Corneal endothelial validation in the eye bank: differences in automated methods and repeatability.

PURPOSE: To evaluate reproducibility of endothelial cell density (ECD) measurements using the Konan Cell Check D in donor corneas by two different ophthalmologists and to compare the two automated cell count methods (center and flex-center) available in the software of this specular microscope. METHODS: ECD values were quantified in 54 donor corneas by two independent investigators using the Cell Check D (Konan Medical USA Inc) with both automated cell count methods. In the center method, at least 30 contiguous cells are marked. For the flex-center method, an area is delineated and only the cells within the designated area are counted. RESULTS: The mean ECD was 2473.81±378.22 cells/mm2. Good ECD intergrader reproducibility for the center (ICC=0.821) and the flex-center method (ICC=0.784) were noted. Poor reliability was observed for coefficient of variation and hexagonality (ICC≤0.265). When both methods for ECD analysis were compared, a moderate correlation for the two independent graders using the two manual (center and flex-center) methods was detected (correlation coefficient of 0.678 and 0.745 for each of the investigators). Comparison between methods yielded significantly higher ECD with the flex-center method (P=0.013). When corneas were divided by ECD, those under 2200 cells/mm2 and those between 2200 and 2700 cells/mm2 also had significantly higher ECD with the flex-center method (P<0.022). CONCLUSIONS: ECD values are reproducible with both methods, although the flex-center method ECDs tend to be higher, particularly in cases of low ECD. Eye banks and surgeons should exercise caution in making decisions based only on small differences in ECD.

Convergence insufficiencyCentral mini-plication of medial rectusDiplopiaConsecutive esotropiaSurgical overcorrection / Detection of anti-SARS-CoV-2 antibodies in tears: Ocular surface immunity to COVID-19

Objetivos Evaluar la presencia de anticuerpos IgA e IgG específicos del SARS-CoV-2 en lágrima de sujetos no vacunados y vacunados contra la COVID-19 con antecedentes de infección SARS-CoV-2. Correlacionar los resultados en lágrima con los de saliva y sangre, datos clínicos y regímenes de vacunación. Métodos Estudio transversal que incluyó a sujetos con antecedentes de infección SARS-CoV-2, tanto no vacunados como vacunados contra la COVID-19. Se recogieron 3muestras: lágrima, saliva y sangre. Se analizaron IgA e IgG frente a S-1 SARS-CoV-2 con ELISA semicuantitativo. Resultados Treinta sujetos, con una edad media 36,4±10, varones 13/30 (43,3%) con historia de infección SARS-CoV-2 leve; 13/30 (43,3%) habían recibido un régimen de 2 dosis y 13/30 (43,3%) un régimen de 3 dosis de vacunación anti-COVID-19, 4/30 (13,3%) no estaban vacunados. Todos los sujetos con vacunación completa presentaron IgA detectable en los 3biofluidos. Entre los no vacunados, se detectó IgA en 3/4 sujetos en lágrima y saliva, mientras que no se detectó IgG. No se observaron diferencias entre la pauta de vacunación de 2 y 3 dosis según los títulos IgA-IgG. Conclusiones Anticuerpos IgA e IgG del SARS-CoV-2 están presentes en lágrimas de pacientes con antecedentes de COVID-19 leve, lo que destaca el papel de la superficie ocular como primera línea de defensa frente a la infección. La mayoría de los sujetos no vacunados presentaron IgA a largo plazo en lágrima y saliva. La inmunización híbrida (infección natural más vacunación) parece potenciar las respuestas IgG mucosas y sistémicas. No se observaron diferencias entre la pauta de 2 y 3 dosis (AU)

