Reaching environmental levels of 244Pu by accelerator mass spectrometry at the Centro Nacional de Aceleradores.

244Pu (T1/2 = 81 My) is the longest-lived, most minor, and the most understudied Pu isotope. The anthropogenic production of 244Pu is linked to nuclear detonations. Reported 244Pu/239Pu atom ratios in environmental samples range from below 10-6 to above 10-3. This work discusses the performance of the 1 MV Accelerator Mass Spectrometry system at the Centro Nacional de Aceleradores (CNA, Seville, Spain) to analyse 244Pu at environmental levels. The presence of 232Th traces in the Pu sample limits the sensitivity of the technique through the formation of the diatomic trication (232Th12C)3+, of mass 244 u, which must be suppressed by adjusting the stripper gas pressure. A244Pu background of 0.0075 fg (2 × 104 at) is demonstrated for samples that have undergone a chemical treatment. The reliability of the technique is proved through the analysis of three reference sediments provided by the International Atomic Energy Agency (IAEA-412, IAEA-465, IAEA-385). 244Pu results are complemented with 239Pu, 240Pu, 241Pu and 236U and their relative isotopic abundances are discussed.

Phosphate-Arsenic Interactions in Halophilic Microorganisms of the Microbial Mat from Laguna Tebenquiche: from the Microenvironment to the Genomes.

Arsenic (As) is a metalloid present in the earth's crust and widely distributed in the environment. Due to its high concentrations in the Andean valleys and its chemical similarity with phosphorus (P), its biological role in Andean Microbial Ecosystems (AMEs) has begun to be studied. The AMEs are home to extremophilic microbial communities that form microbial mats, evaporites, and microbialites inhabiting Andean lakes, puquios, or salt flats. In this work, we characterize the biological role of As and the effect of phosphate in AMEs from the Laguna Tebenquiche (Atacama Desert, Chile). Using micro X-ray fluorescence, the distribution of As in microbial mat samples was mapped. Taxonomic and inferred functional profiles were obtained from enriched cultures of microbial mats incubated under As stress and different phosphate conditions. Additionally, representative microorganisms highly resistant to As and able to grow under low phosphate concentration were isolated and studied physiologically. Finally, the genomes of the isolated Salicola sp. and Halorubrum sp. were sequenced to analyze genes related to both phosphate metabolism and As resistance. The results revealed As as a key component of the microbial mat ecosystem: (i) As was distributed across all sections of the microbial mat and represented a significant weight percentage of the mat (0.17 %) in comparison with P (0.40%); (ii) Low phosphate concentration drastically changed the microbial community in microbial mat samples incubated under high salinity and high As concentrations; (iii) Archaea and Bacteria isolated from the microbial mat were highly resistant to arsenate (up to 500 mM), even under low phosphate concentration; (iv) The genomes of the two isolates were predicted to contain key genes in As metabolism (aioAB and arsC/acr3) and the genes predicted to encode the phosphate-specific transport operon (pstSCAB-phoU) are next to the arsC gene, suggesting a functional relationship between these two elements.

Quiste folicular pigmentado perianal: variante múltiple inusual / Perianal pigmented follicular cyst: unusual multiple variant

Los quistes foliculares pigmentados son quistes epiteliales muy infrecuentes. Se describen como lesiones papulares pigmentadas, de carácter benigno, que generalmente se ubican en la cabeza o cuello. Surgen de manera única, siendo la variante múltiple aún menos frecuente. A continuación, se presenta el caso de un hombre joven, con antecedentes de VIH en terapia antiretroviral, quien consultó por la presencia de múltiples lesiones perianales, asintomáticas, de larga data, cuyo resultado histológico resultó compatible con: quistes pigmentados foliculares múltiples.

Pigmented follicular cysts are a very rare epithelial cysts. They are described as a benign papular lesion, that is usually located in the head or neck. They arise as unique, being the multiple variant even less frequent. We present the case of a young man with a history of HIV in antiretroviral therapy, who consulted for the presence of multiple, long-term asymptomatic perianal lesions whose histological result was: compatible with multiple follicular pigmented cysts.

