Desarrollo de la ciencia y la tecnología en las habilidades del internado rotatorio de Cirugía General / Development of science and technology in the skills of a General Surgery rotatory internship

Introducción: El desarrollo científico técnico mundial impone nuevos retos sociales y económicos, y responde a una educación de calidad, que permita la aplicación de este avance en las nuevas tecnologías. Objetivo: Exponer el desarrollo de la ciencia y la tecnología en el mejoramiento de la enseñanza de las habilidades teórico-prácticas en los estudiantes de medicina del internado rotatorio de Cirugía General. Métodos: El estudio empleó la contrastación de métodos teóricos como el histórico-lógico, el análisis documental y la sistematización teórica, para la recolección de información, la construcción, el desarrollo y la conformación final del producto. Conclusiones: Se actualizaron los fundamentos filosóficos, y los conocimientos teóricos del aprendizaje y las nuevas tecnologías para el mejoramiento de la enseñanza de las habilidades teórico-prácticas en los estudiantes de medicina del internado rotatorio de Cirugía General. El desarrollo tecnológico, la enseñanza y la práctica de la ética médica permiten solucionar los problemas de salud de la población en los distintos niveles de atención, lo cual contribuye con la formación integral del futuro médico general(AU)

Introduction: The global scientific-technical development imposes new social and economic challenges, as well as it responds to a quality education, which allows for the application of this advance to new technologies. Objective: To expose the development of science and technology for improving the theoretical-practical skills of medical students during a general surgery rotatory internship. Methods: The study used the opposition of theoretical methods such as the historical-logical, document analysis and theoretical systematization, for the collection of information, construction, development and final conformation of the product. Conclusions: The philosophical foundations were updated, together with the theoretical knowledge about learning and new technologies for improving the teaching of theoretical-practical skills among medical students during a general surgery rotatory internship. Technological development, teaching and practice of medical ethics allow solving the health problems of the population at different levels of care, which contributes to the integral formation of the future general physician(AU)

Avaliação do nível de sujidade de sistemas rotatório e reciprocante após instrumentação e procedimentos de limpeza pré-esterilização / Evaluation of the dirt level of rotary and reciprocating systems after instrumentation and pre-sterilization cleaning procedures

Objetivos: avaliar a sujidade de limas rotatórias e reciprocantes após instrumentação e procedimentos de limpeza pré-esterilização. Materiais e métodos: 24 limas rotatórias e as 24 limas reciprocantes foram divididas, aleatoriamente, em dois grandes grupos. No primeiro grupo, as 12 limas rotatórias e as 12 limas reciprocantes foram divididas, aleatoriamente, em seis subgrupos (SG): SG1 (controle negativo 1/n=1) ­ 1 lima rotatória não submetida à instrumentação; SG2 (controle negativo 2/n=1) ­ 1 lima reciprocante não submetida à instrumentação; SG3 (controle positivo 1/n=1) ­ 1 lima rotatória submetida à instrumentação e não submetida a qualquer protocolo de limpeza; SG4 (controle positivo 2/n=1) ­ 1 lima reciprocante submetida à instrumentação e não submetida a qualquer protocolo de limpeza; SG5 (grupo teste/n=10) ­ 10 limas rotatórias submetidas à instrumentação e submetidas ao protocolo de lavagem manual; SG6 (grupo teste/ n=10) ­ 10 limas reciprocantes submetidas à instrumentação e submetidas ao protocolo de lavagem manual. No segundo grupo, as 12 limas rotatórias e as 12 limas reciprocantes foram divididas, aleatoriamente, nos mesmos subgrupos, substituindo, nos subgrupos 5 e 6, a lavagem manual pela lavagem em cuba ultrassônica. A análise do nível de sujidade foi realizada por microscopia eletrônica de varredura (MEV), sendo os dados submetidos ao teste de Kruskal-Wallis, com nível de significância de 5%. Resultados: a menor média de sujidade entre os grupos experimentais foi encontrada no SG5 do G1, sem diferença significante em relação aos demais grupos testados (p>0,05). Conclusão: conclui-se que os protocolos de limpeza testados não foram completamente efetivos para a remoção de sujidade das limas endodônticas.(AU)

Objective: to evaluate the dirt of rotary and reciprocating files after instrumentation and pre- -sterilization cleaning procedures. Materials and Methods: 24 rotary files and the 24 reciprocating files were randomly divided into two groups. In the 1st group, 12 rotary files and 12 reciprocating files were randomly divided into six subgroups (SG): SG1 (negative control 1/n=1) ­ 1 rotary file not subjected to instrumentation; SG2 (negative control 2/n=1) ­ 1 reciprocating file not subjected to instrumentation; SG3 (positive control 1/n=1) ­ 1 rotary file submitted to instrumentation and not submitted to any cleaning protocol; SG4 (positive control 2/n=1) ­ 1 reciprocating file submitted to instrumentation and not submitted to any cleaning protocol; SG5 (test group/n=10) ­ 10 rotary files submitted to instrumentation and submitted to the manual cleaning protocol; SG6 (test group/n=10) ­ 10 reciprocating files submitted to instrumentation and submitted to the manual cleaning protocol. In the 2nd group, the 12 rotary files and the 12 reciprocating files were randomly divided into the same subgroups, substituting, in subgroups 5 and 6, manual with ultrasonic bath cleaning. The analysis of dirt levels was performed by scanning electron microscopy (SEM), being the data submitted to the Kruskal-Wallis test, with a significance level of 5%. Results: the lowest average of dirt between the experimental groups was found in SG5 of G1, with no significant difference when compared to the other groups (p>0.05). Conclusion: it could be concluded that the cleaning protocols were not completely effective in removing dirt from endodontic files.(AU)

