Position estimation using neural networks in semi-monolithic PET detectors.

Objective. The goal of this work is to experimentally compare the 3D spatial and energy resolution of a semi-monolithic detector suitable for total-body positron emission tomography (TB-PET) scanners using different surface crystal treatments and silicon photomultiplier (SiPM) models.Approach. An array of 1 × 8 lutetium yttrium oxyorthosilicate (LYSO) slabs of 25.8 × 3.1 × 20 mm3separated with Enhanced Specular Reflector (ESR) was coupled to an array of 8 × 8 SiPMs. Three different treatments for the crystal were evaluated: ESR + RR + B,with lateral faces black (B) painted and a retroreflector (RR) layer added to the top face; ESR +RR, with lateral faces covered with ESR and a RR layer on the top face and; All ESR, with lateral and top sides with ESR. Additionally, two SiPM array models from Hamamatsu Photonics belonging to the series S13361-3050AE-08 (S13) and S14161-3050AS-08 (S14) have been compared. Coincidence data was experimentally acquired using a22Na point source, a pinhole collimator, a reference detector and moving the detector under study in 1 mm steps in thex- andDOI- directions. The spatial performance was evaluated by implementing a neural network (NN) technique for the impact position estimation in thex- (monolithic) andDOIdirections.Results. Energy resolution values of 16 ± 1%, 11 ± 1%, 16 ± 1%, 15 ± 1%, and 13 ± 1% were obtained for theS13-ESR + B + RR,S13-AllESR,S14-ESR + B + RR,S14-ESR + RR,andS14-AllESR, respectively. Regarding positioning accuracy, mean average error of 1.1 ± 0.5, 1.3 ± 0.5 and 1.3 ± 0.5 were estimated for thex- direction and 1.7 ± 0.8, 2.0 ± 0.9 and 2.2 ± 1.0 for theDOI- direction, for the ESR + B + RR, ESR + RR and All ESR cases, respectively, regardless of the SiPM model.Significance. Overall, the obtained results show that the proposed semi-monolithic detectors are good candidates for building TB-PET scanners.

Neumoencéfalo intraventricular secundario a fístula de líquido cefalorraquídeo / Intraventricular pneumocephalus secondary to a cerebrospinal fluid fistula

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Insuficiencia respiratoria aguda como inicio de hemosiderosis pulmonar idiopática en un lactante / Acute respiratory insufficiency as debut of idiopathic pulmonary hemosiderosis in an infant

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Valoración pronóstica del switch arterial en la transposición de grandes arterias / Prognostic evaluation of arterial switch in the transposition of great arteries

Introducción y objetivos: El switch arterial es la intervención de elección para la transposición de grandes arterias con o sin comunicación interventricular. El objetivo ha sido la identificación de factores de riesgo de mortalidad hospitalaria. Métodos: Se intervinieron 121 niños entre enero de 1994 y junio de 2008. De ellos, 80 (66%) fueron diagnosticados de transposición con septo íntegro, y 41 (34%) con comunicación interventricular. Se recogieron variables del preoperatorio, de la intervención y del postoperatorio. Resultados: La edad fue de 11 [8 – 16] días y el peso de 3,5 [3,0 – 3,7] kg. A 11 niños (9,1%) se les cerró la comunicación interventricular. El 81,8% presentaba un patrón coronario normal. Se hizo cierre diferido del tórax en 38 pacientes (31,4%). La mortalidad hospitalaria fue del 11,6%, reduciéndose en los últimos 5 años al 2,1%. El peso, el patrón coronario anormal, el tiempo de circulación extracorpórea, la tensión arterial media al ingreso, el espacio muerto pulmonar y el cierre diferido del esternón fueron factores de riesgo de mortalidad. El modelo que mejor predice la muerte es el constituido por la tensión arterial media al ingreso y el cierre diferido del esternón. Conclusiones: La reducción en el tiempo de circulación extracorpórea y en el cierre diferido del esternón han contribuido a reducir la mortalidad. El patrón coronario anormal continúa siendo un factor de riesgo de mortalidad. En los niños con cierre diferido del esternón, una tensión arterial media al ingreso ≥ 47,5 mmHg es un objetivo a conseguir (AU)

