Trastornos circadianos del sueño / Circadian Sleep Disorders

Resumen El sistema circadiano está sincronizado al ciclo luz-oscuridad que es generado por la rotación de la tierra, asegurando que la vigilia sea durante el día y que el sueño ocurra durante la noche. Sin embargo, el ritmo de sueño-vigilia puede estar desincronizado del ciclo luz-oscuridad o desincronizado de manera endógena, dando como resultado: insomnio, fatiga y bajo rendimiento en las actividades cotidianas. Mientras que los trastornos del sueño están clasificados por la Asociación Americana de Trastornos del Sueño como: disomnias intrínsecas, disomnias extrínsecas, parasomnias o trastornos del sueño médicos/psiquiátricos. Los trastornos circadianos del sueño se han categorizado por separado, en parte para reconocer que en la mayoría de los casos la etiología de los trastornos circadianos es una mezcla de factores internos y ambientales, o por un desajuste temporal entre ambos. Los síntomas generalmente son insomnio o hipersomnia, síntomas comunes en pacientes con trastornos circadianos del sueño, aunque hay otras causas a las que pueden atribuirse y que deben excluirse antes de realizar el diagnóstico de un trastorno circadiano del sueño. En el paciente sin otra patología del sueño, un registro diario de actividades, comidas, ejercicio, siestas y la hora de acostarse es una herramienta esencial para evaluar los trastornos circadianos del sueño. Estos registros deben mantenerse durante 2 semanas o más, ya que una perturbación debida a cambios de trabajo o viajes a través de zonas horarias puede tener efectos sobre el sueño y el estado de alerta durante el día, semanas después del evento.

Abstract The circadian system is synchronized to the light-dark cycle generated by the rotation of the earth, ensuring that wakefulness is during the day and sleep occurs at night. However, the sleep-wake rhythm may be out of sync with the light-dark cycle or endogenously out of sync, resulting in insomnia, fatigue, and poor performance in activities of daily living. Sleep disorders are classified by the American Sleep Disorders Association, as intrinsic dyssomnias, extrinsic dyssomnias, parasomnias, or medical/psychiatric sleep disorders. Circadian sleep disorders have been categorized separately to recognize that in most cases the etiology of circadian disturbances is a mix of internal and environmental factors or a temporary mismatch between the two. Symptoms are usually insomnia or hypersomnia, common symptoms in patients with circadian sleep disorders although other causes can be attributed and must be excluded before a diagnosis of a circadian sleep disorder is made. In the patient without other sleep pathology, a daily record of activities, meals, exercise, naps, and bedtime is an essential tool in assessing circadian sleep disorders. These records should be kept for 2 weeks or more, as a disturbance due to job changes or travel across time zones can have effects on sleep and daytime alertness weeks after the event.

Effect of a light-darkness cycle on the body weight gain of preterm infants admitted to the neonatal intensive care unit.

The Continuous bright light conditions to which premature infants are subjected while hospitalized in Neonatal Intensive Care Units (NICU) can have deleterious effects in terms of growth and development. This study evaluates the benefits of a light/darkness cycle (LDC) in weight and early hospital discharge from the NICU. Subjects were recruited from three participating institutions in Mexico. Eligible patients (n = 294) were premature infants who were hospitalized in the low-risk and high-risk neonatal units classified as stable. The subjects randomized to the experimental group (n = 150) were allocated to LDC conditions are as follows: light from 07:00 to 19:00 and darkness (25 lx) from 19:00 to 07:00. The control group (n = 144) was kept under normal room light conditions (CBL) 24 h a day. Main outcome was weight gain and the effect of reducing the intensity of nocturnal light in development of premature infants. Infants to the LDC gained weight earlier, compared with those randomized to CBL, and had a significant reduction in length of hospital stay. These results highlight those premature infants subjected to a LDC exhibit improvements in physiological development, favoring earlier weight gain and consequently a decrease in hospital stays. ClinicalTrials.gov; 02/09/2020 ID: NCT05230706.

Midazolam reduction with pre-operative melatonin in abdominal hysterectomy: double-blind randomized clinical trial.

