La risa: niveles y factores demográficos, en el contexto de la COVID-19 / Laughter: demographic levels and factors, in the context of COVID-19

Introducción: La pandemia no se detiene, los estudios sobre la misma tampoco; esta pandemia produce dolor, tristeza, desesperación y muertes, cuyos números son incalculables. Ante esta situación difícil y dolorosa, la risa levanta su bandera de esperanza. Objetivo: El estudio tiene el objetivo de describir los niveles y los factores demográficos de la risa, en el contexto la COVID-19. Métodos: El estudio corresponde a un enfoque cuantitativo, de tipo descriptivo, de corte transversal. Los datos sobre los niveles de la risa se obtuvieron mediante una encuesta virtual, cuyos participantes fueron 101, de edades entre 20 y 60 años, quienes participaron voluntariamente, procedentes de las tres regiones del Perú: costa, sierra y selva. Los datos sobre la experiencia de la risa, con misma encuesta, con el tipo Likert: nunca, a veces y siempre. Resultados: De los 101 participantes, 87 (entre 20 y 60 años) presentan una risa en el nivel alto y 14 en el nivel medio. 14 participantes (entre solteros, casados, divorciados y convivientes) revelan una risa en el nivel medio y 87 en el nivel alto. De las tres regiones (costa, sierra y selva), 14 participantes se ubican en el nivel medio y 87 en el nivel alto. Por otro lado, 6 hombres y 8 mujeres practican una risa ubicada en el nivel medio, en el alto 28 y 59, respectivamente. En el factor: religión, 14 (entre católicos, adventistas, evangélicos y otros) revelan una sonrisa en el nivel medio, 87 en el alto. Según el factor: nivel de estudios (primario, secundario y superior), 14 y 87 ubican su risa en el nivel bajo y alto, respectivamente. En el círculo familiar y de los amigos, se experimenta siempre la risa: 58.4% y 66.3%, respectivamente; para los encuestados es más fácil reír, siempre, 54.5% y 66.3%, en el entorno familiar y de los amigos, respectivamente. Declararon que la risa previene las enfermedades, fortalece la salud, evita el covid-19, fortalece el sistema inmunológico y limita la producción de la hormona cortisol (responsable del estrés), siempre 70.3%, 31.7%, 81.2; 31.7%, 71.3% y 83.2%, respectivamente. Conclusión: En el contexto de la COVID-19, los niveles más significativos de la risa encontrados en el estudio son dos: medio y alto; los factores demográficos más ponderados son: edad, sexo, religión y estado laboral.

Introduction: The pandemic does not stop, neither does the studies on it; This pandemic produces pain, sadness, despair and deaths, the numbers of which are incalculable. Faced with this difficult and painful situation, laughter raises its flag of hope. Objective: The study aims to describe the levels and demographic factors of laughter, in the context of COVID-19. Methods: The study corresponds to a quantitative, descriptive, cross-sectional approach. The data were obtained through a virtual survey, whose participants were 101, from the three regions. Results: Of the 101 participants, 87 (between 20 and 60 years old) are located in the high level and 14 in the medium level. Similarly, 14 (among single, married, divorced and cohabitants) in the medium level and 87 in the high level. Of the three regions (coast, mountains and jungle), 14 in the medium level and 87 in the high level. On the other hand, 6 men and 8 women are in the medium level, in the high 28 and 59, respectively. In the factor: religion, 14 (among Catholics, Adventists, Evangelicals and others) in the medium level, 87 in the high. According to the factor: educational level (primary, secondary and higher), 14 and 87 are located in the low and high level, respectively. In the family and friends circle, laughter is always experienced: 58.4% and 66.3%, respectively; for respondents it is easier to laugh, always, 54.5% and 66.3%, in the family environment and with friends, respectively. They declared that laughter prevents diseases, strengthens health, prevents covid-19, strengthens the immune system and limits the production of the hormone cortisol (responsible for stress), always 70.3%, 31.7%, 81.2; 31.7%, 71.3% and 83.2%, respectively. Conclusion: In the context of COVID-19, the most significant levels of laughter found in the study are two: medium and high; the most weighted demographic factors are: age, sex, religion, and employment status.

