Sequential Attractors in Combinatorial Threshold-Linear Networks.

Sequences of neural activity arise in many brain areas, including cortex, hippocampus, and central pattern generator circuits that underlie rhythmic behaviors like locomotion. While network architectures supporting sequence generation vary considerably, a common feature is an abundance of inhibition. In this work, we focus on architectures that support sequential activity in recurrently connected networks with inhibition-dominated dynamics. Specifically, we study emergent sequences in a special family of threshold-linear networks, called combinatorial threshold-linear networks (CTLNs), whose connectivity matrices are defined from directed graphs. Such networks naturally give rise to an abundance of sequences whose dynamics are tightly connected to the underlying graph. We find that architectures based on generalizations of cycle graphs produce limit cycle attractors that can be activated to generate transient or persistent (repeating) sequences. Each architecture type gives rise to an infinite family of graphs that can be built from arbitrary component subgraphs. Moreover, we prove a number of graph rules for the corresponding CTLNs in each family. The graph rules allow us to strongly constrain, and in some cases fully determine, the fixed points of the network in terms of the fixed points of the component subnetworks. Finally, we also show how the structure of certain architectures gives insight into the sequential dynamics of the corresponding attractor.

Principales herramientas epigenéticaspara el diagnóstico y seguimientode neoplasias hematológicas / Main epigenetic tools for the diagnosis and monitoring of hematological malignancies

Resumen: el análisis exhaustivo de los patrones de metilación del ADN es una parte fundamental para entender las bases moleculares del desarrollo y progresión de las neoplasias hematológicas, debido a que la hipermetilación en regiones promotoras afecta directamente vías carcinogénicas y conduce a la inactivación de genes involucrados en procesos celulares fundamentales como el ciclo celular y la apoptosis. En esta revisión de literatura se presenta una descripción de las técnicas más utilizadas para el estudio de la metilación: la reacción en cadena de la polimerasa específica de la metilación (MSP), el análisis combinado restricción bisulfito (COBRA), la secuenciación dependiente de bisulfito (BSP), la pirosecuenciación con bisulfito y las técnicas basadas en micromatrices; describiendo su principio, aplicación en la investigación de las neoplasias hematológicas y algunas de sus fortalezas y debilidades.

Abstract: the comprehensive analysis of DNA methylation patterns is important to understanding the molecular basis of development and progression of hematological malignancies. The hypermethylationin promoter regions directly affects carcinogenic pathways and leads to the inactivationof genes involved in fundamental cellular processes such as cell cycle and apoptosis. In this review are presented the most widely used techniques to DNA methylation analysis: methylation specific polymerase chain reaction (MSP), combined bisulfite restriction analysis (COBRA), bisulfite-sequencing polymerase chain reaction (BSP), bisulfite pyrosequencing and microarrays; describingits principles, usefulness in the hematological malignancies study, and some of its strengths and weaknesses.

Visual design: a step towards multicultural health care.

Standing at the crossroads of anthropology, communication, industrial design and new technology theories, this article describes the communication challenges posed during hospital emergencies resulting from linguistic and cultural differences between health care professionals and patients. In order to overcome communication barriers, the proposal of a visual solution was analyzed. Likewise, the problem was studied based on the concepts of perception, comprehension, interpretation and graphic representation according to visual culture and semiotics theories. One hundred and ffty images showing symptoms were analyzed in order to identify a pluricultural iconographic code. Results enabled to develop a list of design criteria and create the application: "My Symptoms Translator" as an option to overcome verbal language barriers and cultural differences.

Diseño visual: Un paso hacia la atención multicultural / Visual design: A step towards multicultural health care

En la encrucijada de las teorías en antropología, comunicación, diseño industrial y nuevas tecnologías, este artículo presenta los desafíos de comunicación que se encuentran en las urgencias hospitalarias causados por las diferencias lingüísticas y culturales entre los profesionales de la salud y los pacientes. Para sobrepasar las barreras de comunicación, se estudió la propuesta de una solución visual. Asimismo, se estudió la problemática según los conceptos de percepción, comprensión, interpretación y representación gráfica examinados de acuerdo con las teorías de la cultura visual y de la semiótica. Se analizaron 150 imágenes que ilustraban síntomas con el fn de identifcar un código iconográfco pluricultural. Los resultados permitieron desarrollar una lista de criterios de diseño y crear la aplicación: "Mi traductor de síntomas" ("My symptoms translator"), como una alternativa para superar las barreras del lenguaje oral y las diferencias culturales.