Visión respecto a la legislación laboral chilena, desde sujetos en situación de discapacidad con participación política / Vision regarding chilean labor legislation, from subjects in disability situation with political participation

La presente investigación aborda la temática “Discapacidad y legislación laboral chilena”, con el propósito de incorporar en el análisis la visión de sujetos en situación de discapacidad con experiencia organizativa y orientados a la acción política. El objetivo es analizar la visión respecto a la legislación laboral actual chilena desde sujetos en situación de discapacidad que participan activamente en política, pertenecientes al Colectivo Palos de Ciego durante el año 2014. Se utiliza una metodología participativa con enfoque cualitativo, orientada a la emancipación y con perspectiva etnográfica. La recolección de información se realiza a partir de la observación participante, notas de campo y entrevistas en profundidad. El análisis de la información se realiza mediante codificación abierta. Los resultados se estructuran a partir de tres ejes temáticos: visión política de la legislación laboral, limitantes percibidas y propuestas de transformación respecto de la inclusión laboral chilena. La problemática central tiene relación con la lógica dominante bajo la cual el Estado actúa de manera subsidiaria, no reconociendo los Derechos inherentes de los sujetos en situación de discapacidad. Los miembros del Colectivo proponen estrategias de transformación de orden político, con incidencia en aspectos globales y de acción política directa, destacándose la importancia de concientizar a la sociedad respecto a la comprensión de la discapacidad como problema político. Finalmente, se expresa el desafío de ampliar la Terapia Ocupacional al ámbito político, orientando la participación del profesional en los procesos de lucha política de los sujetos en situación de discapacidad.

This research is framed in the thematic “Disability and Chilean labor legislation” with the purpose of incorporating the vision of the subjects in disability situation with experience and political action. The aim of this research is to analyze the political vision regarding the current Chilean labor legislation, from the subjects in disability situation belonging to the group “Palos de ciego” during 2014. A participatory methodology with qualitative focusing is used, oriented to emancipation, with ethnographic perspective. Data gathering is from participant observation, field notes, and in-depth interviews. The analysis of information is done through open coding. Results are structured from three thematic axes: political vision of the labor legislation, limitations and proposals of transformation of the Chilean labor inclusion. The central issue is related to the dominant logic, under which the state acts on a subsidiary basis, not recognizing the inherent rights of the subjects in disability situation. The group proposes strategies of transformation of political order, with incidence in global and specific aspects, standing out the importance of awareness in society regarding compression of disability as a political problem. Finally, is expressed the challenge of enlarge occupational therapy to a political scope, encouraging the professional’s participation in the processes of political struggle of the subjects in situation of disability, as well as political participation thereof.

Low-temperature biosynthesis of fluorescent semiconductor nanoparticles (CdS) by oxidative stress resistant Antarctic bacteria.

Bacterial biosynthesis of nanoparticles represents a green alternative for the production of nanostructures with novel properties. Recently, the importance of antioxidant molecules on the biosynthesis of semiconductor fluorescent nanoparticles (quantum dots, QDs) by mesophilic bacteria was reported. The objective of this work was the isolation of psychrotolerant, oxidative stress-resistant bacteria from Antarctica to determine their ability for biosynthesizing CdS QDs at low temperatures. QDs biosynthesis at 15 °C was evaluated by determining their spectroscopic properties after exposing oxidative-stress resistant isolates identified as Pseudomonas spp. to Cd(2+) salts. To characterize the QDs biosynthetic process, the effect of metal exposure on bacterial fluorescence was determined at different times. Time-dependent changes in fluorescence color (green to red), characteristic of QDs, were observed. Electron microscopy analysis of fluorescent cells revealed that biosynthesized nanometric structures localize at the cell periphery. QDs were purified from the bacterial isolates and their fluorescence properties were characterized. Emission spectra displayed classical CdS peaks when excited with UV light. Thiol content, peroxidase activity, lipopolysaccharide synthesis, metabolic profiles and sulfide generation were determined in QDs-producing isolates. No relationship between QDs production and cellular thiol content or peroxidase activity was found. However, sulfide production enhanced CdS QDs biosynthesis. In this work, the use of Antarctic psychrotolerant Pseudomonas spp. for QDs biosynthesis at low temperature is reported for the first time.