Actualización de la bronquiolitis aguda / Acute bronchiolitis update

La bronquiolitis aguda es una condición respiratoria frecuente en los niños menores de 2 años. Representa la principal causa de hospitalización infantil y se caracteriza por la presencia de sibilancias asociada a signos de una infección respiratoria alta. El agente etiológico más común es el virus respiratorio sincicial. Existe una falta de consenso con respecto a su definición clínica; y por ello, su tratamiento varía en todo el mundo. El diagnóstico es clínico, sin necesidad de emplear laboratorio o imágenes en forma rutinaria. Diversas revisiones han demostrado que los broncodilatadores, adrenalina, corticoides y antibióticos, entre otros, carecen de eficacia por lo que no se sugiere su empleo. El tratamiento sigue siendo de soporte, mediante la administración de oxígeno y manteniendo una adecuada hidratación. Cuando no se logra disminuir el trabajo respiratorio o corregir la hipoxemia se puede utilizar la presión positiva en la vía aérea para prevenir y controlar la insuficiencia respiratoria. Este artículo desarrolla una breve revisión de las principales características clínicas, epidemiológicas, radiológicas, así como algunos de los diferentes tratamientos publicados en las últimas dos décadas.

Acute bronchiolitis is a common respiratory condition in children under 2 years old. It represents the main cause of childhood hospitalization characterized by the presence of wheezing associated with signs of an upper respiratory infection. The most common etiologic agent is respiratory syncytial virus. There is a lack of consensus regarding its clinical definition; and therefore, its treatment varies around the world. Diagnosis is clinical, without the need for routine laboratory or imaging. Various reviews have shown that bronchodilators, epinephrine, corticosteroids, and antibiotics, among others, lack efficacy, so their use is not suggested. Treatment continues to be supportive, by administering oxygen and maintaining adequate hydration. When it is not possible to reduce the work of breathing or correct the hypoxemia, positive airway pressure can be used to prevent and control respiratory failure. This article develops a brief review of the main clinical, epidemiological, and radiological characteristics, as well as some of the different treatments published in the last two decades.

Asma en niños: una revisión en torno a los cambios en su tratamiento / Asthma in children: a review of changes in treatment

El asma leve-moderada representa la mayor proporción de niños y adolescentes con asma en el mundo. Durante más de 25 años el tratamiento del asma permaneció invariable en torno al uso de controladores y rescatadores. Recientemente, diversas guías clínicas y sociedades científicas publicaron actualizaciones en torno al tratamiento de los pasos 1, 2 y 3 según GINA; existiendo diferencias y coincidencias entre ellas, a pesar de usar la misma evidencia publicada disponible. Este artículo de revisión se enfoca en tres guías clínicas qué por su popularidad y fácil acceso, son consultadas por diversos profesionales de la salud mostrando los principales cambios introducidos respecto a su edición previa y analizando brevemente la evidencia que existe detrás de estas recomendaciones. Finalmente se presenta un análisis de las principales limitaciones, contradicciones y aspectos aún por resolver.

Mild-moderate asthma represents the highest proportion of children and adolescents with asthma in the world. For more than 25 years, asthma treatment remained unchanged around the use of controllers and relievers. Recently, many clinical guidelines and scientific societies have published updates regarding the treatment of steps 1,2 and 3 according to GINA, with differences and coincidences between them, despite using the same available published evidence. This review article focuses on three clinical guides which, due to their popularity and easy access, are consulted by various health professionals, showing the main changes introduced compared to their previous edition and analyzing briefly the evidence behind these recommendations. Finally, an analysis of the main limitations, contradictions and aspects still to be resolved is presented.

High Rate of Infection by Only Oncogenic Human Papillomavirus in Amerindians.