Standing at the crossroads of anthropology, communication, industrial design and new technology theories, this article describes the communication challenges posed during hospital emergencies resulting from linguistic and cultural differences between health care professionals and patients. In order to overcome communication barriers, the proposal of a visual solution was analyzed. Likewise, the problem was studied based on the concepts of perception, comprehension, interpretation and graphic representation according to visual culture and semiotics theories. One hundred and ffty images showing symptoms were analyzed in order to identify a pluricultural iconographic code. Results enabled to develop a list of design criteria and create the application: "My Symptoms Translator" as an option to overcome verbal language barriers and cultural differences.

Diseño visual: Un paso hacia la atención multicultural / Visual design: A step towards multicultural health care

En la encrucijada de las teorías en antropología, comunicación, diseño industrial y nuevas tecnologías, este artículo presenta los desafíos de comunicación que se encuentran en las urgencias hospitalarias causados por las diferencias ling³ísticas y culturales entre los profesionales de la salud y los pacientes. Para sobrepasar las barreras de comunicación, se estudió la propuesta de una solución visual. Asimismo, se estudió la problemática según los conceptos de percepción, comprensión, interpretación y representación gráfica examinados de acuerdo con las teorías de la cultura visual y de la semiótica. Se analizaron 150 imágenes que ilustraban síntomas con el fn de identifcar un código iconográfco pluricultural. Los resultados permitieron desarrollar una lista de criterios de diseño y crear la aplicación: "Mi traductor de síntomas" ("My symptoms translator"), como una alternativa para superar las barreras del lenguaje oral y las diferencias culturales.(AU)

Standing at the crossroads of anthropology, communication, industrial design and new technology theories, this article describes the communication challenges posed during hospital emergencies resulting from linguistic and cultural differences between health care professionals and patients. In order to overcome communication barriers, the proposal of a visual solution was analyzed. Likewise, the problem was studied based on the concepts of perception, comprehension, interpretation and graphic representation according to visual culture and semiotics theories. One hundred and ffty images showing symptoms were analyzed in order to identify a pluricultural iconographic code. Results enabled to develop a list of design criteria and create the application: "My Symptoms Translator" as an option to overcome verbal language barriers and cultural differences.(AU)

Visual design: a step towards multicultural health care. / Visual design: a step towards multicultural health care.

Standing at the crossroads of anthropology, communication, industrial design and new technology theories, this article describes the communication challenges posed during hospital emergencies resulting from linguistic and cultural differences between health care professionals and patients. In order to overcome communication barriers, the proposal of a visual solution was analyzed. Likewise, the problem was studied based on the concepts of perception, comprehension, interpretation and graphic representation according to visual culture and semiotics theories. One hundred and ffty images showing symptoms were analyzed in order to identify a pluricultural iconographic code. Results enabled to develop a list of design criteria and create the application: "My Symptoms Translator" as an option to overcome verbal language barriers and cultural differences.

Tres casos de síndrome de ogilvie en manejo crónico con clozapina. Clínica San Juan de Dios, Chía, Colombia / Three cases of ogilvie´s syndrome in patients with chronic medication with clozapine - Clínica San Juan de Dios, Chía, Colombia

El síndrome de Ogilvie es una condición clínica con signos, síntomas y hallazgos radiográficos de obstrucción intestinal sin una causa mecánica. La fisiopatología es aún desconocida, se sugiere un disbalance entre la inervación simpática y parasimpática del colon. Se asocia con una extensa gama de comorbilidades incluyendo trauma, cirugía pélvica (ortopédica, ginecológica, urológica), alteraciones metabólicas o del sistema nervioso central, así como medicamentos en especial antipsicóticos atípicos como clozapina. Sin el diagnóstico y tratamiento oportunos puede progresar a perforación intestinal, peritonitis e incluso la muerte. Se analizan las historias clínicas de tres pacientes tratados por pseudoobstrucción intestinal (síndrome de Ogilvie) en la Clínica San Juan de Dios de Chía, Colombia, en 2011, que requirieron remisión para manejo médico o quirúrgico. Se consideró como causa desencadenante el uso crónico del antipsicótico clozapina...