Instrumental piezoeléctrico en comparación a instrumental rotatorio convencional para la exodoncia de terceros molares mandibulares / Piezoelectric bone surgery versus conventional rotatory system for lower third molar surgery

RESUMEN: Introducción: Tradicionalmente la osteotomía requerida en la exodoncia de terceros molares mandibulares incluidos o semi-incluidos ha sido realizada con instrumental manual o rotatorio. Con el advenimiento de la técnica ultrasónica de la cirugía piezoeléctrica, se hace necesario comparar la seguridad y efectividad de ambas técnicas. Métodos: Realizamos una búsqueda en Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud, la cual es mantenida mediante el cribado de múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Extrajimos los datos desde las revisiones identificadas, analizamos los datos de los estudios primarios, realizamos un metanálisis y preparamos una tabla de resumen de los resultados utilizando el método GRADE. Resultados y conclusiones: Identificamos ocho revisiones sistemáticas que en conjunto incluyeron 22 estudios primarios, de los cuales 12 corresponden a ensayos clínicos aleatorizados. Concluimos que el uso de instrumental piezoeléctrico en comparación con el instrumental rotatorio convencional podría aumentar el tiempo quirúrgico y podría disminuir el dolor temprano y tardío, junto con el edema al día siete, pero la certeza de la evidencia es baja. Por otra parte, el uso de instrumental piezoeléctrico podría resultar en poca o nula diferencia en el desarrollo de alteraciones neurológicas postoperatorias ya que la certeza de la evidencia es baja. Además, el uso de piezoeléctrico probablemente resulte en poca o nula diferencia en la apertura bucal.

ABSTRACT: Introduction: Traditionally, osteotomy techniques required in exodontia of included or semi-included mandibular third molars has been performed with manual or rotary instruments. With the advent of the ultrasonic technique of piezoelectric surgery, it is necessary to evaluate the effectiveness and safety of both osteotomy techniques. Methods: We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed primary studies' data, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. Results and conclusions: We identified eight systematic reviews that together included 22 primary studies overall, of which 12 were randomized trials. We conclude that the use of piezoelectric surgery compared with conventional rotary instruments may increase operative time and reduce early and late pain, along with edema at day seven, but the certainty of the evidence is low. On the other hand, the use of piezoelectric instrumentation may result in little or no difference in the development of postoperative neurologic disturbances as the certainty of the evidence is low. Also, piezoelectric use probably makes little or no differences in mouth opening.

Apical debris extrusion during instrumentation with continuous and reciprocating systems

Objective: to evaluate the amount of apical debris extrusion during root canal preparation using continuous and reciprocating systems. Material and Methods: Forty lower incisors were selected and randomly divided into four groups (n=10) for root canal preparation. Two multifile systems with continuous rotation (iRace® and Mtwo®) and two reciprocating single-file systems (Reciproc® and WaveOne®) were used. In the iRace® group, the R1 (15/.06), R2 (25/.04) and R3 (30/.04) instruments were used. In the Mtwo® group, the 10/.04, 15/.05, 20/.06, and 25/.06 instruments were used. In the Reciproc® and WaveOne® groups, the R25 and 25/.04 instruments were used, respectively. Apical debris extrusion was determined by calculating the difference between the pre- and post-instrumentation weight of the Eppendorf tubes. Statistical analysis was performed using the analysis of variance (ANOVA) test with the Bonferroni correction (p<0.05). Results: The iRace® group demonstrated significantly more apical extrusion than the Reciproc® group (p<0.05). There was no statistically significant difference between the Mtwo®, Reciproc®, and WaveOne® groups (p>0.05). Conclusion: All of the evaluated systems produced apical debris extrusion. The iRace® system produced more apical debris extrusion than the Reciproc® system, and there was no difference observed in this regard between the Mtwo®, Reciproc®, and WaveOne® systems.

Objetivo: avaliar a quantidade de debris extruidos apicalmente durante o preparo do canal radicular usando sistemas de rotação contínua e reciprocante. Materiais e Métodos: Quarenta incisivos inferiores foram selecionados e randomicamente divididos em quatro grupos (n=10) para o preparo do canal radicular. Dois sistemas de limas múltiplas de rotação contínua (iRace® e Mtwo®) e dois sistemas de limas únicas reciprocantes (Reciproc® e WaveOne®) foram usados. No grupo iRace®, foram utilizados os instrumentos R1 (15/.06), R2 (25/.04) e R3 (30/.04). No grupo Mtwo®, foram utilizados os instrumentos 10/.04, 15/.05, 20/.06, 25/.06. Nos grupos Reciproc® e WaveOne®, foram utilizados os instrumentos R25 e 25.04, respectivamente. A extrusão apical de debris foi calculada pela diferença entre os pesos dos tubos Eppendorf antes e após a instrumentação. A análise estatística foi feita usando o teste de análise de variância (ANOVA) seguida do teste de Bonferroni (p<0,05). Resultados: O grupo iRace® demonstrou significativamente mais extrusão quando comparado ao Reciproc (p<0,05). Não houve diferença estatisticamente significativa entre os grupos Mtwo®, Reciproc®, e WaveOne® (p>0,05). Conclusão: Todos os sistemas avaliados produziram extrusão apical de debris. O Sistema iRace® produziu mais extrusão apical de debris do que o Sistema Reciproc® e não foi observada diferença entre os sistemas Mtwo®, Reciproc® e WaveOne®.