Human papillomavirus (HPV), an etiological agent of cervical cancer (CC), has infected humans since ancient times. Amerindians are the furthest migrants out of Africa, and they reached the Americas more than 14,000 years ago. Some groups still remain isolated, and some migrate to towns, forming a gradient spanning urbanization. We hypothesized that, by virtue of their history, lifestyle, and isolation from the global society, remote Amerindian women have lower HPV diversity than do urban women (Amerindian or mestizo). Here we determined the diversity of the 25 most relevant cervical HPV types in 82 Amerindians spanning urbanization (low, medium, and high, consistent with the exposure to urban lifestyles of the town of Puerto Ayacucho in the Venezuelan Amazonas State), and in 29 urban mestizos from the town. Cervical, anal, oral, and introitus samples were taken, and HPVs were typed using reverse DNA hybridization. A total of 23 HPV types were detected, including 11 oncogenic or high-risk types, most associated with CC. Cervical HPV prevalence was 75%, with no differences by group, but Amerindians from low and medium urbanization level had significantly lower HPV diversity than mestizos did. In Amerindians, but not in mestizos, infections by only high-risk HPVs were higher than coinfections or by exclusively low-risk HPVs. Cervical abnormalities only were observed in Amerindians (9/82), consistent with their high HPV infection. The lower cervical HPV diversity in more isolated Amerindians is consistent with their lower exposure to the global pool, and transculturation to urban lifestyles could have implications on HPV ecology, infection, and virulence.IMPORTANCE The role of HPV type distribution on the disparity of cervical cancer (CC) incidence between human populations remains unknown. The incidence of CC in the Amazonas State of Venezuela is higher than the national average. In this study, we determined the diversity of known HPV types (the viral agent of CC) in Amerindian and mestizo women living in the Venezuelan Amazonas State. Understanding the ecological diversity of HPV in populations undergoing lifestyle transformations has important implication on public health measures for CC prevention.

[What is not searched, it is difficult to find: Chagas' disease]. / Quello che non si cerca difficilmente si trova: la malattia di Chagas.

A conservative estimation indicates that more than 400 000 Latin American immigrants are living in Italy. Several studies have shown that among these, the prevalence of Chagas disease is between 3.9% and 17%, so it is not unlikely to find a patient with this disease during a cardiology visit. How many patients from Latin America are diagnosed with heart failure in Italy and no one has ever thought about a possible Chagas disease? This brief review describes the situation of the disease in Italy, its characteristics, the etiology of this disease and its treatment. The latter aspect will be discussed considering the recent published results of the BENEFIT study, where it was found that treatment with benznidazole in patients with Chagas' cardiomyopathy is able to reduce significantly the detection of parasites in the blood, but it is not able to prevent clinical deterioration during 5 years of follow-up. The possible implications of these results will be discussed.

Endothelium trans differentiated from Wharton's jelly mesenchymal cells promote tissue regeneration: potential role of soluble pro-angiogenic factors.

BACKGROUND: Mesenchymal stem cells have a high capacity for trans-differentiation toward many adult cell types, including endothelial cells. Feto-placental tissue, such as Wharton's jelly is a potential source of mesenchymal stem cells with low immunogenic capacity; make them an excellent source of progenitor cells with a potential use for tissue repair. We evaluated whether administration of endothelial cells derived from mesenchymal stem cells isolated from Wharton's jelly (hWMSCs) can accelerate tissue repair in vivo. METHODS: Mesenchymal stem cells were isolated from human Wharton's jelly by digestion with collagenase type I. Endothelial trans-differentiation was induced for 14 (hWMSC-End14d) and 30 (hWMSC-End30d) days. Cell phenotyping was performed using mesenchymal (CD90, CD73, CD105) and endothelial (Tie-2, KDR, eNOS, ICAM-1) markers. Endothelial trans-differentiation was demonstrated by the expression of endothelial markers and their ability to synthesize nitric oxide (NO). RESULTS: hWMSCs can be differentiated into adipocytes, osteocytes, chondrocytes and endothelial cells. Moreover, these cells show high expression of CD73, CD90 and CD105 but low expression of endothelial markers prior to differentiation. hWMSCs-End express high levels of endothelial markers at 14 and 30 days of culture, and also they can synthesize NO. Injection of hWMSC-End30d in a mouse model of skin injury significantly accelerated wound healing compared with animals injected with undifferentiated hWMSC or injected with vehicle alone. These effects were also observed in animals that received conditioned media from hWMSC-End30d cultures. CONCLUSION: These results demonstrate that mesenchymal stem cells isolated from Wharton's jelly can be cultured in vitro and trans-differentiated into endothelial cells. Differentiated hWMSC-End may promote neovascularization and tissue repair in vivo through the secretion of soluble pro-angiogenic factors.