Ogilvie´s syndrome is a clinical condition with signs, symptoms and radiographic appearance of intestinal obstruction without a mechanical cause. Pathophysiology is still unknown. An imbalance between sympathetic and parasympathetic colonic innervation is suggested. It is associated with an extent range of comorbidities including trauma, pelvic surgery (orthopedic, gynecologic, urologic), metabolic alterations or central nervous system alterations, as well as in patients receiving medication especially atypical anti-psychotic agents such as clozapine. Prompt diagnosis and treatment are critical to avoid progression to bowel perforation, peritonitis and even death. Clinical records of 3 patients treated for bowel pseudo-obstruction (Ogilvie´s Syndrome) at San Juan de Dios Clinic in Chía, Colombia, in 2011, who needed referral for medical or surgical treatment, were analyzed. Chronic use of clozapine, an antipsychotic agent, was considered the triggering cause. Peritonitis and bowel perforation was the most serious complication. There was no mortality attributable to this syndrome or its management...

Radiofrecuencia térmica del ganglio de Gasser en pacientes con neuralgia del trigémino / Gasserian ganglion thermal radiofrequency in patients with trigeminal neuralgia

Introducción: La neuralgia del trigémino (NT) afecta principalmente a mujeres mayores de 50 años y es de causa desconocida en la mayoría de pacientes. Los fármacos son la primera línea de tratamiento, aunque son inefectivos en el 40% de los casos; las terapias intervencionistas son entonces una alternativa de manejo. Objetivo: Determinar la eficacia y la seguridad de la radiofrecuencia térmica (RT) en el ganglio de Gasser en pacientes con NT. Materiales y método: Se realizó un estudio de tipo descriptivo, prospectivo, de seguimiento a una cohorte de 15 pacientes con diagnóstico de NT, en quienes se realizó RT del ganglio de Gasser en el Instituto Colombiano del Dolor entre los meses de mayo de 2010 y mayo de 2011, con un seguimiento no inferior a un año. Resultados: La edad promedio de los pacientes intervenidos fue de 52 años. El 73% fueron mujeres, con predominio derecho (67%), y las principales ramas trigeminales comprometidas fueron la segunda y la tercera. Después de la intervención los 15 pacientes pasaron de dolor severo a un estado entre nada de dolor y dolor leve, e incluso el 40% se encontraron libres de dolor al año del procedimiento. Conclusiones: La NT afecta de forma importante la calidad de vida. Su principal tratamiento es farmacológico, pero cuando no es efectivo, la RT del ganglio de Gasser es una alternativa eficaz, segura y disponible en nuestro medio.

Introduction: Trigeminal neuralgia (TN) affects primarily women over 50 years of age and its etiology is unknown in most cases. Drugs are first line treatment, but they are ineffective in 40% of cases. Interventional therapies are a management option in those cases. Objective: To determine the safety and efficacy of Gasserian ganglion thermal (TR) radiofrequency in patients with TN. Materials and method: Descriptive, prospective follow-up study of a cohort of 15 patients with a diagnosis of TN who underwent Gasserian ganglion TR at the Colombian Pain Institute between May 2010 and May 2011, with at least one year follow-up. Results: The mean age of the patients intervened was 52 years, 73% were females with rightsided predominance (67%) with involvement mainly of the second and third branch of the trigeminal nerve. After the intervention, all 15 patients went from severe pain to a condition ranging between mild and no pain, and 50% were event pain-free one year after the procedure. Conclusions: TN has a significant effect on quality of life. The main treatment is pharmacological but when it fails, Gasserian ganglion TR is an effective and safe option available in our setting.

