A computer-aided design tool for biomedical OBT sensor tuning in cell-culture assays.

BACKGROUND AND OBJECTIVES: The biomedical engineering must frequently develop sensor designs by including information from performance of bio-samples (cell cultures or tissues), technical specifications of transducers, and constrains from electronic circuits. A computer program for real-time cell culture monitoring system design is developed; analyzing, modelling and integrating into the program design flow the electrodes, cell culture and test circuit's influences. METHODS: The computer tool, first, generates an equivalent electric circuit model for the cell-electrode bio-systems based on the area covered by cells, which also considers the cell culture dynamics. Second, proposes an Oscillation Based Test (OBT) parameterized circuit, for Electrical Cell-Substrate Sensing (ECIS) measurements of the cell culture system bioimpedance. Third, simulates electrically the full system to define the best system parameter values for the sensor. RESULTS: Reported experimental results are based on commercial gold electrodes and the AA8 cell line. Characteristics of the cell lines, as time-division or cell size, are incorporated into the program design flow, showing that for a given assay, the optimal OBT circuit parameters can be selected with the help of the computer tool. The electrical simulations of the full system demonstrate that the can be correctly predicted the output frequency and amplitude ranges of the voltage response, obtaining accurate results when cell culture approaches to confluence phase. CONCLUSION: It is proposed a computer program for system design of biosensors applied to monitoring cell culture dynamics. The program allows obtaining confident system information by electrical stimulation. All system components (electrodes, cell culture and test circuits) are properly modelled. The employed procedure can be applied to any other 2D electrode layout or alternative circuit technique for ECIS test. Finally, deep insight information on cell size, number, and time-division can be extracted from the comparison with real cell culture assays in the future.

GSK-3ß signaling determines autophagy activation in the breast tumor cell line MCF7 and inclusion formation in the non-tumor cell line MCF10A in response to proteasome inhibition.

The ubiquitin-proteasome system and the autophagy-lysosome pathway are the two main mechanisms for eukaryotic intracellular protein degradation. Proteasome inhibitors are used for the treatment of some types of cancer, whereas autophagy seems to have a dual role in tumor cell survival and death. However, the relationship between both pathways has not been extensively studied in tumor cells. We have investigated both proteolytic systems in the human epithelial breast non-tumor cell line MCF10A and in the human epithelial breast tumor cell line MCF7. In basal condition, tumor cells showed a lower proteasome function but a higher autophagy activity when compared with MCF10A cells. Importantly, proteasome inhibition (PI) leads to different responses in both cell types. Tumor cells showed a dose-dependent glycogen synthase kinase-3 (GSK-3)ß inhibition, a huge increase in the expression of the transcription factor CHOP and an active processing of caspase-8. By contrast, MCF10A cells fully activated GSK-3ß and showed a lower expression of both CHOP and processed caspase-8. These molecular differences were reflected in a dose-dependent autophagy activation and cell death in tumor cells, while non-tumor cells exhibited the formation of inclusion bodies and a decrease in the cell death rate. Importantly, the behavior of the MCF7 cells can be reproduced in MCF10A cells when GSK-3ß and the proteasome were simultaneously inhibited. Under this situation, MCF10A cells strongly activated autophagy, showing minimal inclusion bodies, increased CHOP expression and cell death rate. These findings support GSK-3ß signaling as a key mechanism in regulating autophagy activation or inclusion formation in human tumor or non-tumor breast cells, respectively, which may shed new light on breast cancer control.

Escrofuloderma: la tuberculosis olvidada / Scrofuloderma: the forgotten tuberculosis

INTRODUCCIÓN: La escrofuloderma es una manifestación extrapulmonar de la tuberculosis, siendo su incidencia menor al 1 por ciento de los casos de tuberculosis no pulmonar. Actualmente, la escrofuloderma se presenta con mayor frecuencia en personas inmunocomprometidas o en pacientes que viven en condición de hacinamiento, recintos tales como hogares de ancianos, cárceles o en viviendas de estratos socioeconómicos más bajos. PRESENTACIÓN DEL CASO: A continuación, se presenta el caso de un paciente de 29 años que vive en condiciones de hacinamiento en un recinto penitenciario. Es derivado a policlínico de Medicina Broncopulmonar para estudio con fibrobroncoscopía ante la sospecha de tuberculosis pulmonar. Se pesquisa lesión nodular subcutánea supurativa, asociada a placas cicatriciales rojo-violáceas que, según contexto del paciente, características de las lesiones y resultado de biopsia se diagnosticaron como escrofuloderma. Se inició tratamiento antituberculoso con buena respuesta clínica de las lesiones cutáneas. DISCUSIÓN: Debido al proceso de eliminación que está sufriendo la tuberculosis en Chile, las manifestaciones extrapulmonares de la tuberculosis, entre ellas las cutáneas, representan hoy en día un desafío diagnóstico principalmente por el bajo índice de sospecha que se tiene sobre ellas.

