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Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are examples of severe cutaneous adverse reactions to drugs (SCARs) with several international recommendations for global medical management, ranging from pharmacological systemic therapy to skin wound care. There is no defined best management of the skin wounds in SJS/TEN. The care of wounds is essential to initiate re-epithelialization. Our objective is to improve the cicatrization process, avoiding scarring due to deepening of the wounds, as well as prevent infections, achieve pain control, and avoid loss of serum proteins, fluids, and electrolytes. In this retrospective case series, we highlight the value of systemic therapy and the use of silver nitrate for wound management in four patients with TEN.
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Este artículo constituye una aproximación a la comprensión de las representaciones sociales de paz y conflicto de un grupo de estudiantes de un centro educativo del Catatumbo, territorio ubicado en el departamento Norte de Santander en la frontera con Venezuela y caracterizado por la presencia de grupos ilegales y el aumento de cultivos ilícitos. La investigación se fundamenta en el enfoque procesual de la teoría de las representaciones sociales a partir de las dimensiones de actitud, información y campo de representación. Estas representaciones se entienden como constructos objetivados y anclados en las prácticas sociales de esta población. Los hallazgos muestran una visión dual sobre la paz: una paz en apariencia imposible que se preserva como imaginario de esperanza, una especie de escepticismo que actúa subrepticiamente como factor de sobrevivencia; y una visión de temor y rechazo al conflicto armado, a los actores armados y al olvido del Estado. Se concluye que frente a estas representaciones de una paz indeleble pero motivadora, y un conflicto asociado a la perversidad y a la muerte, solo se puede sobrevivir con la imaginación representada en lo que los jóvenes llaman malicia indígena.
This article is an approach to understanding the social representations of peace and conflict of a group of students from an educational center in Catatumbo, a territory located in the Department of Norte de Santander, on the border with Venezuela, and characterized by the presence of illegal groups and the increase of illicit crops. The research is based on the process approach of the theory of social representations from the dimensions of attitude, information, and field of representation. These representations are understood as objectified constructs anchored in the social practices of this population. The findings show a dual vision of peace: a seemingly impossible peace that is preserved as an imaginary of hope, a kind of skepticism that acts surreptitiously as a survival factor, and a vision of fear and rejection of the armed conflict, the armed actors, and the oblivion of the State. It is concluded that, in the face of these representations of an indelible but motivating peace, and a conflict associated with perversity and death, one can only survive with imagination, represented in what the young people call indigenous malice.
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Resumen Se destaca que el arte actúa como elemento para expresar el dolor y transmitir generacionalmente un mensaje enfocado a la garantía de la no repetición de los hechos, la satisfacción de las víctimas y el respeto por los derechos humanos en el marco del Conflicto Armado que vive aún Colombia. Es así que las experiencias de reparación simbólica a partir del arte, desarrollado por las comunidades víctimas de conflicto armado son vitales para su dignificación, para la memoria histórica y a la reconstrucción de la verdad, así como proceso reparador.
Abstract It is highlighted that art acts as an element to express the pain and transmit generationally a message focused on the guarantee of non-repetition of the facts, the satisfaction of the victims and the respect for human rights in the framework of the Armed Conflict that Colombia still lives. Thus, the experiences of symbolic reparation through art, developed by the communities, which are victims of the armed conflict, are vital for their dignification, for the historical memory and the reconstruction of truth, as well as a compensative process.
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BACKGROUND: Tracheostomy is used for patients who require prolonged mechanical ventilation. Extensive research has described the provision and optimal timing of tracheostomy, but very little describes tracheostomy utilization in low- and middle-income countries, particularly in sub-Saharan Africa. METHODS: This prospective cohort study describes patients admitted to the intensive care unit (ICU) of a tertiary hospital in Malawi who received tracheostomy versus those who did not, with a primary outcome of hospital mortality. We performed subgroup analysis of patients with severe head injuries. RESULTS: The analysis included 451 patients admitted to the study ICU between September 2016 and July 2018. Overall hospital mortality was 40% for patients who received tracheostomy and 63% for patients who did not. Logistic regression modeling revealed an odds ratio (OR) of 0.34 (95% CI 0.18-0.64) for hospital mortality among patients who received tracheostomy versus those who did not (p < 0.001). Standardized mortality ratio weighting revealed an odds ratio of 0.81 (95% CI 0.65-0.99, p < 0.001) for hospital death among patients who received tracheostomy versus those who did not. In the subgroup excluding severe head injury, both ICU (50%) and hospital mortality (75%) were higher overall, but hospital mortality was not more common for patients with tracheostomy versus without (OR 1.28, 95% CI 0.94-1.74, p = 0.104). CONCLUSIONS: Tracheostomy is not associated with hospital mortality in a Malawi ICU cohort, but these results are affected by the presence of head injury. Research may focus on home tracheostomy care given the lack of hospital discharge options for patients in austere settings.