Terapia ocupacional en inclusión laboral: experiencias a nivel local / Occupational therapy in work inclusion: local experiences

El presente estudio exploratorio tiene como objetivo analizar la implementación de dos proyectos de SENADIS para la inclusión laboral de personas con discapacidad (CCR Integral y Proyecto Piloto de Profesionales de Apoyo) en base al relato de Terapeutas Ocupacionales que ejecutaron dichos proyectos en los municipios de Conchalí, Huechuraba, Independencia, La Pintana y Peñalolén entre los años 2011- 2013, contribuyendo a la generación de conocimiento en lo que respecta a políticas públicas de inclusión laboral para personas con discapacidad. Este estudio es de tipo cualitativo y está diseñado en base a la Teoría Fundamentada. La recolección de datos se realizó a través del diseño de una entrevista semi estructurada a las Terapeutas Ocupacionales ejecutoras y a los encargados de dichos proyectos en SENADIS. Las entrevistas abarcaron desde aspectos operativos de la ejecución de los proyectos, hasta refexiones personales en torno a la experiencia. Se identifcan como aspectos signifcativos las siguientes categorías: proceso de implementación de los proyectos en los Municipios, constitución del cargo de las Terapeutas Ocupacionales, equipo de trabajo, factores que facilitaron la implementación de los proyectos, factores que difcultaron la implementación de los proyectos y refexión de las Terapeutas Ocupacionales acerca de la experiencia. La presente investigación se centra en conocer el proceso de implementación de políticas públicas de inclusión laboral a nivel municipal, a partir de la experiencia de Terapeutas Ocupacionales ejecutoras de los proyectos ejecutados.

The aim of this exploratory study is to analyze the execution of two projects proposed by SENADIS for work inclusion, based on the Occupational Therapists report who participated in the execution of both projects in the local councils of: Conchalí, Huechuraba, Independencia, La Pintana and Peñalolén between 2011 and 2013, promoting the knowledge generation related to public policies of work inclusion. This qualitative study is based on Founded Theory. The data recollection was done through semi structured interviews to the Occupational Therapists and two SENADIS professionals in charge of both projects. The interviews included operative aspects like the execution of both projects and also personal thoughts about the experience. The next categories were considered meaningful for the study: The interviewed, execution process of both projects in local councils, Occupational Therapist’s position in both projects, work team, factors that collaborated in the execution, factors that interrupted the execution and personal thoughts about the experience. This study is to recognize the execution process of public policies in work inclusion, generating discussions from the Occupational Therapists experience that executed both projects.

Quantum dot-based assay for Cu(2+) quantification in bacterial cell culture.

A simple and sensitive method for quantification of nanomolar copper with a detection limit of 1.2×10(-10)M and a linear range from 10(-9) to 10(-8)M is reported. For the most useful analytical concentration of quantum dots, 1160µg/ml, a 1/Ksv value of 11µM Cu(2+) was determined. The method is based on the interaction of Cu(2+) with glutathione-capped CdTe quantum dots (CdTe-GSH QDs) synthesized by a simple and economic biomimetic method. Green CdTe-GSH QDs displayed the best performance in copper quantification when QDs of different sizes/colors were tested. Cu(2+) quantification is highly selective given that no significant interference of QDs with 19 ions was observed. No significant effects on Cu(2+) quantification were determined when different reaction matrices such as distilled water, tap water, and different bacterial growth media were tested. The method was used to determine copper uptake kinetics on Escherichia coli cultures. QD-based quantification of copper on bacterial supernatants was compared with atomic absorption spectroscopy as a means of confirming the accuracy of the reported method. The mechanism of Cu(2+)-mediated QD fluorescence quenching was associated with nanoparticle decomposition.

Trayectoria de vida de profesionales universitarios con déficit auditivo: estudio exploratorio de aspectos significativos para inclusión laboral / Life trajectories of university graduates with hearing impairments: exploratory study of meaningful aspects to labor inclusion

El presente estudio ha tenido como propósito conocer los aspectos significativos en el proceso de inclusión laboral de dos profesionales universitarios con hipoacusia severa de la Región Metropolitana, por medio de la realización de entrevistas focalizadas en el desempeño laboral, de manera de avanzar en el conocimiento de estrategias que permitan mejorar las oportunidades de empleo para esta población. Es un estudio de tipo exploratorio, retrospectivo y transversal. Para la recolección de datos se diseñó una entrevista semiestructurada, solicitando previamente el consentimiento informado. La entrevista abarca sus trayectorias de vida focalizándola en el desempeño laboral. Se identifican como aspectos significativos las siguientes categorías: familia nuclear, familia de origen, déficit auditivo, desempeño educativo, desempeño laboral y redes de apoyo. En base a éstas se observa la importancia del capital cultural y económico, las estrategias personales para acceder a la información oral, el origen del déficit, el grado de interacción requerido en sus puestos de trabajo actuales, entre otros aspectos.

