Target-site and non-target-site resistance mechanisms to ALS inhibiting herbicides in Papaver rhoeas.

Target-site and non-target-site resistance mechanisms to ALS inhibitors were investigated in multiple resistant (tribenuron-methyl and 2,4-D) and only 2,4-D resistant, Spanish corn poppy populations. Six amino-acid replacements at the Pro197 position (Ala197, Arg197, His197, Leu197, Thr197 and Ser197) were found in three multiple resistant populations. These replacements were responsible for the high tribenuron-methyl resistance response, and some of them, especially Thr197 and Ser197, elucidated the cross-resistant pattern for imazamox and florasulam, respectively. Mutations outside of the conserved regions of the ALS gene (Gly427 and Leu648) were identified, but not related to resistance response. Higher mobility of labeled tribenuron-methyl in plants with multiple resistance was, however, similar to plants with only 2,4-D resistance, indicating the presence of non-target-site resistance mechanisms (NTSR). Metabolism studies confirmed the presence of a hydroxy imazamox metabolite in one of the populations. Lack of correlation between phenotype and genotype in plants treated with florasulam or imazamox, non-mutated plants surviving imazamox, tribenuron-methyl translocation patterns and the presence of enhanced metabolism revealed signs of the presence of NTSR mechanisms to ALS inhibitors in this species. On this basis, selection pressure with ALS non-SU inhibitors bears the risk of promoting the evolution of NTSR mechanisms in corn poppy.

Unravelling the resistance mechanisms to 2,4-D (2,4-dichlorophenoxyacetic acid) in corn poppy (Papaver rhoeas).

In southern Europe, the intensive use of 2,4-D (2,4-dichlorophenoxyacetic acid) and tribenuron-methyl in cereal crop systems has resulted in the evolution of resistant (R) corn poppy (Papaver rhoeas L.) biotypes. Experiments were conducted to elucidate (1) the resistance response to these two herbicides, (2) the cross-resistant pattern to other synthetic auxins and (3) the physiological basis of the auxin resistance in two R (F-R213 and D-R703) populations. R plants were resistant to both 2,4-D and tribenuron-methyl (F-R213) or just to 2,4-D (D-R703) and both R populations were also resistant to dicamba and aminopyralid. Results from absorption and translocation experiment revealed that R plants translocated less [14C]-2,4-D than S plants at all evaluation times. There was between four and eight-fold greater ethylene production in S plants treated with 2,4-D, than in R plants. Overall, these results suggest that reduced 2,4-D translocation is the resistance mechanism in synthetic auxins R corn poppy populations and this likely leads to less ethylene production and greater survival in R plants.

Cytochrome P450 metabolism-based herbicide resistance to imazamox and 2,4-D in Papaver rhoeas.

Papaver rhoeas biotypes displaying multiple herbicide resistance to ALS inhibitors and synthetic auxin herbicides (SAH) are spreading across Europe. In Spain, enhanced metabolism to imazamox was confirmed in one population, while cytochrome-P450 (P450) based metabolism to 2,4-D in another two. The objectives of this research were to further confirm the presence of P450 mediated enhanced metabolism and, if so, to confirm whether a putative common P450 is responsible of metabolizing both 2,4-D and imazamox. Metabolism studies were undertaken in five P. rhoeas populations with contrasted HR profiles (herbicide susceptible, only HR to ALS inhibitors, only HR to SAH, or multiple HR to both), and moreover, three different P450 inhibitors were used. The presence of enhanced metabolism to these SoA was confirmed in three more HR P. rhoeas populations. This study provides the first direct evidence that imazamox metabolism in these biotypes is P450-mediated, also in one population without an altered target site. Additionally, it was further confirmed that enhanced metabolism of 2,4-D in biotypes only HR to SAH or multiple HR to ALS inhibitors and SAH involves P450 as well. No metabolism was detected using the three inhibitors in all the herbicide-metabolizing P. rhoeas biotypes, suggesting that a common metabolic system involving P450s is responsible of degrading herbicides affecting both SoAs. Thus, selection pressure with either SAH or imidazolinone ALS inhibitors can select not only for resistance to each of them, but it can also confer cross-resistance between them in P. rhoeas.

Point Mutations as Main Resistance Mechanism Together With P450-Based Metabolism Confer Broad Resistance to Different ALS-Inhibiting Herbicides in Glebionis coronaria From Tunisia.

