A serial image analysis architecture with positron emission tomography using machine learning combined for the detection of lung cancer.

INTRODUCTION AND OBJECTIVES: Lung cancer is the second type of cancer with the second highest incidence rate and the first with the highest mortality rate in the world. Machine learning through the analysis of imaging tests such as positron emission tomography/computed tomography (PET/CT) has become a fundamental tool for the early and accurate detection of cancer. The objective of this study was to propose an image analysis architecture (PET/CT) ordered in phases through the application of ensemble or combined machine learning methods for the early detection of lung cancer by analyzing PET/CT images. MATERIAL AND METHODS: A retrospective observational study was conducted utilizing a public dataset entitled "A large-scale CT and PET/CT dataset for lung cancer diagnosis." Various imaging modalities, including CT, PET, and fused PET/CT images, were employed. The architecture or framework of this study comprised the following phases: 1. Image loading or collection, 2. Image selection, 3. Image transformation, and 4. Balancing the frequency distribution of image classes. Predictive models for lung cancer detection using PET/CT images included: a) the Stacking model, which used Random Forest and Support Vector Machine (SVM) as base models and complemented them with a logistic regression model, and b) the Boosting model, which employed the Adaptive Boosting (AdaBoost) model for comparison with the Stacking model. Quality metrics used for evaluation included accuracy, precision, recall, and F1-score. RESULTS: This study showed a general performance of 94% with the Stacking method and a general performance of 77% with the Boosting method. CONCLUSIONS: The Stacking method proved to be a model with high performance and quality for lung cancer detection when analyzing PET/CT images.

The Supera Interwoven Nitinol Stent as a Flow Diverting Device in Popliteal Aneurysms.

PURPOSE: The feasibility of using a compressed interwoven Supera stent as a flow diverting device for popliteal aneurysms was recently demonstrated in patients. It is unclear, however, what the optimal flow diverting strategy is, because of the fusiform shape of popliteal aneurysms and their exposure to triphasic flow. To assess this flow diverting strategy for popliteal aneurysms, flow profiles and thrombus formation likelihood were investigated in popliteal aneurysm models. MATERIALS AND METHODS: Six popliteal aneurysm models were created and integrated into a pulsatile flow set-up. These models covered a bent and a straight anatomy in three configurations: control, single-lined and dual-lined Supera stents. Two-dimensional flow velocities were visualized by laser particle image velocimetry. In addition, the efficacy of the stent configurations for promoting aneurysm thrombosis was assessed by simulations of residence time and platelet activation. RESULTS: On average for the two anatomies, the Supera stent led to a twofold reduction of velocities in the aneurysm for single-lined stents, and a fourfold reduction for dual-lined stents. Forward flow was optimally diverted, whereas backward flow was generally deflected into the aneurysm. The dual-lined configuration led to residence times of 15-20 s, compared to 5-15 s for the single stent configurations. Platelet activation potential was not increased by the flow diverting stents. CONCLUSION: A compressed Supera stent was successfully able to divert flow in a popliteal aneurysm phantom. A dual-lined configuration demonstrated superior hemodynamic characteristics compared to its single-lined counterpart.

Four-year safety follow-up of the tetravalent dengue vaccine efficacy randomized controlled trials in Asia and Latin America.

OBJECTIVE: Our objective was to describe the risk of hospital admission for virologically confirmed dengue (VCD) and the risk of clinically severe hospitalized VCD occurring up to 4 years after the first dose (years 1 to 4) in three randomized clinical trials comparing tetravalent dengue vaccine with placebo. METHODS: The relative risks (RR) for hospitalized VCD from first dose to year 4 were estimated by year and age-group in individual and combined studies. RESULTS: Overall, from Year 1 to Year 4, 233 and 228 participants had at least one episode of hospitalized VCD in the vaccinated (n = 22 603) and placebo (n = 11 301) groups, respectively (RR = 0.511, 95% CI 0.42-0.62). Among these, 48 and 47 cases, respectively, were classified as clinically severe. In children aged ≥9 years, 88 and 136 participants had at least one episode of hospitalized VCD in the vaccinated (n = 17 629) and placebo (n = 8821) groups, respectively (RR = 0.324; 95% CI 0.24-0.43). In vaccinated participants aged <9 years, particularly in those aged 2-5 years, there were more hospitalized VCD cases compared with the control participants in Year 3 but not in Year 4. The overall RR in those aged <9 years for Year 1 to Year 4 was 0.786 (95% CI 0.60-1.03), with a higher protective effect in the 6-8 year olds than in the 2-5 year olds. CONCLUSIONS: The overall benefit-risk remained positive in those aged ≥9 years up to year 4, although the protective effect was lower in years 3 and 4 than in years 1 and 2.

