Curva de aprendizaje para el diagnóstico ecográfico específico de masas anexiales / Learning curve for the specific ultrasound diagnosis of adnexal masses

OBJETIVO: Determinar el tiempo que requiere una curva de aprendizaje para diagnóstico ecográfico específico histopatológico en masas anexiales basándonos en cálculos estadísticos no influidos por la prevalencia según diferentes grados de experiencia. MÉTODOS: Estudio observacional, descriptivo, transversal. Se estudiaron imágenes de 108 masas anexiales. La prueba estándar de oro fue el reporte histopatológico definitivo. Se comparó el rendimiento diagnóstico de 4 examinadores con la siguiente experiencia en diagnóstico ecográfico de patología anexial: A > 20 años, B ≤ 20 hasta > 10 años, C ≤ 10 hasta > 5 años y D ≤ 5 años, analizando solo imágenes y sin datos clínicos de las pacientes, para emitir un diagnóstico específico a libre escritura. RESULTADOS: Prevalencia de masas malignas 17,2 % (15/87). Nivel de confianza en los examinadores se consideró según falta de respuesta diagnóstica: alto (<6 %) con experiencia de más de 10 años y moderado a bajo ≤ 10 años. Examinadores con más de 5 años siempre mostraron likelihood ratio positivo mayor a 10, exactitud diagnóstica mayor a 90 % y Odds ratio diagnóstica mayor a 46, no así para examinador con menor tiempo de experiencia, quién presentó resultados con mala utilidad clínica. El cambio de probabilidad de acierto específico pre-test a post-test mejoró consistentemente con los años de experiencia. CONCLUSIÓN: Se necesitarían más de 10 años de experiencia con especial dedicación a ecografía ginecológica avanzada para un rendimiento diagnóstico específico deseado junto con alta confianza en ecografía de masas anexiales.

OBJECTIVE: To determine the time required for a learning curve of histopathological specific ultrasound diagnosis in adnexal masses based on statistical calculations not influenced by prevalence according to different degrees of experience. METHODS: Observational, descriptive, cross-sectional study. Images of 108 adnexal masses were studied. The gold standard test was the definitive histopathological report. The diagnostic performance of 4 examiners with the following experience in ultrasound diagnosis of adnexal pathology: A > 20 years, B ≤ 20 to > 10 years, C ≤ 10 to > 5 years and D ≤ 5 years was compared, analyzing only images and blinded of clinical data of the patients, to issue a specific diagnosis with free writing. RESULTS: Prevalence of malignant masses 17.2% (15/87). The level of confidence in the examiners was considered according to the lack of diagnostic response: high (<6%) with experience of more than 10 years and moderate to low ≤ 10 years. The examiners with more than 5 years always showed likelihood ratio positive greater than 10, diagnostic accuracy greater than 90% and diagnostic Odds ratio greater than 46, not so for the examiner with less experience time who presented results with little clinical utility. The change in specific probability from pre-test to post-test improved consistently with years of experience. CONCLUSION: More than 10 years of experience with special dedication to advanced gynecological ultrasound are probably needed for a desired specific diagnostic performance coupled with high confidence in adnexal mass ultrasound.

Meningitis aséptica por virus parotídeo asociada a la vacuna

Resumen Comunicamos el caso de un lactante mayor previamente sano, que luego de tres semanas de recibir la vacuna SPR (sarampión, parotiditis, rubeola) presentó fiebre, aumento de volumen parotídeo y compromiso de conciencia. Se diagnosticó una meningitis aséptica, con pleocitosis en el LCR de predominio mononuclear, detectándose virus parotídeo en LCR por biología molecular. En el Instituto de Salud Pública de Chile se realizó serología (IgM e IgG) que resultó positiva. La muestra de saliva confirmó la etiología por virus parotídeo con genotipo N. La evolución fue favorable, sin secuelas al seguimiento a seis meses. Ante esta situación clínica, se revisó la información respecto a la asociación y causalidad de esta entidad clínica y vacuna SPR, focalizado en diferentes cepas del virus parotiditis.