Resistance to acetolactate synthase (ALS) inhibiting herbicides has recently been reported in Glebionis coronaria from wheat fields in northern Tunisia, where the weed is widespread. However, potential resistance mechanisms conferring resistance in these populations are unknown. The aim of this research was to study target-site resistance (TSR) and non-target-site resistance (NTSR) mechanisms present in two putative resistant (R) populations. Dose-response experiments, ALS enzyme activity assays, ALS gene sequencing, absorption and translocation experiments with radiolabeled herbicides, and metabolism experiments were carried out for this purpose. Whole plant trials confirmed high resistance levels to tribenuron and cross-resistance to florasulam and imazamox. ALS enzyme activity further confirmed cross-resistance to these three herbicides and also to bispyribac, but not to flucarbazone. Sequence analysis revealed the presence of amino acid substitutions in positions 197, 376, and 574 of the target enzyme. Among the NTSR mechanisms investigated, absorption or translocation did not contribute to resistance, while evidences of the presence of enhanced metabolism were provided. A pretreatment with the cytochrome P450 monooxygenase (P450) inhibitor malathion partially synergized with imazamox in post-emergence but not with tribenuron in dose-response experiments. Additionally, an imazamox hydroxyl metabolite was detected in both R populations in metabolism experiments, which disappeared with the pretreatment with malathion. This study confirms the evolution of cross-resistance to ALS inhibiting herbicides in G. coronaria from Tunisia through TSR and NTSR mechanisms. The presence of enhanced metabolism involving P450 is threatening the chemical management of this weed in Tunisian wheat fields, since it might confer cross-resistance to other sites of action.

The First Case of Glyphosate Resistance in Johnsongrass (Sorghum halepense (L.) Pers.) in Europe.

Six Johnsongrass populations suspected of being glyphosate resistant were collected from railways and freeways near Cordoba (SW Spain), where glyphosate is the main weed control tool. The 50% reduction in shoot fresh weight (GR50) values obtained for these six populations ranged from 550.4 to 1169 g ae ha-1, which were 4.2 to 9 times greater than the value obtained for the susceptible population. Glyphosate was equally metabolized to the same extent in both resistant and susceptible populations, with no significant differences in either 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) inhibition or basal activity. No amino acid substitutions were observed in any of the resistant populations. Slight but significant differences in glyphosate penetration were observed among some but not all of the resistant populations and for the times of incubation assayed, although these differences were not considered further. The proposed primary mechanism of resistance in these six glyphosate-resistant Johnsongrass populations is reduced herbicide translocation, because the amount of glyphosate that translocated from treated leaves to shoots and roots in the susceptible population was double that observed in the resistant populations. As glyphosate multiple resistance due to more than one mechanism is not uncommon, this is the first time that glyphosate-resistant Johnsongrass populations have been fully described for all known mechanisms.

Pertinencia del uso de estilos de aprendizaje desde la Morfofisiología en la carrera de Estomatología / Pertinence of the use of learning styles through the Morphology-phyisiology in the Odontology career

Los estilos de aprendizaje son los rasgos cognitivos, afectivos y fisiológicos que sirven como indicadores relativamente estables de cómo los alumnos perciben, interaccionan y responden a sus ambientes de aprendizajes. Los autores realizaron una revisión bibliográfica acerca del tema con el objetivo de fundamentar la necesaria pertinencia de estos en el proceso docente educativo desde la disciplina Morfofisiología de la carrera de Estomatología, ya que a los educandos les permite desarrollar estrategias cognitivas efectivas; y en el caso de los profesores, crear acciones pedagógicas para lograr un proceso enseñanza aprendizaje desarrollador.

The learning styles are the cognitive, affective and physiologic features that are good as relatively stable indicators of how the students perceive, interact and respond to their learning environment. The authors carried out a bibliographical review about the topic with the objective to support the necessary pertinence of them in the teaching-learning process through the Morphology-phyisiology discipline of the Odontology career, since they allow to develop cognitive-affective strategies in the students and to create pedagogic actions in the case of the professors, this way to achieve a developing teaching-learning process.

Intervención pedagógica para la dirección del trabajo independiente en Morfofisiología / Educational intervention for the guidance of independent work in Morphophysiology

Fundamento: en el curso 2007-2008 se produjeron cambios en los contenidos de los programas de estudio en la carrera de Estomatología al unirse las ciencias básicas biomédicas en una disciplina académica, la Morfofisiología. Las asignaturas que la componen presentan diferentes formas de organización de la enseñanza, entre ellas el trabajo independiente. Objetivo: analizar los resultados de acciones pedagógicas que favorezcan una correcta dirección del trabajo independiente en la disciplina Morfofisiología, a partir de las condiciones contextuales existentes. Método: se realizó una investigación con carácter analítico prospectivo en la Facultad de Estomatología de Camagüey, desde febrero del 2012 a mayo del 2013, el universo estuvo constituido por los 85 estudiantes matriculados en el primer año de la carrera en el curso 2011-2012. Se trabajó con el universo por la importancia de la investigación. Entre las acciones emprendidas se encuentran: la preparación del colectivo docente, la orientación a los estudiantes de cómo realizar el trabajo independiente y la atención diferenciada a los estudiantes identificados con dificultades en su realización. La evaluación se basó en la comparación del rendimiento académico alcanzado por los estudiantes. Resultados: un porciento elevado de estudiantes reconocieron la realización por parte de los profesores de los elementos fundamentales para una correcta orientación del trabajo independiente, el rendimiento académico de los estudiantes aumentó después de aplicar el plan de acciones. Conclusiones: las acciones pedagógicas que se diseñaron para realizar una correcta dirección del trabajo independiente en la disciplina Morfofisiología mostraron ser efectivas lo que se constató en un aumento en el rendimiento académico de los estudiantes.