Introduction and objectives: The arterial switch is the procedure of choice for transposition of great arteries, with or without ventricular septal defect. The aim of this study was to identify risk factors for hospital mortality. Methods: The study included 121 children between January 1994 and June 2008. Of these, 80 (66%) were diagnosed with intact ventricular septum, and 41 (34%) with ventricular septal defect. Variables were collected pre-operatively, during surgery, and postoperatively. Results: The mean age was 11 [8 to 16] days and a mean weight of 3.5 [3.0 to 3.7] kg. A ventricular septal defect was closed in 11 children (9.1%). A total of 81.8% had a normal coronary pattern. There was delayed closure of the chest in 38 patients (31.4%). The hospital mortality was 11.6%, decreasing over the past 5 years to 2.1%. The weight, abnormal coronary pattern, time of cardiopulmonary bypass, mean arterial pressure at admission, pulmonary dead space, and delayed closure of the chest, were risk factors of mortality. The model that best predicts the death, consists of the mean arterial pressure at admission, and delayed closure of the chest. Conclusions: The reduction in extracorporeal circulation time and the use of delayed closure of the chest, have helped to reduce mortality. The abnormal coronary pattern remains a risk factor for mortality. In children with delayed closure of the chest, a mean arterial pressure at admission ≥ 47.5 mmHg is a goal to achieve (AU)

Infección del tracto urinario en lactantes menores de 3 meses. Concordancia de los test diagnósticos / Urinary tract infection in unweaned babies of less than 3 months. Concordance between diagnostic tests

Objetivos: Determinar la sensibilidad, la especificidad, el valor predictivo positivo (VPP) y el valor predictivo negativo (VPN) dedos test diagnósticos rápidos de infección urinaria (ITU) (tira reactiva y tinción de Gram), así como la concordancia con el urocultivo. Material y métodos: Estudio observacional prospectivo realizado en lactantes menores de 3 meses con clínica sugestiva de ITU, de quienes se recogió una muestra de orina por medio estéril y a quienes se realizó una tira reactiva, una tinción de Gram y un urocultivo. Se recogieron los datos epidemiológicos y los resultados de los tres test, considerando infección comprobada la positividad del urocultivo. Para determinarla sensibilidad, la especificidad, el VPP y el VPN, se realizaron tablas de contingencia; para analizar las diferencias estadísticas entre sensibilidades, se recurrió a los contrastes de la CÖ2, y para la concordancia se utilizó el índice kappa. Resultados: Se incluyeron 151 muestras, un 55,6% de hombres y un 44,3% de mujeres, con una mediana de edad de 35 días (rango: 25-50). Se confirmó la presencia de ITU en un 20,5% de los casos. La sensibilidad de la tira reactiva fue de un 51,6% (rango: 34,8-68) y la de la tinción de Gram fue del87,1% (rango: 71,1-94,9), con una diferencia estadísticamente significativa (p <0,02). La concordancia entre la tira reactiva y el urocultivo fue moderada, con un índice kappa de 0,499, mientras que entre la tinción de Gram y el urocultivo fue muy buena, con un índice kappa de 0,856. Conclusiones: La tinción de Gram urgente en orina puede ser de gran ayuda para el diagnóstico precoz de ITU en lactantes menores de 3 meses. La tira reactiva de orina como única prueba diagnóstica podría no ser suficiente en este grupo de edad (AU)

Objectives: To determine the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of two tests for rapid diagnosis of urinary tract infection (UTI)(reactive strip and Gram stain), as well as their concordance with urine culture. Material and methods: We carried out a prospective, observational study of unweaned babies <3 months old who presented suggestive clinical signs of UTI. Urine was collected from all patients under sterile conditions performing a reactive strip, Gram stain and urine culture. Epidemiological data as well as the results of the three tests were collected. Positive urine culture results confirm the existence of infection. In order to determine the sensitivity, specificity, PPV and NPV of the different tests we used contingency tables. Statistical differences among sensitivity results were analyzed by means of the Chisquare test and concordance was evaluated using the Kappa index. Results: We analyzed 151 urine samples, 55.6% of male patients and 44.3% of females with a mean age of 35 days (25-50). UTI was confirmed in 20.5%. The sensitivity of the reactive strip was of 51.6% (34.8%-68%) and that of Gram stain of87.1% (71.1%-94.9%), with a statistically significant difference (p <0.02). Concordance between the reactive strip and urineculture was moderate, with a Kappa index of 0.499, whereas concordance between Gram stain and urine culture was satisfactory, with a Kappa index of 0.856.Conclusions: Urine Gram stain can be very helpful for the rapid diagnosis of UTI in unweaned babies below 3 months. The urine reactive strip as the only diagnostic test may not be sufficient in this age group (AU)

[Prognostic evaluation of arterial switch in the transposition of great arteries]. / Valoración pronóstica del switch arterial en la transposición de grandes arterias.