Purpose To evaluate the presence of SARS-CoV-2 specific IgA and IgG antibodies in tears of unvaccinated and anti-COVID-19 vaccinated subjects with previous history of SARS-CoV-2 infection. To compare results in tears with those in saliva and serum and correlate with clinical data and vaccination regimens. Methods Cross-sectional study including subjects with a previous history of SARS-CoV-2 infection, both unvaccinated and vaccinated against COVID-19. Three samples were collected: tears, saliva and serum. IgA and IgG antibodies against S-1 protein of SARS-CoV-2 were analyzed with a semi-quantitative ELISA. Results Thirty subjects, mean age 36.4±10, males 13/30 (43.3%) with history of mild SARS-CoV-2 infection were included. 13/30 (43.3%) subjects had received a 2-dose regimen and 13/30 (43.3%) a 3-dose regimen of anti-COVID-19 vaccine, 4/30 (13.3%) subjects were unvaccinated. All the participants with full anti-COVID-19 vaccination (2-or 3-doses) presented detectable anti-S1 specific IgA in all 3biofluids, tears, saliva and serum. Among unvaccinated subjects, specific IgA was detected in 3/4 subjects in tears and saliva, whereas IgG was not detected. Considering IgA and IgG antibodies titers, no differences were observed between the 2- and 3-dose vaccination regimen. Conclusions SARS-CoV-2-specific IgA and IgG antibodies were detected in tears after mild COVID-19, highlighting the role of the ocular surface as a first line of defense against infection. Most naturally infected unvaccinated individuals exhibit long-term specific IgA in tears and saliva. Hybrid immunization (natural infection plus vaccination) appears to enhance mucosal and systemic IgG responses. However, no differences were observed between the 2- and 3-dose vaccination schedule (AU)

[Detection of anti-SARS-CoV-2 antibodies in tears: Ocular surface immunity to COVID-19]. / Detección de anticuerpos anti-SARS-CoV-2 en lágrimas: inmunidad de la superficie ocular frente a COVID-19.

Purpose: To evaluate the presence of SARS-CoV-2 specific IgA and IgG antibodies in tears of unvaccinated and anti-COVID-19 vaccinated subjects with previous history of SARS-CoV-2 infection. To compare results in tears with those in saliva and serum and correlate with clinical data and vaccination regimens. Methods: Cross-sectional study including subjects with a previous history of SARS-CoV-2 infection, both unvaccinated and vaccinated against COVID-19. Three samples were collected: tears, saliva and serum. IgA and IgG antibodies against S-1 protein of SARS-CoV-2 were analyzed with a semi-quantitative ELISA. Results: Thirty subjects, mean age 36.4 ± 10, males 13/30 (43.3%) with history of mild SARS-CoV-2 infection were included. 13/30 (43.3%) subjects had received a 2-dose regimen and 13/30 (43.3%) a 3-dose regimen of anti-COVID-19 vaccine, 4/30 (13.3%) subjects were unvaccinated. All the participants with full anti-COVID-19 vaccination (2-or 3-doses) presented detectable anti-S1 specific IgA in all 3 biofluids, tears, saliva and serum. Among unvaccinated subjects, specific IgA was detected in 3/4 subjects in tears and saliva, whereas IgG was not detected. Considering IgA and IgG antibodies titers, no differences were observed between the 2- and 3-dose vaccination regimen. Conclusions: SARS-CoV-2-specific IgA and IgG antibodies were detected in tears after mild COVID-19, highlighting the role of the ocular surface as a first line of defense against infection. Most naturally infected unvaccinated individuals exhibit long-term specific IgA in tears and saliva. Hybrid immunization (natural infection plus vaccination) appears to enhance mucosal and systemic IgG responses. However, no differences were observed between the 2- and 3-dose vaccination schedule.

Detection of anti-SARS-CoV-2 antibodies in tears: Ocular surface immunity to COVID-19.

PURPOSE: To evaluate the presence of SARS-COV-2 specific IgA and IgG antibodies in tears of unvaccinated and anti-COVID-19 vaccinated subjects with previous history of SARS-COV-2 infection. To compare results in tears with those in saliva and serum and correlate with clinical data and vaccination regimens. METHODS: Cross-sectional study including subjects with a previous history of SARS-CoV-2 infection, both unvaccinated and vaccinated against COVID-19. Three samples were collected: tears, saliva and serum. IgA and IgG antibodies against S-1 protein of SARS-CoV-2 were analyzed with a semi-quantitative ELISA. RESULTS: 30 subjects, mean age 36.4 ±â€¯10, males 13/30 (43.3%) with history of mild SARS-CoV-2 infection were included. 13/30 (43.3%) subjects had received a 2-dose regimen and 13/30 (43.3%) a 3-dose regimen of anti-COVID-19 vaccine, 4/30 (13.3%) subjects were unvaccinated. All the participants with full anti-COVID-19 vaccination (2-or 3-doses) presented detectable anti-S1 specific IgA in all three biofluids, tears, saliva and serum. Among unvaccinated subjects, specific IgA was detected in 3/4 subjects in tears and saliva, whereas IgG was not detected. Considering IgA and IgG antibodies titers, no differences were observed between the 2- and 3-dose vaccination regimen. CONCLUSIONS: SARS-CoV-2-specific IgA and IgG antibodies were detected in tears after mild COVID-19, highlighting the role of the ocular surface as a first line of defense against infection. Most naturally infected unvaccinated individuals exhibit long-term specific IgA in tears and saliva. Hybrid immunization (natural infection plus vaccination) appears to enhance mucosal and systemic IgG responses. However, no differences were observed between the 2- and 3-dose vaccination schedule.