This study aims to know the meaningful aspects to the process of labor inclusion to two college graduates with several hypoacusis in the Metropolitan Region, through interviews focused on job performance to advance the understanding of strategies to improve employment opportunities for this population. It is an exploratory, retrospective and transversal study. It has designed a semistructured interview, previously requesting informed consent, for to collect the data. The interview covers their life trajectories focuses on job performance. They are identified as respects the following categories: nuclear family, family of origin, hearing loss, educational performance, work performance and their social support network. As a result of the former to emerge the importance of cultural and economic capital, personal strategies to access oral information, the source of the deficit, the degree of interaction required in their current jobs, among others.

Experiencia en pacientes neutropénicos febriles de alto y bajo riesgo, según el índice MASCC en linfoma no Hodgkin y leucemia aguda; en el Hospital Dr. Gustavo Fricke de Viña del Mar (2002-2005) / Experience in high and low risk patients with febrile neutropenia according to MASCC index in non Hodgkin lymphoma and acute leukaemia at Hospital Dr. Gustavo Fricke of Viña del Mar (2002-2005)

La neutropenia febril constituye una de las principales complicaciones en pacientes sometidos a quimioterapias con diagnóstico de linfoma no Hodgkin y leucemias agudas. Objetivos: describir las características de pacientes con neutropenia febril, clasificándolos en alto y bajo riesgo, según la probabilidad de presentar complicaciones médicas mayores, incluyendo la muerte, según un índice de riesgo validado de la MASCC (Multinational Association for Supportive Care in Cancer Risk Index). Pacientes y métodos: revisión de fichas de pacientes con linfoma no Hodgkin y leucemias agudas que presentaron episodios de neutropenia febril. Se recolectaron 51 episodios entre enero del 2002 y enero del 2005. Se les aplicó retrospectivamente el índice de riesgo diseñado por la MASCC. Resultados: el score de la MASCC aplicado retrospectivamente identificó los pacientes de bajo riesgo (27,5 por ciento del total), no presentándose en este grupo de pacientes complicaciones y muerte. La diferencia entre pacientes de alto y bajo riesgo no fue estadísticamente significativa (p>0.05) debido a que el total de pacientes era pequeño. Se describieron otras variables de ambos grupos. La diferencia en la pesquisa de focos infecciosos en los pacientes de alto riesgo (86.5 por ciento) con respecto a los de bajo riesgo (21.4 por ciento) fue estadísticamente significativa con un p<0.001. A ningún paciente se le administró terapia antibiótica profiláctica. El éxito del primer esquema antibiótico en pacientes de alto riesgo fue de 64.8 por ciento, mientras que en los de bajo riesgo el 100 por ciento respondió al primer esquema antibiótico aplicado. Los antibióticos que se utilizaron como primer esquema eran de espectro reducido, orientado al hallazgo clínico del foco o al microorganismo aislado. El aislamiento del agente infeccioso por hemocultivos en pacientes de alto riesgo fue de un 21.05 por ciento, mientras que en los de bajo riesgo alcanzó un 28.57 por ciento, predominando en ambos gr...

[Tuberculous meningitis in adults: review of 53 cases]. / Meningitis tuberculosa en adultos: análisis de 53 casos.

Tuberculous Meningitis (TBM) is the most severe form of extrapulmonary tuberculosis. The clinical spectrum is broad and may be non-specific making early diagnosis difficult. This increases the incidence of mortality. We describe the clinical characteristics of patients with TBM in Dr. Lucio Córdova's Infectious Disease Hospital in Santiago, Chile, between 1995 and 2002. We review 53 adult cases of TBM, with a median age of 39 years. At admission 66% of the patients had some mental status deterioration, and the classic triad of symptoms of meningeal irritation was present only in 30%. The cerebrospinal fluid (CSF) examination showed increased protein level, low glucose level and lymphocytic pleocytosis in most. Thirty percent of the patients were coinfected with HIV. The mortality in the later group was greater than in the TBM population as a whole (31 vs 17%). TBM is still a present diagnostic problem, in spite of the new diagnostic methods. A high index of suspicion is required in order to make an early diagnosis.