Abstract We report the case of an older infant with no prior morbidity that approximately 3 weeks after receiving MMR vaccination (measles, mumps, rubella) was hospitalized for feverish symptoms, increased parotid volume and compromised consciousness. Aseptic meningitis was diagnosed, detecting pleocytosis in the CSF, predominantly mononuclear, and confirming by molecular biology, presence of parotid virus in CSF. A study was carried out by the Institute of Public Health of Chile, where serology (IgM and IgG) was positive. Saliva sample confirmed the etiology of parotid virus with genotype N. The evolution was favorable and at 6-month follow-up, there were no sequelae. Given this clinical situation, information regarding the association and causality of this clinical entity and the MMR vaccine, focused on different strains of the mumps virus, was reviewed.

Review: Strategies for enteric methane mitigation in cattle fed tropical forages.

Methane (CH4) is a greenhouse gas (GHG) produced and released by eructation to the atmosphere in large volumes by ruminants. Enteric CH4 contributes significantly to global GHG emissions arising from animal agriculture. It has been contended that tropical grasses produce higher emissions of enteric CH4 than temperate grasses, when they are fed to ruminants. A number of experiments have been performed in respiration chambers and head-boxes to assess the enteric CH4 mitigation potential of foliage and pods of tropical plants, as well as nitrates (NO3-) and vegetable oils in practical rations for cattle. On the basis of individual determinations of enteric CH4 carried out in respiration chambers, the average CH4 yield for cattle fed low-quality tropical grasses (>70% ration DM) was 17.0 g CH4/kg DM intake. Results showed that when foliage and ground pods of tropical trees and shrubs were incorporated in cattle rations, methane yield (g CH4/kg DM intake) was decreased by 10% to 25%, depending on plant species and level of intake of the ration. Incorporation of nitrates and vegetable oils in the ration decreased enteric CH4 yield by ∼6% to ∼20%, respectively. Condensed tannins, saponins and starch contained in foliages, pods and seeds of tropical trees and shrubs, as well as nitrates and vegetable oils, can be fed to cattle to mitigate enteric CH4 emissions under smallholder conditions. Strategies for enteric CH4 mitigation in cattle grazing low-quality tropical forages can effectively increase productivity while decreasing enteric CH4 emissions in absolute terms and per unit of product (e.g. meat, milk), thus reducing the contribution of ruminants to GHG emissions and therefore to climate change.

Análisis de Cienciometría y Patentometría para Determinar el Panorama de Conocimiento en Tecnologías de Innovación: Dos Equipos de Ultrasonido Terapéuticos / Scientometric and Patentometric Analysis to Determine the Knowledge Landscape in Innovation Technologies: The Therapeutic Ultrasound Equipments

Resumen En este artículo se propone un modelo de información para determinar el panorama de las tecnologías emergentes relacionadas con los equipos de terapia de ultrasonido, el cual permite la identificación de cuatro grandes categorías en el área de la investigación y el desarrollo dentro del campo, utilizando una metodología competitiva que incorpora la evaluación de publicaciones científicas y un análisis de patentes; utilizando distintas bases de datos mediante la agrupación por palabras clave y cronología. Se examinaron las bases de datos de Google Académico, Scopus, Springer, Sage Journals, ScienceDirect y Academic.edu para consultar artículos y publicaciones científicas; se encontraron alrededor de 67,000 artículos de los cuales únicamente 119 cumplen con los criterios de exclusión, en donde se analizó cómo está conformado un equipo de ultrasonido, sus distintas aplicaciones y nuevas tendencias desde un enfoque de interfaz humano computadora. Las bases de datos utilizadas para la recolección de las patentes fueron Patentscope, Google Patents, e Invenes, así como las bases de WIPO y USPTO; en las cuales se encontraron alrededor 421 patentes con relación a los equipos de ultrasonido, los países en los que se registró la patente y la forma en la que la clasifican. Finalmente, sólo 16 patentes cumplen con los criterios de exclusión. Los resultados indican que Estados Unidos es la nación con más difusión tanto en la publicación de artículos como en patentes.