On growth measurements of abdominal aortic aneurysms using maximally inscribed spheres.

The maximum diameter, total volume of the abdominal aorta, and its growth rate are usually regarded as key factors for making a decision on the therapeutic operation time for an abdominal aortic aneurysm (AAA) patient. There is, however, a debate on what is the best standard method to measure the diameter. Currently, two dominant methods for measuring the maximum diameter are used. One is measured on the planes perpendicular to the aneurism's central line (orthogonal diameter) and the other one is measured on the axial planes (axial diameter). In this paper, another method called 'inscribed-spherical diameter' is proposed to measure the diameter. The main idea is to find the diameter of the largest sphere that fits within the aorta. An algorithm is employed to establish a centerline for the AAA geometries obtained from a set of longitudinal scans obtained from South Korea. This centerline, besides being the base of the inscribed spherical method, is used for the determination of orthogonal and axial diameter. The growth rate parameters are calculated in different diameters and the total volume and the correlations between them are studied. Furthermore, an exponential growth pattern is sought for the maximum diameters over time to examine a nonlinear growth pattern of AAA expansion both globally and locally. The results present the similarities and discrepancies of these three methods. We report the shortcomings and the advantages of each method and its performance in the quantification of expansion rates. While the orthogonal diameter measurement has an ability of capturing a realistic diameter, it fluctuated. On the other hand, the inscribed sphere diameter method tends to underestimate the diameter measurement but the growth rate can be bounded in a narrow region for aiding prediction capability. Moreover, expansion rate parameters derived from this measurement exhibit good correlation with each other and with growth rate of volume. In conclusion, although the orthogonal method remains the main method of measuring the diameter of an abdominal aorta, employing the idea of maximally inscribed spheres provides both a tool for generation of the centerline, and an additional parameter for quantification of aneurysmal growth rates.

Hepatitis A vaccination of Argentinean infants: comparison of two vaccination schedules.

BACKGROUND: Early immunization to protect infants against hepatitis A (HA) is recommended in intermediate or high endemic areas of the world, but little is known of the effects of maternal antibodies on the immune response. We studied the immunogenicity and reactogenicity of an inactivated HA vaccine administered in two different schedules to 2-month-old infants in an intermediate/high endemic area in Argentina. METHODS: In this double-blind, randomized study 131 infants received either three doses (at 2, 4, 6 months of age [Group A]) or one dose (at 6 months of age [Group B]) of the pediatric inactivated HA vaccine, Avaxim 80, and a booster dose at 15-18 months. HAV antibodies were measured (ELISA) at 2, 7, 15-18 and 16-19 months of age. Immediate (30 min after injection) and solicited local and systemic reactions were recorded for 7 days after each injection. RESULTS: Of 107/131 subjects (81.6%) who completed the study and who provided final serum samples after booster dose, 94 (87.8%) were seropositive at enrolment (>20 mIU/mL) with geometric mean concentrations (GMC) of 2989 and 3637 mIU/mL in Groups A and B, respectively. One month post-booster GMCs were 8236 mIU/ml (95% CI; 6304, 10760) and 1687 mIU/ml (1148, 2479) in Groups A and B, respectively, with 100% seroprotection. CONCLUSIONS: The HA vaccine was well tolerated and induced immunological priming in both groups during the first year of life in spite of the presence of maternal antibodies. Post-booster GMCs achieved after one or three primary doses suggest a long-term protection against HA.

