 15-LOX2 or 15-LOX2sv-b show a passage-related senescence-like phenotype; (3) enforced expression of 15-LOX2 or 15-LOX2sv-b in young NHP cells induce partial cell-cycle arrest and senescence-like phenotypes. Together, these results suggest that 15-LOX2 suppress prostate tumor development and do not necessarily depend on arachidonic acid-metabolizing activity and nuclear localization. Also, 15-LOX2 may serve as an endogenous prostate senescence gene and its tumor-suppressing functions might be associated with its ability to induce cell senescence. ^
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The occurrence of group G streptococci in cats and evaluation of the recovered organisms as potential human pathogens was investigated. Throat swabs were obtained from 89 cats (47 males and 42 females) and vaginal swabs from 39 female cats. Eighty-three of the examined cats were housed in individual cages at a University Animal Care Facility. Six cats, 2 mature males, 2 mature females and 2 young females were family pets in a rural area. Beta-hemolytic streptococci were recovered from 33 (37%) of the 89 cat throats cultured, and 27 (30.3%) were identified as group G. More males (34%) than females (24%) had throat cultures positive for group G. From the 39 vaginal cultures examined, 24 (61.5%) contained beta-hemolytic streptococci and 23 (58.9%) were identified as group G streptococci. Streptococci were not recovered from the vaginal cultures of the 5 females under 6 months of age.^ Thirty one group G streptococci isolated from cats were compared with 37 isolates of group G obtained from humans (health status or site of origin unknown). More group G cat isolates (81%) produced deoxyribonuclease (DNase) than did the human isolates (36%). The proportion of cat throat and vaginal isolates producing DNase was the same. Production of nicotinamide adenine dinucleotide glycohydrolase (NADase) by group G isolates of human origin was 70%, cat throat isolates 53% and cat vaginal isolates 37%. The Serum Opacity Factor was present in 73% of the cat throat isolates of group G, 43.7% of the cat vaginal isolates and 58.6% of the human isolates. Possession of an anti-phagocytic factor (M protein like substance) demonstrated by the ability to multiply in fresh human blood was greater in the group G from cat throats (46.7%) than from cat vagina (37.5%) or from the human isolates (13.5%). Many of the biochemical characteristics of the group G streptococci of cat origin were more similar to the biochemical characteristics of group A streptococci, than to the characteristics of group G of human origin. The group G streptococci, found in a large number of cats, could be potential human pathogens, as their physiological and biological characteristics are very similar to those of group A, a known human pathogen. ^
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Infectious Bovine Keratoconjunctivitis (IBK), known as pinkeye, is a common infectious disease affecting the eyes of cattle. It is characterized by excessive tearing, inflammation of the conjunctiva, and ulceration of the cornea. Although pinkeye is non-fatal, it has a marked economic impact on the cattle industry, due to the decreased performance of infected individuals. Genetic effects on the susceptibility of IBK have been studied and Hereford, Jersey, and Holstein breeds were found to be more susceptible to IBK than Bos Indicus breeds. The objectives of our study were: 1) to estimate genetic parameters of IBK scored in different categories by using genomic threshold model, and 2) to detect markers in linkage disequilibrium with quantitative tract loci (QTL) associated with IBK.