Postinfectious bronchiolitis obliterans in children: the South American contribution.

UNLABELLED: Postinfectious bronchiolitis obliterans (PIBO) is an infrequent chronic lung that causes irreversible obstruction and, or, obliteration of the smaller airways. This review particularly focuses on more than 30 studies from South America. CONCLUSION: The initial PIBO event occurs in the early years of life and is strongly associated with adenovirus infection and the need for mechanical ventilator support. Treatment requires a multidisciplinary strategy. Multicentre studies are needed to determine progression, optimal management and long-term follow-up.

Astenia en pacientes que asisten a la consulta externa: valoración a través de la escala de intensidad de fatiga (FSS) / Asthenia in patients attending the outpatient clinic: valuation through the rating scale fatigue

Muchos pacientes acuden a consulta externa con un conjunto inespecífico de síntomas y signos que sugieren el diagnóstico de astenia, sin encontrarse una causa orgánica que explique dichos síntomas. Se realizó un estudio prospectivo a nivel nacional para diagnosticar y cuantificar la intensidad de la astenia en estos pacientes y medir la eficacia de la sulbutiamina 400 mg/día como tratamiento farmacológicoa corto plazo de primera línea. Se realizó un estudio abierto, prospectivo y multicéntrico,en el cual se ingresaron 341 pacientes, que consultaron ambulatoriamente y que presentaban síntomas de astenia. A través de la escala de Intensidad de Fatiga (por sus siglas en inglés: Fatigue Severity Scale - FSS) se determinó la presencia de astenia en estos pacientes y se evaluó la eficacia de la sulbutiamina 400 mg/día de Laboratorios Leti S.A.V., Venezuela (Tekron®). El estudio tuvo una duración de 15 días, en los cuales el paciente fue evaluado tres veces: día 1 (inicio), día 7 y día 15. Si el paciente presentaba astenia (puntuación ≥ 36 puntos en la FSS), se le indicaba sulbutiamina400 mg/día con el desayuno por 15 días. El 74,7% de los pacientes evaluados fueron del sexo femenino, con una edad media de 43,7 ± 12,5 años y el 25,3% del sexo masculino con una edad media de 41,7 ± 13,5 años. Al inicio del estudio la media de la puntuación de la FSS fue de 49,7 ± 7,3 puntos; a los 7 días de tratamiento con 400 mg/día de sulbutiamina fue de 37,2 ± 8,8 puntos con una disminucióndel 25,2% y al día 15 fue de 28,0 ± 9,8 puntos con una disminución de 43,7% con respecto al inicio del tratamiento, resultando estadísticamente significativo (p< 0,0001 y p< 0,0001 al día 7 y día 15 vs inicio, respectivamente). El 77,7% de los pacientes respondieron al tratamiento al día 15. La sulbutiamina resultó ser un tratamiento muy bien tolerado, se reportaron eventos adversos leves en 132 pacientes (38,7%) al día 7 y en 115 pacientes(33,7%) al día 15...

Many patients attending out patient clinics with a set of nonspecific symptoms and signs that suggest the diagnosis asthenia, without organic cause to explain the symptoms. In order to determine which of was these patients confirmed the diagnosis of functional asthenia, was performed a prospective nation wide, study to diagnose and quantify the intensity of fatigue in these patients and measure the effectiveness of sulbutiamine 400 mg/day treatment short-term drug frontline. Was realized an open, prospective, multicenter study, which entered 341 outpatient patients which showed signs of fati gue. The Fatigue Severity Scale (FSS) was used as a tool for the diagnosis and evaluation of severity of fatigue and was evaluated the effectiveness of sulbutiamine 400 mg/day to Leti Laboratories, S.A.V. (Tekron®), as first line treatment.The duration of the study was 15 days, with 3 evaluations (day 1 or baseline, day 7 and day 15). The score of the FSS had to be ≥ 36 points to be enrolled. 74,7% of patients were females with a mean age of 43,7 ± 12,5 years old and 25,3% were males with a mean age of 41,7 ± 13,5 years old. At baseline, the FSS score was 49,7 ± 7,3 points; at day 7 was 37,2 ± 8,8 points with a decrease of 25,2% and at day 15 was 28,0 ± 9,8 points, with a decrease of 43,7% respective to baseline, being statistically significant (p< 0,0001 and p< 0,0001 at day 7 and day 15, respectively). The percentage of response to treatment was 77,7% at day 15. Sulbutiamine was a very well tolerated treatment, there were reported mild adverse events in 132 patients (38,7%) at day 7 and in 115 patients (33,7%) at day 15. Sulbutiamine 400 mg/day is a secure treatment, it is well tolerated and effective in improving the asthenia symptoms, as demonstrated in this clinical trial by the significant decrease in the FSS mean score and the percentage of patients with asthenia at day 15 of treatment

