Production of positronium chloride: A study of the charge exchange reaction between Ps and Cl.

We present cross sections for the formation of positronium chloride (PsCl) in its ground state from the charge exchange between positronium (Ps) and chloride (Cl-) in the range of 10 meV-100 eV Ps energy. We have used theoretical models based on the first Born approximation in its three-body formulation. We simulated the collisions between Ps and Cl- using ab initio binding energies and positronic wave functions at both the mean-field and correlated levels extrapolated to the complete basis set limit. The accuracy of these ab initio data was benchmarked on the PsF system with the existing highly accurate results, including the very recent quantum Monte Carlo results. We have investigated Ps excited states up to n = 4. The results suggest that the channel Ps(n = 2) is of particular interest for the production of PsCl in the ground state and shows that an accurate treatment of correlation effects (i.e., electron-electron and electron-positron correlations) leads to a significant change in the magnitude of the PsCl production cross section with respect to the mean-field level.

Experimental and numerical analysis of the influence of intramedullary nail position on the cut-out phenomenon.

BACKGROUND AND OBJECTIVE: Proximal femur fractures, colloquially known as hip fractures, are a common pathology with increasing incidence in the last years due to the enhanced ageing population. Regarding the extracapsular fracture, the treatment for this pathology consists of a fixation of the fragments using an osteosynthesis device, mainly the intramedullary nail. This repairing method implies several complications, which may include the failure of the fixation device, frequently occurring due to the "cut-out" mechanism. The present work focuses on the study of how the position of the cephalic screw, which should be fixed during surgery, affects the cut-out risk. Through experimental tests and numerical models some variables that can be critical for the cut-out phenomenon are analysed. METHODS: This study has been carried out through a numerical model based on the finite element method and experimental tests. The digital image correlation technique has been used in experimental tests to measure displacements on the femoral surface with the objective of numerical model validation. Some basic daily activities with different intramedullary nail positions have been analysed through the numerical model, considering variables that can induce the cut-out complication. RESULTS: The results show how the intramedullary nail position clearly influences the cut-out risk, showing that displacements in the upper, anterior and posterior direction increase the cut-out risk, while displacement in the lower direction endangers the intramedullary nail itself. Thus, the centred position is the one which reduces the cut-out risk. CONCLUSIONS: This work supposes an improvement in the knowledge of the cut-out phenomenon thanks to the combination of experimental testing and validated numerical models. The effects of different intramedullary nail positions in the femoral head are studied, including a novelty variable as torque, which is critical for the structural integrity of the fixation. The main conclusion of the work is the determination of the central intramedullary nail position as the most favourable one for decreasing the cut-out risk.

El fenómeno de cut-out en fractura intertrocantérica de fémur: análisis mediante modelo de elementos finitos / The cut-out phenomenon in intertrochanteric femur fracture: analysis using a finite element model

Objetivo: El objetivo del trabajo fue analizar el fenómeno de cut-out, fenómeno que supone desplazamientos oblicuos y/o rotaciones de la cabeza femoral alrededor del componente cefálico del clavo intramedular. El análisis se llevó a cabo mediante modelos numéricos de elementos finitos. Con esta técnica se busca entender el fallo de este tipo de fijaciones y establecer qué posicionamiento del sistema favorece o evita el fallo por cut-out. Material y métodos: El estudio se realizó sobre un modelo numérico de la extremidad proximal de un fémur artificial y un clavo intramedular tipo PFNA (femoral proximal de antirrotación). En el modelo numérico se varió la posición del clavo intramedular en dirección anterior/posterior y superior/inferior para analizar la influencia de la posición en el fenómeno de cut-out. Se analizaron las tensiones en zonas críticas y par torsor sobre el clavo bajo una carga en posición normal. Resultados: La posición más crítica fue aquella en la que el clavo intramedular está colocado en la posición superior, debido a las altas compresiones que aparecen en el hueso trabecular de la cabeza femoral. La posición centrada del clavo disminuyó el riesgo de daño óseo y el par torsor que tiene que soportar el clavo intramedular. Conclusión: Este tipo de modelos permite simular la influencia de la posición del clavo y obtener variables que de otra manera son difíciles de analizar. Aunque se trata de un modelo sencillo con carga estática, confirma que una posición centrada del clavo intramedular disminuye el riesgo de cut-out. (AU)