INTRODUCTION: Scrofuloderma is a manifestation of extrapulmonary tuberculosis, being its incidence less than 1 percent of the non-pulmonary cases. Nowadays, scrofuloderma is presented more frequently in immunosuppressed people or in patients living in overcrowded conditions, in enclosures such as nursing homes, prisons or houses from the lowest socioeconomic status. CASE REPORT: We present a clinical case of a 29-year-old patient living in overcrowded conditions in a penitentiary facility. The patient is referred to the neumology Outpatients Unit for study with fibrobronchoscopy for suspected pulmonary tuberculosis. A nodular subcutaneous suppurative lesion is found, associated to purpurish red cicatricial plaques that according to the clinical context of the patient, characteristics of the lesions and biopsy results, were diagnosed as scrofuloderma. Antituberculosis treatment was initiated, with a positive clinical response of the skin lesions. DISCUSSION: Due to the process of elimination that tuberculosis is suffering in Chile, the extrapulmonary manifestations, being the cutaneous manifestations among them, represent a diagnosis challenge principally because of the low index of suspicion.

La radiación UVA-1: un nuevo aporte en la fototerapia dermatológica / Ultraviolet radiation A1 (UVA-1): therapeutic use in dermatology

La radiación ultravioleta ha sido usada durante décadas para el tratamiento de diversas enfermedades cutáneas. La radiación ultravioleta A1 (UVA-1) que tiene una longitud de onda entre los 340nm y 400 nm está disponible desde el año 1981, pero recién en las últimas dos décadas se ha estudiado, publicado y reportado su potencial uso terapéutico en la dermatología. Los primeros beneficios de su uso se reportaron en la dermatitis atópica donde se utilizaron dosis altas de UVA-1 para tratar las exacerbaciones severas de esta condición. Luego, nuevas indicaciones terapéuticas de su uso se fueron expandiendo a otras enfermedades cutáneas tales como: morfea, liquen escleroso, queratosis liquenoide, linfomacutáneo de células T y otras dermatopatías. La radiación UVA-1 al tener una longitud de onda más larga penetra a las capas más profundas de la dermis, lo que le permite una acción en la modificación de la respuesta inflamatoria, la respuesta inmunológica y los mecanismos de reparación cutánea.

Ultraviolet light radiation has been used for decades for the treatment of several cutaneous diseases. The ultraviolet radiation A1 (UVA-1) with a wave length between 340 nm-400 nm has been available since 1981, but only in the last two decades it has been studied and published for therapeutic use in dermatology. The first reported benefits of its use were reported in atopic dermatitis in which high doses of UVA-1were used to treat severe exacerbations of this condition. Thereafter, new therapeutic indications expanded its use for other cutaneous diseases like: morphea, lichen sclerosus, lichenoid keratosis, cutaneous T cell lymphoma and other skin conditions. The UVA-1 radiation has a long wavelength that make possible to reach the deep dermis and to modify the inflammatory response, immunological response and the cutaneous repair mechanisms.

[Listeria monocytogenes: report of a rise in pregnant women and literature review]. / Listeria monocytogenes: Informe de un aumento de casos en mujeres embarazadas y revisión de la literatura.

Listeria monocytogenes, rare pathogen in the general population, causes serious infections in patients at the extreme ages of life, pregnant woman, and those with immunosuppression. The clinical manifestations are essential to suspect the disease in patients at risk, allowing an early prescription of antimicrobial therapy, before the results of the cultures are available. Clinical course and prognosis depends on how early treatment is started and, in pregnant women, the gestational age. In Clínica Alemana, at Santiago, we detected a 15 fold rate rise of neonatal listeriosis between year 2007 and 2008. Ten cases were diagnosed between January and July 2008 and the seven cases occurring in pregnant women are reported here. All these patients were in their first pregnancy, which could be associated with similar lifestyle and food habits. Considering this new epidemiological scenario, it is important to educate the population, and to conduct an epidemiological study in order to determine the national situation of Listeria monocytogenes infection.