Immunological identification of Trypanosoma cruzi lineages in human infection along the endemic area.

Genotyping studies show a polarized geographic distribution of Trypanosoma cruzi lineages in humans. Here, we assessed their distribution along Latin America through an immunological approach we designated Western blot (WB) assay with Trypomastigote small-surface antigen (TSSA) I and TSSA II (TSSA-WB). These antigens are expressed by T. cruzi I (TCI; now TcI) and T. cruzi II (TCII; reclassified as TcII to TcVI) parasites. TSSA-WB showed good concordance with genotyping tests. An unexpected frequency of TSSA II recognition was observed in Colombia, Venezuela, and Mexico (northern region of Latin America). In Argentina and Paraguay (southern region), immunophenotyping confirmed the already reported TCII (TcII to TcVI) dominance. The lineage distribution between these regions showed significant difference but not among countries within them (except for Colombia and Venezuela). TSSA-WB shows TCII emergence in the northern region where TCI was reported as dominant or even as the unique T. cruzi lineage infecting humans.

An inexpensive antigen for serodiagnosis of Chagas' disease.

UNLABELLED: In this prospective study we evaluated the performance characteristics of a specific and sensitive antigen preparation (AgA) used in an enzyme-linked immunosorbent assay (ELISA) for the detection of anti-Trypanosoma cruzi antibodies in serum samples, for Chagas' disease diagnosis. The antigen production was achieved by combination of nutritional stress and autoclaving the parasites. Specificity and sensitivity were evaluated in two separate tests, using 152 sera from healthy individuals and 175 sera from Chagas' patients (70 by xenodiagnosis). Cross-reactivity was tested using 289 sera from patients who had a parasitological diagnosis of a disease known to induce antigenic responses towards T. cruzi. All of these sera were tested with our AgA-ELISA and with 3 commercial diagnosis kits. To evaluate the agreement of results between our AgA-ELISA and a "gold standard" test for Chagas, we tested 566 sera from an endemic area. RESULTS: sensitivity and specificity were 100%; cross-reactivity was the lowest compared with commercial kits. Overall agreement with the gold standard test was excellent (kappa = 0.92). AgA-ELISA exhibits levels of sensitivity, specificity and cross-reactivity comparable or superior to those shown, obtained with the commercial kits used in our country, while being at least 10 times less expensive. This balance between diagnostic accuracy and cost makes AgA-ELISA useful for blood bank screening in poor regions of the world suffering from Chagas' disease. Further validations of this antigenic formulation in other countries are necessary.

An inexpensive antigen for serodiagnosis of Chagas’ Disease

In this prospective study we evaluated the performance characteristics of a specific and sensitive antigen preparation (AgA) used in an enzyme-linked immunosorbent assay (ELISA) for the detection of anti-Trypanosoma cruzi antibodies in serum samples, for Chagas’ disease diagnosis. The antigen production was achieved by combination of nutritional stress and autoclaving the parasites. Specificity and sensitivity were evaluated in two separate tests, using 152 sera from healthy individuals and 175 sera from Chagas’ patients (70 by xenodiagnosis). Cross-reactivity was tested using 289 sera from patients who had a parasitological diagnosis of a disease known to induce antigenic responses towards T. cruzi. All of these sera were tested with our AgA-ELISA and with 3 commercial diagnosis kits. To evaluate the agreement of results between our AgA-ELISA and a “gold standard” test for Chagas, we tested 566 sera from an endemic area. Results: sensitivity and specificity were 100 percent; cross-reactivity was the lowest compared with commercial kits. Overall agreement with the gold standard test was excellent (kappa=0.92). AgA-ELISA exhibits levels of sensitivity, specificity and cross-reactivity comparable or superior to those shown, obtained with the commercial kits used in our country, while being at least 10 times less expensive. This balance between diagnostic accuracy and cost makes AgA-ELISA useful for blood bank screening in poor regions of the world suffering from Chagas’ disease. Further validations of this antigenic formulation in other countries are necessary.

