Editorial: Neurodegeneration: from Genetics to Molecules

Chronic degenerative diseases are one of the major public health problems, particularly those affecting the nervous system. They are characterized by the degeneration of specific cell populations that include several pathologies which contribute significantly to morbidity and mortality in the elderly population. Therefore, in recent years, the study of neuroscience has gained significant importance. Most of these neurodegenerative disorders are the result of a complex interaction between genetic and environmental factors that generate progression and can even determine its severity. The presence of mutations in genes as LRRK2, SNCA, PARK7, PARK2 or PINK1 is associated with Parkinson's disease. Mutations in genes such as APP, PS1 and PS2 are associated with familial Alzheimer's disease; while HTT gene mutations are the cause of Huntington's disease. In most cases, this condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. It is known that these mutations can also alter the proteins function; however, it has not yet been possible to fully understand how some genetic changes cause the disease or influence the risk of developing these disorders. Most symptoms seen in these conditions occurs when specific nerve cells are damaged or die generating a loss in brain communication. Also many of these mutations generate aggregation of intracellular or extracellular proteins affecting cell function and eventually causing neuronal death. It is unclear whether the presence of these aggregates play an important role in nerve cell death during the development of neurodegenerative diseases, or if they are simply part of the response of cells to the disease. Other mutations affect the mitochondrial function generating alterations in energy production and promoting the formation of unstable molecules such as free radicals. Under normal conditions, the harmful effects caused by free radicals, are offset within the cell. However, in pathological conditions, the presence of mutations can alter this process by allowing the accumulation of radicals and damaging or killing cells. On the other hand, we also know that these diseases may not have a direct genetic component, thus, the study of sporadic type neurodegenerative diseases is much more complex. Histopathological lesions as well as the cellular and molecular alterations are generally indistinguishable from familial cases. For this reason, it is important to understand the genetic and molecular mechanisms associated with this type of pathologies. In this sense, this issue aims to understand the molecular processes that occur in the brain, and how these are influenced by the environment, genetics and behavior

Depresión una causa de baja temporal de los estudiantes de la licenciatura de médico cirujano

Varios autores han señalado que la depresión puede ser causa de abandono de los estudios. Asimismo, se ha demostrado que la prevalencia de depresión en estudiantes de medicina es significativamente más alta que la presentada en población general o en estudiantes de otras licenciaturas. En la Facultad de Medicina una de las causas de baja temporal en los estudiantes es la depresión. Objetivo y metodología: Identificar en tres momentos durante un ciclo escolar los índices de síntomas depresivos que presentaron los estudiantes de primer año de la licenciatura de médico cirujano. Participaron 786 estudiantes de primer año de la carrera de Médico Cirujano (66.4% mujeres, 33.6% hombres; media de edad: 18.6 ± 1.7 años) del ciclo escolar 2010-2011. Se utilizó el Inventario de Beck para Depresión y la subescala de Depresión del SCL90 (SymptomCheckList). Análisis estadístico: Se realizaron análisis descriptivos y Xi2. Resultados: El porcentaje de estudiantes con una sintomatología muy alta de depresión fue aumentando al ir avanzando el ciclo escolar de 17 casos a 128 (p ≤ .004). Se concluye que la excesiva carga de trabajo en la carrera de medicina y la necesidad que tienen la mayoría de los alumnos de demostrar que son buenos estudiantes, pueden ser las causas del deterioro de su salud mental y bajo rendimiento académico e incluso el abandono de los estudios. Ambos factores no sólo afectan la calidad de vida, el desarrollo profesional y académico de los alumnos, sino que representan también un problema para la Universidad, en el sentido de que se destinan recursos que en la mayoría de los casos no se verán reflejados en un aumento en la población de médicos preparados y disponibles para atender las demandas de salud del país