Congenital retinal macrovessels: Case presentation.

We present an uncommon case of a unilateral congenital retinal macrovessel documented with retinography, perimetry, fluorescein angiography and macular optical coherence tomography. In the case presented the macrovessel crossed the horizontal meridian, between macula and optic disk. A literature review has been performed on congenital retinal macrovessels, possible structural and visual alterations they may cause and their association with other pathologies.

Macrovasos congénitos retinianos: presentación de un caso / Congenital retinal macrovessels: Case presentation

Presentamos un caso de macrovaso congénito retiniano estudiado mediante retinografía, campo visual, angiografía fluoresceínica y tomografía óptica de coherencia macular. El macrovaso atravesaba el meridiano horizontal, nasalmente entre papila y mácula. Además, se realiza una revisión de los macrovasos congénitos retinianos, las alteraciones visuales y estructurales que causan su asociación con otras enfermedades y su diagnóstico diferencial (AU)

We present an uncommon case of a unilateral congenital retinal macrovessel documented with retinography, perimetry, fluorescein angiography and macular optical coherence tomography. In the case presented the macrovessel crossed the horizontal meridian, between macula and optic disk. A literature review has been performed on congenital retinal macrovessels, possible structural and visual alterations they may cause and their association with other pathologies (AU)

Photosensitive ganglion cells: A diminutive, yet essential population.

Our visual system has evolved to provide us with an image of the scene that surrounds us, informing us of its texture, colour, movement, and depth with an enormous spatial and temporal resolution, and for this purpose, the image formation (IF) dedicates the vast majority of our retinal ganglion cell (RGC) population and much of our cerebral cortex. On the other hand, a minuscule proportion of RGCs, in addition to receiving information from classic cone and rod photoreceptors, express melanopsin and are intrinsically photosensitive (ipRGC). These ipRGC are dedicated to non-image-forming (NIF) visual functions, of which we are unaware, but which are essential for aspects related to our daily physiology, such as the timing of our circadian rhythms and our pupillary light reflex, among many others. Before the discovery of ipRGCs, it was thought that the IF and NIF functions were distinct compartments regulated by different RGCs, but this concept has evolved in recent years with the discovery of new types of ipRGCs that innervate subcortical IF regions, and therefore have IF visual functions. Six different types of ipRGCs are currently known. These are termed M1-M6, and differ in their morphological, functional, molecular properties, central projections, and visual behaviour responsibilities. A review is presented on the melanopsin visual system, the most active field of research in vision, for which knowledge has grown exponentially during the last two decades, when RGCs giving rise to this pathway were first discovered.

Células ganglionares fotosensibles: una población diminuta pero esencial / Photosensitive ganglion cells: A diminutive, yet essential population

Nuestro sistema visual ha evolucionado para proveernos una imagen de la escena que nos rodea informándonos de su textura, color, movimiento y profundidad con una enorme capacidad de resolución tanto espacial como temporal, y a esta finalidad la formación de imágenes (FI) dedica la inmensa mayoría de nuestras células ganglionares de la retina (CGR) y gran parte de nuestra corteza cerebral. Por otra parte, una proporción minúscula de las CGR, además de recibir información de fotorreceptores clásicos conos y bastones, expresan melanopsina y son intrínsecamente fotosensibles (CGRif). Estas CGRif se dedican a funciones visuales no formadoras de imágenes (NFI), de las que somos inconscientes, pero que resultan imprescindibles para aspectos relacionados con nuestra fisiología cotidiana como la puesta en hora de nuestros ritmos circadianos y nuestro reflejo fotomotor, entre otras muchas. Desde el descubrimiento de las CGRif se pensó que las funciones FI y NFI eran compartimentos distintos regulados por diferentes CGR, pero este concepto ha evolucionado en los últimos años con el descubrimiento de nuevos tipos de CGRif que inervan regiones subcorticales FI y, por tanto, presentan funciones FI. Hoy se conocen 6 tipos diferentes de CGRif que se denominan M1-M6 y difieren en sus propiedades morfológicas, funcionales, moleculares, proyecciones centrales y responsabilidades en comportamientos visuales. En este trabajo revisamos el sistema visual melanopsínico, el campo de investigación más activo en visión y cuyo conocimiento ha crecido exponencialmente durante las últimas 2décadas, desde que se descubrieron por primera vez las CGR que dan origen a esta vía (AU)

