Analysis of flow field and turbulence predictions in a lung model applying RANS and implications for particle deposition.

Airflow and aerosol deposition in the human airways are important aspects for applications such as pulmonary drug delivery and human exposure to aerosol pollutants. Numerical simulations are widely used nowadays to shed light in airflow features and particle deposition patterns inside the airways. For that purpose, the Euler/Lagrange approach is adopted for predicting flow field and particle deposition through point-particle tracking. Steady-state RANS (Reynolds-averaged Navier-Stokes) computations of flow evolution in an extended lung model applying different turbulence models were conducted and compared to measurements as well as high resolution LES (large-eddy simulations) for several flow rates. In addition, various inlet boundary conditions were considered and their influence on the predicted flow field was analysed. The results showed that the mean velocity field was simulated reasonably well, however, turbulence intensity was completely under-predicted by two-equation turbulence models. Only a Reynolds-stress model (RSM) was able predicting a turbulence level comparable to the measurements and the high resolution LES. Remarkable reductions in wall deposition were observed when wall effects were accounted for in the drag and lift force expressions. Naturally, turbulence is an essential contribution to particle deposition and it is well known that two-equation turbulence models considerably over-predict deposition due to the spurious drift effect. A full correction of this error is only possible in connection with a Reynolds-stress turbulence model whereby the predicted deposition in dependence of particle diameter yielded better agreement to the LES predictions. Specifically, with the RSM larger deposition is predicted for smaller particles and lower deposition fraction for larger particles compared to LES. The local deposition fraction along the lung model was numerically predicted with the same trend as found from the measurements, however the values in the middle region of the lung model were found to be somewhat larger.

Determination of the genotype and phenotype of serum paraoxonase 1 (PON1) status in a group of agricultural and nonagricultural workers in the Coquimbo Region, Chile.

Paraoxonase 1 (PON1) is a glycosylated enzyme that is found associated with high-density lipoproteins in blood. In addition to its endogenous antioxidant role, this enzyme is also involved in hydrolysis of organophosphate (OP) pesticides in plasma. PON1 activity shows great variability in the population as a result of a polymorphism in the coding sequence that is expressed as a Glu(Q)/Arg(R) substitution at position 192 of the amino acid sequence. The aim of this study was to determine the activity levels (phenotype) and genotype of PON1 in a group of 85 agricultural workers occupationally exposed to OP pesticides and compared to 97 control subjects without occupational exposure. Allelic and genotypic frequencies of PON1Q192R polymorphism, as well as their catalytic activities, were established for the first time in a group of agricultural Chilean workers. The Q allele was more frequently represented in our studied population (approximately 60%). The Q allele is less efficient than the R allele at metabolizing chlorpyrifos (CPF), the most widely used OP pesticide in the geographical areas where samples were obtained. Further, a large interindividual variability in PON1 activity was observed, suggesting wide variation of individual susceptibility to CPF, an issue that needs to be considered in human monitoring studies.

METABOLITOS AISLADOS DE Zanthoxylum rhoifolium / ISOLATED METABOLITES FROM Zanthoxylum rhoifolium / METABOLITOS ISOLADOS DE Zanthoxylum rhoifolium

Una nueva cumarina llamada 3 -metoxi-4-(3-me t i l b u t -2-enil)-2H-cromen-2-ona fue aislada de la madera de Z. rhoifolium, junto con los compuestos conocidos, dictamnina y N-metilflindersina. Sus estructuras fueron elucidadas por RMN, incluyendo técnicas bidimensionales y por comparación con datos reportados en la literatura.

A novel coumarin named 3-metoxi-4-(3-me tilbut-2-enil)-2H-cromen-2-one was isolated from the wood of Z. rhoifolium, to get her with the known compounds, dictamnine and N-methylflin dersine. Their structures were elucidated by RMN spectraincluding 2D techniques and comparison with literature data.

Da madeira de Zanthoxylum rhoifolium foi iso la da uma nova cu ma ri na, com o name, 3 metoxi-4- (3-metilbut-2-enil)-2H-cromen 2-ona junto con os compostos, conhecidos: dictamnina y N-methyl- flindersina. Suas estruturas foram elucidadas por RMN, incluindo técnicas bidiomensionais e pela comparação comdados da literatura.