INTRODUCTION: Midazolam is a benzodiazepine used for sedation, however, can cause respiratory depression and increases morbidity in patients. Melatonin is an effective alternative to manage anxiety in the perioperative period and could help to reduce the use of benzodiazepines during surgery. The aim of this clinical trial was to determine the efficacy of pre-operative sedation with a single-dose melatonin to reduce intraoperative use of midazolam in women under total abdominal hysterectomy (TAH). MATERIALS AND METHODS: This is a double-blind randomized clinical trial conducted in women over 25 years, scheduled for TAH, with American Society of Anesthesiologists Grade I or II. Each patient was randomly assigned to receive 5 mg of melatonin prolonged-release oral capsules or placebo. Midazolam use for anesthetic management was the decision of the treating anesthesiologist and sedation status was determined using the observer's assessment of alertness/sedation scale. RESULTS: In patients receiving melatonin, the use of midazolam during surgery was less than in patients receiving placebo. In addition, melatonin produces sedation 30 min after administration, the sedative effect was maintained at 60- and 90-min. Furthermore, hospital stay was shorter in patients who received melatonin (p = 0.006). CONCLUSION: Melatonin is effective for reduces intraoperative midazolam consumption and hospital stay in women undergoing TAH.

INTRODUCCIÓN: El midazolam es una benzodiazepina utilizada para la sedación, sin embargo, puede causar depresión respiratoria y aumentar la morbilidad en los pacientes. La melatonina es una alternativa eficaz para controlar la ansiedad en el período perioperatorio y podría ayudar a reducir el uso de benzodiazepinas durante la cirugía. El objetivo de este ensayo clínico fue determinar la eficacia de la sedación preoperatoria con una dosis única de melatonina para reducir el uso intraoperatorio de midazolam en mujeres sometidas a histerectomía abdominal total (HTA). MATERIAL Y MÉTODOS: Se trata de un ensayo clínico aleatorizado doble ciego realizado en mujeres mayores de 25 años, programadas para TAH, con American Society of Anesthesiologists Grado I o II. Cada paciente fue asignado al azar para recibir 5 mg de cápsulas orales de liberación prolongada de melatonina o placebo. El uso de midazolam para el manejo anestésico fue decisión del anestesiólogo tratante y el estado de sedación se determinó mediante la escala OAA/S. RESULTADOS: En las pacientes que recibieron melatonina, el uso de midazolam durante la cirugía fue menor que en las pacientes que recibieron placebo. Además, la melatonina produce sedación 30 min después de la administración, el efecto sedante se mantuvo a los 60 y 90 min. Además, la estancia hospitalaria fue más corta en los pacientes que recibieron melatonina (p = 0.006). CONCLUSIÓN: La melatonina es eficaz para reducir el consumo de midazolam intraoperatorio y la estancia hospitalaria en mujeres sometidas a HTA.

Development of the circadian system and relevance of periodic signals for neonatal development.

Circadian rhythms are generated endogenously with a period of approximately 24h. Studies carried out during the last decade indicate that the circadian system develops before birth, and that the suprachiasmatic nucleus, a structure that is considered the mammalian circadian clock, is present in primates from the middle of pregnancy. Recent evidence shows that the infants' circadian system is sensitive to light from very early stages of development; it has also been proposed that low-intensity lighting can regulate the developing clock. After birth there is a progressive maturation of the outputs of the circadian system with marked rhythms in sleep-wake phenomena and hormone secretion. These facts express the importance of circadian photic regulation in infants. Thus, the exposure of premature babies to light/dark cycles results in a rapid establishment of activity/rest patterns, which are in the light-dark cycle. With the continuous study of the development of the circadian system and the influence on human physiology and disease, it is anticipated that the application of circadian biology will become an increasingly important component in the perinatal care.

The pterional approach for the surgical resection of an orbital cholesteatoma: a case report.