Abstract This paper proposes an information model to determine the panorama of emerging technologies related to ultrasound equipment, which allows the identification of four main categories of research and development within the field, using a competitive methodology that incorporates the evaluation of scientific publications and a patent analysis; by using different databases by keywords clustering and years relevance. Google Scholar, Scopus, Springer, Sage Journals, ScienceDirect and Academic.edu databases were examined to consult articles and scientific publications; about 67,000 articles were found, of which only 119 met the exclusion criteria, the different parts of an ultrasound equipment, its different applications and new trends were analysed. The databases of Patentscope, Google Patents, and Invenes, as well as the bases of WIPO and USPTO were used for the recollection of patents; in which about 421 patents were found in relation to ultrasound equipment, the country in which the patent was registered and the way it is classified. Finally, only 16 patents meet the exclusion criteria. The results show USA as the country with the most diffusion rate in publishing articles and patents.

[Aseptic meningitis due to mumps vaccine. Case report and review of the literature]. / Meningitis aséptica por virus parotídeo asociada a la vacuna.

We report the case of an older infant with no prior morbidity that approximately 3 weeks after receiving MMR vaccination (measles, mumps, rubella) was hospitalized for feverish symptoms, increased parotid volume and compromised consciousness. Aseptic meningitis was diagnosed, detecting pleocytosis in the CSF, predominantly mononuclear, and confirming by molecular biology, presence of parotid virus in CSF. A study was carried out by the Institute of Public Health of Chile, where serology (IgM and IgG) was positive. Saliva sample confirmed the etiology of parotid virus with genotype N. The evolution was favorable and at 6-month follow-up, there were no sequelae. Given this clinical situation, information regarding the association and causality of this clinical entity and the MMR vaccine, focused on different strains of the mumps virus, was reviewed.

Diseño de Exoesqueleto con base en Cuatro Casos de Estudio de Rehabilitación de Miembro Superior / Design of an Exoskeleton based on Four Cases of Upper Limb Rehabilitation Study

Resumen: En este artículo se presenta un enfoque para rehabilitación pasiva de miembro superior mediante la formulación de cuatro casos de estudio haciendo un análisis de las patologías y los ejercicios que se aplican. Para llevar a cabo la experimentación en los casos propuestos se registraron los datos de las trayectorias de las articulaciones del brazo de un paciente realizando los ejercicios de rehabilitación con un terapeuta. Se diseñó el exoesqueleto ERMIS de siete grados de libertad para emular los movimientos anatómicos en el brazo durante la rehabilitación a partir de los requerimientos de los casos de estudio. Para validar el funcionamiento del exoesqueleto en los casos se simuló el modelo dinámico del ERMIS y se compararon los datos con los datos muestreados de los ejercicios. Al final se presentan los resultados obtenidos de los ejercicios realizados con el exoesqueleto, obteniendo en la precisión un desempeño promedio del 95% en los movimientos de hombro, codo y muñeca al emular la terapia con timón.

Abstract: This paper presents an approach for passive upper limb rehabilitation based on four case studies by analyzing the pathologies and exercises that are applied. To carry out the experimentation in the proposed cases, the data from the trajectories of the patient's arm articulations were registered, performing the rehabilitation exercises with a therapist. The ERMIS exoskeleton´s seven degrees of freedom was designed to emulate the anatomical movements in the arm during rehabilitation from the requirements of the case studies. To validate the exoskeleton performance in the study cases, the ERMIS's dynamic model was simulated and the data were compared with the sampled data of the exercises. At the end, the results obtained from exoskeleton exercises emulating rudder therapy, where shoulder, elbow and wrist movements were showed with an accuracy of 95%.