Este estudio fue realizado para evaluar las características de sensibilidad y especificidad de una formulación antigénica (AgA), producida a bajo costo, para detectar anticuerpos dirigidos a Trypanosoma cruzi, en muestras de suero de pacientes con enfermedad de Chagas. El AgA fue producido por el efecto combinado de estrés nutricional y autoclave de los parásitos. La especificidad y sensibilidad fueron evaluadas en dos estudios separados, con 152 sueros de individuos sanos y 175 de pacientes Chagásicos. La reactividad cruzada con 289 sueros de pacientes con diagnóstico parasitológico de enfermedades con anticuerpos que reaccionan con antígenos de T. cruzi. Estos sueros fueron evaluados con AgA-ELISA y con tres estuches comerciales. 566 muestras de suero provenientes de un área endémica, fueron empleadas para estudiar la concordancia entre nuestro diagnostico y una prueba designada por nosotros como patrón oro estándar. Resultados: la sensibilidad y especificidad fue de 100 por ciento. El AgA presento el más bajo porcentaje de reactividad cruzada, respecto a los estuches comerciales evaluados. La concordancia con la prueba patrón oro, en Venezuela, fue excelente (kappa=0,92). En conclusión, Aga-ELISA, presentó niveles de sensibilidad, especificidad y de reactividad cruzada, comparables o superiores a los obtenidos por los tres estuches comerciales mas empleados en el país, pero con costos de producción al menos 10 veces menor. Este balance conveniente, favorece su potencial uso para el despiste en los bancos de sangre de los países pobres y endémicos para la enfermedad de Chagas. Futuras validaciones de esta formulación en otros países es necesaria.

Quilotórax congénito: una causa rara de distres neonatal reporte de caso / Congenital chylothorax: a neonatal case report

Introducción: El quilotórax congénito (QC) es un desorden respiratorio poco común; sin embargo, es la causa más frecuente de derrame pleural en recién nacidos (RN). Objetivo: Presentar un caso de QC como causa infrecuente de distrés respiratorio en un RN sano atendido en nuestro centro. Caso clínico: Un RN a término, sin factores de riesgo conocidos, nació por cesárea de urgencia por una inducción de parto fallida. Luego de un apgar adecuado, desarrolló en la primera hora de vida, retracción subcostal y quejido audible asociado a una saturación de oxígeno de 86% con oxígeno ambiental. La radiografía de tórax a las 2 horas reveló un velamiento total del pulmón derecho y desplazamiento del mediastino contralateral, decidiendo su conexión inmediata a ventilación mecánica convencional (VMC). La toracocentesis mostró 10 ml de un líquido ligeramente turbio, amarillo lechoso; con proteínas 4.1 g/dl; glucosa 95 mg/dl; LDH: 151 U/L; albúmina 3.1 g/dl y un recuento celular (predominio mononuclear) de 4000/mm3 que confirmó el diagnostico de QC. Luego de 36 horas de VMC y régimen cero, se extubó e inició un aporte enteral mínimo, sin requerir nuevamente oxígeno. Se mantuvo control radiológico periódico, observándose la resolución espontánea al 5 dia de vida sin necesidad de drenajes pleurales. Conclusión: El QC es una causa rara de distres respiratorio en el RN. Su reconocimiento y diagnóstico precoz permitió iniciar una terapia conservadora y disminuir el riesgo de complicaciones en este RN.

Serological diagnosis of Chagas disease: evaluation and characterisation of a low cost antigen with high sensitivity and specificity.