Our visual system has evolved to provide us with an image of the scene that surrounds us, informing us of its texture, colour, movement, and depth with an enormous spatial and temporal resolution, and for this purpose, the image formation (IF) dedicates the vast majority of our retinal ganglion cell (RGC) population and much of our cerebral cortex. On the other hand, a minuscule proportion of RGCs, in addition to receiving information from classic cone and rod photoreceptors, express melanopsin and are intrinsically photosensitive (ipRGC). These ipRGC are dedicated to non-image-forming (NIF) visual functions, of which we are unaware, but which are essential for aspects related to our daily physiology, such as the timing of our circadian rhythms and our pupillary light reflex, among many others. Before the discovery of ipRGCs, it was thought that the IF and NIF functions were distinct compartments regulated by different RGCs, but this concept has evolved in recent years with the discovery of new types of ipRGCs that innervate subcortical IF regions, and therefore have IF visual functions. Six different types of ipRGCs are currently known. These are termed M1-M6, and differ in their morphological, functional, molecular properties, central projections, and visual behaviour responsibilities. A review is presented on the melanopsin visual system, the most active field of research in vision, for which knowledge has grown exponentially during the last 2decades, when RGCs giving rise to this pathway were first discovered (AU)

Oral processing and dynamics of texture perception in commercial gluten-free breads.

There is an increasing demand for gluten-free products, with the texture being a critical aspect. The aim of this work was to study the food bolus properties of gluten-free breads in relation to the dynamics of sensations perceived during its consumption. In this study, five-commercial gluten-free breads and two regular breads were analysed for their texture, crumb structure, and moisture content. Bread bolus particle size after three chews, bolus characteristics at the swallowing point, and oral activity were determined. The dynamics of textural sensations during bread consumption was evaluated using the temporal dominance of sensations (TDS) technique. Texture and structure properties vary among gluten-free breads being some of them close to regular breads (crumb with more and smaller cells that shows low hardness and high springiness) that lead to different in-mouth breakdown and TDS patterns. At the beginning, harder breads with low springiness values resulted in hard dominant sensations, in contrast, breads with low hardness and high springiness values were perceived soft and spongy. Breads that fragmented into a greater number of small size particles created crumbly and sandy sensations, characteristic of gluten-free breads with large air cell sizes. Compact sensation appeared in breads with low saliva uptake during bolus formation, while pasty and sticky sensations were related to a cohesive and adhesive bolus, respectively. Not only structure and mechanical properties, but also its oral behaviour in terms of fragmentation and bolus formation can fully explain the dynamics of texture perception of gluten-free breads.

Alternativa de tratamiento para la distalización de molares superiores con una barra traspalatina anclada a un mini-implante / An alternative for the upper molar distalization with a transpalatalbar anchored to mini-implant

La distalización es un tratamiento común en la corrección de las maloclusiones clase II, para lo cualse han diseñado dispositivos dento-soportados como el péndulo, pero con efectos colaterales como la mesialización de premolares y vestibularización de incisivos superiores, actualmente se utilizandiferentes sistemas oseo-soportados eliminando estas reacciones.

Distalization is a common treatment for the correction of class II malocclusion; several tooth supportedappliances such as the pendulum have been designed and used with side effects like mesializationof premolars and labialization of upper incisors; currently different bone supported systems arebeing used in order to eliminate this reaction.

Orthodontic decompensation in class III patients by means of distalization of upper molars.