Conocimientos, prácticas y actitudes sobre alimentación normal en el primer año de vida de los estudiantes de medicina de la Universidad del Valle de Cali, Colombia / Knowledge, attitudes and practices about normal feeding in the first year of life, in the medical students from the Universidad del Valle in Cali, Colombia

Introducción: La alimentación constituye una prioridad en el niño menor de un año. Los profesionales de la salud son una fuente importante de educación sobre alimentación para padres y cuidadores de lactantes, por lo que la formación en esta área de dichos profesionales es trascendental para las instituciones de educación superior, siendo importante evaluar los conocimientos que tienen los estudiantes de medicina en ésta área. Objetivo: Determinar los conocimientos, prácticas y actitudes (CAP) en estudiantes de medicina matriculados en la Universidad del Valle sobre alimentación normal durante el primer año de vida. Metodología: Se realizó un estudio de prevalencia observacional, descriptivo, tipo encuesta que incluyó 105 estudiantes matriculados en el año 2005 en Medicina y Cirugía en la Universidad del Valle (Univalle). Resultados: 46,7% de los estudiantes encuestados posee un conocimiento insuficiente (< 60% de respuestas correctas) sobre alimentación en el primer año de vida, 51,4% posee un nivel aceptable, 1,9% bueno y ninguno muy bueno. Hay menor nivel de conocimiento significativamente entre los estudiantes de cuarto año, pero no en los del quinto ni sexto año. No se encontró diferencias significativas en los estudiantes de sexto año de la Univalle comparados con otras universidades. Conclusiones: Se debe mejorar el conocimiento global sobre alimentación normal en el primer año de vida en los estudiantes de debido a la importancia de su formación para suministrar a los padres y/o cuidadores información relacionada con la alimentación del niño.

Introduction: The nutrition supply is a priority in the child under one year. Health professionals are an important source of nutrition education for parents and caregivers of infants, so training in this area of such professionals is critical to higher education institutions and it is important to assess the knowledge students have medicine in this area. Objective: To determine knowledge, attitudes and practices (KAP) about normal feeding during the first year of life, in medical students enrolled at the Universidad del Valle from Cali, Colombia. Methodology: An observational study of prevalence, descriptive survey included 105 such students enrolled in 2005 in Medicine and Surgery at the Universidad del Valle. Results: 46.7% of the students have insufficient knowledge (<60% correct) on feeding in the first year of life, 51.4% have an acceptable level, 1.9% good and no good. There are significantly lower level of knowledge among seniors, but not in the fifth or sixth year. No significant differences were found among students in sixth year of the Univalle compared with other universities. Conclusions: We must improve the global knowledge on normal diet in the first year of life in students due to the importance of providing training for parents and/or caregivers information about infant feeding.

Haloperidol (but not ziprasidone) withdrawal potentiates sensitization to the hyperlocomotor effect of cocaine in mice.

One important contributing factor in the high prevalence of drug abuse disorders seen among schizophrenic patients seems to be related to chronic treatment with typical neuroleptics. We have previously demonstrated that withdrawal from long-term treatment with the typical neuroleptic haloperidol, but not the atypical neuroleptic ziprasidone, potentiated the hyperlocomotor effect induced by a single cocaine injection and cocaine-induced conditioned place preference in mice. In the present study we investigated whether withdrawal from long-term treatment with these same neuroleptics would also modify cocaine-induced hyperlocomotion sensitization, which has been proposed as an animal model for the intensification of drug craving in cocaine addiction. Swiss male mice were i.p. treated with haloperidol (1.0 mg/kg) or ziprasidone (4.0 mg/kg) for 15 days. Twenty-four hours after the last injection, animals received an i.p. injection of cocaine (10 mg/kg) for 5 consecutive days, being placed after each injection in the open-field apparatus in order to perform a drug-environment conditioning. Seven days after the last drug-environment conditioning procedure, the animals were challenged with an i.p. injection of cocaine (10 mg/kg), placed in the open-field apparatus and had their locomotor activity quantified. Withdrawal from haloperidol (but not ziprasidone) potentiated cocaine-induced behavioral sensitization. These results are suggested to be a consequence of the development of the dopaminergic supersensitivity phenomenon by long-term treatment with the typical compound. Our findings provide additional support for the use of atypical agents like ziprasidone in the treatment of schizophrenic patients with comorbid substance abuse disorder.