Meningitis tuberculosa en adultos: análisis de 53 casos / Tuberculous meningitis in adults: review of 53 cases

La meningitis tuberculosa (MTBC) es la forma más grave de tuberculosis extrapulmonar. El amplio espectro del cuadro clínico y su poca especificidad dificultan su diagnóstico precoz, relacionándose directamente con mayor letalidad. El objetivo de este estudio es analizar las características clínicas de los pacientes con diagnóstico de MTBC en el Hospital de Enfermedades Infecciosas Dr. Lucio Córdova, de Santiago, Chile, entre 1995 y 2002. Se estudiaron 53 casos de MTBC en adultos, con una edad mediana de 39 años. Al ingreso 66 por ciento de los pacientes presentaba algún grado de compromiso de conciencia, pero sólo 30 por ciento la tríada sintomática clásica. El LCR mostró aumento de proteínas, glucosa baja y linfocitosis, en la mayoría de los casos. Treinta por ciento de los pacientes presentó co-infección con VIH; la letalidad en este grupo de pacientes fue mayor, 31 vs 17 por ciento del total de la muestra. La MTBC continúa siendo una enfermedad vigente. El diagnóstico de certeza precoz de esta patología no es posible con los métodos actuales, por lo que la sospecha clínica es importante.

Superficial inflammatory and primary neoplastic lymphadenopathy: diagnostic accuracy of power-doppler sonography.

OBJECTIVE: To evaluate the sensitivity, specificity and diagnostic accuracy of a cut-off of the resistive index of 0.5 for the differentiation between inflammatory and neoplastic primary lymphadenopathies. SUBJECTS AND METHODS: We measured the resistive index of superficial enlarged lymph nodes in a total of 50 patients (29 males and 21 females; age range 12-72 years, mean age 41.6 year) using an ATL 5000 HDI. A resistive index greater than or equal to 0.5 indicated an inflammatory lymph node and a resistive index <0.5 was consistent with neoplastic primary lymphadenopathies. The gold standard was either surgical biopsy or lymph-node reduction seen with ultrasound examination after antibiotic therapy. RESULTS: The sensitivity of the resistive index for distinguishing inflammatory from neoplastic lymphadenopathy was 84.6%, the specificity 100% and the diagnostic accuracy 95.7% (P < 0.001, statistically significant). CONCLUSION: The results of this study indicate that power-Doppler using a resistive index cut-off of 0.5 was a valid technique for distinguishing between inflammatory and primary neoplastic lymph nodes in patients with superficial lymphadenopathies.

Cellular delivery of a double-stranded oligonucleotide NFkappaB decoy by hybridization to complementary PNA linked to a cell-penetrating peptide.

The activation of nuclear factor kappaB (NFkappaB) is a key event in immune and inflammatory responses. In this study, a cell-penetrating transport peptide, transportan (TP) or its shorter analogue TP 10, was used to facilitate the cellular uptake of an NFkappaB decoy. Peptide nucleic acid (PNA) hexamer or nonamer was linked to the transport peptide by a disulfide bond. NFkappaB decoy oligonucleotide consisted of a double-stranded consensus sequence corresponding to the kappaB site localized in the IL-6 gene promoter, 5'-GGGACTTTCCC-3', with a single-stranded protruding 3'-terminal sequence complementary to the PNA sequence was hybridized to the transport peptide-PNA construct. The ability of the transport peptide-PNA-NFkappaB decoy complex to block the effect of interleukin (IL)-1beta-induced NFkappaB activation and IL-6 gene expression was analyzed by electrophoretic mobility shift assay and reverse transcriptase-polymerase chain reaction in rat Rinm5F insulinoma cells. Preincubation with transport peptide-PNA-NFkappaB decoy (1 microM, 1 h) blocked IL-1beta-induced NFkappaB-binding activity and significantly reduced the IL-6 mRNA expression. The same concentration of NFkappaB decoy in the absence of transport peptide-PNA had no effect even after longer incubations. Our results showed that binding of the oligonucleotide NFkappaB decoy to the nonamer PNA sequence resulted in a stable complex that was efficiently translocated across the plasma membrane.