Taxonomy and phylogeny of Trichuris globulosa Von Linstow, 1901 from camels. A review of Trichuris species parasitizing herbivorous.

At the present work, we carried out a morph-biometrical and molecular study of Trichuris species isolated from Camelus dromedarius from Iran and from Ovis aries from South Africa comparatively with other species of Trichuris from different herbivorous hosts and geographical regions. The population from camels from Iran was identified as Trichuris globulosa. Two different morphometrically populations of Trichuris sp. from sheep from South Africa were identified: Trichuris ovis and Trichuris skrjabini. Ribosomal data did not reveal significate differences in the ITS2 sequences between T. ovis and T. globulosa to assess a specific determination. The mitochondrial data suggest that T. globulosa constitute a different genetic lineage to T. ovis. Cytochrome c-oxidase and cytochrome b partial gene sequences corroborated the existence of a different genetic lineage of T. ovis from sheep of South Africa that would be closely related to the populations of T. globulosa from camels from Iran. The cytochrome c-oxidase and cytochrome b partial gene sequences of T. globulosa have been reported for the first time.

Loss of genetic variability in social spiders: genetic and phylogenetic consequences of population subdivision and inbreeding.

The consequences of population subdivision and inbreeding have been studied in many organisms, particularly in plants. However, most studies focus on the short-term consequences, such as inbreeding depression. To investigate the consequences of both population fragmentation and inbreeding for genetic variability in the longer term, we here make use of a natural inbreeding experiment in spiders, where sociality and accompanying population subdivision and inbreeding have evolved repeatedly. We use mitochondrial and nuclear data to infer phylogenetic relationships among 170 individuals of Anelosimus spiders representing 23 species. We then compare relative mitochondrial and nuclear genetic variability of the inbred social species and their outbred relatives. We focus on four independently derived social species and four subsocial species, including two outbred-inbred sister species pairs. We find that social species have 50% reduced mitochondrial sequence divergence. As inbreeding is not expected to reduce genetic variability in the maternally inherited mitochondrial genome, this suggests the loss of variation due to strong population subdivision, founder effects, small effective population sizes (colonies as individuals) and lineage turnover. Social species have < 10% of the nuclear genetic variability of the outbred species, also suggesting the loss of genetic variability through founder effects and/or inbreeding. Inbred sociality hence may result in reduction in variability through various processes. Sociality in most Anelosimus species probably arose relatively recently (0.1-2 mya), with even the oldest social lineages having failed to diversify. This is consistent with the hypothesis that inbred spider sociality represents an evolutionary dead end. Heterosis underlies a species potential to respond to environmental change and/or disease. Inbreeding and loss of genetic variability may thus limit diversification in social Anelosimus lineages and similarly pose a threat to many wild populations subject to habitat fragmentation or reduced population sizes.

Embarazo cornual: tratamiento médico con dosis única de metotrexato / Cornual pregnancy treated with single intramuscular methotrexate dose

Presentamos un caso de embarazo cornual o intersticial diagnosticado en forma precoz a través de ecografía transvaginal, tratado exitosamente, en forma conservadora, con dosis única sistémica de metotrexato.

We present a case of cornual or interstitial pregnancy diagnosed during early stage through transvaginal ultrasound, treated successfully with single systemic intramuscular methotrexate dose.

Complete separation along matrilines in a social spider metapopulation inferred from hypervariable mitochondrial DNA region.

