Amiloidosis AL: reporte de caso clínico en adulto mayor / Amyloidosis AL: clinical case report in elderly

Se presenta el caso clínico de una paciente de 63 años, con indicación de tiroidectomía total, a causa de un bocio multinodular con infiltrado neoplásico folicular. La evolución posquirúrgica fue tórpida y se caracterizó por la presencia de insuficiencia cardiaca aguda, hepatomegalia, neuropatía periférica y equimosis periorbitaria, condiciones clínicas sugerentes de amiloidosis, la que fue confirmada por medio de estudios como amiloidosis de cadenas ligeras (AL).

We present the clinical case of a 63-year-old patient, with indication of total thyroidec-tomy, due to a multinodular goiter with a follicular neoplastic infiltrate. Postoperative evolution was torpid and was characterized by the presence of acute heart failure, hepatomegaly, peripheral neuropathy and periorbital ecchymosis, clinical conditions suggestive of amyloidosis, which was confirmed by studies such as amyloidosis of light chains (AL).

Automatic CDR Estimation for Early Glaucoma Diagnosis.

Glaucoma is a degenerative disease that constitutes the second cause of blindness in developed countries. Although it cannot be cured, its progression can be prevented through early diagnosis. In this paper, we propose a new algorithm for automatic glaucoma diagnosis based on retinal colour images. We focus on capturing the inherent colour changes of optic disc (OD) and cup borders by computing several colour derivatives in CIE L∗a∗b∗ colour space with CIE94 colour distance. In addition, we consider spatial information retaining these colour derivatives and the original CIE L∗a∗b∗ values of the pixel and adding other characteristics such as its distance to the OD centre. The proposed strategy is robust due to a simple structure that does not need neither initial segmentation nor removal of the vascular tree or detection of vessel bends. The method has been extensively validated with two datasets (one public and one private), each one comprising 60 images of high variability of appearances. Achieved class-wise-averaged accuracy of 95.02% and 81.19% demonstrates that this automated approach could support physicians in the diagnosis of glaucoma in its early stage, and therefore, it could be seen as an opportunity for developing low-cost solutions for mass screening programs.

Near-Edge X-ray Absorption Fine Structure Investigation of the Quasi-One-Dimensional Organic Conductor (TMTSF)2PF6.

We present high-resolution near-edge X-ray absorption fine structure (NEXAFS) measurements at the P L2/3 edges, F K edge, C K edge, and Se M2/3 edges of the quasi-one-dimensional (1D) conductor and superconductor (TMTSF)2PF6. NEXAFS allows probing the donor and acceptor moieties separately; spectra were recorded between room temperature (RT) and 30 K at normal incidence. Spectra taken around RT were also studied as a function of the angle (θ) between the electric field of the X-ray beam and the 1D conducting direction. In contrast with a previous study of the S L2/3-edges spectra in (TMTTF)2AsF6, the Se M2/3 edges of (TMTSF)2PF6 do not exhibit a well-resolved spectrum. Surprisingly, the C K-edge spectra contain three well-defined peaks exhibiting strong and nontrivial θ and temperature dependence. The nature of these peaks as well as those of the F K-edge spectra could be rationalized on the basis of first-principles DFT calculations. Despite the structural similarity, the NEXAFS spectra of (TMTSF)2PF6 and (TMTTF)2AsF6 exhibit important differences. In contrast with the case of (TMTTF)2AsF6, the F K-edge spectra of (TMTSF)2PF6 do not change with temperature despite stronger donor-anion interactions. All these features reveal subtle differences in the electronic structure of the TMTSF and TMTTF families of salts.

Donor-anion interactions at the charge localization and charge ordering transitions of (TMTTF)2AsF6 probed by NEXAFS.