Sistema rotatorio protaper: un modelo educativo en la enseñanza de grado / Protaper rotary system: an educational model in predoctoral teaching

Objetivos: El objetivo del presente trabajo fue analizar el nivel de eventos (estiramiento/fractura) en el instumental rotatorio endodonticode niquel- titanio después del uso en Practicas Preclínicas de Grado en dientes ex vivos y tacos de acrílico Materiales y métodos: Seseleccionaron alumnos de grado de la materia Endodoncia de cuatro comisiones (n= 60) que en las pruebas de apropiación deconocimientos y destrezas, superaron el valor de 7/10. A cada alumno se le entregó un kit de ProTaper Universal, nuevo para larealización de dos prácticas: 1° en tacos de acrílicos simuladores de piezas dentarias y 2° en una pieza unirradicular extraída de bajacomplejidad. Se evaluaron las series de limas S1, S2, F1, F2 y F3 en cada población. Se realizó una lectura macro de cada instrumentocon lupa 4X, efectuada por un operador entrenado. Previamente, se realizó en el unaevaluación de los instrumentos sin uso y luego de los estirados o fracturados. Para el análisis de eventos producidos en cada serie de limas seutilizó el Test de Chi cuadrado de homogeneidad con niveles de significación de p= 0,05 (sofware estadístico Infostat) Resultados: No seencontraron diferencias significativas entre las distribuciones de los eventos en dientes y en taco. (Test de Chi2 p=0.0957). En el primeruso, de un total de 300 instrumentos utilizados, 6 sufrieron un evento, siendo en el segundo uso de 270, 12 sufrieron un evento. Para cadainstrumento, las diferencias no resultaron estadísticamente significativas (p valor de Irwin Fisher) S1 p=0.29, S2 p=0.10, F1 p=0.33,F2 p=0.81, F3 p=0.81. Observamos la frecuencia de eventos por instrumento, surgiendo que son más frecuentes los eventos con F1 y F2que con los restantes instrumentos...

Objective: The aim of this study was to analyze the behavior (events: stretching/fracture) of Ni-Ti rotatory Endodontic instruments afterthe utilization in preclinical practice, either ex vivo teeth or acrilic dowels. Materials and methods: undergraduate Endodontic studentsbelonging to four different courses with higher califications (more than 7/10) have been selected (n = 60). Each student has been deliveredwith a brand new ProTaper Universal Kit with the purpose of carrying out two endodontic practices, 1° in acrilics dowels, simulating ateeth and, 2° in a natural low complexity single rooted teeth. The series of files S1, S2, F1, F2 y F3 were assessed in each population. Amacro observation with a 4x magnified lens was performed by a qualified operator. Previously, a MEB observation had been performed onthe brand new instruments and in the post-use stretched or fractured instruments. The Chi square test of homogenity with significancelevels of p = 0.05 have been utilized for the analysis of the events (Infostat Estatistical Software). Results: No significant differences hasbeen found between the event distributions (Teeth/Acrilics dowels) (Test Chi2 p = 0,0957). A total of 300 files used for first time, 6suffered some kind of event, while in the second, a total of 270 files, 12 suffered some kind of event (stretching/fracture). The differenceswere not statistically significant on each file (p = Irwin Fisher value) S1 p=0.29, S2 p=0.10, F1 p=0.33, F2 p=0.81, F3 p=0.81.The event for each instrument has been detected to be more frequent with files F1 and F2 than with other files...

Percepción de los alumnos del internado rotatorio de una patología prevalente en un hospital público / Perception of rotary boarding students of a prevalent pathology in a public hospital

El objetivo del presente estudio fue conocer el nivel de percepción de los alumnos del Internado Rotatorio de Medicina (IR) sobre una patología prevalente no infecciosa, en un hospital público.Se realizó un estudio observacional, donde participaron 138 alumnos del IR, divididos en 8 rotaciones, con un promedio de 18 alumnos por rotación. Se determinó el nivel de percepción de los mismos a través de un instrumento de medición de opción simple, laencuesta, que contenía 8 indicadores a través de 48 enunciados. El instrumento se validó a través de opiniones del Docente Investigador, junto con sus colaboradores en Medicina Interna. Se obtuvo la confiabilidad del método a través de procedimientos matemáticos, y para el análisis de resultados, se empleó estadística no paramétrica.En cuanto a los resultados, el instrumento contó con un índice de fiabilidad del 0.94, y los niveles de percepción por parte de los alumnos fueron moderados así como el reconocimiento de los indicadores clínicos respectivos. La percepción de los alumnos del Internado sobre una patología prevalente no infecciosa en un hospital público fue moderada.En última instancia, llamamos a la reflexión crítica para propiciar una educaciónparticipativa, ya que las actividades de enseñanza posiblemente no favorecieron el encuentro entre la teoría y práctica.Palabras Clave: Percepción -Internado Rotatorio -Educación Médica