BACKGROUND: Cholesteatomas are benign tumors mainly composed of cholesterol crystals that rarely arise within the orbit. However, orbital cholesteatomas require a complete surgical resection due to their recidivating potential. Transcranial approaches offering a broad surgical exposure of the orbital cavity have been scarcely used for the management of these tumors. Here, we provide evidence of the benefits of the pterional craniotomy for the surgical resection of orbital tumors by sharing our experience in the surgical management of a cholesteatoma of the superotemporal orbital wall. CASE PRESENTATION: A 45-year-old Hispanic man with a 2-year history of progressive proptosis of the left eye attended to our center complaining of diplopia and migraine. At his arrival, physical examination revealed ptosis, palpebral edema, and exophthalmos of the left eye, as well as the abolishment of the ipsilateral photomotor and consensual responses. Fundoscopy showed mild optic atrophy, whereas a T2-weighted magnetic resonance imaging (MRI) of the head showed a hyperintense mass arising at the superotemporal wall of the orbit that was displacing the eyeball. The tumor was resected using a pterional craniotomy without postoperative complications. The histopathological analysis of the tumor revealed a cholesteatoma. The patient recovered the functionality of the left eye with no visual sensitive deficits nor tumor recurrence 1 year after the surgery. CONCLUSIONS: Our results support the use of the pterional craniotomy as a safe procedure for the surgical resection of cholesteatomas arising at the superotemporal walls of the orbit, with low postoperative morbidity.

A Complete and State of the Art Pre-mortem Diagnostic Approach to Creutzfeldt-Jakob Disease: A Case Report.

Sporadic Creutzfeldt-Jakob disease (sCJD) is a fatal and rapidly progressive form of dementia caused by the spread of a prion protein within the brain. Its real incidence is unknown since its definitive diagnosis requires histopathological analysis of brain specimens. However, novel tests that detect prion proteins in cerebrospinal fluid samples, such as the real-time quaking-induced conversion (RT-QuIC) technique, now allow the pre-mortem diagnosis of sCJD. Here, we report the first case of sCJD confirmed by RT-QuIC in Latin America, providing evidence of its diagnostic performance and clinical correlation.

Enfermedad pulmonar obstructiva crónica (EPOC). Bases para el médico general / Chronic Obstructive Pulmonary Disease (COPD). Bases for the General Practitioner

Resumen La enfermedad pulmonar obstructiva crónica (EPOC) es una enfermedad crónico-degenerativa frecuente, prevenible y tratable, caracterizada por persistentes síntomas respiratorios y limitación del flujo aéreo. En 2016, el Instituto Nacional de Enfermedades Respiratorias (INER) la ubicó en el cuarto lugar en la tabla de morbi-mortalidad anual en México. Su prevalencia está directamente relacionada con la del tabaquismo; sin embargo, su desarrollo es multifactorial. Para el estudio de la EPOC es importante conocer los antecedentes de exposición a factores de riesgo y la presencia de los principales síntomas; es esencial una historia clínica bien detallada, donde se recabe la mayor cantidad de datos de todo nuevo paciente en el que se conozca o se sospeche de la enfermedad, así como una espirometría para establecer el diagnóstico. Debido a la gran variabilidad que existe entre los pacientes con EPOC, es necesario establecer tratamiento farmacológico individualizado. Los fármacos utilizados en su tratamiento reducen los síntomas, la frecuencia y la gravedad de las exacerbaciones; sin embargo, no hay ningún medicamento que modifique el deterioro a largo plazo de la función pulmonar. Por lo tanto, el conocimiento básico de este padecimiento por el médico de primer contacto es esencial para la sospecha en una etapa inicial, y así ofrecer al paciente una intervención médica inmediata. El presente trabajo tiene la finalidad de acercar al médico general una visión básica de la EPOC.

Abstract Chronic obstructive pulmonary disease (COPD) is a chronic degenerative disease. It is a frequent, preventable and treatable disease characterized by persistent respiratory symptoms and airflow limitation. The National Institute of Respiratory Diseases (INER), ranked COPD in 2016 in fourth place in the table of annual morbidity and mortality in Mexico. The prevalence of COPD is directly related to smoking; however, its development is multifactorial. For its study it is important to know of any prior exposure to risk factors and of any manifestation of the main symptoms. To make a diagnosis, a detailed clinical history, where the largest amount of data is collected from every new possible COPD patient, and a spirometry are essential. Individual pharmacological treatment is necessary due to the great variability among COPD patients. The drugs used in the treatment of COPD reduce the symptoms, the frequency and severity of exacerbations; however, there is no medication that modifies the long-term deterioration of the lung function. Therefore, a basic knowledge of this condition by the medical doctor first contacted, is essential for the suspicion of COPD in its initial stage and thus, offer the patient immediate medical intervention. The objective of the present work is to provide a basic overview of COPD to the general practitioner.