The distribution and quantity of genetic diversity may be profoundly influenced by the emergence and dynamics of social groups. Permanent social living in spiders has resulted in the subdivision of their populations in more or less isolated colony lineages that grow, proliferate and become extinct without mixing with one another. A newly discovered hypervariable mitochondrial DNA region allowed us to examine the fine scale metapopulation structure in the social Anelosimus eximius. We sampled 39 colonies in Ecuador and French Guiana and identified 25 haplotypes. The majority of colonies contained one haplotype. Additional haplotypes occurred in approximately 15% of the colonies, and were always closely related to the common colony haplotype. Our findings confirm that colonies consist of single matrilines, with within-colony variation explained by mutations within the matriline. We thus found no evidence of mixing of matrilines. Likewise, colonies in a cluster often shared a haplotype, implying common colony ancestry. In few cases, however, haplotypes were shared between more distant colonies, providing evidence for occasional longer distance dispersal and/or widespread colony lineages. The geographical localities of colonies were incongruent with phylogenetic trees and haplotype networks, showing that some areas contained two or more matrilines. Hence, females do not migrate into foreign colonies, but faithfully remain within their own colony lineage, even when they disperse into new areas. These results indicate that the fine scale metapopulation structure of pure matrilines is maintained over the long term and that colony turnover is not extensive or radical enough to homogenize entire geographical areas. Genetic diversity is thus preserved to some extent at the metapopulation level.

Mitogen-activated protein kinase phosphatase-1 (MKP-1) impairs the response to anti-epidermal growth factor receptor (EGFR) antibody cetuximab in metastatic colorectal cancer patients.

BACKGROUND: The validation of KRAS mutations as a negative marker of response to anti-epidermal growth factor receptor (EGFR) antibodies has meant a seminal advance towards treatment individualisation of colorectal cancer (CRC) patients. However, as a KRAS wild-type status does not guarantee a response to anti-EGFR antibodies, a current challenge is the identification of other biomarkers of response. On the basis of pre-clinical evidence, we hypothesised that mitogen-activated protein kinase phosphatase-1 (MKP-1), a phosphatase that inactivates MAPKs, could be a mediator of resistance to anti-EGFR antibodies. METHODS: Tumour specimens from 48 metastatic CRC patients treated with cetuximab-based chemotherapy were evaluated for KRAS and BRAF mutational status and MKP-1 expression as assessed by immunohistochemistry. RESULTS: As expected, clinical benefit was confined to wild-type KRAS and BRAF patients. Mitogen-activated protein kinase phosphatase-1 was overexpressed in 16 patients (33%) and was not associated with patient baseline clinicopathological characteristics and KRAS mutational status. All patients with BRAF mutations (n=3) had MKP-1 overexpression. Among KRAS wild-type patients, MKP-1 overexpressors had a 7% response rate (RR), whereas patients not overexpressing MKP-1 had a 44% RR (P=0.03). Moreover, median time to progression was significantly longer in MKP-1 non-overexpressing patients (32 vs 13 weeks, P=0.009). CONCLUSION: These results support the concept of MKP-1 as a promising negative marker of response to cetuximab-based treatment in CRC patients with wild-type KRAS.

Síndrome hemolítico urémico asociado a infección intestinal por Escherichia coli productora de shigatoxina (STEC) en pacientes chilenos: aspectos clínicos y epidemiológicos / Hemolytic uremic syndrome associated to shigatoxin producing Escherichia coli in Chilean children: clinical and epidemiological aspects

Clinical and epidemiological aspects of shigatoxin producing E. coli (STEC) infections and hemolytic uremic syndrome (HUS) are reviewed. Surveillance results from 14 sentinel centers during 2000-2002 showed a mean incidence rate of 3.4 HUS cases per 100.000 children, with the highest incidence in the 6 to 28 month age group. Disease is endemic with summer peaks. Between 1988 and 2002 we obtained the clinical characteristics of a group of 119 HUS children with the following results: mean age 16 months, bloody diarrhea 57.8 percent, no previous diarrhea 9 percent, 60 percent received antibiotics, 72 percent had oligoanuria, 53 percent required dialysis, 15 percent had seizures and 31 percent had dizziness; mortality was 3 percent. Four foodborne outbreaks have been detected in Santiago, two outbreaks occurred in household settings, one in a Day Care Center and one in a Neonatal Unit. Recommendations for diagnosis, treatment and prevention of STEC infections, including potential vaccines are discussed.

