[Spectral analysis of the electroencephalogram in subjects with mild cognitive impairment]. / Análisis espectral del electroencefalogramaen sujetos con deterioro cognitivo leve.

INTRODUCTION: Mild cognitive impairment (MCI) is defined as a state of the ageing brain midway between normal cognition and dementia. Special attention has been paid to the electrophysiological substrate underlying Alzheimer's disease and MCI in order to identify as early as possible which subjects with MCI progress towards Alzheimer, which could be crucial for starting rehabilitation or pharmacological therapies. AIM: To perform a spectral characterisation of the electroencephalogram in subjects with MCI. PATIENTS AND METHODS: An electroencephalogram was carried out on 41 subjects with MCI in order to analyse the spectral measurements; apolipoprotein E genotype was also performed. RESULTS: In all, 94.8% of the sample displayed a significant increase in energy, and in 66.6% of them this was observed in the theta and delta bands, or both. Significant differences were found in the spectral measurements between carriers and non-carriers of the apolipoprotein E epsilon4 allele in the theta and alpha bands; there was also a statistically significant association between the years of schooling and being a carrier of this allele or not. An increase in the theta-alpha bands was observed in the left temporal region in subjects with a below-average number of years of schooling and carriers of the epsilon4 allele. CONCLUSIONS: In subjects with MCI and carriers of the epsilon4 allele, the alpha and theta cortical rhythms can be affected by similar pathological mechanisms and may be expressed earlier in subjects who have a lower level of schooling.

Análisis espectral del electroencefalogramaen sujetos con deterioro cognitivo leve / Spectral analysis of the electroencephalogram in subjects with mild cognitive impairment

Introducción. El deterioro cognitivo leve (DCL) se define como un estado del cerebro envejecido intermedio entrela cognición normal y la demencia; se ha prestado una especial atención al sustrato electrofisiológico de la enfermedad de Alzheimer y el DCL con la finalidad de identificar lo antes posible qué sujetos con DCL progresan a Alzheimer, lo cual podría ser crucial para el inicio de terapias de rehabilitación o farmacológicas. Objetivo. Caracterización espectral del electroencefalograma en sujetos con DCL. Pacientes y métodos. Se estudió a 41 sujetos con DCL a los cuales se les realizó electroencefalograma para el análisis de las medidas espectrales; además se realizó genotipo de apolipoproteína E. Resultados. El94,8por ciento de la muestra reveló un incremento significativo de energía; en el 66,6 por ciento de ellos se observó en las bandas theta y delta,o ambas. Se encontraron diferencias significativas en las medidas espectrales entre portadores y no portadores del alelo epsilon4 de la apolipoproteína E en las bandas theta y alfa, y además existió una asociación estadísticamente significativa entrelos años de escolaridad y ser portador o no de dicho alelo. Se observó un incremento en las bandas theta-alfa en la región temporal izquierda en los sujetos por debajo de la media de años de escolaridad y portadores del alelo epsilon4. Conclusiones. En los sujetos con DCL y portadores del alelo epsilon4, los ritmos corticales alfa y theta pueden verse afectados por mecanismospatológicos similares, y puede expresarse de forma más precoz en los sujetos que presentan un nivel de escolaridad bajo(AU)

INTRODUCTION: Mild cognitive impairment (MCI) is defined as a state of the ageing brain midway between normal cognition and dementia. Special attention has been paid to the electrophysiological substrate underlying Alzheimer's disease and MCI in order to identify as early as possible which subjects with MCI progress towards Alzheimer, which could be crucial for starting rehabilitation or pharmacological therapies. AIM: To perform a spectral characterisation of the electroencephalogram in subjects with MCI. PATIENTS AND METHODS: An electroencephalogram was carried out on 41 subjects with MCI in order to analyse the spectral measurements; apolipoprotein E genotype was also performed. RESULTS: In all, 94.8percent of the sample displayed a significant increase in energy, and in 66.6 percent of them this was observed in the theta and delta bands, or both. Significant differences were found in the spectral measurements between carriers and non-carriers of the apolipoprotein E epsilon4 allele in the theta and alpha bands; there was also a statistically significant association between the years of schooling and being a carrier of this allele or not. An increase in the theta-alpha bands was observed in the left temporal region in subjects with a below-average number of years of schooling and carriers of the epsilon4 allele. CONCLUSIONS: In subjects with MCI and carriers of the epsilon4 allele, the alpha and theta cortical rhythms can be affected by similar pathological mechanisms and may be expressed earlier in subjects who have a lower level of schooling(AU)