Chocolate for breakfast prevents circadian desynchrony in experimental models of jet-lag and shift-work.

Night-workers, transcontinental travelers and individuals that regularly shift their sleep timing, suffer from circadian desynchrony and are at risk to develop metabolic disease, cancer, and mood disorders, among others. Experimental and clinical studies provide evidence that food intake restricted to the normal activity phase is a potent synchronizer for the circadian system and can prevent the detrimental metabolic effects associated with circadian disruption. As an alternative, we hypothesized that a timed piece of chocolate scheduled to the onset of the activity phase may be sufficient stimulus to synchronize circadian rhythms under conditions of shift-work or jet-lag. In Wistar rats, a daily piece of chocolate coupled to the onset of the active phase (breakfast) accelerated re-entrainment in a jet-lag model by setting the activity of the suprachiasmatic nucleus (SCN) to the new cycle. Furthermore, in a rat model of shift-work, a piece of chocolate for breakfast prevented circadian desynchrony, by increasing the amplitude of the day-night c-Fos activation in the SCN. Contrasting, chocolate for dinner prevented re-entrainment in the jet-lag condition and favored circadian desynchrony in the shift-work models. Moreover, chocolate for breakfast resulted in low body weight gain while chocolate for dinner boosted up body weight. Present data evidence the relevance of the timing of a highly caloric and palatable meal for circadian synchrony and metabolic function.

Síndrome de jet lag o cambio de zonas de tiempo / The jet lag syndrome or time-zone changes

Resumen Nuestro planeta, así como la vida que en él se desarrolla, se encuentra en constante movimiento. Los ritmos geofísicos influyen en la actividad de los organismos, de tal manera que los seres vivos han desarrollado mecanismos adaptativos para poder responder a las variaciones diarias del medio ambiente. El sistema circadiano es el responsable de responder a estas variaciones cíclicas ambientales. Cuando se modifican las señales ambientales, como en un viaje que implica atravesar varias zonas horarias, se ocasionan cambios fisiológicos que han llevado a buscar estrategias para contrarrestar los síntomas que se presentan; estas estrategias incluyen el ejercicio programado, la exposición a la luz brillante, la melatonina y la alimentación programada.

Abstract Our planet and the life that develops in it are in constant movement, therefore, the geophysical rhythms influence the activity of organisms, in such a way that living beings have developed adaptative mechanims in order to respond to the daily variations of the environment. The circadian system is responsible for responding to these cyclical environmental variations. When the environmental signals are modified, like for instance, on a trip that involves crossing several time zones, physiological changes occur. This results in searching for possible strategies to counteract the symptomatology. These strategies include scheduled exercise, exposure to a bright light, melatonin and scheduled meals.

Social jet-lag potentiates obesity and metabolic syndrome when combined with cafeteria diet in rats.

BACKGROUND/OBJECTIVES: Modern lifestyle promotes shifted sleep onset and shifted wake up time between weekdays and weekends, producing a condition termed "social-jet lag." Disrupted sleep promotes increased appetite for carbohydrate and fat-rich food, which in long term leads to overweight, obesity and metabolic syndrome. In order to mimic the human situation we produced an experimental model of social-jet lag (Sj-l). With this model, we explored the link between shifted sleep time with consumption of a cafeteria diet (CafD) and the development of obesity and metabolic syndrome. SUBJECTS/METHODS: The first experiment was designed to create and confirm the model of Sj-l. Rats (n=8-10/group) were exposed to a shifted sleep time protocol achieved by placing the rats in slow rotating wheels from Monday to Friday during the first 4h of the light period, while on weekends they were left undisturbed. The second experiment (n=8-12/group) explored the combined effect of Sj-l with the opportunity to ingest CafD. All protocols lasted 12weeks. We evaluated the development of overweight and indicators of metabolic syndrome. The statistical significance for all variables was set at P<0.05. RESULTS: Sj-l alone did not affect body weight gain but induced significant changes in cholesterol in metabolic variables representing a risk factor for metabolic syndrome. Daily restricted access to CafD in the day or night induced glucose intolerance and only CafD during the day led to overweight. Sj-l combined with CafD induced overconsumption of the diet, potentiated body weight gain (16%) and promoted 5 of the criteria for metabolic syndrome including high insulin and dislipidemia. CONCLUSION: Present data provide an experimental model of social-jet lag that combined with overconsumption of CafD, and maximized the development of obesity and metabolic syndrome. Importantly, access to CafD during the night did not lead to overweight nor metabolic syndrome.