INTRODUCTION AND OBJECTIVES: The arterial switch is the procedure of choice for transposition of great arteries, with or without ventricular septal defect. The aim of this study was to identify risk factors for hospital mortality. METHODS: The study included 121 children between January 1994 and June 2008. Of these, 80 (66%) were diagnosed with intact ventricular septum, and 41 (34%) with ventricular septal defect. Variables were collected pre-operatively, during surgery, and postoperatively. RESULTS: The mean age was 11 [8 to 16] days and a mean weight of 3.5 [3.0 to 3.7] kg. A ventricular septal defect was closed in 11 children (9.1%). A total of 81.8% had a normal coronary pattern. There was delayed closure of the chest in 38 patients (31.4%). The hospital mortality was 11.6%, decreasing over the past 5 years to 2.1%. The weight, abnormal coronary pattern, time of cardiopulmonary bypass, mean arterial pressure at admission, pulmonary dead space, and delayed closure of the chest, were risk factors of mortality. The model that best predicts death, consists of the mean arterial pressure at admission, and delayed closure of the chest. CONCLUSIONS: The reduction in extracorporeal circulation time and the use of delayed closure of the chest, have helped to reduce mortality. The abnormal coronary pattern remains a risk factor for mortality. In children with delayed closure of the chest, a mean arterial pressure at admission ≥ 47.5 mmHg is a goal to achieve.

Polymerase chain reaction genotyping of Epstein-Barr virus in scraping samples of the tongue lateral border in HIV-1 seropositive patients.

The Epstein-Barr virus (EBV) is the etiological agent of oral hairy leukoplakia (OHL), an oral lesion with important diagnostic and prognostic value in acquired immunodeficiency disease syndrome. The two EBV genotypes, EBV-1 and EBV-2, can be distinguished by divergent gene sequences encoding the EBNA-2, 3A, 3B, and 3C proteins. The purpose of this study was to identify the EBV genotype prevalent in 53 samples of scrapings from the lateral border of the tongue of HIV-1 seropositive patients, with and without OHL, and to correlate the genotypes with presence of clinical or subclinical OHL with the clinic data collected. EBV-1 and EBV-2 were identified through PCR and Nested-PCR based on sequence differences of the EBNA-2 gene. EBV-1 was identified in the 31 samples (15 without OHL, 7 with clinical OHL and 9 with subclinical OHL), EBV-2 in 12 samples (10 without OHL, 1 with clinical and 1 subclinical OHL), and a mixed infection in 10 samples (2 without OHL, 3 with clinical and 5 with subclinical OHL). The presence of EBV-1 was higher in women, but a significant statistical result relating one the EBV genotypes to the development of OHL was not found. We conclude that the oral epithelium in HIV-1 seropositive patients can be infected by EBV-1, EBV-2 or by a mixed viral population.

Polymerase chain reaction genotyping of Epstein-Barr virus in scraping samples of the tongue lateral border in HIV-1 seropositive patients

The Epstein-Barr virus (EBV) is the etiological agent of oral hairy leukoplakia (OHL), an oral lesion with important diagnostic and prognostic value in acquired immunodeficiency disease syndrome. The two EBV genotypes, EBV-1 and EBV-2, can be distinguished by divergent gene sequences encoding the EBNA-2, 3A, 3B, and 3C proteins. The purpose of this study was to identify the EBV genotype prevalent in 53 samples of scrapings from the lateral border of the tongue of HIV-1 seropositive patients, with and without OHL, and to correlate the genotypes with presence of clinical or subclinical OHL with the clinic data collected. EBV-1 and EBV-2 were identified through PCR and Nested-PCR based on sequence differences of the EBNA-2 gene. EBV-1 was identified in the 31 samples (15 without OHL, 7 with clinical OHL and 9 with subclinical OHL), EBV-2 in 12 samples (10 without OHL, 1 with clinical and 1 subclinical OHL), and a mixed infection in 10 samples (2 without OHL, 3 with clinical and 5 with subclinical OHL). The presence of EBV-1 was higher in women, but a significant statistical result relating one the EBV genotypes to the development of OHL was not found. We conclude that the oral epithelium in HIV-1 seropositive patients can be infected by EBV-1, EBV-2 or by a mixed viral population.