Pre-surgical orthodontic treatments have the objective of establishing harmony between the dental arches by moving the teeth to ideal positions in relation to their bony bases, in order to achieve adequate antero-posterior occlusal and transverse relationships at the moment of surgery. Among the typical requirements in terms of dental compensations presented by Class III patients that require surgery, the inclination of anterior teeth must be changed in most cases by proclination of the lower incisors and retroclination of upper incisors. To achieve the inclination of the upper incisors, many different alternatives have been proposed, such as inter-proximal reduction, extractions, or distalization of upper molars, which has not been widely reported in the literature as a means to decompensate Class III malocclusion prior to surgery. This article describes the Bone Supported Pendulum (BSP) as an efficient therapeutic option to distalize molars through the use of an appliance stabilized to the palate by mini-implants, thus avoiding extractions and providing good interdigitation and coordination of the dental arches.

Expansión del Aedes aegypti a localidades rurales de Cajamarca / Spread of Aedes aegypti to rural locations in Cajamarca

Objetivos: Determinar la presencia, magnitud y expansión de Aedes aegypti en las localidades rurales de las provinciasde Jaén y San Ignacio, departamento de Cajamarca. Materiales y métodos: Estudio transversal realizado entreabril y mayo de 2004, en 21 (100) localidades rurales ubicadas en las márgenes de la carretera Jaén-San Ignacioy al interior de ella, hasta en 90 minutos. Se inspeccionó recipientes de 1460 viviendas para la búsqueda de larvas yadultos del mosquito, se determinaron los índices aédicos, de recipiente y de Breteau. Resultados: Se demostró lapresencia de Aedes aegypti en tres localidades rurales de la provincia de Jaén y en cuatro de la provincia de San Ignacio.Los índices aédicos variaron de 1,2 a 16,6 . Los recipientes infestados con mayor frecuencia fueron las llantas ylos artículos en desuso. Conclusiones: Se reporta la expansión de A. aegypti en la tercera parte de localidades ruralesde las provincias de Jaén y San Ignacio; esta expansión necesita ser más estudiada y considerada al implementarselas estrategias de prevención y control del dengue en la DISA Jaén, para evitar la aparición de brotes de dengue clásico,dengue hemorrágico, incluso fiebre amarilla urbana.

Objectives: Determine the presence, magnitude and spread of Aedes aegypti in rural locations of the Jaen and San Ignacio provinces, department of Cajamarca. Materials and methods: Cross-sectional study conducted between April and May 2004 in 21 (100%) rural locations alongside the Jaen-San Ignacio road and on the road itself, up to 90 minutes. Artificial containers from 1460 houses were inspected for larvae and adult mosquitos. Aedic indexes from the container and Breteau indexes were derived. Results: The presence of Aedes aegypti was demonstrated in three rural locations of the province of Jaén and in four locations of the province of San Ignacio. Aedic indexes varied from 1,2 and 16,6%. The containers most frequently infested were tires and discarded items capable of holding water. Conclusions: The spread of A. aegypti is reported in one third of the rural locations of the provinces of Jaen and San Ignacio. This spread warrants further study and needs to be taken into consideration when dengue prevention and control strategies are implemented for the Jaen Health Directorate. Outbreaks of dengue fever, dengue hemorrhagic fever, and even urban yellow fever can be reduced if control measures can more accurately target the breeding areas of the vector.

Evaluation of right and left ventricular volume and ejection fraction using a mathematical cardiac torso phantom.

UNLABELLED: The availability of gated SPECT has increased the interest in the determination of volume and ejection fraction of the left ventricle (LV) for clinical diagnosis. However, the same indices for the right ventricle (RV) have been neglected. The objective of this investigation was to use a mathematical model of the anatomical distribution of activity in gated blood-pool imaging to evaluate the accuracy of two ventricular volume and ejection fraction determination methods. In this investigation, measurements from the RV were emphasized. METHODS: The mathematical cardiac torso phantom, developed to study LV myocardium perfusion, was modified to simulate the radioactivity distribution of a 99mTc-gated blood-pool study. Twenty mathematical cardiac torso phantom models of the normal heart with different LV volumes (122.3 +/- 11.0 ml), RV volumes (174.6 +/- 22.3 ml) and stroke volumes (75.7 +/- 3.3 ml) were randomly generated to simulate variations among patients. An analytical three-dimensional projector with attenuation and system response was used to generate SPECT projection sets, after which noise was added. The projections were simulated for 128 equidistant views in a 360 degrees rotation mode. RESULTS: The radius of rotation was varied between 24 and 28 cm to mimic such variation in patient acquisitions. The 180 degrees and 360 degrees projection sets were reconstructed using the filtered backprojection reconstruction algorithm with Butter-worth filtering. Comparison was made with and without application of the iterative Chang attenuation correction algorithm. Volumes were calculated using a modified threshold and edge detection method (hybrid threshold), as well as a count-based method. A simple background correction procedure was used with both methods. CONCLUSION: Results indicate that cardiac functional parameters can be measured with reasonable accuracy using both methods. However, the count-based method had a larger bias than the hybrid threshold method when RV parameters were determined for 180 degrees reconstruction without attenuation correction. This bias improved after attenuation correction. The count-based method also tended to overestimate the end systolic volume slightly. An improved background correction could possibly alleviate this bias.