Background: in the academic year 2007-2008, changes occurred in the contents of the Dentistry curriculum with the merging of the basic biomedical sciences in a single discipline, Morphophysiology. The subjects that comprise it have different forms of organization of teaching, and independent work is one of them. Objective: to analyze the results of pedagogical actions that contribute to a correct guidance of independent work in the discipline Morphophysiology, considering the existing contextual conditions. Methods: prospective analytical study was conducted in the Faculty of Dentistry of Camagüey, from February 2012 to May 2013. The universe consisted of 85 students enrolled in the first year of study in the academic year 2011-2012. The study included the universe due to the importance of the issue. The actions taken included: preparation of the teaching staff, guidance to students on how to perform independent work and individualized attention to students who had shown difficulties in this area. The assessment was based on comparing the academic performance achieved by the students. Results: a high percentage of students acknowledged the implementation, by teachers, of the key elements for a successful guidance of independent work, and the academic performance of students improved after implementing the action plan. Conclusions: the educational actions that were designed to provide a correct guidance of independent work in the discipline Morphophysiology were found to be effective, which was demonstrated by an improvement in the academic performance of students.

Uso de células madre en el complejo bucofacial / Use of stem cells in the orofacial complex

Introducción: las células madre tienen la capacidad de dividirse indefinidamente y diferenciarse en distintos tipos de células especializadas, no solo desde el punto de vista morfológico sino también de forma funcional. Los conocimientos que en este campo de la medicina se realizan, han elevado las expectativas de enfermos y profesionales de la salud que contribuyen a la curación de múltiples enfermedades. Desarrollo: se realizó una revisión bibliográfica acerca del uso de las células madre en el complejo bucofacial, las cuales pueden clasificarse en embrionarias y adultas según su estado evolutivo, y en relación con su potencialidad celular en totipotentes, pluripotentes y multipotentes, que actúan en la regeneración del tejido óseo, el ligamento periodontal, la dentina y el diente. Conclusiones: se demostró que las células madre juegan un importante papel en la regeneración de diferentes estructuras del complejo bucofacial y tienen su mecanismo de acción a nivel del complejo pulpo-dentinal, el ligamento periodontal, y en la regeneración de deficiencias esqueléticas cráneo-faciales.

Introduction: stem cells have the capacity of dividing themselves into various types of specialized cells, not only from the morphological point of view but functionally as well. Scientific advances in the field of regenerative medicine have increased life expectancy of sick people and also better results of dental professionals. These advances do contribute to cure various diseases. Discussion: a bibliographical review on the use of stem cells in the orofacial complex was carried out. These cells are classified according to their evolution state into embryonic and adult, and according to their cellular potentiality into totipotent, pluripotent and multipotent. They regenerate bone tissue, periodontal ligament, dentine and tooth. Conclusion: it has been demonstrated that stem cells play an important role in the regeneration of different structure of the orofacial complex. They have their mechanism of action in the pulp-dentinal complex, periodontal ligament and in the regeneration of craniofacial skeletal defects.

Acción analgésica de la digitopuntura previa al tratamiento estomatológico convencional en las pulpitis agudas / Analgesic action of digitopuncture previous to the conventional stomatological treatment in acute pulpitis

Los pacientes con pulpitis aguda, producto al dolor que las caracteriza, en ocasiones no permiten realizar un tratamiento endodóntico de urgencia satisfactorio. Objetivo: evaluar la acción analgésica de la digitopuntura previo al tratamiento estomatológico convencional en las pulpitis agudas. Método: se realizó un estudio de evaluación, cuasi-experimental de tipo antes y después, en la consulta de urgencias estomatológica del policlínico Previsora desde septiembre de 2008 hasta abril de 2009, el universo de estudio se conformó por los pacientes que acudieron a la consulta con dolor producido por pulpitis aguda, la muestra quedó se integró por 40 pacientes que no habían recibido tratamiento previo. Se evaluó la intensidad del dolor a los 30min y se valoró la cooperación del paciente durante el tratamiento convencional. Resultados: en el 90 por ciento de los casos se evaluó como eficaz el tratamiento realizado y los pacientes refirieron sentirse satisfechos.