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Respiração Artificial , Traqueostomia , Mortalidade Hospitalar , Humanos , Unidades de Terapia Intensiva , Tempo de Internação , Malaui , Estudos Prospectivos , Estudos RetrospectivosRESUMO
PURPOSE: Operable triple-negative breast cancers (TNBCs) have a higher risk of relapse than non-TNBCs with standard therapy. The GEICAM/2003-11_CIBOMA/2004-01 trial explored extended adjuvant capecitabine after completion of standard chemotherapy in patients with early TNBC. PATIENTS AND METHODS: Eligible patients were those with operable, node-positive-or node negative with tumor 1 cm or greater-TNBC, with prior anthracycline- and/or taxane-containing chemotherapy. After central confirmation of TNBC status by immunohistochemistry, patients were randomly assigned to either capecitabine or observation. Stratification factors included institution, prior taxane-based therapy, involved axillary lymph nodes, and centrally determined phenotype (basal v nonbasal, according to cytokeratins 5/6 and/or epidermal growth factor receptor positivity by immunohistochemistry). The primary objective was to compare disease-free survival (DFS) between both arms. RESULTS: Eight hundred seventy-six patients were randomly assigned to capecitabine (n = 448) or observation (n = 428). Median age was 49 years, 55.9% were lymph node negative, 73.9% had a basal phenotype, and 67.5% received previous anthracyclines plus taxanes. Median length of follow-up was 7.3 years. DFS was not significantly prolonged with capecitabine versus observation [hazard ratio (HR), 0.82; 95% CI, 0.63 to 1.06; P = .136]. In a preplanned subgroup analysis, nonbasal patients seemed to derive benefit from the addition of capecitabine with a DFS HR of 0.53 versus 0.94 in those with basal phenotype (interaction test P = .0694) and an HR for overall survival of 0.42 versus 1.23 in basal phenotype (interaction test P = .0052). Tolerance of capecitabine was as expected, with 75.2% of patients completing the planned 8 cycles. CONCLUSION: This study failed to show a statistically significant increase in DFS by adding extended capecitabine to standard chemotherapy in patients with early TNBC. In a preplanned subset analysis, patients with nonbasal phenotype seemed to obtain benefit with capecitabine, although this will require additional validation.
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Antimetabólitos Antineoplásicos/uso terapêutico , Capecitabina/uso terapêutico , Quimioterapia Adjuvante/métodos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Adulto , Idoso , Intervalo Livre de Doença , Feminino , Humanos , Pessoa de Meia-Idade , Terapia Neoadjuvante , Adulto JovemRESUMO
There are various treatments available for soil decontamination, including physical, chemical, thermal and biological treatments. However, when pollutants are persistent or toxic, it is often necessary to use an integrated set of techniques, to enhance decontamination effects. Integrated treatments typically include soil washing, heat treatment, stabilization processes or phytoremediation. The biological recovery of soils contaminated with hydrocarbons or heavy metals is a topic of central interest, since many treatment processes are often extremely aggressive and destroy the flora and microflora of the treated environments and can interfere with the natural properties of the soil. The objective of this work was to analyze the biological recovery of soils treated with an electrokinetic remediation (ER) method at laboratory, pilot and field-scale tests which measure the germination of seeds and growth of maize (Zea mays L.) using a 2D circular arrangement of electrodes (IrO2-Ta2O5 |Ti| |Ti). The hydrocarbon removal rates obtained were greater than 80% for both the hydrocarbon's medium and heavy fractions; after this ER method was employed a phytoremediation treatment was also completed, using maize, which increased the removal rates up to 90%. A coupled electro- and phyto-remediation process was develop at the field-scale within an oil refinery property in Guanajuato, Mexico to demonstrate the successful biological recovery of soils contaminated with hydrocarbons as proved by the germination of seeds and growth of maize in the on-site fields.