High-resolution near-edge X-ray absorption fine structure (NEXAFS) measurements at the As M-edge, F K-edge and S L-edge of the Fabre salt (TMTTF)2AsF6 were performed from room temperature (RT) to 90 K, allowing to reach the charge localization regime below Tρ ≈ 230 K and to cross the charge ordering (CO) transition at TCO ≈ 102 K. The F K-edge and S L-edge spectra exhibit several transitions which have been indexed on the basis of first-principles DFT calculations. Upon cooling from RT significant energy shifts up to +0.8 eV and -0.4 eV were observed in transitions exhibited by the F 1s and S 2p spectra respectively, while the As 3p doublet does not show a significant shift. Opposite energy shifts found in the F 1s and S 2p spectra reflect substantial thermal changes in the electronic environment of F atoms of the anion and S atoms of TMTTF. The changes found around the charge localization crossover suggest an increase of the participation of the S d orbitals in the empty states of TMTTF as well as an increase of the strength of donoranion interactions. A new F 1s pre-edge signal detected upon entry into the CO phase is a clear fingerprint of the symmetry breaking occurring at TCO. We propose that this new transition is caused by a substantial mixing between the HOMO of the AsF6(-) anion and the unoccupied part of the TMTTF HOMO conduction band. Analysis of the whole spectra also suggests that the loss of the inversion symmetry associated with the CO is due to an anion displacement increasing the strength of SF interactions. Our data show unambiguously that anions are not, as previously assumed, innocent spectators during the electronic modifications experienced by the Fabre salts upon cooling. In particular the interpretation of the spectra pointing out a thermally dependent mixing of anion wave functions with those of the TMTTF chains demonstrates for the first time the importance of anion-donor interactions.

Detección automatizada de microaneurismas mediante crecimiento de regiones y red neuronal Fuzzy Artmap / Automated detection of microaneurysms by using region growing and fuzzy artmap neural network

Objetivo: Comprobar si las modificaciones metodológicas de este nuevo algoritmo mejoran el resultado de otra estrategia presentada anteriormente. Métodos: Se realza y filtra la imagen negada del canal verde de la retinografía digital en color. Se aplica una umbralización multitolerancia para obtener puntos candidatos y en cada semilla se realiza un crecimiento de regiones por variación de intensidades. Se toman 15 características de cada región y entrenamos una red neuronal Fuzzy Artmap con 42 retinografías. Se aplica la red en el estudio de 11 retinografías del programa de detección precoz de retinopatía diabética, de buena calidad, con lesiones iniciales, obtenidas con el retinógrafo no midriático Topcon NW200. Resultados: Dos oftalmólogos experimentados detectan 52 microaneurismas en las 11 imágenes. El algoritmo detecta 39 microaneurismas y 3.752 regiones más, confirmando 38 microaneurismas y 135 falsos positivos. La sensibilidad ha mejorado respecto al algoritmo anterior del 60,53 al 73,08%. Los falsos positivos has disminuido de 41,8 por imagen a 12,27. Conclusiones: El nuevo algoritmo presenta indudables mejoras respecto al anterior, pero aún se puede perfeccionar, sobre todo en la determinación inicial de semillas(AU)

Objective: To assess whether the methodological changes of this new algorithm improves the results of a previously presented strategy. Methods: We enhance the image and filter out the green channel of the digital color retinography. Multitolerance thresholding was applied to obtain candidate points and make a seed growing region by varying intensities. We took 15 characteristics from each region to train a Fuzzy Artmap neural network using 42 retinal photographs. This network was then applied in the study of 11 good quality retinal photographs included in the diabetic retinopathy early detection screening program, with initial stages of retinopathy, obtained with the Topcon NW200 non-mydriatic retinal camera. Results: Two experienced ophthalmologists detected 52 microaneurysms in 11 images. The algorithm detected 39 microaneurysms and 3,752 more regions, confirming 38 microaneurysm and 135 false positives. The sensitivity is improved compared to the previous algorithm, from 60.53 to 73.08%. False positives have dropped from 41.8 to 12.27 per image. Conclusions: The new algorithm is better than the previous one, but there is still room for improvement, especially in the initial determination of seeds(AU)

[Automated detection of microaneurysms by using region growing and Fuzzy Artmap neural network]. / Detección automatizada de microaneurismas mediante crecimiento de regiones y red neuronal Fuzzy Artmap.