Objective: To fix the perception of student interns Revolving Medicine on a non-infectious disease prevalent in a public hospital.Methods: observational study, where about 138 students participated Rotatory of Medicine, 8 rotations, with an average of 18 students per rotation. The level of awareness of students was determined using a measuring instrument simple choice, survey indicators containing 8 through 48 statements. The instrument was validated by the Educational Research Review, together with its partners in Internal Medicine. Reliability of the method was obtained through mathematical procedures, and results analysis nonparametric statistics were used.Results: The instrument had a reliability index of 0.94. And the levels of perception of the students were moderate and recognition of clinical indicators respective. The perception of boarding school students on a non-infectious disease prevalent in a public hospital, has been moderate.Discussion: call critical thinking and encourage participatory education as teaching activities may not favored the meeting between theory and practice

Condiciones generales de los estudiantes medicina de la generación 2010 durante su internado rotatorio de pregrado en la escuela superior de medicina del instituto politécnico nacional / Condições gerais dos estudantes de medicina da turma 2010 durante o seu internato rotatório de graduação na escola superior de medicina do instituto politécnico nacional / General conditions of medicine students, class 2010, during their pre-degree rotatory internship of medical school, national polytechnic institute

En la Escuela Superior de Medicina del Instituto Politécnico Nacional, el Internado se cursa antes del servicio social y consiste en un año de formación dentro del hospital, frente a pacientes, bajo supervisión directa de médicos. Se realizó un estudio descriptivo a la generación de estudiantes de 2010, a quienes se aplicó una encuesta al término de su Internado en 2010. El 57 por ciento fueron mujeres; al 71 por ciento las autoridades no lo respetaron durante su horario de comida; al 60 por ciento los profesores no lo respetaron en su horario de clases; el 25 por ciento fue objeto de hostigamiento; el 35 por ciento objeto de violencia y maltrato, y el 35 por ciento víctima de discriminación. El 61 por ciento se percató de que personal del hospital se alcoholiza o usa estupefacientes dentro del hospital en horas de servicio. Para el 58 por ciento, las autoridades de la escuela no dieron seguimiento a su estancia y el 15 por ciento fue víctima de acoso sexual por médicos de base, residentes y personal de enfermería. Es importante señalar que este es un estudio inicial y único en su tipo. Se realizarán estudios en las siguientes generaciones para encontrar patrones de incidencia o prevalencias significativas, denunciarlas y evitar que se repitan en el futuro.

In the School of Medicine of the National Polytechnic Institute, internship takes place before social service and consists of a training year inside the Hospital, in which trainees see patients under direct supervision of physicians. A descriptive study was carried out of student’s class 2010, to whom a survey was applied by the end of their internship in 2010. 57 percent of students were women; for 71 percent, lunch time was not respected by authorities; for 60 percent, schedules of classes were not respected by professors; 25 percent students were harassed; 35 percent students were object of violence and maltreatment; and 35 percent students were victim of discrimination. 61 percent students realized that Hospital staff consumes alcohol or drugs inside the Hospital in service hours. For 58 percent students, School authorities did not monitor their stay and 15 percent students were victim of sexual harassment by physicians, residents and nurse staff. It is important to point out that this is an initial study unique in its type. More studies will be carried out in the following generations to find out incidence patterns or significant prevalence, in order to denounce them and to avoid their future repetition.

Na Escola Superior de Medicina do Instituto Politécnico Nacional, o Internato é cursado antes do servicio social e consiste em um ano de formação dentro do hospital, junto a pacientes, sob supervisão direta de médicos. Foi realizado um estudo descritivo na turma de estudantes de 2010, aos quais foi aplicada uma enquete no término de seu Internato em 2010. 57 por cento eram mulheres; para 71 por cento as autoridades não respeitaram seu horário de refeição; para 60 por cento os professores não respeitaram o seu horário de aulas; 25 por cento foram objeto de hostilização; 35 por cento foram objeto de violência e maltrato, e 35 por cento foram vítimas de discriminação. 61 por cento se conscientizaram de que o pessoal do hospital se alcooliza ou usa estupefacientes dentro do hospital no horário de serviço. Para 58 por cento as autoridades da escola não deram seguimiento ao seu estágio e 15 por cento foram vítimas de assédio sexual por médicos de base, residentes e pessoal de enfermagem. É importante assinalar que este é um estudo inicial e único de sua categoria. Foram realizados estudos nas turmas seguintes para encontrar padrões de incidência ou prevalências significativas, denunciá-las e evitar que se repitam no futuro.

Effects of Hypericum perforatum on turning behavior in an animal model of Parkinson's disease

Parkinson's disease (PD) is an age-related neurodegenerative disorder characterized by the slow and progressive death of dopaminergic neurons in the (substantia nigra pars compact). Hypericum perforatum (H. perforatum) is a plant widely used as an antidepressant, that also presents antioxidant and anti-inflammatory properties. We evaluated the effects of H. perforatum on the turning behavior of rats submitted to a unilateral administration of 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle as an animal model of PD. The animals were treated with H. perforatum (100, 200, or 400 mg/kg, v.o.) for 35 consecutive days (from the 28th day before surgery to the 7th day after). The turning behavior was evaluated at 7, 14 and 21 days after the surgery, and the turnings were counted as contralateral or ipsilateral to the lesion side. All tested doses significantly reduced the number of contralateral turns in all days of evaluation, suggesting a neuroprotective effect. However, they were not able to prevent the 6-OHDA-induced decrease of tyrosine hydroxylase expression in the lesioned striatum. We propose that H. perforatum may counteract the overexpression of dopamine receptors on the lesioned striatum as a possible mechanism for this effect. The present findings provide new evidence that H. perforatum may represent a promising therapeutic tool for PD.