Consideraciones generales sobre el mercurio, el timerosal, y su uso en vacunas pediátricas / General considerations about mercury, thimerosal in pediatrics vaccines

El timerosal, derivado del mercurio, ha sido utilizado en medicina por sus propiedades antisépticas. Desde hace más de 60 años ha sido usado como conservante en vacunas para evitar el sobrecrecimiento bacteriano, especialmente en frascos multidosis. Sin embargo, desde fines de la década de 1990 su uso ha sido cuestionado en Estados Unidos y Europa por el riesgo teórico de exposición en niños pequeños, con sus potenciales efectos en el desarrollo neurológico. Este cuestionamiento motivó a organizaciones internacionales, gubernamentales y no gubernamentales, entre ellas a grupos de asesores de la OMS, desde el año 2001, a revisar la información disponible hasta la fecha. Estos grupos de expertos concluyeron que actualmente no existe evidencia del daño por exposición al mercurio en niños y adultos que reciben vacunas con timerosal y, en consecuencia, no existe razón para cambiar las actuales prácticas de inmunización con vacunas que contienen timerosal.

Efecto de la administración previa de la vacuna DPT en la respuesta de anticuerpos anti- PRP: en niños inmunizados con la vacuna PRP-T: informe preliminar / Effect of prior administration of DPT vaccine in the response of anti-PRP antibody: in children immunized with the vaccine PRP-T: preliminary report

El objetivo del estudio fue evaluar los efectos de la vacunación DPT dos semanas antes de la primera dosis de la administración de la vacuna PRP-T, sobre la respuesta de anticuerpos anti-PRP en lactantes vacunados a los 2, 4 y 6 meses de edad. Luego de la obtención del consentimiento informado escrito, 141 niños de 2 meses de edad fueron distribuidos al azar en uno de tres grupos, para ser vacunados a los 2, 4 y 6 meses de edad respectivamente. El Grupo A incluyó vacunados con DPT dos semanas previas a la primeras dosis de PRP-T; el Grupo B a aquellos vacunados con PRP-T y DPT simultáneamente, en sitios separados; y el Grupo C a los vacunados con PRP-T, dos semanas previas a la primera dosis de DPT. La segunda y la tercera dosis de ambas vacunas se administraron simultáneamente en los tres grupos. Se tomaron muestras de sangre a los 2,4, 6 y 7 meses de vida. Los sueros fueron conservados a menos de 20º centígrados hasta su envío a la Universidad de Vanderbilt, donde fueron procesados en ciego y en paralelo por el método de ELISA. Los datos serológicos fueron transformados logarítmicamente para su análisis, reportándose su antilogaritmo. Para el análisis estadístico se aplicó la prueba ANOVA, un valor p<0,05 fue considerado estadísticamente significativo. Los títulos de anticuerpos posteriores a la primera dosis en los grupos A, B y C fueron respectivamente de 6,3, 1,9 y 1,05 mcg/ml; para la segunda dosis se obtuvieron títulos de 14.6; 9,20 y 8,93 mcg/ml para cada grupo y para la tercera, los resultados fueron respectivamente de 25,68; 17,38 y 26,47 mcg/ml. El análisis de varianza demostró que después de la primera dosis el grupo A inmunizado previamente con DTP obtuvo títulos de anticuerpos significativamente más altos que los otros dos que dicha diferencia se mantuvo después de la segunda inyección, (p<0,0001 y 0,04 respectivamente) sin embargo no hubo significación estadística posterior a la aplicación de la tercera dosis (p=0,23).

Safety, immunogenicity and antibody persistence of an inactivated hepatitis A vaccine in 4 to 15 year old children.

Among 277 healthy Venezuelan children, aged between 4 and 15 years, who were screened for hepatitis A virus (HAV) antibodies, 118 seronegative children were enrolled in an open study. Each child received one dose of the Pasteur Mérieux Connaught inactivated hepatitis A vaccine (AVAXIM¿trade mark omitted¿, 160 antigen units), followed by a booster dose 24 weeks later. All seronegative subjects seroconverted 2 weeks after immunisation (antibody titres greater, similar20 mIU/ml), and antibody titres were still over greater, similar20 mIU/ml after 24 weeks, at the moment of the booster dose. The anti-HAV antibody geometric mean titre (GMT), as measured by a modified radio-immunoassay (HAVAB(R), Abbott Laboratories, North Chicago, IL, USA), was 73.7 mIU/ml, 2 weeks after the first dose. Four weeks after the booster, the GMT value reached 6999 mIU/ml, representing a 29.6-fold rise from pre-booster levels. One year after the booster dose, the GMT value was 1673 mIU/ml in the 92 subjects who provided blood samples at this time, all of whom were still seroconverted ( greater, similar20 mIU/ml). No serious adverse event related to the vaccination occurred during the study. No immediate systemic reaction occurred. Local reactions were reported by 9.3% of subjects who received the primary injection and 5.5% of those given the booster dose. The systemic reactions were mainly fever and myalgia reported over the 7 days following the injection by 3.4% of subjects after the first dose and 5.5% of subjects after the booster dose. A clinically significant elevation of serum transaminase from pre-immunisation levels was noted in one subject (AST level 2.2 times the upper normal limit) 2 weeks after the first injection, although this was not associated with any clinical signs of impaired liver function. This trial demonstrated that AVAXIM¿trade mark omitted¿ containing 160 antigen units is safe and highly immunogenic in healthy children aged between 4 and 15 years, and could be included in the childhood vaccination schedule to control infection in areas endemic for hepatitis A.