Desarrollo de improntas para el diagnostico del virus epstein-barr por inmunofluorescencia indirecta / Development of slides for Epstein-Barr virus diagnosis by indirect immunofluorescence

El vírus de Epstein-Barr (VEB) es el principal agente oncogénico linfotrópico dentro de la família Herpesviridae y se encuentra mundialmente distribuído. La primoinfección se produce en adultos jovenes y se manifesta como mononucleosis infecciosa. La detección de anticuerpos anti-viral cápside antigen (VCA) indica infección previa o presente com VEB. Además, se observan títulos elevados de anticuerpos anti-VCA en las enfermidades neoplásicas asociadas al VEB como los linfomas, em indivíduois HIV-positivos. El objetivo de este estúdio fue el desarrollo y puesta a punto de improntas de células P3HR1 para la detección serológica del VEB por técnicas de inmunofluorescencia indirecta (IFI). Se estimularon cultivos de células P3HR1 en crecimiento exponencial com phorbol-12-mirystoil-13-acetato y se recolectaron alícuotas a distintos tiempos para realizar improntas. Se realizó uma IFI com cada impronta usando como anticuerpo primário um suero VEB-positivo. Se observo un aumento del 11% em la expresión del VCA a las 40 horas post-estimulación, deyendo al 3.5% a las 48 horas. Estos datos fueron corroborados por ensayo de Western blot com inmunodetección. La precisión intra- e inter-lote de las improntas fue evaluada para anticuerpos IgM e IgG, com sueros probados previamente por equipos para esta determinación disponibles en el mercado para el VEB y com sueros reactivos para otros miembros de la família Herpesviridae. No se obtuvieron resultados falsos-negativos ni falsos-positivos para el VEB ni se observo reactividad cruzada com otros herpesvirus. Las improntas desarrolladas constituyen un instrumento para el diagnóstico de la primoinfección del VEB y la detección serológica de anticuerpos IgG anti-VCA de neoplasias asociadas al VEB.

Colposcopic scoring system for biopsy decisions in different patient groups.

Colposcopic scoring system have been used for distinguishing low-grade from high-grade cervical lesions. However, none of the previous studies have reported colposcopic scoring systems for biopsy decisions in different patient groups. The purpose of our study was to evaluate the safety of biopsy decisions using the colposcopic score elaborated by Stellato and Paavonen (IL) in 21 nonpregnant HIV infected patients (NP+) and 36 uninfected patients (NP-), 12 HIV infected pregnant patients (P+) and 20 uninfected pregnant patients (P-) in the diagnosis of cervical intraepithelial neoplasias (CIN) and HPV infection. The receiving operator curve was used for the establishment of a cut-off point in the scoring system graduation. The chi-square test was used for the statistical analysis. We obtained a safety cut-off value in the colposcopic scoring system for each patient group: 4.5 for NP+; 4.0 for NP- and 3.5 for P+ and P- patients. The sensitivity and specificity of the colposcopic score for the detection of high-grade lesions for each group were respectively: 87.5 and 92.3% for NP+ patients; 90.9 and 92% for NP- patients; 100 and 87.5% for P+ patients and 100 and 91.7% for P- patients. Our results suggest that the colposcopic scoring system is a practical tool for a colposcopy-guided punch biopsy decision and detection of high-grade cervical lesions in different patient groups. Further studies are needed to prove its clinical utility.

Characterization of hepatitis C virus genotypes in an hemodyalisis unit Paysandú, Uruguay

Los genotipos del virus de hepatitis C fueron investigados utilizando muestras seroactivas-PCR positivas provenientes de 8 pacientes que concurrieron a nuestra Unidad de Diálisis en Paysandú, Uruguay. Con posteridad a la detección de HCV RNA por reacción de transcripción reversa y reacción de polimerasa en cadena, la genotipificación fue llevada a cabo por ampliación tipo "nested PCR" de la región core de HCV, utilizando sondas genotipo-específicas. Los resultados obtenidos fueron a su vez confirmados por metodología basada en hibridización reversa que detecta los productos ampliados a través de sondas genotipo-específicas marcadas, dirigidas contra porciones de la región 5'UTR. Los genotipos de HCV fueron asignados según la clasificación de Simmonds. Cinco pacientes observaron genotipo 1b, uno presentó tipo 3a y uno no fue clasificable. Un paciente negativizó su PCR en el momento en que se llevó a cabo la genotipificación

Characterization of hepatitis C virus genotypes in an hemodialysis unit in Paysandú, Uruguay.