La comida por la noche como factor inductor de obesidad / Food during the night is a factor leading to obesity

Resumen: Esta revisión tiene como objetivo presentar evidencias obtenidas mediante observaciones clínicas y modelos animales que señalan la relevancia que tiene el horario de alimentación sobre el metabolismo y el mantenimiento del peso corporal. Hallazgos recientes han puesto en evidencia que la misma cantidad de alimento ingerida durante el día o la noche afecta diferencialmente el metabolismo, lo que determina una diferencia significativa en el desarrollo del sobrepeso y la obesidad. Este conocimiento se fundamenta en el estudio del sistema circadiano, regido por el reloj biológico del hipotálamo anterior, que le transmite tiempos a todas las funciones del cuerpo, incluyendo aquellas para el gasto y el ahorro de energía. A pesar de que estos ciclos circadianos están normalmente regulados por los cambios de iluminación resultantes de la alternancia del día y la noche, los cambios metabólicos que resultan de una comida han mostrado también ser señales de tiempo que modifican el orden temporal de algunos sistemas y grupos celulares. De ello se desprende que para que el sistema circadiano funcione sincronizado, las horas de alimentación deben coincidir con los ciclos dictados por el reloj biológico. De tal manera, comer durante las horas normalmente asignadas al reposo lleva a la pérdida de coordinación de los ritmos circadianos metabólicos con respecto al reloj biológico. Esta desincronización sucede a diferentes niveles, tanto entre las células de los tejidos como en una misma célula a nivel molecular. En esta revisión se enfatizarán los efectos adversos de las comidas por la noche sobre el metabolismo energético, además se presentarán resultados recientes que describen los cambios circadianos y metabólicos a diversos niveles de regulación.

Abstract: The present review aims to present evidence obtained in clinical surveys and experimental studies that point out the relevance of meal schedules on metabolism and body weight. Recent findings indicate that in spite of ingesting equivalent amounts, food ingestion during the day or during the night can have completely different effects on metabolism determining bodyweight gain and propensity to obesity. Such findings find support in studies of the circadian rhythms, driven by a biological clock located in the anterior hypothalamus, which transmits temporal signals to the body including functions for energy balance. Circadian cycles are normally driven by the alternation of the day- night luminosity cycles, however metabolic changes resulting from food have proven to be powerful temporal signals capable of modifying de temporal order in tissues and cells. Considering the power of food elicited signals, the feeding schedule must coincide with the timing signals driven by the biological clock. Thus eating during the hours normally assigned for sleep and rest leads to a loss of coordination between metabolic rhythms and the biological clock. This circadian disruption occurs at different levels, among cells in a specific tissue as well as in the molecular processes in cells. The aim of this review is to emphasize the adverse effects that meals during the night can exhert on metabolism, we provide evidence about circadian and metabolic alterations at different regulatory levels.

Loss of melatonin daily rhythmicity is asociated with delirium development in hospitalized older adults.

Delirium is associated with circadian rhythm disruption. In this study we have explored whether circadian variation of melatonin is an indicator for delirium. Melatonin levels were determined from the first day of hospitalization and up to three days after the onset of delirium. Patients who did not developed delirium exhibited a daily melatonin rhythm, while in patients that developed delirium, the melatonin rhythm was lost and mean melatonin levels were found decreased as early as three days before the diagnosis of delirium, indicating that on arrival to the hospital circadian melatonin disruption can be used as an indicator of delirium.