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Técnicas Eletroquímicas/métodos , Hidrocarbonetos/química , Poluentes do Solo/química , Zea mays/crescimento & desenvolvimento , Biodegradação Ambiental , Recuperação e Remediação Ambiental , Germinação , Zea mays/química , Zea mays/fisiologiaRESUMO
BACKGROUND: Langerhans cell histiocytosis is a rare disease in the adult, predominates in the pediatric age and is more common in men than in women. The sites of greater affection are the long bones, followed by the bones of the skull. Patients usually have symptoms related to the site of affection, usually polyostotic lesions, monostotic lesions occur less frequently. The study of choice and treatment depends on the site affected, in the skull the main one is the magnetic resonance and the treatment is the surgical excision of the lesion. CLINICAL CASE: A 29-year-old female patient who entered the hospital due to a non-painful, rapidly growing, progressive tumor on the frontal region of the skull. Physical examination revealed a rounded mass of approximately 5 cm in diameter in the left, non-painful, non-painful, left-frontoparietal region. Magnetic resonance imaging of the skull showed a lytic lesion in the frontal bone. It was surgically excised with clean edges; titanium plate was placed. Histopathological diagnosis was histiocytosis of Langerhans cells. CONCLUSIONS: It is a rare case, with a patient of an uncommon age of presentation, absence of metastasis by means of study protocol and due to the monostotic presentation improves the prognosis for this patient.
ANTECEDENTES: la histiocitosis de células de Langerhans es una enfermedad rara en el adulto, que predomina en la edad pediátrica, y es más común en los hombres que en las mujeres. Los sitios de mayor afectación son los huesos largos, seguidos de los huesos del cráneo. Suele cursar con sintomatología relacionada con el sitio de afectación. Por lo general son lesiones poliostóticas; las lesiones monostóticas se presentan con menor frecuencia. El estudio de elección y el tratamiento dependen del sitio afectado; en el cráneo, el principal es la resonancia magnética, y el tratamiento es la escisión quirúrgica de la lesión. CASO CLÍNICO: Mujer de 29 años que ingresó al hospital debido a una tumoración no dolorosa de crecimiento rápido y progresivo sobre la región frontal del cráneo. A la exploración física se observó una masa redondeada, de aproximadamente 5 cm de diámetro, en la región frontoparietal izquierda, no dolorosa, de consistencia blanda, no móvil. La resonancia magnética de cráneo mostró una lesión lítica en el hueso frontal. Se extirpó quirúrgicamente con bordes limpios y se colocó una malla de titanio. El diagnóstico histopatológico fue de histiocitosis de células de Langerhans. CONCLUSIONES: Se trata de un caso poco frecuente, en una paciente de una edad no común de presentación, con ausencia de metástasis por medio de protocolo de estudio, y debido a la presentación monostótica mejora el pronóstico para esta paciente.
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Doenças Ósseas , Osso Frontal , Histiocitose de Células de Langerhans , Adulto , Doenças Ósseas/diagnóstico , Doenças Ósseas/cirurgia , Feminino , Histiocitose de Células de Langerhans/diagnóstico , Histiocitose de Células de Langerhans/cirurgia , HumanosRESUMO
Resumen Objetivo: Realizar una aproximación al estado del arte de las investigaciones en representaciones sociales en América Latina. Método: Investigación de tipo documental que consideró las siguientes fases: preoperatoria, heurística y hermenéutica. La información, correspondiente a 172 artículos de investigación empírica y 102 artículos de naturaleza teórica, fue clasificada mediante la construcción de bases de datos y matrices en la Hoja de Cálculo Excel. Resultados: Los trabajos de investigación más relevantes han sido desarrollados en países como Brasil, México, Venezuela y Argentina, los cuales están principalmente orientados por el enfoque procesual y se enfocan principalmente en áreas temáticas como salud, género, problemáticas sociales, educación, política y cultura. Conclusiones: En América Latina se han realizado aportes significativos en el campo de la Teoría de las Representaciones Sociales como enfoque investigativo de las Ciencias Sociales y Humanas. Con un predo minio del enfoque procesual, los estudios se orientan hacia la comprensión y transformación de la realidad social.