A Doença de Parkinson é uma doença neurodegenerativa relacionada à idade, caracterizada pela morte lenta e progressiva de neurônios dopaminérgicos da substância negra pars compacta. O Hypericum perforatum (H. perforatum) é um fitoterápico utilizado como antidepressivo, apresentando propriedades antioxidantes, anti-inflamatórias e nootrópicas. Neste trabalho, avaliaram-se os efeitos do tratamento com H. perforatum no comportamento rotatório de ratos no modelo da doença de Parkinson induzido pela administração unilateral de 6-OHDA no feixe prosencefálico medial. Ratos Wistar machos foram tratados com H. perforatum (100, 200 ou 400 mg/kg, v.o.) por 35 dias (do 28º dia antes até o 7º dia após a lesão). As rotações ipsilaterais e contralaterais à lesão foram registradas no 7º, 14º e 21º dias após a cirurgia. As três doses de H. perforatum utilizadas reduziram o número de rotações contralaterais, indicando um possível efeito neuroprotetor da planta. Porém, o H. perforatum não impediu a redução na expressão da enzima tirosina hidroxilase no estriado lesionado, quantificada por Western blot. Propomos que o H. perforatum possa bloquear o aumento da expressão dos receptores dopaminérgicos no estriado lesionado com 6-OHDA. Entretanto, estudos adicionais são necessários para identificar o mecanismo exato pelo qual o H. perforatum reduziu o número de rotações contralaterais. Os resultados do presente estudo sugerem o H. perforatum como um potencial agente terapêutico para a doença de Parkinson.

Técnica de la punta libre con sistema injecta / Free tip technique with system injects

El propósito de esta monografía es conocer la técnica de preparación biomecánica de punta libre, conceptualizarla, describiendo la técnica realizada con el sistema rotatorio Injecta. Con el objetivo de conceptualizar el sistema rotatorio injecta uno de los varios ya existentes en el mercado, caracterizarlo, describir sus componentes y su técnica de utilización se realiza esta monografìa recopilando información actualizada muy escasa debido a la poca o inexistente información con que contamos en nuestro medio al respecto.

Influência da velocidade de rotação no número de ciclos para a fratura de instrumentos endodônticos ProTaper Universal S2 / Influence of rotation speed on the number of cycles to fracture engine-driven ProTaper Universal S2

O presente trabalho avaliou a influência da velocidade de rotação no número de ciclos necessários para fraturar instrumentos endodônticos de NiTi mecanizados. Instrumentos ProTaper Universal S2 de 25 mm de comprimento a 300 e 600 rpm foram usados em um canal curvo. Os resultados indicaram que o número de ciclos requerido para causar a fratura foi influenciado pela velocidade de rotação.

La desincronización interna como promotora de enfermedad y problemas de conducta / Internal desynchrony as promotor of disease and behavioral disturbance