Esclerosis múltiple: enfermedad neurológica de alto impacto social: de vuelta al antiguo tratamiento / Multiple sclerosis, neurological disease with high social impact: back to the old treatment

Resumen La esclerosis múltiple (EM) es una enfermedad inmune-inflamatoria y crónico-degenerativa, que afecta a personas jóvenes y tiene un alto impacto social por los costos directos e indirectos. Objetivo: Regular el proceso neurodegenerativo a través de una adecuada modulación de los factores inflamatorios mediante el uso de metilprednisolona y la evaluación con estudios de resonancia magnética. Pacientes y métodos: Pacientes mujeres que se encuentran entre la 1ª y 5ª década de la vida, con diagnóstico de EM, que se incluyeron por cumplir con los criterios diagnósticos de McDonald 2010 (sobre todo la diseminación en tiempo y espacio). Se les administraron bolos de metilprednisolona de manera regular, aun cuando no presentaran recaídas y se evaluaron con estudios de resonancia magnética (RM) anual, con un seguimiento de hasta 15 años. Resultados: Se observa una marcada disminución de las lesiones en función del tiempo y la administración de los bolos de metilprednisolona, y entre los 3 y 10 años las lesiones desaparecen en su totalidad. Conclusiones: La administración de bolos de metilprednisolona de manera regular atenúa el proceso inflamatorio y el daño a la barrera hematoencefálica, y por lo tanto, coadyuva en la remielinización y previene la neurodegeneración.

Abstract Multiple sclerosis (MS) is a chronic inflammatory and immune-degenerative disease that affects young people and has a high social impact due to direct and indirect costs. Objective: Regulate neurodegenerative process through a suitable modulation of inflammatory factors by using methylprednisolone and evaluation with Magnetic Resonance studies. Patients and methods: Female patients between the 1st and 5th decade of life, with diagnosis of Multiple Sclerosis, were included in the study if they met the criteria of McDonal 2010 (specially space and time monitoring) methylprednisolone boluses were administered regularly, even when the patient had no relapses, and the patients were then evaluated with Magnetic Resonance per annum, with a follow-up of up to 15 years. Results: There is a marked decrease of lesion in function of time and the bolus administration of methylprednisolone, and lesions disappeared entirely after 3 to 10 years of administration. Conclusions: The regular bolus administration of methylprednisolone attenuates the inflammatory process and the damage to the blood brain barrier and thus contributes in preventing neurodegeneration and is coadyuvant in remyelination.

A light/dark cycle in the NICU accelerates body weight gain and shortens time to discharge in preterm infants.

BACKGROUND: Bright constant light levels in the NICU may have negative effects on the growth and development of preterm infants OBJECTIVE: The aim of this study is to evaluate the benefits of an alternating light/dark cycle in the NICU on weight gain and early discharge from the therapy in premature infants. PATIENTS AND METHODS: A randomized interventional study was designed comparing infants in the NICU of Hospital Juarez de México, exposed from birth either to an LD environment (LD, n=19) or to the traditional continuous light (LL, n=19). The LD condition was achieved by placing individual removable helmets over the infant's heads. Body weight gain was analyzed, as the main indicator of stability and the main criteria for discharge in preterm infants born at 31.73±0.31week gestational age. RESULTS: Infants maintained in an LD cycle gained weight faster than infants in LL and therefore attained a shorter hospital stay, (34.37±3.12 vs 51.11±5.29days; P>0.01). Also, LD infants exhibited improved oxygen saturation and developed a daily melatonin rhythm. CONCLUSIONS: These findings provide a convenient alternative for establishing an LD environment for preterm healthy newborns in the NICU and confirm the beneficial effects of an alternating LD cycle for growth and weight gain and for earlier discharge time. Here we provide an easy and practical alternative to implement light/dark conditions in the NICU.