OBJECTIVE: To assess whether the methodological changes of this new algorithm improves the results of a previously presented strategy. METHODS: We enhance the image and filter out the green channel of the digital color retinography. Multitolerance thresholding was applied to obtain candidate points and make a seed growing region by varying intensities. We took 15 characteristics from each region to train a Fuzzy Artmap neural network using 42 retinal photographs. This network was then applied in the study of 11 good quality retinal photographs included in the diabetic retinopathy early detection screening program, with initial stages of retinopathy, obtained with the Topcon NW200 non-mydriatic retinal camera. RESULTS: Two experienced ophthalmologists detected 52 microaneurysms in 11 images. The algorithm detected 39 microaneurysms and 3,752 more regions, confirming 38 microaneurysm and 135 false positives. The sensitivity is improved compared to the previous algorithm, from 60.53 to 73.08%. False positives have dropped from 41.8 to 12.27 per image. CONCLUSIONS: The new algorithm is better than the previous one, but there is still room for improvement, especially in the initial determination of seeds.

[Automatic detection of microaneurysms in colour fundus images]. / Detección automática de microaneurismas en retinografías.

PURPOSE: We present the development of a tool for the automatic detection of microaneurysms and its clinical evaluation. The intention of this tool is to facilitate the diagnosis of diabetic retinopathy in general screening programs. METHOD: The designed and developed tool consists of three stages of processing: 1) Obtaining of the basic image of eye with the retinal camera, inverted image on the green channel, and a high-pass filter of the image. This phase enhances the microaneurysms. 2) Detection of the candidates for microaneurysms, by means of an adaptive prediction filter and regions growth. 3) Selection, among the candidates, of whom microaneurysms must be considered to fulfil the criteria of circular shape, high intensity in the inverted green channel and contrasts with respect to the surrounding pixels. RESULTS: We selected to 20 retinal photographs of good quality and dimensions 600x600 pixels from patients with nonproliferative diabetic retinopathy. The ophthalmologists detected 297 microaneurysms in these images. The tool for automatic detection correctly located 252 microaneurysms, with a mean sensitivity of 89% and a false positives rate of 93%. CONCLUSIONS: The results obtained seem to indicate that the tool developed will be very useful for its potential use in screening programs in primary care centres. On the other hand, more work is needed on the algorithm to decrease the rate of false positives.

Detección automática de microaneurismas en retinografías / Automatic detection of microaneurysms in colour fundus images

Propósito: Presentamos el desarrollo de una herramienta para la detección automática de microaneurismas y su evaluación clínica. El propósito de esta herramienta es facilitar el diagnóstico de lesiones diabéticas en programas generales de detección.MétodoLa herramienta diseñada y desarrollada consta de tres etapas de procesamiento: 1) Obtención de la imagen de fondo de ojo con el retinógrafo, inversión del canal verde y filtrado paso de alta de la imagen. Esta fase realza los microaneurismas. 2) Detección de los candidatos a microaneurismas, mediante un filtrado de predicción adaptativo y un crecimiento de regiones. 3) Selección, de entre los candidatos, de los que deben considerarse microaneurismas por cumplir con los criterios de: forma circular, intensidad alta en el canal verde invertido y contraste respecto a los píxeles de alrededor.ResultadosSe seleccionaron 20 retinografías de buena calidad y dimensiones 600×600 píxeles de pacientes con retinopatía diabética no proliferante. Los oftalmólogos detectaron un total de 297 microaneurismas en estas imágenes. La herramienta de detección automática localizó adecuadamente 252 microaneurismas, con una sensibilidad media del 89% y una tasa de falsos positivos del 93%.ConclusionesLos resultados obtenidos parecen indicar que la herramienta desarrollada podría ser muy útil para su potencial utilización en programas de detección en los centros de asistencia primaria. Por otro lado, es necesario seguir trabajando en el algoritmo para disminuir la tasa de falsos positivos (AU)