Objetive: This work aimed to analyze the cut-out phenomenon, which involves oblique displacements and/or rotations of the femoral head around the cephalic component of the intramedullary nail. The analysis was carried out using finite element numerical models. This technique seeks to understand the failure of this type of fixation and establish what positioning of the system favors or prevents failure due to cut-out. Material and methods: The study was carried out on a numerical model of the proximal limb of an artificial femur and an intramedullary nail type PFNA (proximal femoral nail anti-rotation). In the numerical model, the position of the intramedullary nail was varied in the anterior/posterior and superior/inferior directions to analyze the influence of the position on the cut-out phenomenon. Stresses in critical areas and torque on the nail under normal position loading were analyzed. Results: The most critical position was the one in which the intramedullary nail is placed in the superior position, due to the high compressions that appear in the trabecular bone of the femoral head. The centered position of the nail decreased the risk of bone damage and the torque that the intramedullary nail has to support. Conclusion: This type of model allows us to simulate the influence of the nail position and obtain variables that are otherwise difficult to analyze. Although it is a simple model with static load, it confirms that a centered position of the intramedullary nail reduces the risk of cut-out. (AU)

Validación experimental de un modelo de análisis de elementos finitos en fractura de cadera y su aplicabilidad clínica / Experimental validation of finite elements model in hip fracture and its clinical applicability

La fractura de la extremidad proximal de fémur es objeto de interés en investigación. La complejidad del entramado óseo y la ineficiencia estructural asociada al envejecimiento hacen que existan muchas variables todavía por comprender desde el punto de vista experimental, pero no existe un modelo de investigación estructural y biomecánico de la fractura de cadera claramente definido. La hipótesis de este trabajo es que es posible desarrollar un modelo de experimentación computacional que caracterice el hueso de la extremidad proximal del fémur como un material heterogéneo a partir de la traslación directa de los parámetros mecánicos obtenidos de piezas anatómicas de experimentación. Material y método: Trabajo experimental que compara la experimentación real en cadáver y un modelo numérico basado en análisis de elementos finitos (AEF). Las variables que se han empleado son: punto de inicio de la fractura, su propagación, carga progresiva y la carga máxima hasta fractura. Al modelo computacional se trasladaron los parámetros mecánicos reales obtenidos de las piezas anatómicas basándose en la relación entre las unidades Hounsfield de la TAC de alta resolución y la densidad mineral ósea de cada elemento virtual, mientras que la propagación de la fractura se modeló mediante desarrollo computacional propio del equipo investigador, con disminución de las propiedades mecánicas de los elementos dañados conforme avanza la línea fractuaria. Resultados: El modelo computacional fue capaz de determinar el punto de inicio de la fractura, con una discreta tendencia a la medialización anatómica de dicho punto respecto a lo ocurrido de manera experimental. El grado de correlación fue muy alto al comparar el valor real de deformación progresiva de las muestras frente al obtenido por el modelo computacional. Sobre 32 puntos analizados, se obtuvo una pendiente de 1,03 en regresión lineal, con un error relativo entre las deformaciones del 6% y un coeficiente de Pearson de R2=0,99. El modelo computacional infraestimó discretamente la carga máxima de fractura, con un error relativo aproximado al 10%. Conclusión: El modelo computacional de AEF desarrollado por este equipo investigador multidisciplinar se puede considerar, en conjunto, un modelo completo de AEF de la extremidad proximal del fémur con aplicabilidad clínica futura al ser capaz de simular e imitar el comportamiento biomecánico de fémures humanos contrastado con un modelo experimental clásico realizado en piezas anatómicas. Sobre esta base podrán evaluarse interacciones cualitativas y cuantitativas que lo consoliden como un potente banco de ensayos de experimentación computacional sobre el fémur proximal humano