Leiomioma con extensión intracardiaca que condiciona insuficiencia cardiaca aguda: Reporte de caso / Leiomyoma with intracardiac extensión leading to acute heart failure: (case report)

Son raros los casos de leiomiomas intravenosos con extensión intracardiaca. En pacientes con manifestaciones de sobrecarga de cavidades derechas o quienes debutan con síntomas de insuficiencia cardiaca aguda y cuyos síntomas no mejoran con el manejo convencional, se debe considerar esta entidad, y es importante evaluar de forma integral con estudios de gabinete como electrocardiograma, ecocardiograma, tomografía o resonancia magnética. Reportamos el caso de una mujer de 46 años que manifiesta síntomas de insuficiencia cardiaca aguda e inadecuada respuesta a los fármacos convencionales. Con hallazgos ecocardiográficos de tumoración en atrio derecho que protruye a ventrículo derecho y causa insuficiencia tricuspídea. Por estudio tomográfico se confirma la extensión del tumor a vena cava inferior y ventrículo derecho; se resuelve de forma quirúrgica con resección radical y se confirma la extirpación histológica mediante estudio anatomopatológico.

Cases of intravenous leiomyoma with intracardiac extension are rare. Patients with signs of right-sided overload who present symptoms of acute heart failure and whose symptoms do not improve with conventional management, we must consider this entity. It is important to comprehensively assess with imaging studies such as electrocardiogram, echocardiogram, Tomography (CT scan) or magnetic resonance. The following is a report of the case of a 46 year old woman with symptoms of acute heart failure and inadequate response to conventional drugs. The echocardiographic show findings of a tumor in the right atrium, protruding to the right ventricle causing tricuspid regurgitation. The CT scan confirmed the extent of the tumor to the inferior vena cava and right ventricle, and was resolved surgically with radical resection and histology lineage confirmed by pathologic examination.

La mala calidad de sueño es factor promotor de obesidad / Poor quality sleep is a contributing factor to obesity

La presente revisión tiene como objetivos presentar a la comunidad académica evidencias recientes que proponen una relación entre la mala calidad y cantidad de sueño y la propensión al sobrepeso y obesidad. Se presentan en este escrito evidencias obtenidas en estudios clínicos controlados y de investigación básica experimental que demuestran que una cantidad o calidad deficiente de sueño lleva a corto plazo a alteraciones de tipo metabólico y conductual conducentes a la sobre ingestión de alimentos y al sobrepeso. También se discuten los posibles mecanismos que pudieran subyacer a este fenómeno, a nivel cerebral, metabólico y celular. El objetivo de esta revisión es presentar a las horas de sueño como un factor poco considerado en los estudios epidemiológicos y experimentales y posible desencadenante de alteraciones metabólicas. Con este escrito esperamos poder interesar a otros profesionistas involucrados en el estudio de este fenómeno para incluir la calidad y cantidad de sueño entre sus variables de estudio y/o incluir la higiene del sueño entre sus propuestas de tratamiento y prevención.

The aim of this revisión is to highlight recent evidence that links low quality and quantity of sleep with an increased propensity to develop overweight or obesity. In this text we present evidence obtained with controlled clinical studies as well as with experimental models, both indicating that decreased hours of sleep lead to metabolic and behavioral changes that then induce overconsumption of food, which then results in weight gain. With this review we want to present sleep as an additional factor contributing to metabolic disease and we aim to raise interest in professional involved in the study of overweight and obesity in order to include this factor as an additional variable in their research and strategies of intervention.

Desarrollo de los ritmos biológicos en el recién nacido. Cátedra Especial "Dr. Ignacio Chávez" / Development of biological rhythms in the newborn child

Los ritmos circadianos se generan de forma endógena con un período de aproximadamente 24 h. Estudios realizados durante la última década indican que el sistema circadiano se desarrolla antes del nacimiento y que el núcleo supraquiasmático, estructura que se considera el reloj circadiano del mamífero, está presente en los primates desde la mitad de la gestación. Evidencias recientes muestran que el sistema circadiano de los infantes es sensible a la luz desde etapas muy tempranas del desarrollo; también se ha propuesto que la iluminación de baja intensidad puede regular el reloj en desarrollo. Después del nacimiento se presenta una maduración progresiva de las salidas del sistema circadiano con marcados ritmos en los fenómenos de sueño-vigilia y secreción de hormonas. Estos hechos expresan la importancia de la regulación fótica circadiana en los lactantes. Así, la exposición de los bebés prematuros a ciclos de luz/oscuridad tiene como resultado un rápido establecimiento de patrones de actividad/reposo, los que se encuentran en el ciclo luz-oscuridad. Con el continuo estudio del desarrollo del sistema circadiano y la influencia sobre la fisiología humana y la enfermedad, se prevé que la aplicación de la biología circadiana se convertirá en un componente cada vez más importante en la atención neonatal.