Life on our planet is ruled by a temporary structure that governs our activities, our days and our calendars. In order to cope with a daily changing environment, organisms have developed adaptive strategies by exhibiting daily behavioral and physiological changes. Biological rhythms are properties conserved in all the levels of organization, from unicellular to prokaryotes to upper plants and mammals. A biological rhythm is defined as the recurrence of a biological phenomenon in regular intervals of time. Biological rhythms in behaviour and physiology are controled by an internal clock which synchronizes its oscillations to external time cues that have the capacity to adjust the clock's mechanism and keep it coupled to external fluctuations. The suprachiasmatic nucleus (SCN) of the hypothalamus in mammals is the master circadian clock which is mainly entrained by the light-dark cycle. The SCN transmits time signals to the brain and then to the whole body and by means of its time signals the SCN keeps a temporal order in diverse oscillations of the body and adjusted to the light-dark cycle. The correct temporal order enables an individual to adequate functioning in harmony with the external cycles. Biological rhythms have a hereditary character, thus its expression is genetically determined. All animals, plants, and probably all organism show some type of physiological rhythmic variation (metabolic rate, production of heat, flowering, etc.) that allow for the adaptation to a rhythmic environment. Biological rhythms enable individuals to anticipate and to be prepared to the demands of the prominent cyclic environmental changes, which are necessary for survival. Also, biological rhythms promote showing maximum levels of a physiological variable at the right moment when the environment requires a maximal response. In humans, an example of circadian rhythms is the sleep-wake cycle; simultaneously, a series of physiological changes are exhibited, also with circadian characteristics (close to 24 hours). Circadian oscillations are observed in the liberation of luteinizant hormone, in plasma cortisol, leptin, insulin, glucose and growth hormone just to mentions some examples. The SCN controls circadian rhythmicity via projections to the autonomic system and by controlling the hypothalamus-adenohipofisis-adrenal axis. In this way, the SCN transmits phase and period to the peripheral oscillators to maintain an internal synchrony. Modern life favors situations that oppose the time signals in the environment and promote conflicting signals to the SCN and its effectors. The consequence is that circadian oscillators uncouple from the master clock and from the external cycles leading to oscillations out of synchrony with the environment, which is known as internal desynchronization. The consequence is that physiological variables reach their peak expression at wrong moments according to environmental demands leading then to deficient responses and to disease in the long run. Also, levels of attention, learning and memory reach peak expression at wrong moments of the day leading individuals to exhibit a deficient performance at school or work. The disturbed sleep patterns promote fatigue and irritability, which difficult social interaction. Internal desynchronization results from transmeridional traveling for which people pass multiple hourly regions. This results in an abrupt change in the time schedule and a syndrome known as <>. Frequent travelers complain about difficulties to adjust their sleep-wake cycle to the new schedule, thus resulting in fatigue, increased sleepiness and reduced attention. Jet lag results from a loss of synchrony among biological rhythms and among diverse functions, which remain out of phase with the day-night cycle. This <> is the cause of general discomfort, decrement in the physical and mental performance, as well as irritability and depression. Frequently, gastrointestinal disorders are a by-product of food consumption at an unusual schedule. The state of internal desynchrony is transitory and depends on the number of time zones that were crossed; thus, adaptation to a new external cycle can take from four to seven days. Another example of internal desynchrony is observed in individuals exposed to work shifts or to nocturnal work schedules (night work). In such conditions, circadian fluctuations in behavioral, hormonal and metabolic parameters are observed but their temporary relation with the external cycles is modified. The internal synchrony is thus affected by troubled environmental signs, out of phase with the daily activities of the individual; among them are the hours of food intake, the exposure to light during resting hours, the low temperature of the night, and the forced activity when homeostatic processes indicate a need to rest. This internal desynchrony leads to gastrointestinal disorders, disturbed metabolic fluctuations, disturbed cardiovascular functions, altered menstrual cycle, sleep disorders, sleepiness, increase of work accidents, etc. Internal desynchrony is especially due to the fact that circadian fluctuations are influenced by daily external cycles, but also by homeostatic factors, and can suffer from additional disturbance by sleep deprivation. Despite years of night work experience, incapacity to adapt to night work may persist. Only a minority of shift workers achieve spontaneous adjustment of the rhythms of core body temperature, melatonin, cortisol, thyroid stimulating hormone, or prolactin secretion to shifts by nocturnal work. Therefore shift and night workers develop a propensity to smoke, drink alcoholic beverages and use stimulant products. After five years of shift or night work, health problems appear with a higher incidence than in the general population. The growing social demand of shift work makes it necessary to decide on the characteristics and forms of shifts to carry out, and up to now organizing such working schedules remaing a serious problem. The improvement of health services has increased life expectancies and thus the general population is becoming old and people survive more years. Older people ail from health and behavioral problems including a deterioration of the biological rhythms. Main alterations consist of a loss of expression of the circadian functions or a decrease of the amplitude of the rhythms, and instability of synchronization mechanisms day by day. All in all, this implies a decreased capacity of the clock to adjust to the solar day. The decreased efficacy of the aging biological clock is evident in the fragmented sleep patterns and the disturbed sleep/wake rhythms, characterized by short sleep episodes during the day and decreased sleep during the night. Some studies suggest that the disturbed circadian rhythms may be the cause of diverse diseases associated with the elderly. In conclusion, during the last 100 years we have changed our lifestyle so radically that we lack already a physiological design to adapt so quickly to modernity. We can state that our body is designed for a world that does not exist. In this article we present a review of the main alterations of the biological rhythms generated by the transmeridional trips, shift-work and aging, their behavioral and physiological consequences that lead to disease and poor mental performance. We also discuss possible strategies that need to be explored and that may help people to improve their quality of life and to prevent internal desynchrony.

La vida se rige por una estructura temporal que gobierna nuestras horas, nuestros días y nuestros calendarios. Como parte de la adaptación a los ciclos de tiempo que impone el planeta, todo organismo presenta ritmos en su actividad y fisiología. Los ritmos biológicos son una propiedad conservada en todos los niveles de organización, desde organismos unicelulares procariontes hasta plantas superiores y mamíferos. De ellos, los más sólidos son aquellos asociados a los ciclos externos por la alternancia del día y la noche y por la alternancia de las estaciones del año. Los ritmos biológicos fisiológicos y conductuales son procesos dependientes de un reloj interno capaz de ajustar sus oscilaciones a claves de tiempo externas que lo mantienen sincronizado a estas fluctuaciones externas. El núcleo supraquiasmático del hipotálamo (NSQ) es en los mamíferos el principal reloj circadiano y se sincroniza principalmente por el ciclo luz-oscuridad. El NSQ transmite señales de tiempo al cerebro y de ahí al resto del organismo, y por medio de estas señales de tiempo mantiene un orden temporal en diversas funciones del cuerpo y las mantiene ajustadas al ciclo luz-oscuridad. El correcto orden temporal interno permite un adecuado funcionamiento del individuo en armonía con el medio externo y le permite exhibir respuestas adecuadas a un ambiente cambiante y predecible. El estilo de vida del hombre moderno propicia situaciones que llevan a alteraciones de nuestros ritmos biológicos que causan una desadaptación temporal, que a su vez redunda en daños a la salud, ya que afecta tanto la fisiología como la forma en que organizamos nuestra conducta. Un ejemplo de ello son los viajes a través de múltiples regiones horarias. Estos cambios de horario bruscos provocan un síndrome conocido como jet-lag, que consiste en un conflicto transitorio entre el tiempo <> y el tiempo <>, lo cual se denomina <>. El jet-lag se define como un conjunto de síntomas causados por una alteración del patrón de sueño, y de la expresión de ritmos biológicos fuera de fase entre sí y fuera de fase con el ciclo del día y la noche. Esta es la causa del malestar general, el deterioro del desempeño mental y físico, así como de la irritabilidad y depresión. Son frecuentes también las alteraciones gastrointestinales, resultado del consumo de alimento en un horario inusual. Otro ejemplo de alteraciones en los ritmos circadianos se observa en los trabajadores con turnos rotatorios o en turnos nocturnos. En estas condiciones se produce un conflicto entre las señales temporales asociadas al ciclo diurno y que transmite el reloj con las actividades y alimentos del trabajador en turnos. De este esquema de trabajo resulta una reducción de las horas de sueño y una alteración de los ritmos circadianos, que llevan a una desincronización interna. Ésta, al igual que en el caso del jet-lag, redunda en un deterioro de las funciones mentales y de la capacidad de atención y memorización, que se asocian a irritabilidad y problemas emocionales. Además, se observan consecuencias en la salud con incremento en la incidencia de malestares gastrointestinales, enfermedades cardiovasculares, obesidad y diabetes. La mejoría en los servicios de salud ha incrementado las expectativas de vida, lo que entonces enfrenta a la humanidad a una población que logra sobrevivir muchos años de su vejez con los cambios de conducta y salud propios de su edad, entre los que se incluye un deterioro de los ritmos biológicos. En este trabajo presentamos una revisión de las principales alteraciones de los ritmos biológicos generadas por los viajes transmeridionales, la vejez y el trabajo en turnos. También discutimos la relevancia de una buena adaptación de los ritmos biológicos y las consecuencias conductuales y fisiológicas que por su alteración llevan a la enfermedad y a un desempeño mental deficiente. También sugerimos estrategias que necesitan ser exploradas y que podrían ayudar prevenir la desincronización interna para mejorar la calidad de vida.

