Increased expression of gamma-aminobutyric acid transporter-1 in the forebrain of infant rats with corticotropin-releasing hormone-induced seizures but not in those with hyperthermia-induced seizures.

High affinity, gamma-aminobutyric acid (GABA) plasma membrane transporters (GATs) influence the availability of GABA, the main inhibitory neurotransmitter in the brain. Recent studies suggest a crucial role for GATs in maintaining levels of synaptic GABA in normal as well as abnormal (i.e., epileptic) adult brain. However, the role of GATs during development and specifically changes in their expression in response to developmental seizures are unknown. The present study examined GAT-1-immunolabeling in infant rats with two types of developmental seizures, one induced by corticotropin-releasing hormone (CRH) lasting about 2 h and the other by hyperthermia (a model of febrile seizures) lasting only 20 min. The number of GAT-1-immunoreactive (ir) neurons was increased in several forebrain regions 24 h after induction of seizures by CRH as compared to the control group. Increased numbers of detectable GAT-1-ir cell bodies were found in the hippocampal formation including the dentate gyrus and CA1, and in the neocortex, piriform cortex and amygdala. In contrast, hyperthermia-induced seizures did not cause significant changes in the number of detectable GAT-1-ir somata. The increase in GAT-1-ir somata in the CRH model and not in the hyperthermia model may reflect the difference in the duration of seizures. The brain regions where this increase occurs correlate with the occurrence of argyrophyllic neurons in the CRH model

Alzheimer\u27s Disease: From Animal Models to the Human Syndrome

Some animal models, genetically modified (such as murine) and sporadic (as others species), enable the study of the origin of specific lesions observed in human neurodegenerative diseases. In particular, Alzheimer\u27s disease (AD) models have been designed to test the hypothesis that certain lesions are associated with functional and morphological changes beginning with memory loss and impairment in activities of daily life. This review compares and evaluates the phenotypes of different AD animal models, on the basis of the specific objectives of each study, with the purpose of encompassing their contributions to the comprehension of the AD signs and symptoms in humans. All these models contribute to the comprehension of the human AD mechanisms regarding the heterogeneity of AD phenotypes: the overlap between AD and age‐related changes, the variability of AD onset (early or late), the probable reactiveness of amyloid‐β and tau proteins, the scarcity of senile plaques and/or neurofibrillary tangles in some AD cases, the spatial correlation of the pathology and cerebral blood vessels, and the immunological responses (microglial aging) and synaptopathy. Altogether, these considerations may contribute to find therapies to treat and prevent this disease

Selective Estrogen Receptor Modulators Regulate Dendritic Spine Plasticity in the Hippocampus of Male Rats

Some selective estrogen receptor modulators, such as raloxifene and tamoxifen, are neuroprotective and reduce brain inflammation in several experimental models of neurodegeneration. In addition, raloxifene and tamoxifen counteract cognitive deficits caused by gonadal hormone deprivation in male rats. In this study, we have explored whether raloxifene and tamoxifen may regulate the number and geometry of dendritic spines in CA1 pyramidal neurons of the rat hippocampus. Young adult male rats were injected with raloxifene (1 mg/kg), tamoxifen (1 mg/kg), or vehicle and killed 24 h after the injection. Animals treated with raloxifene or tamoxifen showed an increased numerical density of dendritic spines in CA1 pyramidal neurons compared to animals treated with vehicle. Raloxifene and tamoxifen had also specific effects in the morphology of spines. These findings suggest that raloxifene and tamoxifen may influence the processing of information by hippocampal pyramidal neurons by affecting the number and shape of dendritic spines

Automated tracing of myelinated axons and detection of the nodes of Ranvier in serial images of peripheral nerves

The development of realistic neuroanatomical models of peripheral nerves for simulation purposes requires the reconstruction of the morphology of the myelinated fibres in the nerve, including their nodes of Ranvier. Currently, this information has to be extracted by semimanual procedures, which severely limit the scalability of the experiments. In this contribution, we propose a supervised machine learning approach for the detailed reconstruction of the geometry of fibres inside a peripheral nerve based on its high-resolution serial section images. Learning from sparse expert annotations, the algorithm traces myelinated axons, even across the nodes of Ranvier. The latter are detected automatically. The approach is based on classifying the myelinated membranes in a supervised fashion, closing the membrane gaps by solving an assignment problem, and classifying the closed gaps for the nodes of Ranvier detection. The algorithm has been validated on two very different datasets: (i) rat vagus nerve subvolume, SBFSEM microscope, 200 × 200 × 200 nm resolution, (ii) rat sensory branch subvolume, confocal microscope, 384 × 384 × 800 nm resolution. For the first dataset, the algorithm correctly reconstructed 88% of the axons (241 out of 273) and achieved 92% accuracy on the task of Ranvier node detection. For the second dataset, the gap closing algorithm correctly closed 96.2% of the gaps, and 55% of axons were reconstructed correctly through the whole volume. On both datasets, training the algorithm on a small data subset and applying it to the full dataset takes a fraction of the time required by the currently used semiautomated protocols. Our software, raw data and ground truth annotations are available at http://hci.iwr.uni-heidelberg.de/Benchmarks/. The development version of the code can be found at https://github.com/RWalecki/ATMA