Abstract Objective: this review paper aims to submit an approach towards a state of the art on social representa tions in Latin America. It shows an overview in relation with the Theory of Social Representations' contri bution as a research topic of Social Human Sciences. Method: This research was conducted through a documentary review, classified by the creation of databases and matrices in the Worksheet Excel, as follows: 172 empirical research articles and 102 theoretical articles: considering the following phases: preoperative, heuristic and hermeneutic. Results: The most relevant research projects mainly oriented by the approach process and focus on fields such as health, gender, social problems, education, politics and culture, have been developed in countries such as Brazil, Mexico, Venezuela and Argentina. Conclusions: In Latin America, the Theory of Social Representations as a research approach has made signif icant contributions in Social and Human Sciences field. Toward the understanding and transformation of social reality, the studies are conducted suggesting a predominance of the processual approach.
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Humanos , Política , Arte , Ciências Sociais , Redes Comunitárias , Compreensão , Ciência , Problemas Sociais , Condicionamento Psicológico , Pesquisa Empírica , Hermenêutica , América LatinaRESUMO
Objetivo: Comparar, a las 48 horas, la microdureza superficial de las resinas para reconstrucción de muñones Luxa- core DMG America, Absolute Dentin Parkell y Z350 XT 3M. Materiales y métodos: El grupo de estudio estuvo conformado por 33 discos de resina, distribuidos en tres subgrupos: dos experimentales cada uno conformado por (n = 11), y uno control (n = 11). Los dos primeros grupos son resinas de foto activación y el tercero, una resina de activación dual. Estos fueron sometidos al instrumento microdurómetro Vickers, marca LG, en el laboratorio de ensayos mecánicos. Se aplicó una carga de 200 gramos fuerza por 10 segundos para cada indentación. El análisis estadístico se realizó con ayuda del programa SPSS versión 24 y se realizó la prueba de Anova y la prueba de comparación múltiple de Tukey. Resultados: Luego del ensayo de microdureza Vickers (VHN), los resul- tados fueron: para G1, el valor promedio para la variable microdureza fue 55,24 ± 1,7 VHN; el G2 arrojó un valor promedio de 54,34 ± 3,82 VHN, y para G3 fue de 75.66 ± 4.4 VHN. Conclusión: Las resinas compuestas foto activadas, como material de reconstrucción de muñones sometidos a la prueba de microdureza superficial, mostraron propiedades mecánicas mejoradas en comparación con las resinas duales evaluadas. (AU)
Objective: Compare the superficial microhardness at 48 hours of the core build-up resins Luxacore DMG America, Absolute Dentin PARKELL and Z350 XT 3M. Materials and methods: The study group consisted of 33 resin discs, distrib-uted in three sub-groups: two experi-mental groups (n = 11) and one control group (n = 11). The first two groups were photo activation resins and the third group was a dual activation resin, subjected to the Micro-Vickers Hardness Tester - LG Brand in the mechanical testing labo-ratory. A test force of 200 grams was applied for 10 seconds for each indenta-tion. Statistical analysis was conducted with the help of the SPSS version 24 program and the Anova test and Tukey multiple comparison test were performed. Results: Following the Vickers micro-hardness test (vhn), the mean results for the indentations are shown in Table 1 in vhn values. f or g1 the average microhardness variable was 55.24 ± 1.7 vhn. g2 exhibited an average value of 54.34 ± 3.82 vhn. the average micro-hardness value for G3 was 75.66 ± 4.4 vhn.Conclusions: Composite photo activated resins as a core build-up mate-rial subjected to surface microhardness testing displayed improved mechanical properties compared to the dual resins evaluated. (AU)
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Cimentos Dentários , Polimerização , DurezaRESUMO
The purpose of this manuscript is to report the case of an 81-year-old patient who presented with bilateral keratitis after phacoemulsification surgery. Cultures came back positive for Mycobacterium chelonae. Despite aggressive topical and systemic antimicrobial treatment, the patient developed a corneal perforation in both eyes, treated with corneal glue in the right eye and corneoscleral patch in the left eye. After two years of follow-up, patient was free of infection in the right eye with visual acuity of 20/200 and the left eye progressed to phthisis bulbi. We present an unusual case of bilateral Mycobacterium chelonae keratitis associated with phacoemulsification cataract surgery. This case represents the importance of making clinicians aware of this devastating infection and highlights the need for better management to improve outcomes.