Medida de Anticuerpos Anti-CCP en suero mediante un nuevo procedimiento de Fluoroenzimoinmunoanálisis / Measure of Antibodies anti-CCP by a new Fluoroenzymoimmunoanalysis in serum

Comparar los resultados obtenidos con un nuevo método automatizado de fluoroenzimoinmunoanálisis de segunda generación con los encontrados con un procedimiento ELISA bien establecido, así como comprobar el valor diagnóstico de este nuevo marcador en los casos de artritis reumatoide presentes en nuestra población. MÉTODOS El número total de pacientes seleccionados para el estudio fue de 284: 105 pacientes con artritis reumatoide y los 179 restantes pertenecían a pacientes del grupo control, que incluyó donantes de sangre, pacientes sin historia reumatológica conocida y pacientes con enfermedad reumática no artritis reumatoide. Los anticuerpos anti-CCP de isotipo IgG fueron medidos mediante el nuevo método automatizado de fluoroenzimoinmunoanálisis de segunda generación (EliATM CCP) desarrollado por Pharmacia. Así mismo, la medida también se llevó a cabo con un método semicuantitativo de enzimoinmunoanálisis (QUANTA LiteTM CCP IgG ELISA. INOVA Diagnostics, Inc.). RESULTADOS Para el valor discriminante seleccionado mediante curva de rendimiento diagnóstico de 12 μg/l, la sensibilidad diagnóstica conseguida para los anticuerpos anti-péptido cíclico citrulinado fue del 74.3% y la especificidad diagnóstica fue del 94%. El área bajo la curva de rendimiento diagnóstico fue 0.845. La correlación entre los dos métodos empleados para la determinación de anticuerpos anti-CCP resultó ser buena (r = 0.936), no existiendo errores sistemáticos estadísticamente significativos entre ellos (p 0.05). CONCLUSIONES La determinación de anticuerpos anti-CCP tiene gran interés en el diagnóstico de la artritis reumatoide, interés que aumenta cuando para la medida de estos autoanticuerpos empleamos nuevos métodos totalmente automatizados como el analizado en este trabajo

OBJECTIVE The aim of the present study was to compare the results obtained with a new automated second generation method of fluoroenzymoimmunoanalysis with the results obtained with a well established ELISA procedure, as well as to study the diagnostic value of this new marker in the present cases of rheumatoid arthritis in our population. METHOD Patients selected for the study was 284: 105 patients with rheumatoid arthritis and the others 179 belonged to patients of the group control, that included blood donors, patients without well-known reumatologic history and patients with rheumatic disease (no rheumatoid arthritis). Anti-CCP antibodies were measured by the new automated method (EliA‘ CCP) developed by Pharmacia and, with a semiquantitative method of enzymoimmunoanalisys (QUANTA Lite‘ CCP IgG ELISA. INOVA Diagnostics, Inc.). RESULTS At a cut-off value of 12 μg/l, diagnostic sensitivity was 74,3% and diagnostic specificity was 94% for the Pharmacia procedure, being the area under the ROC curve of 0,845. The correlation between methods was good (r = 0,936), not existing statistically significant bias among them (p 0,05). CONCLUSIONS The determination of anti-CCP antibodies is usefull in the diagnosis of rheumatoid arthritis, and the procedure is improved with the use of a new automated fluoroimmunoassay

Osteomielitis pélvica y absceso del músculo aproximador mayor / Pelvic osteomyelitis and adductor magnus muscle abscess