Fracture of the proximal extremity of the femur is the subject of research interest. The complexity of the bone framework and the structural inefficiency associated with ageing leave many variables yet to be understood from an experimental perspective. However, there is no clearly defined structural and biomechanical research model for hip fracture. The hypothesis of this paper is that it is possible to create a computational experimentation model that characterises the bone of the proximal extremity of the femur as a heterogeneous material from directly translating the mechanical parameters obtained from anatomical experimentation specimens. Material and method: An experimental paper comparing real experimentation on cadavers and a numerical model based on finite element analysis (FEA). The variables uses were: the start point of the fracture, propagation of the fracture, progressive load and maximum load until fracture. The real mechanical parameters obtained from the anatomical specimens were translated to the computational model based on the relationship between the Hounsfield units of the high resolution CAT scan and the bone mineral density of each virtual element, whereas the propagation of the fracture was modelled by the research team's own computational design, reducing the mechanical properties of the damaged elements as the fracture line advanced. Results: The computational model was able to determine the start point of the fracture, with a slight tendency towards anatomical medialisation of this point compared to what happened experimentally. The degree of correlation was very high on comparing the real value of progressive deformation of the samples compared to that obtained by the computational model. Over 32 points analysed, a slope of 1.03 in lineal regression was obtained, with a relative error between the deformations of 16% and a Pearson's coefficient of R2=.99. The computational model slightly underestimated the maximum fracture load, with a relative error of approximately 10%. Conclusion: The FEA computational model developed by this multi-disciplinary research team could be considered, as a whole, a complete FEA model of the proximal extremity of the femur with future clinical applicability since it was able to simulate and imitate the biomechanical behaviour of human femurs contrasted with a traditional experimental model made from anatomical specimens. On this basis, qualitative and quantitative interactions can be assessed which consolidate it as a powerful computational experimentation test bench for the human proximal femur

Experimental validation of finite elements model in hip fracture and its clinical applicability. / Validación experimental de un modelo de análisis de elementos finitos en fractura de cadera y su aplicabilidad clínica.

Fracture of the proximal extremity of the femur is the subject of research interest. The complexity of the bone framework and the structural inefficiency associated with ageing leave many variables yet to be understood from an experimental perspective. However, there is no clearly defined structural and biomechanical research model for hip fracture. The hypothesis of this paper is that it is possible to create a computational experimentation model that characterises the bone of the proximal extremity of the femur as a heterogeneous material from directly translating the mechanical parameters obtained from anatomical experimentation specimens. MATERIAL AND METHOD: An experimental paper comparing real experimentation on cadavers and a numerical model based on finite element analysis (FEA). The variables uses were: the start point of the fracture, propagation of the fracture, progressive load and maximum load until fracture. The real mechanical parameters obtained from the anatomical specimens were translated to the computational model based on the relationship between the Hounsfield units of the high resolution CAT scan and the bone mineral density of each virtual element, whereas the propagation of the fracture was modelled by the research team's own computational design, reducing the mechanical properties of the damaged elements as the fracture line advanced. RESULTS: The computational model was able to determine the start point of the fracture, with a slight tendency towards anatomical medialisation of this point compared to what happened experimentally. The degree of correlation was very high on comparing the real value of progressive deformation of the samples compared to that obtained by the computational model. Over 32 points analysed, a slope of 1.03 in lineal regression was obtained, with a relative error between the deformations of 16% and a Pearson's coefficient of R2=.99. The computational model slightly underestimated the maximum fracture load, with a relative error of approximately 10%. CONCLUSION: The FEA computational model developed by this multi-disciplinary research team could be considered, as a whole, a complete FEA model of the proximal extremity of the femur with future clinical applicability since it was able to simulate and imitate the biomechanical behaviour of human femurs contrasted with a traditional experimental model made from anatomical specimens. On this basis, qualitative and quantitative interactions can be assessed which consolidate it as a powerful computational experimentation test bench for the human proximal femur.

Análisis de la variación del comportamiento mecánico de la extremidad proximal del fémur mediante el método XFEM (eXtended Finite Element Method) / Analysis of mechanical behavior variation in the proximal femur using X-FEM (Extended Finite Element Method)