Purpose: We present the development of a tool for the automatic detection of microaneurysms and its clinical evaluation. The intention of this tool is to facilitate the diagnosis of diabetic retinopathy in general screening programs.MethodThe designed and developed tool consists of three stages of processing: 1) Obtaining of the basic image of eye with the retinal camera, inverted image on the green channel, and a high-pass filter of the image. This phase enhances the microaneurysms. 2) Detection of the candidates for microaneurysms, by means of an adaptive prediction filter and regions growth. 3) Selection, among the candidates, of whom microaneurysms must be considered to fulfil the criteria of circular shape, high intensity in the inverted green channel and contrasts with respect to the surrounding pixels.ResultsWe selected to 20 retinal photographs of good quality and dimensions 600x600 pixels from patients with nonproliferative diabetic retinopathy. The ophthalmologists detected 297 microaneurysms in these images. The tool for automatic detection correctly located 252 microaneurysms, with a mean sensitivity of 89% and a false positives rate of 93%.ConclusionsThe results obtained seem to indicate that the tool developed will be very useful for its potential use in screening programs in primary care centres. On the other hand, more work is needed on the algorithm to decrease the rate of false positives (AU)

The metallic transport of (TMTSF)2X organic conductors close to the superconducting phase.

Comparing resistivity data of the quasi-one-dimensional superconductors (TMTSF)2PF6 and (TMTSF)2ClO4 along the least conducting c(⋆)-axis and along the high conductivity a-axis as a function of temperature and pressure, a low temperature regime is observed in which a unique scattering time governs the transport along both directions of these anisotropic conductors. However, the pressure dependence of the anisotropy implies a large pressure dependence of the interlayer coupling. This is in agreement with the results of first-principles density functional theory calculations implying methyl group hyperconjugation in the TMTSF molecule. In this low temperature regime, both materials exhibit for ρ(c) a temperature dependence aT + bT(2). Taking into account the strong pressure dependence of the anisotropy, the T-linear ρ(c) is found to correlate with the suppression of the superconducting Tc, in close analogy with ρ(a) data. This work reveals the domain of existence of the three-dimensional coherent regime in the generic (TMTSF)2X phase diagram and provides further support for the correlation between T-linear resistivity and superconductivity in non-conventional superconductors.

[Automatic detection of vessels in color fundus images]. / Detección automática de vasos en retinografías.

PURPOSE: The main purpose of the paper is to evaluate an automated method for blood vessels segmentation in color fundus images, due to its important role in the diagnosis of several pathologies such as diabetes. The final objective is to introduce the algorithm into a Computer Aided Diagnosis (CAD) tool that would be available in those local medical centers without specialists. METHOD: An automated method for blood vessels segmentation in color fundus images was implemented and tested. The algorithm starts with the extraction of vessel centerlines, which are used as guidelines for the subsequent vessel filling phase. The outputs of four directional differential operators are processed in order to select connected sets of candidate points to be further classified as centerline pixels using vessel derived features. The final segmentation is obtained using an iterative region growing method that integrates the contents of several binary images, resulting from vessel width dependent morphological filters. The method was evaluated using the images of two publicly available databases (STARE and DRIVE) and a database with 24 images. RESULTS: The algorithm outperforms other published algorithms and approximates the average accuracy of a human observer without a significant degradation of sensitivity and specificity. In addition, results have been subject to the experts' valuation that they think that retinal vessels remain represented with valuable accuracy on having analyzed the test's images. CONCLUSION: Due to the good segmentation results, the algorithm proposed could be implemented as part of a complete CAD tool in the local medical centers. This would reduce cost and diagnosis time.