Intracoronary Doppler assessment of moderate coronary artery disease: comparison with 201Tl imaging and coronary angiography. FACTS Study Group.

BACKGROUND: Coronary angiography may not reliably predict whether a stenosis causes exercise-induced ischemia. Intracoronary Doppler ultrasound may enhance diagnostic accuracy by providing a physiological assessment of stenosis severity. The goal of this study was to compare intracoronary Doppler ultrasound with both 201Tl imaging and coronary angiography. METHODS AND RESULTS: Fifty-five patients with 67 stenotic coronary arteries underwent coronary angiography with intracoronary Doppler ultrasound and had exercise 201Tl testing within a 1-week period. Coronary flow reserve was measured, and analyses were performed by independent core laboratories. The mean stenosis was 59+/-12%; 51 of 67 stenoses were intermediate in severity (40% to 70%). A coronary flow reserve < 1.7 predicted the presence of a stress 201Tl defect in 56 of 67 stenoses (agreement=84%; kappa=0.67; 95% CI=0.48 to 0.86). In the patients who achieved 75% of their predicted maximum heart rate, the Doppler and 201Tl imaging data agreed in 46 of 52 stenoses (agreement=88%; kappa=0.77; 95%CI=0.57 to 0.97). Scatter was evident when angiography was compared with coronary flow reserve (r=.43), and the angiogram did not reliably predict the results of the 201Tl stress test (kappa=0.21; agreement=57% to 63%). CONCLUSIONS: Doppler-derived coronary flow reserve accurately predicts the presence of exercise-induced ischemia on stress 201Tl imaging, and coronary angiography does not reliably assess the physiological significance of an intermediate coronary stenosis.

Estimation of attenuation maps from scatter and photopeak window single photon-emission computed tomographic images of technetium 99m-labeled sestamibi.

BACKGROUND: In single photon-emission computed tomographic imaging of the chest, nonuniform attenuation correction requires use of a patient-specific attenuation map. The aim of this study was to determine whether an estimate of the regions of the lungs and nonpulmonary tissues of the chest could be obtained by segmenting the photopeak and Compton scatter window images in a phantom and in patients to estimate patient-specific attenuation maps. METHODS AND RESULTS: The photopeak and scatter window slices from 16 consecutive 99mTc-labeled sestamibi perfusion studies were segmented interactively. In these studies, visually reasonable regions could be obtained by estimating a "cold" lung region from scatter window data with additional anatomic information of the myocardium region, the backbone and sternum locations, the liver, and the rib cage from the photopeak window data. In an anthropomorphic torso phantom study and a patient study, comparison was made between the attenuation maps based on segmentation of the emission images and transmission imaging with a slant-hole collimator. It was determined that good agreement in the estimation of the body regions can be achieved with segmentation of the emission images in both the phantom and patient data. Attenuation correction using the maximum-likelihood expectation maximization method was performed on the phantom and the patient data. In both studies, attenuation correction with the segmented attenuation map improved uniformity of the inferior wall region in comparison with the other walls. CONCLUSIONS: The estimation of patient-specific attenuation maps by segmenting the scatter and photopeak window slices of 99mTc-labeled sestamibi studies may be a way of reducing the loss of specificity due to attenuation artifacts. The potential limitations on the accuracy of correction inherent in the method due to the estimation of the regions and assignment of the attenuation coefficients need to be determined further, and the method needs to be further automated before it can be considered for routine clinical use.