Estudio epidemiológico de virus respiratorios en niños en el Hospital Pediátrico Dr. Elías Toro IVSS, Caracas / Epidemiology study of respiratory viruses in children in Hospital Pediátrico Dr. Elías Toro IVSS, Caracas

Con el objeto de determinar el tipo de virus respiratorios causantes de síndromes tipo influenza en niños, demostrar la circulación de virus influenza y evaluar la compatibilidad con la cepa de las vacunas recomendadas para 1995 y 1996, se realizó un estudio epidemiológico en el Hospital Pediátrico "Elías Toro", (HPET) de Caracas, entre junio de 1995 y diciembre de 1996. Usando hisopos tipo VIROCULT, se recolectaron 70 muestras de secreción nasal en 1995 y 56 en 1996, provenientes de niños entre los 2 meses y los 13 años de edad, llevados al HPET con síndrome tipo influenza. Las muestras se analizaron en Francia, en el Centro Nacional de Referencia de la OMS en Lyon. Los resultados fueron: En 1995 se detectaron 22/70 virus respiratorios (31,4 por ciento), de los cuales el 21 por ciento (15) correspondieron a VSR, 7 por ciento (5) a influenza A, 1,4 por ciento (1) a parainfluenza y 1,4 por ciento (1) a ADV tipo 2. En 1996 se detectaron 11/56 (19,6 por ciento), de los cuales 10,7 por ciento (6) correspondieron a influenza A, 3,5 por ciento (2) a VSR y 1,7 por ciento (1) tanto para ADV tipo 1, ECHO tipo 1 y Coxsackie respectivamente. Los virus influenza aislados estuvieron relacionados con las cepas de las vacunas correspondientes al año de aislamiento. Se confirma la circulación de virus influenza en 1995 y 1996 en Venezuela. Las cepas de la vacuna para 1995 y 1996 se adaptaron a la epidemiología local. Se propone mejorar la toma de muestras, reactivar la vigilancia de virus respiratorios a nivel local, promover la importancia y necesidad de la vigilancia de virus causantes de infecciones respiratorias agudas y continuar chequeando la compatibilidad entre los virus influeza circulantes y las cepas contenidas anualmente en la vacuna

Paragonimiasis pulmonar en el oriente ecuatoriano

El presente es un estudio realizado al sur del Puerto Francisco de Orellana (Recinto Laconde) donde se seleccionaron dos pacientes de un grupo investigado de 25 personas con antecedente de ingestión de crustáceos (pangoras) para observar la variación clínica de la paragonimiasis pulmonar. Se obtuvieron los siguientes resultados: El 100 por ciento de los pacientes desconocen el método de contagio. De los siete pacientes detectados, 2 (28.5 por ciento) presentaron un cuadro clínico grave. En estos dos casos se observó hipereosinofilia 34 por ciento y 30 por ciento respectivamente.

Paragonimiasis pulmonar en el oriente ecuatoriano

El presente es un estudio realizado al sur del Puerto Francisco de Orellana (Recinto Laconde) donde se seleccionaron dos pacientes de un grupo investigado de 25 personas con antecedentes de ingestión de crustáceos (pangoras) para observar la variación clínica de la paragonimiasis pulmonar. Se obtuvieron los siguientes resultados: El 100 por ciento de los pacientes desconocen el método de contagio. De los siete pacientes detectados, 2 (28.5 por ciento) presentaron un cuadro clínico grave. En estos dos casos se observó hiperosinofilia 34 por ciento y 30 por ciento respectivamente.