Olfactory processing and Alzheimer’s disease

Most of the studies on olfactory perception in Alzheimer´s Disease show a reduction or loss of ability to identify recognize and detect scents. This loss is noticeable during the first stages of Alzheimer´s Disease. Sensitivity loss in terms of detection thresholds can occur but as the cognitive impairment increases there are also problems with odor identification or memory. In our studies we have demonstrated that the familiarity of odors plays an important role in identifying scents. Other elements that may affect odor evaluation are its dispersal vehicle and concentration.Sociedad Argentina de Fisiologí

Natriuresis after a water load in humans under different sodium body content

The present study was aimed at observing the diuretic and natriuretic responses after a water load (2% body weight) in four groups of young consenting volunteers submitted previously, during three days, to a hypersodie (500 mEq Na/day), hyposodic (35 rnEq Na/day), and normosodic (200 mEq Na/day) diet, or treated with furosemide (Lasix, 40 rag/day). During the treatment urine was collected each day. On the fourth day, in the morning, the bladder was emptied, the water load was ingested, and the urine collected during 10 periods of 20 min each. The urinary, sodium, and chloride flows were determined. The four groups displayed diuretic curves following a similar pattern. In contrast, the natriuretic curves of the four groups were completely different; totally fiat with low values for the furosernide group and a large initial natriuretic curve for the hypersodic group with a gradual decrease but maintaining high values. The results indicate that the way the organism compensates for the excess of water by means of urinary water loss is independent of the body sodium content, whereas the way in which sodium loss is accomplished is determined by its body content and is independent of the way in which the water is lost

Deficiency in the Essential Amino Acids l-Isoleucine, l-Leucine and l-Histidine and Clinical Measures as Predictors of Moderate Depression in Elderly Women: A Discriminant Analysis Study

Increases in depression are common in some elderly women. Elderly women often show moderate depressive symptoms, while others display minimal depressive symptoms. These discrepancies have produced contradictory and inconclusive outcomes, which have not been explained entirely by deficits in neurotransmitter precursors. Deficiency in some amino acids have been implicated in major depression, but its role in non-clinical elderly women is not well known. An analysis of essential amino acids, depression and the use of discriminant analysis can help to clarify the variation in depressive symptoms exhibited by some elderly women. The aim was to investigate the relationship of essential amino acids with affective, cognitive and comorbidity measures in elderly women without major depression nor severe mood disorders or psychosis, specifically thirty-six with moderate depressive symptoms and seventy-one with minimal depressive symptoms. The plasma concentrations of nineteen amino acids, Beck Depression Inventory (BDI) scores, Geriatric Depression Scale (GDS) scores, global cognitive scores and comorbidities were submitted to stepwise discriminant analysis to identify predictor variables. Seven predictors arose as important for belong to the group based on amino acid concentrations, with the moderate depressive symptoms group characterized by higher BDI, GDS and cognitive scores; fewer comorbidities; and lower levels of l-histidine, l-isoleucine and l-leucine. These findings suggest that elderly women classified as having moderate depressive symptoms displayed a deficiency in essential amino acids involved in metabolism, protein synthesis, inflammation and neurotransmission

Distribution of Adiponectin Receptors 1 and 2 in the Rat Olfactory Bulb and the Effect of Adiponectin Injection on Insulin Receptor Expression

Background. Adiponectin (APN) is an adipocyte-derived hormone that has peripheral beneficial effects. Although its receptors AdipoR1 and AdipoR2 are expressed in the brain, their function in neurons is poorly understood. The aims of this work were to describe the distribution of APN receptors in the olfactory bulb (OB) as well as the possible effects of APN injection on the insulin receptor (InsR) content and Akt kinase. Method. We performed the double immunofluorescence technique to describe the distribution of AdipoRs and the cellular type they were expressing. mRNA transcript and protein content were assessed by RT-PCR and Western blot, respectively. APN injection was performed to analyze its possible effect on the insulin pathway. Results. We found that AdipoRs were localized in all cell layers and in both neurons and astrocytes. We observed the presence of mRNA transcripts and immunoblot analysis confirmed the protein on the intact OB; APN injection in the OB resulted in a slight decrease of the total InsR and Akt phosphorylation and a reduction of phopho-InsR content. Conclusions. These data demonstrated that AdipoRs are expressed in OB regions, and APN injection could act as an insulin pathway modulator in the OB and thus possibly contribute to olfaction physiology