Detección automática de vasos en retinografías / Automatic detection of vessels in color fundus images

Propósito: El propósito de este trabajo es la evaluación de un método automático para lasegmentación del árbol vascular en imágenes de retinografías, dado su importante papelen el diagnóstico de numerosas enfermedades, como la diabetes mellitus. El objetivo finales introducir el algoritmo en una herramienta de diagnóstico asistido por computadora(CAD, del inglés Computer Aided Diagnosis) que estaría disponible en los centros médicoslocales sin especialistas.Método: Se ha implementado y probado un método automático para la segmentación devasos. El algoritmo comienza con la extracción de las líneas centrales de los vasos, que seemplean como guías para la fase posterior de rellenado de vasos. Las salidas de 4 operadoresdireccionales se procesan para obtener conjuntos conexos de puntos candidatos que seclasificarán como píxeles pertenecientes a las líneas centrales mediante característicasderivadas de los vasos. La segmentación final se obtiene empleando un proceso iterativode crecimiento de regiones que integra los contenidos de varias imágenes binarias, resultadode aplicar determinados filtros morfológicos que dependen del ancho del vaso. Elmétodo se ha evaluado empleando las imágenes de 2 bases de datos públicas (STARE yDRIVE) y por una base de datos compuesta por 24 imágenes.Resultados: El algoritmo mejora otras soluciones y se aproxima en precisión a la obtenidapor un observador humano, sin por ello experimentar una degradación de la sensibilidady la especificidad. Asimismo, los resultados del algoritmo se han sometido a la valoraciónde expertos que consideran que los vasos quedan representados con apreciable exactitudal analizar las imágenes de prueba.Conclusión: Dados los buenos resultados obtenidos en la segmentación, el algoritmo propuestopodría implementarse e introducirse en una herramienta CAD disponible en los centrosmédicos locales. La reducción en coste y tiempo de exploración podría ser significativa(AU)

Purpose: The main purpose of the paper is to evaluate an automated method for bloodvessels segmentation in color fundus images, due to its important role in the diagnosis ofseveral pathologies such as diabetes. The final objective is to introduce the algorithm intoa Computer Aided Diagnosis (CAD) tool that would be available in those local medicalcenters without specialists.Method: An automated method for blood vessels segmentation in color fundus images wasimplemented and tested. The algorithm starts with the extraction of vessel centerlines,which are used as guidelines for the subsequent vessel filling phase. The outputs of fourdirectional differential operators are processed in order to select connected sets ofcandidate points to be further classified as centerline pixels using vessel derived features.The final segmentation is obtained using an iterative region growing method thatintegrates the contents of several binary images, resulting from vessel width dependentmorphological filters. The method was evaluated using the images of two publicly availabledatabases (STARE and DRIVE) and a database with 24 images.Results: The algorithm outperforms other published algorithms and approximates theaverage accuracy of a human observer without a significant degradation of sensitivity andspecificity. In addition, results have been subject to the experts’ valuation that they thinkthat retinal vessels remain represented with valuable accuracy on having analyzed thetest’s images.Conclusion: Due to the good segmentation results, the algorithm proposed could beimplemented as part of a complete CAD tool in the local medical centers. This wouldreduce cost and diagnosis time(AU)

Exchange coupling in cyano-bridged homodinuclear Cu(II) and Ni(II) complexes: synthesis, structure, magnetism, and density functional theoretical study.

The synthesis and structural characterization of several new cyano-bridged copper(II) and nickel(II) homodinuclear complexes is presented. The measure of magnetic properties for these complexes is complemented with a computational study of the exchange coupling for several model structures representing this family of compounds. The influence of several factors on the coupling constant has been examined, coordination position occupied by the bridging ligand, distortions of the coordination environment, and relative disposition of the cyanide ion with respect to the M-M vector. Comparison of experimental and calculated coupling constants allows for the rationalization of the most relevant features of the exchange interaction between two identical metal ions through a cyano bridge.

Exchange coupling in carboxylato-bridged dinuclear copper(II) compounds: a density functional study.