In spite of evident progress in the serology of Chagas disease, the requirement for new diagnostic antigens persists. We have evaluated different antigens obtained from Trypanosoma cruzi grown in medium rich in nutrients or under nutrient stress, autoclaved or sonicated and fractionated by differential centrifugation. The resulting antigens were evaluated for diagnosis of Chagas disease using ELISA. Immunofluorescence of the parasites demonstrated that nutrient stress induced changes in the distribution and density of antigens recognised by a pool of sera from experimentally infected mice. When evaluated using ELISA, it was evident that most fractions had good sensitivity but poor specificity. Surprisingly, the best specificity and sensitivity was observed with parasites cultured under nutrient stress and autoclaved. Furthermore this antigen had low cross reactivity with sera from other parasitic diseases, Leishmaniasis in particular. Western blot analysis demonstrated that autoclaving seems to non-specifically eliminate cross-reactive antigens. In conclusion, autoclaving epimastigotes of T. cruzi, after nutrient stress, allowed us to obtain an antigen that could be used in the serological diagnosis of Chagas disease.

[Clinical characteristics of respiratory infection due to Mycoplasma pneumoniae in hospitalized children]. / Características clínicas de la enfermedad respiratoria causada por Mycoplasma pneumoniae en niños hospitalizados.

INTRODUCTION: Studies on Mycoplasma pneumoniae infection are scarce in Chile. OBJECTIVE: To describe clinical characteristics associated with M. pneumoniae in children requiring hospitalization. MATERIAL AND METHODS: All children with a respiratory infection requiring hospitalizations between 2000-2005, whom had a M. pneumoniae specific IgM > or = 1:32, were analyzed. RESULTS: Fifty children meeting study criteria were identified with an average length of hospitalization of 4 days (range: 1-10); mean age was 5.4 years (46% were younger than 5 years). Common clinical features were cough (92%), fever (82%), malaise (74%) and respiratory distress (72%). At admission 40/45 children had hypoxemia. Chest-X ray showed interstitial pattern (69.3%), consolidation (51%) and hyperinsuflation (28.5%). Six patients had pleural effusion. Eighty four percent of patients had a favorable clinical outcome; eight children required admission to the PICU all of whom recovered. CONCLUSION: Respiratory infections associated with M. pneumoniae in our series of children had a highly variable and non-specific clinical spectrum. Chest-X rays showed different pattern in concordance with previous publications.

Serological diagnosis of Chagas disease: evaluation and characterisation of a low cost antigen with high sensitivity and specificity

In spite of evident progress in the serology of Chagas disease, the requirement for new diagnostic antigens persists. We have evaluated different antigens obtained from Trypanosoma cruzi grown in medium rich in nutrients or under nutrient stress, autoclaved or sonicated and fractionated by differential centrifugation. The resulting antigens were evaluated for diagnosis of Chagas disease using ELISA. Immunofluorescence of the parasites demonstrated that nutrient stress induced changes in the distribution and density of antigens recognised by a pool of sera from experimentally infected mice. When evaluated using ELISA, it was evident that most fractions had good sensitivity but poor specificity. Surprisingly, the best specificity and sensitivity was observed with parasites cultured under nutrient stress and autoclaved. Furthermore this antigen had low cross reactivity with sera from other parasitic diseases, Leishmaniasis in particular. Western blot analysis demonstrated that autoclaving seems to non-specifically eliminate cross-reactive antigens. In conclusion, autoclaving epimastigotes of T. cruzi, after nutrient stress, allowed us to obtain an antigen that could be used in the serological diagnosis of Chagas disease.