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A major challenge in developing drug-releasing electrospun nanofibers is obtaining long-term drug release over many weeks with no burst release of drug. Here, we present new methods capable of prolonging the diffusive release of small molecule drugs from electrospun poly-L-lactic acid (PLLA) nanofibers. The methods focus on removal of retained electrospinning solvent through fiber heating, maintaining fibers in a laboratory setting, or a combination of these methods. These post-fabrication methods altered the release characteristics of a model small molecule drug, 6-aminonicotinamide (6AN), from PLLA fibers. Specifically, untreated fibers released 6AN over 9 days, and fibers that underwent a combined treatment of maintenance in a laboratory setting and heating released 6AN over 44 days. The unique and simple method presented here prolongs diffusive release of a small molecule drug from electrospun fibers and has potential to assist in lengthening small molecule drug release from a variety of polymeric nanomaterials.
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In this work, the reflectance, optical absorption, and band gap have been determined for CdTe thin films grown on planar and microstructured substrates. The treated surface was prepared by laser ablation of a silicon wafer, forming holes in a periodic arrangement. Thin films were grown by pulsed laser ablation on silicon samples kept at 200 °C inside a vacuum chamber. The presence of CdTe was verified with X-ray diffraction and Raman spectroscopy indicating a nanocrystalline zinc blended structure. The optical absorption of thin films was calculated by using the Fresnel laws and the experimental reflectance spectrum. Results show that reflectance of 245 nm films deposited on modified substrates is reduced by up to a factor of two than the obtained on unchanged silicon and the optical absorption is 16% higher at ~456 nm. Additionally, it was determined that the band gap energy for planar and microstructured films is about 1.44 eV for both cases.
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OBJECTIVE: A high proportion of patients with stroke do not qualify for repetitive transcranial magnetic stimulation (rTMS) clinical studies due to the presence of metallic stents. The ultimate concern is that any metal could become heated due to eddy currents. However, to date, no clinical safety data are available regarding the risk of metallic stents heating with rTMS. METHODS: We tested the safety of common rTMS protocols (1 Hz and 10 Hz) with stents used commonly in stroke, nitinol and elgiloy. In our method, stents were tested in gelled saline at 2 different locations: at the center and at the lobe of the coil. In addition, at each location, stent heating was evaluated in 3 different orientations: parallel to the long axis of coil, parallel to the short axis of the coil, and perpendicular to the plane of the coil. RESULTS: We found that stents did not heat to more than 1°C with either 1 Hz rTMS or 10 Hz rTMS in any configuration or orientation. Heating in general was greater at the lobe when the stent was oriented perpendicularly. CONCLUSIONS: Our study represents a new method for ex vivo quantification of stent heating. We have found that heating of stents was well below the Food and Drug Administration standards of 2°C. Thus, our study paves the way for in vivo testing of rTMS (≤10 Hz) in the presence of implanted magnetic resonance imaging-compatible stents in animal studies. When planning human safety studies though, geometry, orientation, and location relative to the coil would be important to consider as well.
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Ligas , Ligas de Cromo , Cobalto , Procedimentos Endovasculares/instrumentação , Stents , Acidente Vascular Cerebral/terapia , Estimulação Transcraniana por Corrente Contínua , Procedimentos Endovasculares/efeitos adversos , Análise de Falha de Equipamento , Calefação , Humanos , Teste de Materiais , Desenho de Prótese , Falha de Prótese , Medição de Risco , Estimulação Transcraniana por Corrente Contínua/efeitos adversosRESUMO
Resumen (analítico): El propósito central de este artículo se orienta a la comprensión del sentido que le otorga a la pasión de aprender un grupo de estudiantes universitarios de cuatro universidades de la ciudad de Cúcuta, Colombia. La investigación logra una aproximación al fenómeno de la pasión por el conocimiento y alcanza a visualizar los significados que los jóvenes apasionados por el saber le dan al acto de aprender. El enfoque de la investigación es de corte comprensivo, y se sitúa desde la perspectiva epistémica del sujeto conocido. Se utilizan como técnicas para recoger la información el grupo focal y entrevistas en profundidad. El análisis de datos se apoya en la teoría fundamentada. Se encuentra que los participantes asumen su pasión de aprender como actos inteligentes, por vocación y amor por una carrera, por placer, para saborear el saber, y como un desafío que requiere rigor y esfuerzo permanente.