Listeria monocytogenes: informe de un aumento de casos en mujeres embarazadas y revisión de la literatura / Listeria monocytogenes: report of a rise in pregnant women and literature review

Listeria monocytogenes, rare pathogen in the general population, causes serious infections in patients at the extreme ages of life, pregnant woman, and those with immunosuppression. The clinical manifestations are essential to suspect the disease in patients at risk, allowing an early prescription of antimicrobial therapy, before the results of the cultures are available. Clinical course and prognosis depends on how early treatment is started and, in pregnant women, the gestational age. In Clínica Alemana, at Santiago, we detected a 15 fold rate rise of neonatal listeriosis between year 2007 and 2008. Ten cases were diagnosed between January and July 2008 and the seven cases occurring in pregnant women are reported here. All these patients were in their first pregnancy, which could be associated with similar lifestyle and food habits. Considering this new epidemiological scenario, it is important to educate the population, and to conduct an epidemiological study in order to determine the national situation of Listeria monocytogenes infection.

Listeria monocytogenes, es un patógeno poco frecuente en la población general, causante de infecciones graves en pacientes en edades extremas de la vida, mujeres embarazadas e inmunodeprimidos. La sospecha de la enfermedad en pacientes de riesgo se basa principalmente en el cuadro clínico, lo que permite iniciar un tratamiento empírico antes de contar con los resultados de los cultivos. La evolución y pronóstico dependen de la precocidad con que se inicia la terapia y de la edad gestacional. En Clínica Alemana de Santiago detectamos un aumento de 15 veces en la tasa de listeriosis comparando el año 2007 con el 2008. Entre enero y julio 2008, se diagnosticaron 10 casos, de los cuales siete fueron en primigestas, lo que podría tener relación con un hábito alimentario y características de vida similar. Es fundamental, a la vista de esta nueva realidad epidemiológica, educar a la población en hábitos alimentarios y de higiene, como también realizar un estudio epidemiológico que determine la situación nacional de infección por L. monocytogenes.

Determinación de la eficacia analgésica de los bloqueos del ganglio estrellado en el síndrome doloroso regional complejo con dolor mediado por el sistema nervioso simpático: estudio preliminar / Study of the analgesic efficacy of stellate ganglion blockade in the management of the complex regional pain syndrome in patients with pain mediated by sympathetic nervous system: preliminary study

Objetivo: Este estudio fue realizado con el propósito de determinar la eficacia analgésica de los bloqueos del ganglio estrellado, en el alivio del dolor mediado por el sistema nervioso simpático, en pacientes con síndrome doloroso regional complejo. Pacientes y métodos: Se realizó un ensayo clínico controlado con asignación aleatoria y enmascaramiento simple. Treinta y nueve pacientes fueron tratados con una serie de bloqueos de ganglio estrellado, terapia física y tratamiento farmacológico, mientras que treinta y dos pacientes fueron tratados con fisioterapia y el mismo esquema farmacológico. Para determinar la asociación entre las variables se utilizó el riesgo relativo con sus respectivos intervalos de confianza. Resultados: En la evaluación clínica realizada un mes postratamiento se encontró alivio del dolor en 84,6% de los pacientes del grupo de intervención y en 78,1% de los controles (RR= 1,08; I.C. 95%=0,8-1,4; p=0.48), sin encontrarse diferencias estadísticamente significativas. No se encontró asociación entre la eficacia analgésica y tabaquismo, dominancia, género, tipo de SDRC, causa desencadenante y nivel educativo (AU)

Objective: The purpose of this study was to determine the analgesic efficacy of stellate ganglion blockade in pain mediated by the sympathetic nervous system in patients with Complex Regional Pain Syndrome (CRPS). Patients and methods: A randomized, simple-blinded controlled clinical trial was conducted. Thirty nine patients were randomly assigned to an intervention group which was treated with a series of stellate ganglion blockades, physical therapy and pharmacological treatment, and thirty two to a control group which was treated with physical therapy and the same pharmacological treatment. Risk ratio was used to evaluate outcome and determine association with predictor variables. Results: At the end of the first month post treatment, it was found that 84.6% of patients in the intervention group had alleviation of their pain while 78.1% of the control group had alleviation of their pain; there was not a statistically significant difference (RR=1.08; C.I. 95%=0.8-1.4; p=0.48). We found no association between analgesic efficacy, smoking, dominance, gender, and type of CRPS, unleashing cause or educational level (AU)

Volatile anaesthetic halothane causes DNA damage in A549 lung cells.