Introducción: El fémur humano ha sido ampliamente estudiado desde hace muchos años de manera experimental con análisis in vitro, y ahora, gracias a los avances de la informática, también se puede analizar de manera numérica. Algunos autores han demostrado la capacidad del método de los elementos finitos para predecir el comportamiento mecánico de este hueso, pero todavía son muchas las posibilidades recurriendo a la sinergia entre el método de los elementos finitos y ensayos experimentales. En este trabajo, por ejemplo, se estudia cómo afectan distintas simulaciones de osteoporosis a las cargas de fractura del fémur. El objetivo de este estudio es predecir la fractura de cadera, tanto la carga a la que se produce ésta como la propagación de la fisura sobre el hueso. Aplicando el método de los elementos finitos al campo de la biomecánica se puede realizar una simulación que muestre el comportamiento del hueso bajo diferentes condiciones de carga. Material y métodos: A partir de imágenes DICOM de tomografía computarizada de la extremidad proximal del fémur derecha de un varón se ha obtenido la geometría del hueso. Mediante un programa informático se han generado las propiedades mecánicas dependientes de la densidad mineral ósea de cada vóxel, y posteriormente se ha utilizado un código de elementos finitos para aplicar diferentes configuraciones de carga y estudiar los valores de fractura del hueso. El modelo numérico ha sido validado a través de un artículo de la literatura científica. Resultados: La carga de fractura en configuración de caída lateral es aproximadamente la mitad que la carga en el caso de la posición normal, lo cual concuerda con diferentes estudios experimentales presentes en la literatura científica. Además se han estudiado diferentes condiciones de carga en situaciones cotidianas, en las que se ha observado que la carga de fractura es mínima en la posición monopodal. También se han simulado condiciones de osteoporosis en las que se ha comprobado cómo desciende la carga de fractura al disminuir las propiedades mecánicas óseas. Conclusiones: Mediante el método de los elementos finitos en conjunto con una imagen médica DICOM es posible el estudio de la biomecánica de la cadera y obtener una estimación del fallo del hueso. Además se pueden aplicar diferentes configuraciones de carga y variar las propiedades mecánicas del hueso para simular el comportamiento mecánico de éste bajo condiciones osteoporóticas (AU)

Introduction: For years, the human femur has been extensively studied experimentally with in vitro analysis. Nowadays, with computer advances, it can also be analyzed numerically. Some authors report the usefulness of finite method in predicting the mechanical behavior of this bone. There are many possibilities using the synergy between the method finite element and experimental trials. In this paper, for example, we study how they affect different osteoporotic simulations involving femur fracture loads. The aim of this study is to predict hip fracture, both the load to which this occurs as the propagation of the crack in the bone. By applying the finite element method to the field of bio-mechanics, simulation can be carried out to show the behavior under different bone load conditions. Material and methods: Using DICOM images, CT scan of the proximal end of the right femur of a male has been obtained bone geometry. By a computer program they have been generated dependent mechanical properties of the BMD each voxel, and then used a finite code to apply different load configurations and study values bone fracture elements. The numerical model has been validated in the literature. Results: Load breaking in lateral fall configuration is approximately half the load in the case of the normal position, which agrees with different experimental studies published. In addition, we have studied various load conditions in everyday situations, where it was observed that the load fracture is minimal in mono-podal position. Osteoporotic conditions have also been simulated which confirmed that the load fracture has been reduced by decreasing mechanical properties. Conclusions: By using the finite element method in conjunction with DICOM medical imaging, it is possible to study the biomechanics of the hip and obtain an estimate of bone failure. In addition, different load configurations can be applied and vary the mechanical properties of bone to simulate the mechanical behavior of low osteoporotic conditions (AU)

A simple approach to the state-specific MR-CC using the intermediate Hamiltonian formalism.

This paper presents a rigorous state-specific multi-reference coupled cluster formulation of the method first proposed by Meller et al. [J. Chem. Phys. 104, 4068 (1996)]. Guess values of the amplitudes of the single and double excitations (the T operator) on the top of the references are extracted from the knowledge of the coefficients of the Multi-Reference Singles and Doubles Configuration Interaction (MR-CISD) matrix. The multiple parentage problem is solved by scaling these amplitudes from the interaction between the references and the singles and doubles. Then one proceeds to a dressing of the MR-CISD matrix under the effect of the triples and quadruples, the coefficients of which are estimated from the action of exp(T). This dressing follows the logic of the intermediate effective Hamiltonian formalism. The dressed MR-CISD matrix is diagonalized and the process is iterated to convergence. As a simplification, the coefficients of the triples and quadruples may in practice be calculated from the action of T(2) only, introducing 5th-order differences in the energies. The so-simplified method is tested on a series of benchmark systems from Complete Active Spaces (CASs) involving 2-6 active electrons up to bond breakings. The comparison with full configuration interaction results shows that the errors are of the order of a few millihartree, five times smaller than those of the CAS-CISD, and the deviation to strict separability is lower than 10 µ hartree. The method is totally uncontracted, parallelizable, and extremely flexible since it may be applied to selected MR and/or selected CISD. Some potential generalizations are briefly discussed.

Accurate nonrelativistic ground-state energies of 3d transition metal atoms.