Ulceras venosas de las piernas: en busca del mejor tratamiento / Venous leg ulcers: searching of the best treatment

El objetivo de este trabajo fue evaluar la eficacia de un tratamiento con pentoxifilina y curación no tradicional en las úlceras venosas en nuestro medio. Se diseñó un estudio prospectivo, randomizado, de grupos paralelos, doble ciego y control placebo. Se estudiaron 49 pacientes de bajo nivel socioeconómico, ulcerados venosos, sin otra patología. Método: se distribuyeron en 3 grupos de 12 y 1 de 13 pacientes, que recibieron placebo y curación tradicional (g.1a), placebo y curación no tradicional (g.2b), pentoxifilina y curación tradicional (g.3c) y pentoxifilina y curación no tradicional (g.4d). Se concluye que la cicatrización de las úlceras venosas mejora significativamente con un tratamiento conjunto de pentoxifilina y curaciones con apósitos bioactivos e interactivos, agregando la compresión elástica y el reposo posible en una población de bajo nivel socioeconómico. En este trabajo, no pudo determinarse la importancia relativa de la pentoxifilina y la curación no tradicional

Prognostic utility of increased pulmonary thallium uptake in patients without ischemia.

BACKGROUND: Although the combination of increased pulmonary thallium uptake and ischemia has demonstrated prognostic utility, the value of pulmonary uptake independent of ischemia has not been evaluated critically. Accordingly, our purpose was to evaluate the prognostic utility of thallium lung uptake in patients who do not have stress-induced defects. METHODS AND RESULTS: We studied 184 patients who were divided into three groups. Patients with increased pulmonary uptake were grouped into either the normal perfusion (n = 48) or fixed defect (n = 44) scan group and were compared with a third group (n = 92) of control patients who had normal scans and no lung uptake. During a mean follow-up of 23 +/- 13 months, there were 13 cardiac events (death or myocardial infarction) and the incidence per year was 0.6%, 2%, and 12% in the control, normal, and fixed defect groups, respectively (p < 0.00001). Life table analysis demonstrated greater event-free survival rates in the control and normal groups compared with the group with fixed defects. A Cox regression analysis showed that the number of fixed defects (infarct segments) was the most important independent prognostic factor (p < 0.00001) for future cardiac events. CONCLUSION: In patients with increased pulmonary thallium uptake and no stress perfusion defects, the prognosis is similar to that of control patients. However, patients with infarct segments and lung uptake have a significantly worse prognosis.

Left ventricular cavity size determined by preoperative dipyridamole thallium scintigraphy as a predictor of late cardiac events in vascular surgery patients.

We hypothesized that left ventricular (LV) cavity size measured on dipyridamole thallium scintigraphy identifies patients at risk for late nonfatal myocardial infarction and cardiovascular death. Accordingly, we retrospectively evaluated the predictive value of clinical and scintigraphic variables, including transendocardial LV cavity measurement performed on formatted images, in 335 vascular surgery patients. A nonhomogeneous perfusion pattern and enlarged LV cavity size were the most significant predictors of late events, and the interaction between these two variables was more predictive than was either variable alone. Life-table analysis demonstrated that patients with normal perfusion patterns had the lowest incidence of late events regardless of cavity size (p < 0.0005). Conversely, patients with a nonhomogeneous perfusion pattern and the largest LV cavity measurements were at the highest risk for late cardiac events (p < 0.0001). Therefore, this study demonstrated that a measurement of LV scintigraphic cavity size can provide important risk stratification for late cardiac events.

Transmission imaging of large attenuators using a slant hole collimator on a three-headed SPECT system.

By combining conjugate views, truncation-free attenuation profiles of patients can be obtained by using slant hole collimators on three-headed SPECT systems. The alterations in reconstruction algorithms necessary for use with slant hole collimators and potential image artifacts are discussed. Based on an evaluation of the size of objects that can be imaged without truncation and the size of the overlap region in the conjugate views, a 15 degrees slant angle was determined to be optimal. Studies with a 30 degrees slant hole collimator verified the ability of slant hole transmission imaging to provide accurate, truncation-free attenuation maps of a 56 cm lateral width phantom. The center of rotation was determined to be dependent on the slant angle and radius of rotation of the slant collimator. These studies also demonstrated that the spatial resolution in the transaxial plane of the attenuation maps depends on radius of rotation of the slant hole collimator, but does not depend on the radius of rotation of an uncollimated transmission source. A multiline transmission source was investigated for use with estimating the attenuation map in Tc-99m labeled sestamibi perfusion imaging.