The present study was performed to elucidate the extent of damage and the ability of lung epithelial cells to recover or to undergo apoptosis after in vitro treatment with the volatile anaesthetic halothane. The results obtained from the comet assay clearly show that halothane, applied at 3.0mM concentration, causes DNA and cell damage. Cells exhibited nuclear fragmentation and budding early after treatment and these events gradually increased during the next few days. The presence of a large number of mini-comets after single cell gel electrophoresis was found to represent apoptotic bodies with fragmented DNA. Our results demonstrate apoptosis-like changes after in vitro exposure of A549 cells to the volatile anaesthetic halothane. The majority of the affected cells did not recover and were directed to cell death.

Guía terapéutica en atención primaria basada en la evidencia, 2. ª edición: una obra honesta y práctica / Therapeutic guide to Primary Care based on the evidence, 2nd edition: an honest and practical work

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The comet assay differentiates efficiently and rapidly between genotoxins and cytotoxins in quiescent cells.

Our main aim was to establish the efficiency of the single cell electrophoresis technique for differentiating between drugs that bind DNA and those that do not. The alkaline comet assay was used to test the responses of human leukocytes (quiescent cells) to damage induced by reportedly genotoxic and reportedly cytotoxic agents. Incubation of G0 leukocytes for 1 h with the genotoxic agents camptothecin and actinomycin C provoked DNA migration, observed as comet figures. On the other hand, when cells were treated with the cytotoxic agents cordycepin, fluorodeoxyuridine and puromycin, the leukocyte nuclei were indistinguishable from those of untreated cells. In addition, we have developed a rapid method using non-proliferating cells that requires neither culture nor lymphocyte isolation. This method promises to be useful as a rapid in vitro screening assay.

DNA strand-breaks induced by the topoisomerase I inhibitor camptothecin in unstimulated human white blood cells.

Camptothecin (CPT) and actinomicyn-induced strand-breaks, repair and apoptosis in unstimulated human blood cells were studied using the DNA comet assay, and electrophoresis of low molecular weight DNA extracts. On the one hand, incubation of G0 leukocytes for 1 h with CPT induced DNA strand-breaks that were observed using the single cell gel electrophoresis technique. On the other hand, internucleosomal DNA fragments were not observed, suggesting that apoptosis had not occurred. DNA-strand-breaks caused by CPT were repaired 24 h after treatment; the migration of DNA fragments was assessed by a reduction in the number of comets. These data strongly suggest that the unexpected clastogenic effect of this topoisomerase I inhibitor is not due to the collision of the cleavage complex with the replication fork, since replication does not occur in G0. In our opinion, this effect could be due instead to the topoisomerase I enzyme being able to bind DNA in the absence of replication, probably in a way that is not strictly related to the progression of the cell cycle. Thus, CPT does not provoke apoptosis in quiescent leukocytes.

[Epidural anesthesia in a child with femoral fracture and congenital pain insensitivity]. / Anestesia epidural a un niño con fractura de fémur e insensibilidad congénita al dolor.

An 8-year-old boy with congenital insensitivity to pain underwent open reduction of a fractured femur with osteosynthesis under epidural block, without complications and with intraoperative hemodynamic stability. The postoperative course was favorable with minimal analgesia. Congenital insensitivity to pain is a rare hereditary condition characterized by abnormal response to painful stimuli and associated with orthopedic complications requiring surgery. Anesthesia is essential because, even though pain is absent, autonomic dysfunction and catecholamine metabolism alterations are present. An epidural block can be recommended for patients with congenital insensitivity to pain who must undergo surgery.

Psychometric comparability of English- and Spanish-language measures of anxiety and related affective symptoms.