We present accurate nonrelativistic ground-state energies of the transition metal atoms of the 3d series calculated with Fixed-Node Diffusion Monte Carlo (FN-DMC). Selected multi-determinantal expansions obtained with the CIPSI (Configuration Interaction using a Perturbative Selection made Iteratively) method and including the most prominent determinants of the full configuration interaction expansion are used as trial wavefunctions. Using a maximum of a few tens of thousands determinants, fixed-node errors on total DMC energies are found to be greatly reduced for some atoms with respect to those obtained with Hartree-Fock nodes. To the best of our knowledge, the FN-DMC/(CIPSI nodes) ground-state energies presented here are the lowest variational total energies reported so far. They differ from the recently recommended non-variational values of McCarthy and Thakkar [J. Chem. Phys. 136, 054107 (2012)] only by a few percents of the correlation energy. Thanks to the variational property of FN-DMC total energies, our results provide exact lower bounds for the absolute value of all-electron correlation energies, |Ec|.

Calidad de la recogida de la medicación domiciliaria en urgencias: discrepancias en la conciliación / Quality of Home Medication Collection in the Emergency Department: Reconciliation Discrepancies

Introducción El objetivo del estudio fue valorar la calidad de la recogida de información de la medicación domiciliaria en el servicio de Urgencias de un hospital de tercer nivel, e identificar si las posibles deficiencias en esta recogida se tradujeron en errores de conciliación al ingreso, analizar estos y clasificarlos, así como identificar los grupos farmacológicos implicados. Métodos Se realizó un estudio observacional prospectivo en el que se analizó la información farmacoterapéutica recogida en el servicio de Urgencias. Se incluyeron los pacientes que ingresaron en la Unidad de Neumología y de Medicina Interna del Hospital Universitario Miguel Servet de Zaragoza. Se elaboró un listado con la medicación domiciliaria del paciente antes del ingreso, y se valoró si las deficiencias de calidad en la información recogida en urgencias se tradujeron en errores de conciliación al ingreso. Se tuvieron en cuenta las discrepancias no justificadas y se clasificaron siguiendo los criterios del Documento de consenso sobre terminología, clasificación y evaluación de los programas de Conciliación de la Medicación 2009.ResultadosSe incluyeron 136 pacientes, hallando errores de conciliación en el 86,8%. El número total de errores de conciliación encontrados fue 519. Siendo los subtipos más frecuentes: omisión de algún medicamento, falta de dosis y falta de frecuencia de administración. Cerca de un 40% de los errores de conciliación encontrados en el servicio de Medicina Interna no fueron resueltos, el doble de los encontrados en el servicio de Neumología. El grupo farmacológico en el que se encontraron más discrepancias fue el de aparato digestivo y metabolismo, con un 24%.ConclusionesEl porcentaje de pacientes con errores de conciliación es elevado (86%), observándose una importante oportunidad de mejora al ingreso de los pacientes en el servicio de Urgencias (AU)

Introduction The objective of the study was to assess home medication data collected at the emergency department in a tertiary hospital. It also aimed to identify whether any possible deficiencies in this collection were translated as reconciliation errors on admission, to analyse and classify these data and identify the pharmacological groups involved. Methods A prospective observational study was carried out which analysed the pharmacotherapeutic data collected at the emergency department. Patients who were admitted to the Pneumology and Internal Medicine wards at the Miguel Servet University Hospital in Zaragoza were included. A list of the home drugs taken before the hospital stay was compiled, assessing whether the quality deficiencies in data collected in the emergency department translated as reconciliation errors at admission. Unjustified discrepancies were considered and classified in line with the criteria of the consensus document on terminology, classification and assessment of the drug reconciliation programmes for 2009.ResultsWe included 136 patients, finding reconciliation errors in 86.8%. The total number of reconciliation errors found was 519. The most frequent types were: omitting a drug, missing dose information, missing administration frequency information. Almost 40% of the reconciliation errors found in the Internal Medicine ward were not resolved, which was double to that of the Pneumology ward. Most discrepancies were found for the Digestive System and Metabolism group (24%).Conclusions The percentage of patients that experienced reconciliation errors was high (86%), observing an important opportunity to improve at patient admission to the emergency department (AU)

[Quality of home medication collection in the Emergency Department: reconciliation discrepancies]. / Calidad de la recogida de la medicación domiciliaria en urgencias: discrepancias en la conciliación.