La osteomielitis pélvica es infrecuente, representa aproximadamente un 6-8% del total de osteomielitis agudas hematógenas. Es más frecuente en varones. Su presentación clínica es variable y poco especffica,lo que contribuyea un retraso en el diagnóstico. No existe ninguna prueba de laboratorio específica para su diagnóstico. No es infrecuente encontrar casos de pacientes con osteomielitis y cultivos negativos. Las complicaciones son infrecuentes. Se presenta el caso clínico de un niño de 10 años, sin antecedentes personales de interés, al que que se diagnostica una osteomielitis de la rama isquiopubiana izquierda complicada con un absceso del músculo aproximador mayor

Pelvic osteomyelitis is a rare disease that represents between 6-8% of the cases of acute hematogenous osteomyelitis. It is more frequent in males, and its clinical presentation is variable and non specific, circumstances that contribute to delaying the diagnosis. There is no specific laboratory test to aid in the diagnosis, and patients with osteomyelitis of ten have negative cultures. Complications are unusual. We reportt he case of a ten-year-old boy, whose medical history was unremarkable with acute osteomyelitis of the left ischio pubic region complicated by an abscess in adductor magnums uscle

[Susceptibility of Enterococcus genus to new antimicrobial agents]. / Sensibilidad del género Enterococcus a nuevos antimicrobianos.

The aim of this study was to determine the prevalence of resistance to different antibiotics in 109 clinical strains of Enterococcus isolated consecutively in hospital over a four-month period in 2002. The strains were identified by species using the semiautomatic system Microscan walk away 40 (Dade Behring) and the API20 STREP system (Biomerieux). Three different methods for the susceptibility study were used: Sensititre, E-test and disc diffusion. The percentage of Enterococcus faecalis and Enterococcus faecium isolated was 92% and 8%, respectively. The following resistance to Enterococcus faecalis was detected: erythromycin (53%), telithromycin (36%), penicillin (2%), ampicillin (1%), vancomycin, teicoplanin and linezolid (0%), high level resistance to streptomycin (51%) and gentamicin (32%). A high percentage of strains resistant to penicillin and ampicillin was detected in E. faecium (six of nine strains). For two species, high susceptibility to linezolid and glycopeptides was found.

Staphylococcus aureus resistente a la meticilina, prevalencia en La Rioja / Methicillin-resistant staphylococcus aureus. Prevalence in La Rioja

Las cepas de Staphylococcus aureus resistentes a meticilina (SARM) suponen un problema en el medio hospitalario. Conocer la prevalencia de estas cepas es importante para aplicar una terapia empírica adecuada cuando se sospeche la implicación de SARM en la infección. Se estudió todas las cepas de Staphylococcus aislados en La Rioja desde febrero de 2001 hasta Febrero de 2002, incluyendo un solo aislamiento por paciente. Tras su identificación fueron valoradas frente a 13 antibióticos, hallándose una elevada insensibilidad a la oxacilina (34.81 por ciento), observándose también elevada resistencia a otros antimicrobianos como el ciprofloxacino (36.12 por ciento) y la eritromicina (21.98 por ciento) . No se encontró ningún aislamiento de SARM resistente a vancomicina. Los aislamientos se produjeron de forma más frecuente en muestras de orina (63 por ciento). SARM es un problema grave en La Rioja y su prevalencia sigue aumentando progresivamente, así como la mutiresistencia, es necesario ampliar las medidas de vigilancia y control (AU)

Síndrome de Waterhouse-Friderichsen por Streptococcus pneumoniae / Fatal pneumococcal sepsis with Waterhouse-Friderichsen syndrome

Presentamos un caso de sepsis con síndrome de Waterhouse-Friderichsen, como forma de presentación de enfermedad neumocócica invasora en un niño previamente sano. El cuadro clínico evolucionó de forma fulminante y el paciente falleció a las 5 horas de su ingreso. El estudio necrópsico demostró apoplejía suprarrenal bilateral. Este caso demuestra que Streptococcus pneumoniae puede desencadenar un cuadro de sepsis fulminante con Síndrome de Waterhouse-Friderichsen en niños previamente sanos, siendo un cuadro clínico excepcional, muy poco descrito en la literatura científica. Debemos insistir en que es posible evitar la enfermedad neumocócica invasora en el niño, mediante la vacuna conjugada heptavalente, que ha demostrado ser segura y eficaz (AU)

Diagnóstico serológico de la artritis reumatoide. Utilidad de los anticuerpos anti-CCP / Serologic diagnosis of rheumatoid arthritis. Anti-CCP antibodies utility

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