Se revisan y actualizan aspectos clínicos y epidemiológicos de las infecciones por Escherichia coli productora de shigatoxina (STEC), y el síndrome hemolítico urémico (SHU). Se incluyen resultados de una vigilancia de SHU en 14 centros centinelas (2000-2002), que mostró una incidencia promedio de 3,4 casos por 100.000 niños, 78 por ciento) en el grupo de 6 a 48 meses. Esta vigilancia reflejó una situación endémica, con aumento en verano. Se analiza la observación clínica protocolizada de 119 pacientes con SHU hospitalizados en la Región Metropolitana (RM) (1988 y 2002). Edad promedio: 16 meses. El 578 por ciento> tenía diarrea con sangre, 9 por ciento> no tenía diarrea previa, 60 por ciento> recibió antibacterianos, 72 por ciento> presentó oligoanuria y 53 por ciento> necesitó diálisis. El 31 por cientoo tuvo compromiso de conciencia y 15 por cientoo presentó convulsiones. Letalidad 3 por ciento. Se analizan brotes de STEC asociados a alimentos ocurridos en la RM en el hogar (2), un jardín infantil (1) y en un servicio de neonatología (1). Finalmente, se entregar recomendaciones para el manejo clínico y prevención, se revisan los criterios diagnósticos, nuevas estrategias terapéuticas y progresos en el desarrollo de vacunas.

Follaje de árboles y arbustos en los sistemas de producción bovina de doble propósito / Foliage of trees and shrubs in livestock systems of dual purpose

El follaje de arbustivas y arbóreas tropicales representan una fuente importante de nutrimentos para el ganado bovino en pastoreo de gramíneas tropicales. La composición química, digestibilidad y consumo del follaje de arbustivas y arbóreas son generalmente satisfactorios para su aprovechamiento por los rumiantes, aportando proteína en el rumen que favorece una rápida disponibilidad de nitrógeno para el crecimiento microbiano. Sin embargo, la disponibilidad de energía en relación a la del nitrógeno en el rumen, parece ser una restricción para el uso eficiente del follaje. La incorporación del follaje de arbustivas y árboles forrajeros en la ración de rumiantes tiene el potencial para aumentar la producción animal en sistemas de doble propósito en los trópicos, ya que son una fuente importante de nutrimentos para el ganado que consume gramíneas bajo pastoreo.

Foliage of tropical trees and shrubs represents an important source of nutrients for cattle grazing tropical grasses. Chemical composition, digestibility and intake of foliage of shrubs and trees are generally satisfactory for their utilization by ruminants, supplying protein to the rumen that promotes a readily available nitrogen for microbial growth. However, energy availability relative to nitrogen in the rumen, seems to be a constraint to the efficient use of foliage Incorporation of foliage of trees and shrubs in ruminant rations has the potential to increase animal production in dual-purpose systems in the tropics, since they are an important source of nutriments for livestock under grazing conditions.

Survival benefits select for group living in a social spider despite reproductive costs.