Evaluación de la instrumentación de conductos radiculares con limas manuales y rotatorias de níquel titanio aspecto morfológico de las limas antes y despues / Evaluation of root canal instrument with hand files and nickel titanium rotary limes morphological appearance before and after

En el presente estudio se hizo una evaluación in vitro del preparo del conducto radicular en el nivel apical de raíces mesiales de molares inferiores comparando el aspecto morfológico de la superficie de instrumentos manuales y rotatorios de níquel cromo antes y después de su uso. Se tomaron 30 molares inferiores humanos extraídos, con conductos radiculares mesiovestibulares y mesiolinguales independientes y sin obstrucciones en los cuales fueron evaluados la extensión de transporte del centro axial del conducto radicular, área del conducto radicular desgastada después de la instrumentación y el tiempo empleado para el preparo de dicho conducto. Se realizó el análisis estadístico de Kruskal- Wallis y Test U de Mann Whitney que no encontraron diferencia significativa entre ambas limas en el transporte del centro axial del conducto ni en el área desgastada después de la instrumentacion, hubo diferencia significativa en el tiempo empleado y en la alteración de la morfología de las limas antes y después de su uso y las limas rotatórias presentaron mayor cantidad de defectos morfológicos antes y después de su uso

In the following study there was made an in vitro evaluation of the prepare of the radicular conduct at the apical level of mesial roots of inferior molars comparing the morphological aspect of the surface of manual and rotational instruments of nickel chromus before and after their use. There were taken 30 extracted human inferior molars, with independent and non- obstructed mesiovestibular and mesiolingual radicular conducts. In them was evaluated the transport extension of the axial centre of the conduct, wore area of the conduct after instrumentation and time used to prepare the conduct. The statistical evaluation was made according Kruskal- Wallis and Test U of Mann Whitney that did not find significant difference between the lines neither at the transportation of the axial centre of the conduct nor at the wore area after the instrumentation. There was a significant difference at the time used at the prepare and at the morphological alteration of the limes before and after their use and the rotational limes presented more deffects before and after their use

Avaliação clínica do desempenho do sistema rotatório RaCe® / Clinical assessment of the performance of the RaCe® rotary sytem

O objetivo do tratamento endodôntico é possibilitar sua limpeza, modelagem e desinfecção do sistema de canais radiculares para seu posterior selamento. Sistemas rotatórios de níquel-titânio têm sido empregados, principalmente devido a sua grande flexibilidade e baixo módulo de elasticidade. Vários estudos buscam equacionar a rapidez e facilidade da instrumentação rotatória com sua eficiência e segurança. Assim, o objetivo deste estudo foi divulgar a técnica e avaliar o desempenho clínico da instrumentação rotatória com o sistema RaCe. Estes instrumentos foram introduzidos recentemente no mercado pela FKG apresentando um desenho inovador de suas lâminas cortantes. Cinco molares foram tratados no curso de Especialização em Endodontia da Universidade do Sagrado Coração, por um mesmo operador. Os tratamentos foram analisados radiograficamente, fatores como dilatação dos canais, manutenção da trajetória, desvio apical e manutenção do comprimento de trabalho, além de fraturas ou deformação de instrumentos. O novo sistema mostrou bons resultados em relação a todos os quesitos. Concluiu-se que todos os canais biomecanizados com o sistema RaCe resultaram num tratamento endodôntico adequado tanto clínica quanto radiograficamente, obtendo-se eficiência e facilidade no preparo.