An array of measures of anxiety and related disorders (viz., Albany Panic and Phobia Questionnaire; Anxiety Sensitivity Index; Beck Anxiety Inventory; Beck Depression Inventory-II; Body Sensation Questionnaire; Fear Questionnaire; Padua Inventory; Penn State Worry Questionnaire; Post-Traumatic Stress Disorder Diagnostic Scale; Social Interaction Anxiety Inventory; and Worry Scale) was edited or translated from English into Spanish. Following an extensive edit and translation process, bilingual participants (n = 98) were assessed with the English and Spanish versions of these measures. Coefficient alphas were excellent and comparable across language versions. Means and standard deviations were also comparable across language versions. Evidence of convergent and discriminant validity was found for both language versions. The two language versions of each measure correlated highly with each other. This psychometric comparability adds confidence in using the newly edited or translated Spanish language measures in clinical practice and research.

A high yield of translocations parallels the high yield of sister chromatid exchanges in the CHO mutant EM9.

The fluorescence plus Giemsa (FPG) and fluorescence in situ hybridization (FISH) techniques have been used to determine, respectively, the frequencies of sister chromatid exchanges (SCEs) and stable chromosome aberrations (translocations) induced by different concentrations of BrdU in the Chinese hamster ovary cell mutant EM9 and its parental line AA8. The results indicate that BrdU induced a high frequency of SCEs and translocations in EM9 as compared with AA8, and that the translocation/dicentric ratio was also higher in the mutant cell line than in the parental cell line in both untreated and BrdU-treated cultures. These observations may indicate a possible relationship between the molecular mechanisms involved in the formation of SCEs and translocations.

Radiosensitivity and double-strand break rejoining in tumorigenic and non-tumorigenic human epithelial cell lines.

Radiosensitivity and repair of DNA damage induced by ionizing radiation and restriction enzymes were investigated in three human epithelial cell lines: two tumorigenic squamous carcinoma cell lines (SCC-4 and SCC-25), and a non-tumorigenic epidermal keratinocyte cell line (RHEK-1). Sensitivity to ionizing radiation was determined using a clonogenic cell survival assay, which showed SCC-4 to be more radiosensitive than SCC-25 and RHEK-1, which in turn displayed about equal sensitivity. Using DNA precipitation under alkaline conditions for the analysis of induction and repair of DNA single-strand breaks (ssb), an increased level of ssb induction was found for SCC-4 while the efficiency of ssb repair was about equal in all three cell lines. Using pulsed-field gel electrophoresis (PFGE) for the measurement of induction and repair of DNA double-strand breaks (dsb), no consistent differences were detected between the three cell lines. A plasmid reconstitution assay was used to determine the capacity to rejoin restriction enzyme-induced dsb in whole-cell extracts prepared from the three cell lines. In these experiments, dsb rejoining was shown to be significantly reduced in the most radiosensitive SCC-4 cell line while it was about equal in RHEK-1 and SCC-25. The results indicate that plasmid reconstitution in cell-free extracts is a sufficiently sensitive assay to detect differences in repair capacity among tumour cell lines of different radiosensitivity which remain undetectable by DNA precipitation and PFGE.

Mechanisms of nonhomologous DNA end-joining in frogs, mice and men.

DNA end-joining, a process related to illegitimate recombination and capable of rejoining unrelated pairs of DNA ends in the absence of sequence homology, is considered the major pathway of double-strand break (DSB) repair in mammalian cells. Whole cell and nuclear extracts from three human and one mouse cell line were investigated for their capacities to promote nonhomologous DNA end-joining and their relative activities of DNA-PK, a mammalian DNA end-binding protein complex implicated in DSB-repair. The levels of DNA end-joining and the spectra of junctions of the human systems were identical with the ones of a previously described cell-free joining system derived from Xenopus laevis eggs. Due to the presence of potent 3'-5'-exonuclease activities the mouse system displayed decreased levels of DNA end-joining and larger fractions of junctions containing deletions but otherwise the basic mechanisms of junction formation appeared to be identical with the Xenopus system. DNA-PK activity was found to be equally low in the Xenopus and the mouse system but 4- to 6-fold increased in the human systems. Our results suggest that the mechanisms of DNA end-joining may be modulated by the level of exonuclease activities and/or DNA end-protecting factors but are otherwise highly conserved in vertebrate cells.