The evolution of cooperation requires benefits of group living to exceed costs. Hence, some components of fitness are expected to increase with increasing group size, whereas others may decrease because of competition among group members. The social spiders provide an excellent system to investigate the costs and benefits of group living: they occur in groups of various sizes and individuals are relatively short-lived, therefore life history traits and Lifetime Reproductive Success (LRS) can be estimated as a function of group size. Sociality in spiders has originated repeatedly in phylogenetically distant families and appears to be accompanied by a transition to a system of continuous intra-colony mating and extreme inbreeding. The benefits of group living in such systems should therefore be substantial. We investigated the effect of group size on fitness components of reproduction and survival in the social spider Stegodyphus dumicola in two populations in Namibia. In both populations, the major benefit of group living was improved survival of colonies and late-instar juveniles with increasing colony size. By contrast, female fecundity, female body size and early juvenile survival decreased with increasing group size. Mean individual fitness, estimated as LRS and calculated from five components of reproduction and survival, was maximized for intermediate- to large-sized colonies. Group living in these spiders thus entails a net reproductive cost, presumably because of an increase in intra-colony competition with group size. This cost is traded off against survival benefits at the colony level, which appear to be the major factor favouring group living. In the field, many colonies occur at smaller size than expected from the fitness curve, suggesting ecological or life history constraints on colony persistence which results in a transient population of relatively small colonies.

Control de dispositivos intratubarios Essure mediante estudios de imágenes / Detection and control of Essure device by pelvic radiography and ultrasound

Objetivo: Comparar la efectividad en la detección y control del dispositivo intratubario (DIT) Essure por medio de la radiografía abdominopélvica y el ultrasonido. Método: Control de los primeros 5 casos de esterilización tubaria ambulatoria con Essure, después de 1 y 2 años de su inserción, mediante radiografía abdominopélvica y ecografía transvaginal. Resultados: Ambos exámenes de imágenes permitieron corroborar la presencia del dispositivo Essure en las 5 pacientes, al completar su primer y segundo año desde su inserción. Conclusión: Tanto la radiografía abdominopélvica como la ecografía transvaginal, permiten detectar y controlar la presencia del DIT Essure. El ultrasonido realizado por el ginecólogo en la consulta, puede reemplazar a la radiografía simple, como método de detección y control de los dispositivos intra-tubarios (Essure). Las ventajas comparativas permiten concluir que el ultrasonido, no irradia a la paciente y permite explorar el resto de la anatomía de los órganos sexuales internos durante el mismo procedimiento. Sin embargo, es de mayor costo que la radiografía.

Objective: To compare the effectiveness in the detection and control of Essure by pelvic radiography and ultrasound. Method: Control of the first 5 cases of ambulatory sterilization with Essure after 1 and 2 years. Detection and control by pelvic x-ray and transvaginal ultrasonography. Results: Both methods allowed corroborating the presence of the Essure device in the 5 patients, when completing their first and second year from the insertion. Conclusion: As much the pelvic x-ray as the transvaginal ultrasound allows to detect and check the presence of the Essure device. The transvaginal ultrasonography can replace the x-ray like method of detection and check of the Essure devices. The comparative advantages allow concluding that the ultrasound usually is available for the gynecologist, does not radiate the patient and allows exploring the internal sexual organs anatomy during the same act. Nevertheless, it is of greater cost than x-ray.

Tratamiento selectivo de los episodios de neutropenia febril en niños con cáncer: Comité de Infectología, Programa Infantil Nacional de Drogas Antineoplásicas (PINDA) / Selective treatment of febrile neutropenia in pediatric cancer patients

El manejo de los pacientes pediátricos con cáncer y neutropenia febril (NF) requiere de su clasificación en alto o bajo riesgo de adquirir infecciones bacterianas invasoras (IBI), con el fin de implementar estrategias selectivas de tratamiento. Basados en nuestra experiencia y publicaciones internacionales al respecto, proponemos recomendaciones para el diagnóstico y manejo de niños con cáncer y NF, categorizadas según riesgo de IBI. Todos los pacientes pediátricos que presenten episodios de NF deben ser ingresados al hospital por al menos 24 horas. Durante este lapso se efectuará su evaluación clínica y de laboratorio con el objeto de clasificar el riesgo de este episodio y precisar el (los) posible(s) foco(s). Los pacientes de alto riesgo deben continuar internados hasta su recuperación. Los de bajo riesgo pueden ser manejados en forma ambulatoria. La elección de la terapia antimicrobiana inicial y los criterios para su ajuste deberán basarse en el hallazgo o no de focos infecciosos y en los patrones epidemiológicos e institucionales de susceptibilidad. La reevaluación de ambos grupos debe ser periódica (al menos en los días 3, 5 y 7 de evolución), y la respuesta terapéutica será clasificada como favorable o desfavorable según criterios clínicos y parámetros de laboratorio preestablecidos.