Bulliform cells in Loudetiopsis chrysothrix (Nees) Conert and Tristachya leiostachya Nees (Poaceae): structure in relation to function

This work reports anatomic and ultrastructural characteristics of bulliform cells in Loudetiopsis chrysothrix (Nees) Conert and Tristachya leiostachya Nees. Both the species presented leaf rolling under water stress. The main characteristics observed in these cells were: periclinal wall thinner than the adjacent epidermal wall; abundance of pectic substances in cuticular layer; sinuous anticlinal walls with ramified plasmodesmata; vacuome formed by a developed vacuole or innumerous small vacuoles; abundance of phenolic substances and oil drops. These characteristics suggested the involvement of bulliform cells in the mechanism of foliar involution in the studied species.

Este trabalho relata as características anatômicas e ultra-estruturais das células buliformes em Loudetiopsis chrysothrix (Nees) Conert e Tristachya leiostachya Nees. Ambas as espécies apresentam enrolamento foliar em condições de estresse hídrico. As principais características observadas nessas células foram: paredes periclinais mais delgadas que as epidérmicas adjacentes; abundância de substâncias pécticas na camada cuticular; paredes anticlinais sinuosas com plasmodesmas ramificados; vacuoma formado por um vacúolo desenvolvido ou inúmeros vacúolos pequenos; abundância de substâncias fenólicas e gotas de óleo dispersas. As características observadas sugerem o envolvimento das células buliformes no mecanismo de involução foliar nas espécies estudadas.

Haloperidol (but not ziprasidone) withdrawal enhances cocaine-induced locomotor activation and conditioned place preference in mice.

It has been empirically suggested that the high incidence of drug abuse in schizophrenic patients is related to chronic neuroleptic treatment. We investigated the effects of withdrawal from long-term administration of the typical neuroleptic haloperidol and/or the atypical agent ziprasidone on the acute locomotor stimulant effect of cocaine as well as on cocaine-induced conditioned place preference (CPP). In the first experiment, mice were i.p. treated with haloperidol (1.0 mg/kg) and/or ziprasidone (4.0 mg/kg) for 15 days. At 72 h after the last injection, animals received an i.p. injection of cocaine (10 mg/kg) and their locomotor activity was quantified. In the second experiment, mice were withdrawn from the same haloperidol or ziprasidone treatment schedule and submitted to CPP. Withdrawal from haloperidol (but not ziprasidone or ziprasidone plus haloperidol) increased both cocaine-induced hyperactivity and CPP. These findings indicate that withdrawal from long-term treatment with typical neuroleptic drugs such as haloperidol (but not the atypical compound ziprasidone) may enhance some behavioral effects of cocaine in mice which have been related to drug dependence in humans.

Amphetamine-induced rapid-onset sensitization: role of novelty, conditioning and behavioral parameters.

BACKGROUND: Environmental factors may modulate sensitization to the locomotor-activating effects of psychostimulants. In addition, some parameters of locomotor activity seem to be more sensitive to detect cocaine-induced behavioral sensitization. We examined how novelty and conditioning can modulate a previously described rapid-onset type of behavioral sensitization to amphetamine (AMP) in mice, using total, peripheral and central open-field locomotion frequencies as experimental parameters. METHODS: In the first experiment, mice received an ip injection of saline (SAL) or 5.0 mg/kg AMP paired or not with the open-field or in their home-cages. Four hours later, all the animals received an ip SAL challenge injection and, 15 min later, were observed in the open-field for quantification of total, peripheral and central locomotion frequencies. The second experiment had a similar protocol, except that mice received a challenge injection of 1.5 mg/kg AMP. RESULTS: The priming AMP injection significantly increased all the parameters of locomotion of SAL-challenged mice firstly exposed to or previously paired (but not unpaired) with the open-field. AMP priming injection enhanced total and peripheral locomotion of all AMP-challenged mice but only increased central locomotion of mice submitted to novelty or environmental conditioning. CONCLUSION: Our results showed: 1) the development of an AMP-induced rapid-onset sensitization to novelty and rapid-onset environmental conditioning in mice, 2) the potentiation of the AMP-induced rapid-onset sensitization to an AMP challenge injection by novelty and environmental conditioning and 3) the importance of measuring different locomotor activity parameters in behavioral sensitization experiments.