Hepatitis C virus types were investigated by using samples from eight sero-reactive and PCR positive patients attending our Hemodialysis Unit en Paysandú, Uruguay. After HCV RNA detection by reverse transcription and polymerase chain reaction, HCV genotyping was carried out by a nested PCR amplification, using type specific primers of HCV core region. These results were confirmed using a method based upon reverse hybridation of amplified products by enzyme-labeled type-specific probes to portions of the 5' UTR region. HCV genotypes were assigned according to Simmonds' classification. Type 1b was found in five patients, type 3a was found in one and one patient was not classified. There was a patient who became PCR negative at the moment the genotyping was carried out.

[Hepatitis A virus infection in children in Argentina: a pilot study]. / Infección por virus de hepatitis A (HAV) en niños en Argentina. Ensáyo piloto.

UNLABELLED: The severity and/or the prognostic of infections with the hepatitis A virus (HAV) is related to the age at which the infection occurs. Since transmission of the virus occurs by the fecal-oral route, the prevalence and age-relate incidence of infection is determined by the adequacy of sanitation hygienic measures and the socio economic level of exposed populations. Thus, the disease is having an increasing impact in developing countries with improving sanitary standards whereas inhabitants of industrialized countries are particularly at risk while visiting under-developed countries. We have established a cooperative group for the serologic study of children range between six months to ten years old, without sintomatology of acute hepatitis. The patients live in Buenos Aires, San Justo, Trelew, Rosario and Tucumán cities. We studied 3699 children. The specific Ab-antiHAV IgG were measured by enzyme immunoassay with commercial available kits (Organon and-or Abbott). The variable of study were age, sex and water quality. RESULTS: 45.19% were of San Justo, 26.15% of Rosario, 13% of Buenos Aires, 8.37% of Trelew and 7.29% of Tucumán. We observed the highest of possibility percentage (%POS) in Tucumán (81.4%), followed by San Justo (57.8%), Rosario (46.5%), Trelew (41.99%) and Buenos Aires (29.4%). In all the cities the lowest %POS was found in children under three years old. Between three and six years old the results were variable and an increase in %POS was observed related to the growth. The global %POS was 51.56%. CONCLUSIONS: This study confirms Argentina as a high endemic country for HAV infection. A global vaccination program is the only strategy that has the potential to prevent recurrent epidemics of hepatitis A and its erradication.

Infeccion por virus de hepatitis A (HAV) en ninos en Argentina: ensayo piloto / Hepatitis A virus infection in children in Argentina: a pilot study

Objetivos: Determinar la curva de infección del HAV en niños menores de diez años. Establecer estrategias de vacunación en la Argentina. Material y Métodos: se etableció un grupo cooperativo para el rastreo serológico de niños entre los seis meses y los diez años de edad, sin sintomatología y/o cuadro clínico de hepatitis aguda, tomando como grupo inicial de trabajo a Centros de las ciudades de Bs. As., San Justo (Pcia, de Bs. As.), Trelew (Chubut), Rosario (Santa Fe) y Tucumán. Se estudiaran 3699 niños para Anti-HAV-IgG por ELISA (Oragnon y Abbott). Las variables de inclusión fueron: edad, sexo y calidad de agua. Resultados: 45.19 por ciento de las muestras fueron de San Justo, 26.15 por ciento de Rosario, 13 por ciento de Buenos Aires, 7.29 por ciento de Tucumán y 8.37 por ciento de Trelew. 1) Se observó el mayor porcentaje de positividad (porcentajePOS) en Tucuman (81.4 por ciento) seguido por San Justo (57.8 por ciento) y Rosario (44.3 por ciento). 2) En todas las ciudades los menores porcentajePOS correspondieron a menores de tres años. 3) La mayor dispersión del porcentajePOS ocurre entre los tres y seis años de edad. 4) en todo el muestreo se observó un valor creciente de porcentajePOS con pendientes similares, excepto para Trelew, donde aparece un pico a los cuatro años atribuíble a las características de la muestra. 5) El porcentajePOS global para la muestra fue de 51.56 por ciento. Conclusiones: 1) Este trabajo demuestra que nuestro país es de alta endemicidad para la infección por HAV. 2) La vacunación a corta edad sería la estrategia más adecuada para el control de la hepatitis A y la erradicación de la infección por el HAV.