Mucormicosis en Pediatría / Mucormycosis in Pediatrics

La mucormicosis es una infección infrecuente causada por hongos oportunistas que pertenecen al orden Mucorales, familia Mucoraceae, cuyas características son invasión vascular por hifas, lo que determina trombosis e infartos. En general afecta pacientes con enfermedades subyacentes y produce infecciones severas invasoras y a menudo fulminantes. Algunas condiciones de riesgo para contraer la mucormicosis son: cetoacidosis diabética, terapia inmunosupresora, leucemia y linfomas con neutropenia prolongada. Se describen varias presentaciones clínicas, según su localización anatómica, siendo la forma rinocerebral la más frecuente, especialmente en pacientes diabéticos. Aunque esta infección tiene una alta morbimortalidad, su pronóstico ha mejorado los últimos años, en base a medidas terapeuticas como la oportuna corrección de los factores predisponentes, uso de anfotericina B y una cirugía precoz y agresiva. Es muy importante sospechar esta infección en pacientes con factores predisponentes de manera de hacer un diagnóstico precoz.

Mucormicosis pulmonar / Pulmonary mucormycosis

Se presenta el caso de un niño de 10 años portador de una leucemia linfoblástica aguda, que encontrándose neutropénico a consecuencia de su tratamiento quimioterápico, presentó un absceso pulmonar. Recibió varios antimicrobianos previos a su drenaje quirúrgico. El estudio histopatológico identificó una mucormicosis siendo tratado con anfotericina B deoxicolato, con buena respuesta y evolución. La sospecha clínica precoz de la infección micótica en un niño con factores de riesgo, especialmente inmunocomprometidos y diabéticos, y su tratamiento oportuno, son fundamentales para disminuir la alta mortalidad de está enfermedad oportunista. Se enfatiza la importancia del tratamiento combinado médico quirúrgico.

Agentes causantes de infecciones del torrente circulatorio en niños con cáncer, en cinco hospitales de Santiago, 1994-1998 / Causative agents of bloodstream infections in Chilean pediatric patients with cancer

Background: Pediatric patients in treatment for cancer can have fatal bacterial infections. Thus, in the presence of fever or other signs infection, antimicrobials have to be prescribed empirically. Aim: To know the causative agents of bacteremia in children with cancer, their changes with time and between different hospitals and their patterns of susceptibility. Material and methods: We reviewed the blood cultores of children with cancer in five hospitals of Santiago, from 1994 at 1998. Results: During the study period, 707 agents were isolated. The most frequently isolated species or genus were coagulase negative Staphylococcus (43 percent), Staphylococcus aureus (16 percent), Escherichia coli (9 percent), Klebsiella spp. (8 percent), Pseudomonas spp. (5 percent) and Candida spp. (4 percent). Coagulase negative Staphylococcus was 55 percent resistant to meticilin and S. aureus was 44 percent resistant. Enterobacteriae had 15 percent resistance to gentamicin and amikacin, 2 percent to imipenem, 26 percent to ceftriaxone, 21 percent to cefotaxim and 20 percent to ceftazidim. Among non fermenting agents resistance was 6 percent for imipenem, 9 percent for amikacin 10 percent for ciprofloxacin, 19 percent for ceftazidim and 22 percent for cefoperazone. The resistance of Streptococcus spp. (non pneumoniae) to penicillin reached 50 percent and that of Enterococcus spp. was of 33 percent. Conclusions: Treatment for pediatric patients with cancer must be modified and new guidelines including more active medications for patients at risk for bacteremia, should be devised