Patients with acute pulpitis caused to the pain that characterizes it, in occasions allow carrying out a satisfactory endodontic treatment of urgency. Objective: to evaluate the analgesic action of digitopuncture previous to the conventional stomatological treatment in acute pulpitis. Method: a before and after type quasi-experimental, evaluation study was performed, in the stomatological urgency consultation at Previsora polyclinic from September 2008 to April 2009, the study universe was conformed by patients that came to the consultation with pain caused by acute pulpitis and the sample was integrated by 40 patients who had not received previous treatment. The intensity of pain was evaluated to 30 minutes and patient's cooperation was valued during the conventional treatment. Results: in 90 percent of cases was evaluated as effective the treatment carried out and patients referred to feel satisfied with the treatment received (90 percent).

Aspectos epidemiológicos asociados a alteraciones del desarrollo en embarazadas añosas / Epidemiological aspects associated to alterations of development in old pregnant woman

Fundamento: la edad materna avanzada constituye un factor asociado que muestra un riesgo estadísticamente significativo en la aparición de las malformaciones congénitas. Objetivo: determinar la edad específica del grupo etáreo donde ocurrieron las alteraciones del desarrollo, así como la posible relación de algunos factores de riesgos con estas alteraciones. Método: se realizó un estudio descriptivo prospectivo en las nueve áreas de salud del municipio Camagüey, desde enero del año dos mil cinco a junio del año dos mil siete. El universo de estudio se constituyó por quinientas doce gestantes de treinta y cinco o más años de edad captadas en la consulta de riesgo genético; la muestra (cincuenta y tres gestantes que presentaron alteraciones del desarrollo embrionario o fetal) se tomó por muestreo no probabilístico y criterio de expertos. Resultados: las alteraciones del desarrollo prenatal que presentaron mayor frecuencia fueron los abortos espontáneos y las cromosomopatías. El grupo etáreo más afectado fue el de 35 a 36 años de edad y la ingestión de medicamentos fue el agente teratógeno que más se asoció a las alteraciones del desarrollo. Conclusiones: las alteraciones del desarrollo prenatal más frecuente encontradas en las embarazadas con edad materna avanzada fueron los abortos espontáneos, cromosomopatías, malformaciones congénitas y óbitos fetales, siendo los abortos espontáneos los que predominaron.

Background: the advanced maternal age constitutes an associate factor that shows a statistically significant risk in the appearance of congenital malformations. Objective: to determine the specific age of the age group where alterations of development occurred, as well as the possible relationship of some risk factors with these alterations. Method: a prospective descriptive study in the nine health areas of Camagüey municipality was conducted, from January 2005 to June 2007. The study universe was constituted by five-hundred and twelve pregnant women of thirty-five years or more captured in the genetic risk consultation; the sample (fifty-three pregnant women presented alterations of embryonal or fetal development) it was took by non-probabilistic sampling and experts' criterion. Results: alterations of prenatal development that presented greater frequency were spontaneous abortions and chromosomopathies. The most affected age group was the one from 35 to 36 years and drugs intake was the teratogen agent more associated to the alterations of development. Conclusions: the most frequent alterations of prenatal development found in pregnant women with advanced maternal age were spontaneous abortions, chromosomopathies, congenital malformations and fetal deaths, being spontaneous abortions those that prevailed.

Sarcomas de partes blandas de localizaciones parameníngeas en el niño: valoración del tratamiento radiante / Childhood soft tissue sarcoma in parameningeal sites: assessment of radiation therapy

En un grupo de 21 niños con sarcomas de partes blandas de localizaciones parameningeas (nasofaringe, senos perinasales, órbita, fosas nasales y oido medio) tratados con la asociación radioterapia-poliquimioterapia se alcanzó una supervivencia del 27,09% En 12 niños, donde la irradiación estuvo localizada en el área del tumor con una dosis en el rango de 56 a 60 Gy,la supervivencia alcanzada fue de 20.83%, estabilizada a partir de los 38 meses de evoluciòn. En 9 niños la irradiación incluyó, además del tumor primario con dosis entre 55 y 65 Guy, la irradiación de todo el cráneo con dosis entre 24 y 30 Guy, con una supervivencia del 40 %, estabilizada en el mes 13 de la evolución. En ambos grupos se empleó la quimioterapia con la combinación vincristina,ciclofosfamida y actinomicin D (VAC) y además la adriamicina (VACA). La diferencia en la supervivencia alcanzada en ambos grupos es estadisticamente significativa a favor de la irradiación extendida al cráneo y demuestra la utilidad de esta en el tratamiento de estos tumores parameníngeos