Abstract (analytical): The central purpose of this article aims at understanding the sense that a group of university students from four universities from the city of Cúcuta, Colombia confer to the passion for learning. The research attains a certain approximation to the phenomenon of the passion for knowledge and manages to visualize the significance that young people with a passion for knowledge give to the act of learning. The approach of the research is of the understanding type, and it is placed from the epistemic perspective of the known subject. The focal group and in depth interviews are used as techniques to collect information. The data analysis is supported on the wellfounded theory. It was found that the participants assume their passion for learning as intelligent acts, out of vocation and love for a career, out of pleasure, to be able to savor knowledge, and as a challenge that requires rigor and permanent effort.
Resumo (analítico): O propósito central deste artigo se orienta à compreensão do sentido que é conferido à paixão de aprender por um grupo de estudantes universitários de quatro universidades da cidade de Cúcuta, Colômbia. A investigação busca uma aproximação ao fenômeno da paixão pelo conhecimento e alcança visualizar os significados que os jovens apaixonados pelo saber conferem ao ato de aprender. O enfoque da investigação é de corte compreensivo e se situa a partir da perspectiva epistêmica do sujeito conhecido. São utilizadas como técnicas para a coleta de dados o grupo focal e entrevistas em profundidade. A análise de dados se apoia na teoria fundamentada. Conclui-se que os participantes assumem a sua paixão por aprender como atos inteligentes, por vocação e por amor a uma carreira, por prazer, para saborear o saber e como um desafio que requer rigor e esforço permanentes.
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Pesquisa , Estudantes , Universidades , Prazer , Aprendizagem , AmorRESUMO
En este artículo indagamos sobre las ideas de paz de un grupo de jóvenes desplazados y desplazadas de la ciudad de Cúcuta. Profundizar en este tema aporta elementos pedagógicos para la construcción del bachillerato de Paz como Cultura, propuesta educativa con la cual la Universidad Francisco de Paula Santander atiende a esta población, forzada a abandonar sus lugares de residencia por causa del conflicto armado que se presenta en la frontera colombo-venezolana.Para el análisis tuvimos en cuenta los datos que aportaron las entrevistas abiertas a través de la técnica de codificación progresiva: categorías abierta, axial y selectiva. Los hallazgos permiten la comprensión de la paz en el ámbito de la familia como paz negativa, positiva, imperfecta y neutra.
Este artigo indaga sobre as idéias de paz de um grupo de jovens deslocados e deslocadas da cidade de Cúcuta, Colômbia. Aprofundar neste assunto contribui com elementos pedagógicos para a construção do Segundo Grau de Paz como Cultura. Esta é a proposta com a qual a Universidade Francisco de Paula Santander atende esta povoação, forçada a abandonar seus lugares de residencia devido ao conflito armado existente na fronteira Colômbia-Venezuela.Para fazer a analise contamos com os dados resultantes das entrevistas abertas através da técnica de codificação progressiva: categorias aberta, axial e seletiva. Os achados permitem a compreensão da paz no âmbito da familia como paz negativa, imperfeita e neutra.
This paper examines the idea of peace in a group of displaced young people from Cúcuta, Colombia. Deepen this topic provides teaching materials for the construction of Peace and Culture school, This educational proposal with which the University Francisco de Paula Santander serving this population, forced to leave their homes because of armed conflict that occurs in the Colombian-Venezuelan border.For the analysis was taken into account data provided by open interviews with progressive encoding technique: open, axial and selective categories. The findings allow the understanding of peace within the family as negative, positive, neutral, imperfect peace.