A computational study of the exchange coupling is presented for a selected sample of carboxylato-bridged dinuclear copper(II) compounds. Model calculations have been used to examine the influence of several factors on the coupling constants: a) the electron-withdrawing power of the bridging ligands; b) the nature of the axial ligands; c) the number of bridging carboxylato groups; d) some structural distortions frequently found in this family of compounds; and e) the coordination mode of the carboxylato bridge. Coupling constants calculated for some complete structures, as determined by X-ray diffraction, are in excellent agreement with experimental data, confirming the ability of the computational strategy used in this work to predict the coupling constant for compounds for which experimental data are not yet available.

Through-ring bonding in edge sharing dimers of octahedral complexes.

A study of the preferred structures for the M2X2 rings in the binuclear complexes of types [M2(mu-XR2)2L8] and [M2(mu-XR3)2L8] is presented, based on qualitative orbital arguments supported by extended Hückel calculations on Cr compounds. The main conclusions are confirmed by DFT calculations on key compounds of Cr and Mn and agree well with the results of a structural database analysis. With the simplified electron counting scheme deduced, complexes with six or four electrons available for bonding of the M2X2 framework are predicted to have two possible minimum energy structures, with either a short M-M or X-X distance, whereas compounds with eight framework electrons are expected to present no short through-ring distance. Such a behavior is consistent with the framework electron rules reported earlier for compounds with different coordination spheres and provides a general description of the structure and bonding in a variety of compounds with M2X2 diamonds. Metal-metal bonding across the ring can be equally predicted taking into account only the bonding characteristics of the t2g-like orbitals for the XR2- but not for the XR3-bridged complexes. In addition, the framework electron counting scheme has the advantage of being independent of the formal oxidation state assigned to the metal atom.

Asymmetry and magnetism in bis(oximato)-bridged heterobimetallic compounds: a computational approach.

A density functional study of exchange coupling was carried out for a series of heterobinuclear oximato-bridged transition metal complexes. Model calculations were used to examine the influence of the electronic configuration of the metal atoms on the coupling constants. This analysis was complemented by a study of the variation of the coupling constant with the most usual structural distortions within this family of compounds. The influence of the nature of the terminal ligands as well as that of the symmetry on the bridge were also investigated.

Diverticulum of the left ventricle associated with subvalvar aortic stenosis.

Diverticula of the left ventricle are rare and only a few cases have been documented in adults. They may be asymptomatic or may present with embolization, pain, endocarditis, or sudden death. We report the case of a 34-year-old woman who presented a cardiac arrest with ventricular fibrillation which required electrical cardioversion. She was found to have a left ventricular diverticulum associated with a subvalvar aortic stenosis. The diverticulum arose from the apex with a narrow connection to the ventricular cavity. A subvalvar fibrous ridge stenosis with a systolic pressure gradient of 115 mmHg was observed. Coronary angiography revealed normal coronary arteries. The diverticulum and the subvalvar fibrous ridge were resected. Histologic examination of the diverticulum wall demonstrated the presence of the three normal layers with marked muscle cell hypertrophy, atypical plexiform structure and fibrous endocardium. The pathophysioloy of diverticula associated with subvalvar aortic stenosis are discussed.

Lymphoepithelial-like carcinoma of the uterine cervix. Study of a case with in situ hybridization of the Epstein-Barr virus genome and the human papillomavirus genome.

Lymphoepithelial-like carcinoma of the uterine cervix is very rare in Caucasian women. We present a new case in a 74 year-old European. Morphologically the undifferentiated carcinoma was accompanied by intense lymphocytic infiltration. Immunohistochemically the tumor expressed epithelial markers such as cytokeratin CAM 5.2, and a large proportion of cells expressed the proliferating cell nuclear antigen. The accompanying lymphocytic reaction was composed predominantly of T-lymphocytes which express the UCHL1 antigen. The in situ hybridization of the Epstein-Barr virus genome and the human papillomavirus proved negative.