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Este trabajo se propone analizar el intertexto que une al escritor Edouard Glissant con William Faulkner a través de dos obras: el ensayo Faulkner, Mississipi (1996) y la novela Sartorius (1999). En el primer texto, el autor enfatiza cuestiones presentes en su propia obra novelesca: la genealogía, la relación con el espacio de la plantación, el mestizaje, la (i)legitimidad de derechos con respecto a la posesión de la tierra, la opacidad. En el segundo, traza una línea genealógica de un personaje perteneciente a una etnia africana imaginaria, haciéndolo llegar hasta las plantaciones del sur de los Estados Unidos; paralelamente, presenta la línea genealógica de los Sartoris. En esta dirección, busco mostrar cómo el proyecto literario de Glissant dialoga con la obra de Faulkner, indagando e inventariando las mismas problemáticas con respecto al transplante de poblaciones y su inserción en el espacio de las plantaciones, tanto en el sur de los Estados Unidos como en las islas del Caribe. En las obras de ambos escritores puede percibirse el mismo vértigo trágico que persigue a los personajes, conduciéndolos a la locura, el sufrimiento y la muerte
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El artículo analiza la situación actual de los archivos en Uruguay en relación a las leyes de Acceso a la Información Pública y de Sistema Nacional de Archivos, normativas que surge cuando el Estado uruguayo inicia una fase de reordenación de su gestión promoviendo cambios que fomentan la democratización y la eficiencia, a la vez que anulan la opacidad y extrema reserva en su administración. Se analiza cómo los profesionales archivólogos estuvieron estrechamente involucrados en el proceso de gestación de ambas leyes, dando inicio a una etapa de consecución de fuertes voluntades políticas que apoyaran los proyectos, convencidos que la premisa evidente del Derecho de Acceso es que el documento al que se pretenda acceder exista y sea recuperable. Se estudia como la coexistencia de ambas normas implicaban un cambio cultural, una evolución en el comportamiento de las organizaciones que no acompañó a la puesta en marcha de los instrumentos legales. Se concluye que el Derecho de Acceso a la Información Pública está basado en el principio fundamental de transparencia de los Órganos del Estado, por lo que no es de extrañar que una ley que obliga a brindar información tenga el riesgo de devenir en letra muerta. El Archivo debe ser "condición" administrativa, lo que exige una nueva dimensión de ellos y de sus profesionales dentro de los organismos del Estado, de forma tal que se conviertan en una inmejorable herramienta para el cumplimiento de los objetivos de la Ley de Derecho de Acceso a la Información Pública
Resumo:
Este trabajo se propone analizar el intertexto que une al escritor Edouard Glissant con William Faulkner a través de dos obras: el ensayo Faulkner, Mississipi (1996) y la novela Sartorius (1999). En el primer texto, el autor enfatiza cuestiones presentes en su propia obra novelesca: la genealogía, la relación con el espacio de la plantación, el mestizaje, la (i)legitimidad de derechos con respecto a la posesión de la tierra, la opacidad. En el segundo, traza una línea genealógica de un personaje perteneciente a una etnia africana imaginaria, haciéndolo llegar hasta las plantaciones del sur de los Estados Unidos; paralelamente, presenta la línea genealógica de los Sartoris. En esta dirección, busco mostrar cómo el proyecto literario de Glissant dialoga con la obra de Faulkner, indagando e inventariando las mismas problemáticas con respecto al transplante de poblaciones y su inserción en el espacio de las plantaciones, tanto en el sur de los Estados Unidos como en las islas del Caribe. En las obras de ambos escritores puede percibirse el mismo vértigo trágico que persigue a los personajes, conduciéndolos a la locura, el sufrimiento y la muerte
Resumo:
El artículo analiza la situación actual de los archivos en Uruguay en relación a las leyes de Acceso a la Información Pública y de Sistema Nacional de Archivos, normativas que surge cuando el Estado uruguayo inicia una fase de reordenación de su gestión promoviendo cambios que fomentan la democratización y la eficiencia, a la vez que anulan la opacidad y extrema reserva en su administración. Se analiza cómo los profesionales archivólogos estuvieron estrechamente involucrados en el proceso de gestación de ambas leyes, dando inicio a una etapa de consecución de fuertes voluntades políticas que apoyaran los proyectos, convencidos que la premisa evidente del Derecho de Acceso es que el documento al que se pretenda acceder exista y sea recuperable. Se estudia como la coexistencia de ambas normas implicaban un cambio cultural, una evolución en el comportamiento de las organizaciones que no acompañó a la puesta en marcha de los instrumentos legales. Se concluye que el Derecho de Acceso a la Información Pública está basado en el principio fundamental de transparencia de los Órganos del Estado, por lo que no es de extrañar que una ley que obliga a brindar información tenga el riesgo de devenir en letra muerta. El Archivo debe ser "condición" administrativa, lo que exige una nueva dimensión de ellos y de sus profesionales dentro de los organismos del Estado, de forma tal que se conviertan en una inmejorable herramienta para el cumplimiento de los objetivos de la Ley de Derecho de Acceso a la Información Pública