Infección sistémica por paecilomyces lilacinus en un paciente inmunodeprimido pediátrico / Paecilomyces lilacinus systemic infection in an immunocompromised chil: report of 1 case

The incidence of systemic fungal infections increased during the last two decades. Rare fungi, such as Mucor, Fusarium and Paecilomyces, are emerging as causes of systemic fungal infections in immunocompromised hosts. There are reports of cutaneous infections, endophthalmitis, keratitis, sinusitis, neumopathy and fungemia in immunocompromised and immunocompetent adult patients. We report a 5 years old neutropenic patient with acute myeloid leukemia treated with multiple courses of chemotherapy, with a fungemia caused by Paecilomyces lilacinus (PL). His initial clinical course was characterized by fever, skin lesions, respiratory distress and shock. Blood and bone marrow cultures were positive. The patient was treated with amphotericin B and itraconazole with a good clinical response

Osteo-articular, mammographic and thoracic films: clinical evaluation of digital view box versus conventional view box.

PURPOSE: To compare in a clinical setting a conventional view box with a digital view box (Smart Light 2000 Digital Film Viewer System, Smart Light, Israel) in the identification of osteo-articular, mammographic and thoracic lesions. MATERIALS AND METHODS: Six radiologists (two for each imaging procedure), experts in osteo-articular, mammographic and thoracic diseases, independently, compared 600 plain films (100 patient with two projections for each imaging procedure). The radiologists evaluated the films by filling-out a multiple choice questionnaire containing questions concerning the type of pathology seen and the technical quality of the radiography in terms of exposure along with specific questions concerning each of the imaging procedures. RESULTS: We observed a higher sensitivity of the digital view box for lesion identification (p<0.05); furthermore, we analyzed a greater number of radiographs, recovering technically unsuitable films, because of over or under-exposure (high or low optical density). The interreader agreement was also good (> 0.75). The better lesion perception derived from the increase luminance of the digital view box in the evaluation of higher film densities, such as in overexposed films. DISCUSSION. The technical characteristics of the digital view box reduce or eliminate negative factors that reduce perceptional performance, and often permit the recovery of films that would have otherwise been considered technically unreadable.

Encuesta telefónica sobre posición al dormir en lactantes menores de un año que asisten a una muestra de salas cuna privadas en Santiago de Chile / Telephonic survey on infant sleeping position in private day care centers at Santiago de Chile

El síndrome de muerte súbita infantil es causa significativa de mortalidad infantil en Chile y otros países. Un factor de riesgo conocido es colocar lactantes en prono para dormir. Un estudio reciente en Estados Unidos demostró fallas al respecto ya que en 49 por ciento de salas cuna encuestadas lactantes dormían en prono. Objetivo: conocer las conductas que dice adoptar el personal de una muestra de salas cuna de Santiago, respecto de la posición en que son colocados a dormir lactantes menores. Pacientes y Métodos: realizamos una encuesta telefónica a 126 salas cuna de Santiago para determinar la posición al dormir de los lactantes. No se visitó las salas cuna para validar las respuestas. Resultados: Obtuvimos respuesta de 91 en que dijieron atender el lactante menores. Sesenta y tres declararon tener normas sobre el tema, pero solamente 20 eran escritas (22 por ciento). Entre las salas cuna que dijieron tener norma, 38 por ciento incluía la posición prona como única alternativa. Cicuenta y siete salas cuna (63 por ciento) declararon tener lactantes menores durmiendo en prono y en 17 (19 por ciento) exclusivamente en prono. Conclusión: Un alto porcentaje de salas cuna mantienen el factor de riesgo para muerte súbita "posición prona al dormir" presente en la práctica diaria. Se debe mejorar la información sobre el tema para disminuir este factor de riesgo de muerte súbita

Increased gene expression of interleukin-1alpha and interleukin-6 in rat primary glial cells induced by beta-amyloid fragment.