Depresión una causa de baja temporal de los estudiantes de la licenciatura de médico cirujano

Varios autores han señalado que la depresión puede ser causa de abandono de los estudios. Asimismo, se ha demostrado que la prevalencia de depresión en estudiantes de medicina es significativamente más alta que la presentada en población general o en estudiantes de otras licenciaturas. En la Facultad de Medicina una de las causas de baja temporal en los estudiantes es la depresión. Objetivo y metodología: Identificar en tres momentos durante un ciclo escolar los índices de síntomas depresivos que presentaron los estudiantes de primer año de la licenciatura de médico cirujano. Participaron 786 estudiantes de primer año de la carrera de Médico Cirujano (66.4% mujeres, 33.6% hombres; media de edad: 18.6 ± 1.7 años) del ciclo escolar 2010-2011. Se utilizó el Inventario de Beck para Depresión y la subescala de Depresión del SCL90 (SymptomCheckList). Análisis estadístico: Se realizaron análisis descriptivos y Xi2. Resultados: El porcentaje de estudiantes con una sintomatología muy alta de depresión fue aumentando al ir avanzando el ciclo escolar de 17 casos a 128 (p ≤ .004). Se concluye que la excesiva carga de trabajo en la carrera de medicina y la necesidad que tienen la mayoría de los alumnos de demostrar que son buenos estudiantes, pueden ser las causas del deterioro de su salud mental y bajo rendimiento académico e incluso el abandono de los estudios. Ambos factores no sólo afectan la calidad de vida, el desarrollo profesional y académico de los alumnos, sino que representan también un problema para la Universidad, en el sentido de que se destinan recursos que en la mayoría de los casos no se verán reflejados en un aumento en la población de médicos preparados y disponibles para atender las demandas de salud del país

La formación docente evaluada por método mixto Teaching training assessed through mixed-method

Introducción. Actualmente, los planes de estudio de medicina en el mundo enfatizan el desarrollo de las competencias profesionales. Para ello es indispensable contar con programas de capacitación docente que incidan en el cambio de referentes pedagógicos de los profesores y adquirir así estrategias de enseñanza que se dirijan al logro del perfil del egresado. Para evaluar el cumplimiento de lo anterior, los beneficios de una metodología mixta son particularmente evidentes cuando se estudian iniciativas nuevas y sus interacciones en investigación educativa médica. Objetivo. Evaluar por metodología mixta la formación docente de un grupo de profesores que asistieron a un curso-taller. Sujetos y métodos. Se evaluó cuantitativamente el impacto del curso por los cambios en los referentes pedagógicos de los profesores que asistieron al curso y cualitativamente por grupos focales que permitieron la agrupación de las narrativas. Resultados. El referente tradicional después de la impartición del curso denotó una gran heterogeneidad entre tres de las estrategias (planeación, metodología y evaluación), no así con las de aprendizaje y relación docente-alumno; las estrategias en el referente alternativo y tecnología educativa se mantuvieron homogéneas. Los profesores expresaron que los cursos eran beneficiosos para la implementación de las competencias, pero que era necesario enfatizar más sobre la aplicación de las estrategias. Conclusión. Los análisis cuantitativo y cualitativo mostraron que el curso-taller de formación docente coadyuvó a modificar la preferencia de los profesores por referentes pedagógicos distintos al tradicional, lo cual resulta de trascendencia para el desarrollo adecuado de un modelo educativo orientado a competencias. Palabras clave. Estrategias de enseñanza. Evaluación mixta. Formación docente