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Late Eocene microtektites and crystal-bearing microkrystites extracted from DSDP and ODP cores from the Atlantic, Pacific, and Indian oceans have been analyzed to address their provenance. A new analysis of Nd and Sr isotopic compositions confirms previous work and the assignment of the uppermost microtektite layer to the North American tektites, which are associated with the 35.5 Ma, 85 km diameter Chesapeake impact structure of Virginia, USA. Extensive major element and Nd and Sr isotopic analyses of the microkrystites from the lowermost layer were obtained. The melanocratic microkrystites from Sites 216 and 462 in the Indian and Pacific oceans possess major element chemistries, Sr and Nd isotopic signatures and Sm-Nd, T CHUR, model ages similar to those of tagamite melt rocks in the Popigai impact structure. They also possess Rb-Sr, T UR, model ages that are younger than the tagamite TCHUR ages by up to ~1 Ga, which require a process, as yet undefined, of Rb/Sr enrichment. These melanocratic microkrystites are consistent with a provenance from the 35.7 Ma, 100 km diameter Popigai impact structure of Siberia, Russia, while ruling out other contemporaneous structures as a source. Melanocratic microkrystites from other sites and leucocratic microkrystites from all sites possess a wide range of isotopic compositions (epsilon (143Nd) values of -16 to -27.7 and epsilon (87Sr) values of 4.1-354.0), making the association with Popigai tagamites less clear. These microkrystites may have been derived by the melting of target rocks of mixed composition, which were ejected without homogenization. Dark glass and felsic inclusions extracted from Popigai tagamites possess epsilon (143Nd) and epsilon (87Sr) values of -26.7 to -27.8 and 374.7 and 432.4, respectively, and T CHUR and T UR model ages of 1640-1870 Ma and 240-1830 Ma, respectively, which require the preservation of initially present heterogeneity in the source materials. The leucocratic microkrystites possess diverse isotopic compositions that may reflect the melting of supra-basement sedimentary rocks from Popigai, or early basement melts that were ejected prior to homogenization of the Popigai tagamites. The ejection of melt rocks with chemistries consistent with a basement provenance, rather than the surface ~1 km of sedimentary cover rocks, atypically indicates a non-surficial source to some of the ejecta. Microkrystites from two adjacent biozones possess statistically indistinguishable major element compositions, suggesting they have a single source. The occurrence of microkrystites derived from a single impact event, but in different biozones, can be explained by: (1) diachronous biozone boundaries; (2) post-accumulation sedimentary reworking; or (3) erroneous biozonation.
Resumo:
Este trabajo se propone analizar el intertexto que une al escritor Edouard Glissant con William Faulkner a través de dos obras: el ensayo Faulkner, Mississipi (1996) y la novela Sartorius (1999). En el primer texto, el autor enfatiza cuestiones presentes en su propia obra novelesca: la genealogía, la relación con el espacio de la plantación, el mestizaje, la (i)legitimidad de derechos con respecto a la posesión de la tierra, la opacidad. En el segundo, traza una línea genealógica de un personaje perteneciente a una etnia africana imaginaria, haciéndolo llegar hasta las plantaciones del sur de los Estados Unidos; paralelamente, presenta la línea genealógica de los Sartoris. En esta dirección, busco mostrar cómo el proyecto literario de Glissant dialoga con la obra de Faulkner, indagando e inventariando las mismas problemáticas con respecto al transplante de poblaciones y su inserción en el espacio de las plantaciones, tanto en el sur de los Estados Unidos como en las islas del Caribe. En las obras de ambos escritores puede percibirse el mismo vértigo trágico que persigue a los personajes, conduciéndolos a la locura, el sufrimiento y la muerte
Resumo:
El artículo analiza la situación actual de los archivos en Uruguay en relación a las leyes de Acceso a la Información Pública y de Sistema Nacional de Archivos, normativas que surge cuando el Estado uruguayo inicia una fase de reordenación de su gestión promoviendo cambios que fomentan la democratización y la eficiencia, a la vez que anulan la opacidad y extrema reserva en su administración. Se analiza cómo los profesionales archivólogos estuvieron estrechamente involucrados en el proceso de gestación de ambas leyes, dando inicio a una etapa de consecución de fuertes voluntades políticas que apoyaran los proyectos, convencidos que la premisa evidente del Derecho de Acceso es que el documento al que se pretenda acceder exista y sea recuperable. Se estudia como la coexistencia de ambas normas implicaban un cambio cultural, una evolución en el comportamiento de las organizaciones que no acompañó a la puesta en marcha de los instrumentos legales. Se concluye que el Derecho de Acceso a la Información Pública está basado en el principio fundamental de transparencia de los Órganos del Estado, por lo que no es de extrañar que una ley que obliga a brindar información tenga el riesgo de devenir en letra muerta. El Archivo debe ser "condición" administrativa, lo que exige una nueva dimensión de ellos y de sus profesionales dentro de los organismos del Estado, de forma tal que se conviertan en una inmejorable herramienta para el cumplimiento de los objetivos de la Ley de Derecho de Acceso a la Información Pública