Circadian rhythms are endogenously generated with a period length of approximately 24 hours. Studies performed during the past decade indicate that the circadian timing system develops prenatally and the suprachias-matic nucleus, considered the site of the circadian clock, is present by midgestation in primates. Recent evidence also shows that the circadian system of primate infants is responsive to light since very early stages of development and that low-intensity lighting can regulate the developing clock. After birth, there is progressive maturation of the circadian system outputs, with pronounced rhythms on sleep-wake phenomena and hormone secretion; showing the importance of photic regulation on infants. Thus, exposure of premature infants to light/dark cycles results in the fast establishment of rest-activity patterns, which are in phase with the light-dark cycle. The continual study of circadian system development and its influence on human physiology and illness, it is foreseen that the application of circadian biology will become increasingly important for neonatal care.

Disruption of circadian rhythms due to chronic constant light leads to depressive and anxiety-like behaviors in the rat.

Depression is strongly associated with the circadian system, disruption of the circadian system leads to increased propensity to disease and to mood disorders including depression. The present study explored in rats the effects of circadian disruption by constant light on behavioral and hormonal indicators of a depressive-like condition and on the biological clock, the suprachiasmatic nucleus (SCN). Exposure to constant light for 8 weeks resulted in loss of circadian patterns of spontaneous general activity, melatonin and corticosterone. Moreover these rats exhibited anhedonia in a sucrose consumption test, and increased grooming in the open-field test, which reflects an anxiety-like condition. In the SCN decreased cellular activation was observed by c-Fos immunohistochemistry. In rats exposed to constant darkness, circadian behavioral and hormonal patterns remained conserved, however mild depressive-like indicators were observed in the anhedonia test and mild anxiety-like behaviors were observed in the open field test. Data indicate that chronic conditions of LL or DD are both disruptive for the activity of the SCN leading to depression- and anxiety-like behavior. Present results point out the main role played by the biological clock and the risk of altered photoperiods on affective behavior.

Trastornos temporomandibulares: Complejo clínico que el médico general debe conocer y saber manejar. Cátedra especial "Dr. Ignacio Chávez" / Temporomandibular disorders: Clinical complex that the general practitioner must recognize and know how to treat. Special professorship "Dr. Ignacio Chávez"

Los trastornos temporomandibulares (TTM), abarcan un conjunto de problemas clínicos que comprometen diferentes estructuras anatómicas como son: músculos de la masticación, la articulación temporomandibular y estructuras asociadas. Se consideran como una subclasificación de desórdenes musculoesqueléticos y han sido identificados como una causa importante de dolor en la región facial de origen no dentario. Los trastornos temporomandibulares se caracterizan clínicamente por dolor en músculos de la masticación, área preauricular o directamente en la articulación (usualmente agravado por la manipulación y alteración de los movimientos mandibulares principalmente debido a limitación del movimiento), presencia de ruidos articulares como crepitación y chasquidos (clicking). Epidemiológicamente la prevalencia va del 20 al 70% en la población general, motivo por el que creemos que es importante que el médico general tenga el conocimiento básico sobre estos trastornos que generalmente los desconoce y los delega al médico odontólogo. El tratamiento de los TTM va desde fomentar el autocuidado, tratamiento conservador y, de ser necesario, tratamiento quirúrgico.

Temporomandibular disorders (TMDs) are a set of clinical problems that involve different anatomical structures such as masticatory muscles, the temporomandibular joint and related anatomical structures. They are considered a subclass of musculoskeletal disorders and have been identified as a major cause of non-dental facial pain. TMDs are characterized by pain in the masticatory muscles, either in the pre-auricular area or directly in the joint (usually worsened by manipulation or altered movement of the jaw, mainly due to movement limitation) and the presence of clicking sounds during movement. Epidemiologically, TMDs have a prevalence ranging from 20% to 70% in the general population, that is why we believe it is important for the general practitioner to have the basic knowledge about these disorders, often unknown to the general practitioner who leaves the to the odontologist. Treatment includes fostering self-care measures, conservative treatment, or surgical treatment when necessary.