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Conflitos Armados , FamíliaRESUMO
Mammalian cells exhibit a frequent pericentrosomal Golgi ribbon organization. In this paper, we show that two AKAP450 N-terminal fragments, both containing the Golgi-binding GM130-interacting domain of AKAP450, dissociated endogenous AKAP450 from the Golgi and inhibited microtubule (MT) nucleation at the Golgi without interfering with centrosomal activity. These two fragments had, however, strikingly different effects on both Golgi apparatus (GA) integrity and positioning, whereas the short fragment induced GA circularization and ribbon fragmentation, the large construct that encompasses an additional p150glued/MT-binding domain induced separation of the Golgi ribbon from the centrosome. These distinct phenotypes arose by specific interference of each fragment with either Golgi-dependent or centrosome-dependent stages of Golgi assembly. We could thus demonstrate that breaking the polarity axis by perturbing GA positioning has a more dramatic effect on directional cell migration than disrupting the Golgi ribbon. Both features, however, were required for ciliogenesis. We thus identified AKAP450 as a key determinant of pericentrosomal Golgi ribbon integrity, positioning, and function in mammalian cells.
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Movimento Celular , Centrossomo/metabolismo , Cílios/metabolismo , Complexo de Golgi/metabolismo , Proteínas de Ancoragem à Quinase A/metabolismo , Células Cultivadas , Proteínas do Citoesqueleto/metabolismo , Células Epiteliais/metabolismo , Humanos , Microtúbulos/metabolismoRESUMO
BACKGROUND: The Golgi apparatus in mammals appears as a ribbon made up of interconnected stacks of flattened cisternae that is positioned close to the centrosome in a microtubule-dependent manner. How this organisation is achieved and retained is not well understood. GMAP210 is a long coiled-coil cis-Golgi associated protein that plays a role in maintaining Golgi ribbon integrity and position and contributes to the formation of the primary cilium. An amphipathic alpha-helix able to bind liposomes in vitro has been recently identified at the first 38 amino acids of the protein (amphipathic lipid-packing sensor motif), and an ARF1-binding domain (Grip-related Arf-binding domain) was found at the C-terminus. To which type of membranes these two GMAP210 regions bind in vivo and how this contributes to GMAP210 localisation and function remains to be investigated. RESULTS: By using truncated as well as chimeric mutants and videomicroscopy we found that both the N-terminus and the C-terminus of GMAP210 are targeted to the cis-Golgi in vivo. The ALPS motif was identified as the N-terminal binding motif and appeared concentrated in the periphery of Golgi elements and between Golgi stacks. On the contrary, the C-terminal domain appeared uniformly distributed in the cis-cisternae of the Golgi apparatus. Strikingly, the two ends of the protein also behave differently in response to the drug Brefeldin A. The N-terminal domain redistributed to the endoplasmic reticulum (ER) exit sites, as does the full-length protein, whereas the C-terminal domain rapidly dissociated from the Golgi apparatus to the cytosol. Mutants comprising the full-length protein but lacking one of the terminal motifs also associated with the cis-Golgi with distribution patterns similar to those of the corresponding terminal end whereas a mutant consisting in fused N- and C-terminal ends exhibits identical localisation as the endogenous protein. CONCLUSION: We conclude that the Golgi localisation of GMAP210 is the result of the combined action of the two N- and C-terminal domains that recognise different sub-regions of the cis-GA. Based on present and previous data, we propose a model in which GMAP210 would participate in homotypic fusion of cis-cisternae by anchoring the surface of cisternae via its C-terminus and projecting its distal N-terminus to bind the rims or to stabilise tubular structures connecting neighbouring cis-cisternae.