One of the pathological hallmarks of Alzheimer's disease (AD) is the presence of amyloid plaques. The main constituent of the amyloid plaques is the amyloid beta-peptide (A beta) shown to activate glial cells in vitro. A growing body of evidence suggests that these cells contribute to neurotoxicity through production of inflammatory cytokines, chemokines, and neurotoxic substances, such as reactive oxygen species (ROS). In this study, mRNA levels of the inflammatory cytokines interleukin (IL)-1alpha and beta, and IL-6 were analysed by reverse transcriptase-polymerase chain reaction (RT-PCR) in rat primary mixed glial cells after treatment with A beta(25-35), a biologically active fragment of A beta peptide with neurotoxic properties. Clear morphological changes of the astrocytes, as well as proliferation and clustering of microglial cells were observed by light and immunofluorescence microscopy after 24 h treatment. Significant increases in IL-1alpha and IL-6 mRNA levels were detected after 24 and 72 h, whereas significantly increased levels of IL-1beta mRNA could only be detected after 4 h treatment. The most pronounced effect was seen on IL-6 mRNA expression, which increased approx two- to threefold after treatment. In addition, increased secretion of IL-6 was detected after 96 h exposure. Recently, association of IL-1alpha and IL-6 gene polymorphism with AD was reported, suggesting that these cytokines may play an important role in the development of the disease. The increased mRNA levels of IL-1alpha and IL-6 in parallel with the morphological changes in the mixed glial-cell cultures support that these cytokines may be involved in A beta-induced gliosis and in the pathogenesis of AD.

Enfermedad de Hodgkin en el hospital Dr. Gustavo Fricke: revisión de pacientes en el período 1988-1998 / Hodgkin disease at Dr. G. Fricke Hospital: patient review, 1988-1998

La enfermedad de Hodgkin (E.H.) se define como una neoplasia del tejido linfoide, manifestada por adenopatias. Presenta una incidencia de 3-3,2 casos/100000habs/año, con mayor frecuencia en hombres, raza blanca, nivel socioeconómico alto y reducido grupo familiar; sigue una curva de edad bimodal con dos pics marcados: adolescentes y mayores de 55 años. Se clasifica histologicamente en 4 tipos, que por frecuencia son: esclerosis nodular, celularidad mixta, predominio linfocitario y deplecion linfocitaria, que junto al estadio, determinan en forma importante el pronostico de la enfermedad. El objetivo de este trabajo esconocer las caracteristicas de los pacientes con E.H. diagnosticados en el Hospital G. Fricke de Viña en el período entre enero 1988 y diciembre 1998

Hypersensitive cytokine response to beta-amyloid 25-35 in astroglial cells from IL-1 receptor type I-deficient mice.

betaA25-35, a neurotoxic fragment of the Alzheimer beta-amyloid peptide (betaA), acts as a strong inducer of pro-inflammatory cytokines, such as interleukin (IL)-1 and IL-6, in glial cells. Since IL-1 is known to induce expression of both IL-1 and IL-6, we have investigated to what extent the induction of IL-1alpha and IL-6 by betaA25-35, is dependent on the IL-1 receptor type I (IL-1RI), the only known signalling IL-1 receptor. Primary astroglial cell cultures prepared from wild-type and IL-1RI-deficient mice were incubated in the presence of betaA25-35 (100 microM) for 19 h, followed by analysis of mRNA levels of IL-1alpha and IL-6. Cell cultures treated with betaA25-35 showed a significant increase in mRNA levels for IL-1alpha and IL-6 and in addition increased levels of IL-1alpha immunoreactivity. A supersensitive IL-1alpha response was observed in astroglial cell cultures lacking the IL-1 RI as compared to betaA25-35 treated cell cultures from wild-type mice. In contrast the betaA25-35-induced increase of IL-6 was lower in the absence of IL-1RI. In conclusion, these results suggest that a functional IL-1 signal transduction is not necessary for induction of mRNA levels of IL-1alpha and IL-6 in astroglial cell cultures treated with betaA25-35, but that induction of IL-6 involves at least two distinct mechanisms, one of which occurs via activation of the IL-1RI.

Computerized case-based instructional system for computed tomography and magnetic resonance imaging of brain tumors.

RATIONALE AND OBJECTIVES: A computerized system that applies the case-based approach to training radiologists to diagnose brain tumors was designed. The authors attempted to provide residents a tool that supports their visual memory and inducts case-based reasoning. METHODS: A relational database with a digital image library was implemented and incorporated into a computer aided instruction environment based on case presentation. An indexing system was structured around case features (case history and radiologic findings). "If-then" type rules were used to control the search direction within the case library and to generate lists of diagnostic hypotheses. The indexing system was evaluated against cases "known" to the system. RESULTS: The current case library consists of 122 cases with 640 digitized images (computed tomography and magnetic resonance imaging). The accuracy of retrieval for "known" to the system cases was 80.7%. CONCLUSIONS: A case library stored on a personal computer can be efficiently searched for a combination of radiologic findings and can offer quality images for comparison to the case in question. A case library is a source of the information that may be used by different teaching applications.