Características clínicas de la enfermedad respiratoria causada por Mycoplasma pneumoniae en niños hospitalizados / Clinical characterizes of respiratory infection due to Mycoplasma pneumoniae in hospitalized children

Introduction: Studies onMycoplasmapneumoniae infection are scarce in Chile. Objective: To describe clinical characteristics associated withM. pneumoniae in children requiring hospitalization. Material and Methods: All children with a respiratory infection requiring hospitalizations between 2000-2005, whom had aM. pneumoniae specific IgM ≥ 1:32, were analyzed. Results: Fifty children meeting study criteria were identified with an ave-rage length of hospitalization of 4 days (range: 1-10); mean age was 5.4 years (46 percent were younger than 5 years). Common clinical features were cough (92 percent), fever (82 percent), malaise (74 percent) and respiratory distress (72 percent). At admission 40/45 children had hypoxemia. Chest-X ray showed interstitial pattern (69.3 percent), consolidation (51 percent) and hyperinsuflation (28.5 percent). Six patients had pleural effusion. Eighty four percent of patients had a favorable clinical outcome; eight children required admission to the PICU all of whom recovered. Conclusión: Respiratory infections associated withM. pneumoniae in our series of children had a highly variable and non-specific clinical spectrum. Chest-X rays showed different pattern in concordance with previous publications.

Introducción: La infección por Mycoplasma pneumoniae es una condición respiratoria poco estudiada en nuestro medio. Objetivo: Describir las características clínicas de los niños hospitalizados porM. pneumoniae. Materiales y Métodos: Se analizaron todos los pacientes hospitalizados por infecciones respiratorias durante el 2000-2005, con IgM específica; se utilizó como diagnóstico de enfermedad por M. pneumoniae la presencia de fluorescencia verde manzana 2 a 3 positivo en títulos ≥ 1:32 diluciones. Resultados: Se analizaron 50 hospitalizaciones, con estadía promedio de 4 días (rango: 1-10); la edad promedio fue 5,4 años (46 por ciento bajo 5 años). Los síntomas más frecuentes fueron tos (92 por ciento), fiebre (82 por ciento), compromiso del estado general (74 por ciento) y dificultad respiratoria (72 por ciento). Al momento del ingreso 40/45 presentaron hipoxemia. La radiografía de tórax (RT) reveló infiltrado intersticial (69,3 por ciento), foco de consolidación (51 por ciento) e hi-perinsuflación (28,5 por ciento). Seis presentaron efusión pleural asociada. En 84 por ciento la evolución fue favorable; sin embargo, 8 niños ingresaron a la Unidad de Paciente Critico para monitorización. No hubo decesos Conclusiones: La infección respiratoria asociada aM. pneumoniae en niños produjo manifestaciones inespecíficas y variables de un caso a otro. La RT reveló una variedad de presentaciones similar a lo mostrado en la literatura médica.

Proliferation and bystander suppression induced by membrane and flagellar antigens of Trypanosoma cruzi.

We have studied, in vitro, proliferation induced by flagella (FE) and membrane (ME) antigenic fractions of T. cruzi epimastigotes, as well as their regulatory effect on the proliferative response to PPD (Protein Purified Derivative). Crude flagella as well as bands from Western blots of flagella and membrane of epimastigotes were tested. Crude flagella elicited higher proliferation in mononuclear cells from patients with Chagasic cardiomyopathy (CDM) than in patients with no evidence of cardiac pathology (INF). Fractionated antigens induced a lower proliferative response, in intensity as well as in frequency, than the crude extracts. With FE, bands between 150 and 24.3 kDa (B3 to B18 with the exception of B4 and B13) induced higher CPM (Counts Per Minute) in CDM. In INF only bands B7 (87.3 to 80.1 kDa), 9 (69.8 to 64.6 kDa) and 13 (45.4 to 41.5 kDa) had high CPM. ME bands also elicited higher proliferation in CDM. However, only 5 out of 14 bands gave CPM higher than 1000 in CDM and none in INF. The mean down regulation (DR) of most bands was similar in both groups. But the frequency of relevant DR elicited by FE was significantly higher in CDM. In contrast the frequency of up regulation (UR) was higher in INF. Bands 13 and 14 of ME did not induce DR in most INF. The discordance between the frequency of relevant DR in CDM and INF was more evident with ME than with FE. The frequency of (UR) was 50% or higher with all ME bands in INF, but, lower than 12% in CDM. The higher UR in INF and of DR in CDM, suggest the presence of some balance or interaction in INF that is lost in CDM. In ME there might be antigens that could be relevant for the immunoprofilaxis of Chagas' disease. The difference in the clinical status of the two groups seems to be associated with the recognition of different groups of antigens together with variations in the nature of the regulation of the response of mononuclear cells to these antigens.