DESARROLLO DE UN INSTRUMENTO PARA LA EVALUACIÓN DE LOS PROGRAMAS DE EDUCACIÓN SUPERIOR EN CIENCIAS DE LA SALUD

Se elaboró un instrumento para la evaluación de programas de educación superior en ciencias de la salud en México. El objetivo es contribuir a la mejoría continua de los procesos de evaluación y acreditación a los que actualmente están sometidos dichos programas. Se hacen explícitos los pasos para la elaboración del instrumento, así como sus contenidos, modelos y escalas; de igual manera, los procedimientos para la obtención de la información requerida por el propio instrumento. Por último, se hacen breves consideraciones sobre cuestiones éticas de la evaluación y la forma en que se abordan en el instrumento desarrollado.Palabras clave: Evaluación de programas, Métodos de evaluación, Criterios de evaluación, Educación de profesionales de la salud, Educación médica.Program evaluation, Evaluation methods, Evaluation criteria, Allied health occupations education, Medical education

Optimization the soda-AQ process for cellulose pulp production and energy content of black liquor from L. leucocephala K360

A commercial variety of Leucaena leucocephala K360 was used for pulp production and papermaking employing the soda-anthraquinone process. Also, the chemical and energy contents of the resultant black liquors were determined to simultaneously optimize: pulp and paper production and energy generation. A process temperature of (185 °C), an operating time of (120 min) and an active alkali concentration of (21%) provided sheets of paper with good strength (tensile index of 12.12 N m/g, burst index of 0.38 kPa m2/g, tear index of 1.29 mN m2/g and a Kappa number of 20.5) and black liquor with a greater calorific value (14.1 MJ/kg) than that obtained with higher active alkali concentrations. However, reducing the active alkali concentration to a level in the low operation range led to less marked degradation of cellulose and allowed paper sheets with good properties to be obtained and energy to be optimally produced from the black liquor

Estudio teórico y experimental del sistema 9 Be + 51 V y sistemas similares

En este trabajo de tesis se presenta el estudio sistemático de los sistemas 7Li + 51V, 9Be + 51V y 8B + 58Ni. Para los sistemas ( 7Li, 9 Be) + 51V se midieron las secciones eficaces de fusión a energías cercanas a la barrera Coulombiana (EB,lab=11.75 y 16.16 MeV, respectivamente) empleando la técnica de rayos γ. El experimento para medir la fusión se llevó a cabo en el Laboratorio del Acelerador Tan- dem, del Instituto Nacional de Investigaciones Nucleares (ININ), siendo éstas las primeras mediciones realizadas para estos proyectiles a las energías consideradas. De forma simultánea, se hizo el análisis de los posibles núcleos residuales usando los códigos computacionales de fusión-evaporación PACE2, LILITA y CASCADE. Los resultados obtenidos fueron comparados con los datos experimentales me- didos. De forma preliminar, para el sistema 7Li + 51V, se hicieron cálculos usando la teoría de canales acoplados de reacción para estimar la contribución de la sección eficaz de transferencia de un protón a la producción del núcleo residual 52Cr. Para el sistema 8B + 58Ni, se hizo un análisis teórico de canales acoplados con el continuo discretizado y canales acoplados de reacción para estudiar los procesos de rompimiento y de transfe- rencia de un protón, 58Ni(8B,7Be)59Cu, a energías alrededor de la barrera Coulombiana (EB,lab=22.95 MeV). Para calcular las secciones eficaces correspondientes se usó un potencial de Modelo Óptico se- mimicroscópico, el cual combina un potencial real de doble convolución, un potencial de polarización y un potencial imaginario tipo Woods-Saxon. A partir de la comparación de nuestros cálculos con datos experimentales se determinaron los factores espectroscópicos Sexpt y astrofísicos S17(0) del protón en la interacción 8B → 7Be+p

Genotoxic Effect of Chronic Exposure to DDT on Lymphocytes, Oral Mucosa and Breast Cells of Female Rats

The genotoxicity of some environmental contaminants may affect human health directly by damaging genetic material and thus plays an important role in cancer development. Xenoestrogens are one kind of environmental pollutants that may alter hormonal routes or directly affect DNA. The number of available biomarkers used to assess genetic risk and cancer is very extensive. The present study evaluated genotoxicity produced by the pesticide DDT on systemic and mammary gland cells obtained from adult female Wistar rats. Oral mucosa cells micronuclei were assessed; the comet assay in peripheral blood-isolated lymphocytes and mammary epithelial cells was also carried out. Additionally, oxidative stress was studied in mammary tissue through a lipid peroxidation assay. Our data showed an increase in lipid peroxidation, product of an increase in free oxygen radical levels, which leads to an oxidative stress status. Our results suggest that DDT is genotoxic, not only for lymphocytes but also to mammary epithelial cells

Ehlers-Danlos Syndrome Type VIIC: A Mexican Case Report

Ehlers-Danlos syndrome (EDS) is a heterogeneous group of heritable connective tissue disorders whose primary clinicalfeatures include soft and extensible skin, articular hypermobility and tissue fragility. EDS type VIIC or ‘human dermatosparaxis’ is an autosomal recessive disease characterized by severe skin fragility and sagging redundant skin (major criteria) with a soft, doughy texture, easy bruising, premature rupture of fetal membranes and large hernias (minor criteria). Dermatosparaxis (meaning ‘tearing of skin’), which has been described in several non-human species, is a disorder of the connective tissue resulting from a deficiency of the enzyme that cleaves the registration peptide off the N-terminal end of collagen after it has been secreted from fibroblasts. We describe a Mexican case from consanguineous parents with all the phenotypical characteristics previously described, plus skeletal abnormalities