INTRODUCTION: The objective of the study was to assess home medication data collected at the Emergency Department in a tertiary hospital. It also aimed to identify whether any possible deficiencies in this collection were translated as reconciliation errors on admission, to analyse and classify these data and identify the pharmacological groups involved. METHOD: A prospective observational study was carried out which analysed the pharmacotherapeutic data collected at the Emergency Department. Patients who were admitted to the Pneumology and Internal Medicine wards at the Miguel Servet University Hospital in Zaragoza were included. A list of the home drugs taken before the hospital stay was compiled, assessing whether the quality deficiencies in data collected in the emergency department translated as reconciliation errors at admission. Unjustified discrepancies were considered and classified in line with the criteria of the consensus document on terminology, classification and assessment of the drug reconciliation programmes for 2009. RESULTS: We included 136 patients, finding reconciliation errors in 86.8%. The total number of reconciliation errors found was 519. The most frequent types were: omitting a drug, missing dose information, missing administration frequency information. Almost 40% of the reconciliation errors found in the Internal Medicine ward were not resolved, which was double that of the Pneumology ward. Most discrepancies were found for the Digestive System and Metabolism group (24%). CONCLUSIONS: The percentage of patients that experienced reconciliation errors was high (86%), observing an important opportunity to improve at patient admission to the Emergency Department.

Effect of a new emulsifier containing sodium stearoyl-2-lactylate and carrageenan on the functionality of meat emulsion systems.

The emulsion capacity and stability of a new emulsifier containing sodium stearoyl lactylate plus iota carrageenan (SSL/iC) in comparison to caseinate and soy isolate was analysed. The emulsion capacity and stability of SSL/iC in oil/water (O/W) model system emulsions was higher than shown by caseinate and soy isolate. However, the O/W emulsion stability was negatively affected by sodium chloride addition, but positively affected by an increase in temperature. Meat batters were made with caseinate, soy isolate, and SSL/iC at the minimum concentration that showed a good performance (>75% stability) in the O/W emulsions. The emulsifier SSL/iC produced high cook yields and good stability when used in meat batters. However, the cooked meat batters containing SSL/iC showed texture characteristics highly detrimental to the sensory analysis. On the other hand, the addition of 2% potato starch reduced the differences in texture parameters among the samples made with the different emulsifiers.

In vivo studies on the anti-inflammatory activity of pachymic and dehydrotumulosic acids.

Pachymic and dehydrotumulosic acids were studied in different models of acute and chronic inflammation. They proved to be active in most of the methods applied. None of them were active against arachidonic acid-induced ear edema. Dehydrotumulosic acid significantly diminished the mouse ear edema induced by ethyl phenylpropiolate, while pachymic acid was ineffective. When the putative corticoid-like mechanism of both compounds was explored, pachymic acid activity was partially abolished by the glucocorticoid receptor antagonist progesterone, but dehydrotumulosic acid activity was not affected. In vivo experiments demonstrated the inhibition by both principles of the phospholipase A2 (PLA2)-induced extravasation. The previous report on the effects of both compounds in vitro against PLA2, together with the present in vivo results, support the idea that the inhibition of this enzyme probably constitutes their main mechanism of action.

[Diffuse normolipemic xanthoma planum]. / Xantoma plano difuso normolipémico.

We comment on the case of a 75-year-old woman whose dermatologic process had started 15 years before with the onset of xanthelasma on the lower eyelids which were surgically removed, recurring on the scar areas two months later. At the same time new lesions involved the forehead as well as the periorbital and malar regions. Some months later new yellow papular lesions appeared involving the neck, thorax, pelvis and extremities which grew eccentrically covering large areas. Five years later the lesions localized on the face and showed a progressive tendency to atrophy in their centers while those localized on the trunk showed an evolution to sclerosis of their central area. There was no mucosal involvement or ulceration in any of the xanthomatous lesions. The microscopic study revealed the existence of a dermal infiltrate formed by histiocyte foamy frothy cells and Touton cells, among which there were some lymphocytes, which occasionally adopted a perianexial, perineural and perivascular pattern but there were no signs of thrombosis or degenerative changes in the perilesional connective tissue. The study by chromatography of the lipid composition of the pathologic skin revealed an increase in cholesterol esters. The laboratory exams as well as the general physical examination performed every six months for a period of 15 years' time were always normal except for a moderate elevation of ESR which persisted throughout the process.(ABSTRACT TRUNCATED AT 250 WORDS)