Assuntos
Complexo de Golgi/metabolismo , Proteínas Nucleares/metabolismo , Via Secretória/fisiologia , Sequência de Aminoácidos , Autoantígenos/metabolismo , Linhagem Celular , Centrossomo/metabolismo , Centrossomo/ultraestrutura , Proteínas do Citoesqueleto , Citosol/metabolismo , Citosol/ultraestrutura , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/ultraestrutura , Expressão Gênica , Complexo de Golgi/ultraestrutura , Humanos , Proteínas de Membrana/metabolismo , Microscopia de Fluorescência , Microscopia de Vídeo , Modelos Biológicos , Dados de Sequência Molecular , Proteínas Mutantes Quiméricas/química , Proteínas Mutantes Quiméricas/metabolismo , N-Acetil-Lactosamina Sintase/genética , Proteínas Nucleares/química , Proteínas Nucleares/genética , Biossíntese de Proteínas , Domínios e Motivos de Interação entre Proteínas , Transporte Proteico , RNA Interferente Pequeno , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Epitélio Pigmentado da Retina , TransfecçãoRESUMO
We report that microtubule (MT) nucleation at the Golgi apparatus requires AKAP450, a centrosomal gamma-TuRC-interacting protein that also forms a distinct network associated with the Golgi. Depletion of AKAP450 abolished MT nucleation at the Golgi, whereas depletion of the cis-Golgi protein GM130 led to the disorganisation of AKAP450 network and impairment of MT nucleation. Brefeldin-A treatment induced relocalisation of AKAP450 to ER exit sites and concomitant redistribution of MT nucleation capacity to the ER. AKAP450 specifically binds the cis-side of the Golgi in an MT-independent, GM130-dependent manner. Short AKAP450-dependent growing MTs are covered by CLASP2. Like for centrosome, dynein/dynactin complexes are necessary to anchor MTs growing from the Golgi. We further show that Golgi-associated AKAP450 has a role in cell migration rather than in cell polarisation of the centrosome-Golgi apparatus. We propose that the recruitment of AKAP450 on the Golgi membranes through GM130 allows centrosome-associated nucleating activity to extend to the Golgi, to control the assembly of subsets of MTs ensuring specific functions within the Golgi or for transporting specific cargos to the cell periphery.
Assuntos
Proteínas de Ancoragem à Quinase A/metabolismo , Autoantígenos/metabolismo , Proteínas do Citoesqueleto/metabolismo , Complexo de Golgi/metabolismo , Proteínas de Membrana/metabolismo , Microtúbulos/metabolismo , Proteínas de Ancoragem à Quinase A/genética , Autoantígenos/genética , Brefeldina A/metabolismo , Linhagem Celular , Movimento Celular/fisiologia , Centrossomo/metabolismo , Proteínas do Citoesqueleto/genética , Complexo Dinactina , Dineínas/metabolismo , Retículo Endoplasmático/metabolismo , Células Epiteliais/citologia , Células Epiteliais/fisiologia , Humanos , Membranas Intracelulares/metabolismo , Proteínas de Membrana/genética , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Inibidores da Síntese de Proteínas/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Epitélio Pigmentado da Retina/citologiaRESUMO
Realizou-se um estudo clínico prospectivo, fase III, multicêntrico, aberto, aleatório e comparativo. Foram avaliadas 60 pacientes portadoras de câncer de mama localmente avançado, estádio IIIA, divididas em dois grupos. As pacientes foram submetidas à quimioterapia primária, com ou sem intensificaçäo de dose, por quatro ciclos, e à cirurgia. Utilizou-se o protocolo FEC 50 no Grupo A (5-FU 500 mg/m², epirubicina 50 mg/m² e ciclofosfamida 500 mg/m²) e o FEC 100 no Grupo B (5-FU 500 mg/m², epirubicina 100 mg/m² e ciclofosfamida 500 mg/m²). Foram analisados, durante a quimioterapia, o estado geral, variaçÝo ponderal, alopécia, alteraçöes digestivas, hematológicas e cardiotoxicidade. Após a quimioterapia avaliou-se a resposta tumoral clínica e, na peça cirúrgica, a resposta anatomopatológica. A resposta clínica objetiva (resposta completa e resposta parcial) nos grupos A e B foi 93 porcento e 96 porcento, respectivamente. Os resultados foram similares, porém no Grupo B houve um percentual maior de respostas clínicas completas. Avaliou-se a doença residual no sítio primário e nos linfonodos axilares. No Grupo A houve 4 (13 porcento) casos de resposta anatomopatológica completa, 12 (40 porcento) de tumor residual microscópico e 14 (47 porcento) de tumor macroscópico. No Grupo B ocorreram 10 (33 porcento) casos de resposta anatomopatológica completa, 7 (23 porcento) de tumor residual microscópico e 13 (44 porcento) de tumor macroscópico. Concluiu-se que a quimioterapia primária proporcionou resposta clínica e anatomopatológica maior no grupo com intensificaçäo de dose. A toxicidade, tolerável e reversível, foi mais acentuada no grupo de altas doses.