Evaluación del funcionamiento de un tambor rotatorio aplicado a la biorremediación de un suelocontaminado con hidrocarburos

Entre los procesos de biorremediación, los biorreactores de tambor rotatorio son una alternativa promisoria para la restauración ad situ de suelos contaminados con hidrocarburos. Se estudió el efecto del número de mamparas, tipo de mampara y velocidad de rotación, en el proceso de remoción de hidrocarburos tratados en un biorreactor tipo tambor rotatorio abierto a la atmósfera, de 4l de capacidad. Se utilizó suelo intemperizado tipo migajón-limoso, con una concentración promedio de 50000mg/kg de hidrocarburos totales de petróleo (HTPs). De acuerdo a los resultados obtenidos y un análisis de varianza, la velocidad de rotación es la variable más significativa (contribución del 96% de la varianza) en el proceso de remoción de hidrocarburos, observándose una velocidad óptima de 10rpm, en el intervalo 5-20rpm. El nivel máximo promedio de remoción de HTPs fue de 65%, cuando se operó el reactor con 4 mamparas acanaladas y 10rpm. El número y tipo de mamparas no tuvo efecto significativo sobre la remoción de HTPs. De acuerdo con los niveles de remoción alcanzados, se considera que los reactores abiertos a la atmósfera podrían ser aplicados exitosamente en el campo a la remediación de suelos intemperizados y altamente contaminados, con la ventaja de que los tiempos de tratamiento son los más bajos.

Among bioremediation processes, the rotating drum bioreactor is a promising alternative for the ad situ restoration of soils polluted with hydrocarbons. The effects of number and type of baffles, as well as rotating speed, on the hydrocarbon removal process were examined in a soil treated in a rotating open drum of 4l. An aged silty-loam soil was used, containing 50000mg/kg of total hydrocarbon oil (HTP). The rotating speed was the variable with the greatest effect on the degradation process, and an optimal speed of 10rpm was identified in the interval 5-20rpm. The maximal percentage of HTP removal obtained was 65%, when the drum was operated with 4 baffles and 10rpm. The number and type of baffles did not have a significant effect over the implemented operational conditions. According to the results obtained, the open drums could be successfully applied, with lower treatment times, to the remediation of aged heavily contaminated soil.

Entre os processos de biorremediação, os bioreatores de tambor rotatório são uma alternativa otimista para a restauração ad situ de solos contaminados com hidrocarbonetos. Estudou-se o efeito do número de membranas, tipo de membranas e velocidade de rotação, no processo de remoção de hidrocarbonetos tratados em um biorreactor tipo tambor rotatório aberto à atmosfera, de 4lts de capacidade. Utilizou-se solo intemperizado tipo "migajon-limoso" (pastoso-limoso), com uma concentração média de 50.000 mg/kg de hidrocarbonetos totais de petróleo (HTPs). De acordo aos resultados obtidos e uma análise de variação, a velocidade de rotação é a variável mais significativa (contribuição do 96% da variação) no processo de remoção de hidrocarbonetos, observando-se uma velocidade ótima de 10 rpm, no intervalo 5-20 rpm. O nível máximo médio de remoção de HTPs foi de 65%, quando se operou o reator com 4 membranas acanaladas e 10 rpm. O número e tipo de membranas não teve efeito significativo sobre a remoção de HTPs. De acordo com os níveis de remoção alcançados, se considera que os reatores abertos à atmosfera poderiam ser aplicados exitosamente no campo à remediação de solos intemperizados e altamente contaminados, com a vantagem de que os tempos de tratamento são os mais baixos.

Instrumental utilizado en el trabajo biomecánico en endodoncia. Investigación bibliográfica / Instruments used in biomechanical work in endodontics. Bibliographic research

A través de los años, la Endodoncia ha evolucionado tratando de interponer instrumentos mecánicos capaces de reproducir los mismos movimientos del operador al instrumental; en un tiempo menor, o al menos semejante. Existe un significativo volumen de investigaciones endodóncicas que definen las múltiples dificultades implícitas en la limpieza de estos pequeños y complejos espacios. El objetivo de los procedimientos endodóncicos de modelado o conformación consiste en ayudar a limpiar los conductos y lo que es más importante a crear una forma de éstos que permita el relleno total y controlado de todo el sistema de conductos radiculares, en todas las dimensiones. El presente trabajo es una revisión de la literatura que ofrece información acerca del estado actual del instrumental manual y rotatorio para la preparación biomecánica de los conductos radiculares, así como innovaciones que puedan ser utilizadas con nuevas técnicas o con las ya existentes, aportando así una fuente bibliográfica donde se pueda encontrar características del instrumental pudiendo optar a la utilización de cualquiera de los mencionados en el desarrollo del trabajo, con el debido entrenamiento y asesoría en el caso del instrumental rotatorio.

Through the years, Endodontics has evolved trying to interpose mechanical instruments capable of reproducing the same movements from the operator to the instruments; in a less time, or at least similar. There is a significant volume of endodontic research that defines the multiple difficulties involved in cleaning these small and complex spaces. The goal of shaping or shaping endodontic procedures is to help clean the canals and, most importantly, to create a shape for the canals that allows full and controlled filling of the entire root canal system, in all dimensions. The present work is a review of the literature that offers information about the current state of manual and rotary instruments for the biomechanical preparation of root canals, as well as innovations that can be used with new or existing techniques, thus providing a source bibliographic where you can find characteristics of the instruments being able to choose to use any of those mentioned in the development of the work, with due training and advice in the case of rotary instruments.