Análisis espectral del electroencefalograma en sujetos con deterioro cognitivo leve / Spectral analysis of the electroencephalogram in subjects with mild cognitive impairment

El deterioro cognitivo leve (DCL) se define como un estado del cerebro envejecido intermedio entrela cognición normal y la demencia; se ha prestado una especial atención al sustrato electrofisiológico de la enfermedad de Alzheimer y el DCL con la finalidad de identificar lo antes posible qué sujetos con DCL progresan a Alzheimer, lo cual podríaser crucial para el inicio de terapias de rehabilitación o farmacológicas. Objetivo. Caracterización espectral del electroencefalograma en sujetos con DCL. Pacientes y métodos. Se estudió a 41 sujetos con DCL a los cuales se les realizó electroencefalograma para el análisis de las medidas espectrales; además se realizó genotipo de apolipoproteína E. Resultados. El 94,8% de la muestra reveló un incremento significativo de energía; en el 66,6% de ellos se observó en las bandas theta y delta,o ambas. Se encontraron diferencias significativas en las medidas espectrales entre portadores y no portadores del alelo epsilon4 de la apolipoproteína E en las bandas theta y alfa, y además existió una asociación estadísticamente significativa entre los años de escolaridad y ser portador o no de dicho alelo. Se observó un incremento en las bandas theta-alfa en la región temporal izquierda en los sujetos por debajo de la media de años de escolaridad y portadores del alelo epsilon4. Conclusiones. En los sujetos con DCL y portadores del alelo epsilon4, los ritmos corticales alfa y theta pueden verse afectados por mecanismospatológicos similares, y puede expresarse de forma más precoz en los sujetos que presentan un nivel de escolaridad bajo

Mild cognitive impairment (MCI) is defined as a state of the ageing brain midway between normalcognition and dementia. Special attention has been paid to the electrophysiological substrate underlying Alzheimer’s disease and MCI in order to identify as early as possible which subjects with MCI progress towards Alzheimer, which could be crucial forstarting rehabilitation or pharmacological therapies. Aim. To perform a spectral characterisation of the electroencephalogram in subjects with MCI. Patients and methods. An electroencephalogram was carried out on 41 subjects with MCI in order to analyse the spectral measurements; apolipoprotein E genotype was also performed. Results. In all, 94.8% of the sampledisplayed a significant increase in energy, and in 66.6% of them this was observed in the theta and delta bands, or both. Significant differences were found in the spectral measurements between carriers and non-carriers of the apolipoprotein E epsilon4 allele in the theta and alpha bands; there was also a statistically significant association between the years of schoolingand being a carrier of this allele or not. An increase in the theta-alpha bands was observed in the left temporal region in subjects with a below-average number of years of schooling and carriers of the epsilon4 allele. Conclusions. In subjects withMCI and carriers of the epsilon4 allele, the alpha and theta cortical rhythms can be affected by similar pathological mechanisms and may be expressed earlier in subjects who have a lower level of schooling

Circular and linear DNA molecules in the Entamoeba histolytica complex molecular karyotype.

Entamoeba histolytica genome was analysed by pulsed field gel electrophoresis under conditions to separate linear chromosomes in the 170-1400 kb range. We identified linear DNA molecules of 227, 366, 631, 850, 1112 and 1361 kb (mean sizes obtained by three different methods) and we estimated their reorientation times and migration velocities at various experimental conditions. DNA shift mobility assays, using ethidium bromide, suggested that bands migrating at 227 and 631 kb contain linear and circular DNA, whereas a band at 436 kb has only circular DNA. We obtained a regression equation relating sizes of supercoiled DNA molecules with their migration velocities during a pulse at constant electric field and temperature. We also developed a computer program (EHPATTERNS) that predicts the migration per pulse and the resolution order of circular and linear E. histolytica DNA at different pulse times and constant driving and frictional forces. The simulation showed that linear DNA molecules frequently co-migrate with circular molecules, but circular molecules change when the pulse time varies. This molecular mixture generates broad bands and difficulties in the interpretation of the molecular karyotype of E. histolytica.

Comparison of DNA migrations in two clamped homogeneous electric field chambers of different sizes. Relation between sample thickness and electrophoresis time.

We present here a method to compare the mathematical descriptions of DNA migration per pulse as a function of pulse time. It is based on obtaining robust estimates and variances of DNA reorientation time, migration velocities during and after DNA reorientation; and on the statistical comparisons of these estimates. We demonstrated an equal description for the migration per pulse of each DNA molecule separated under identical conditions in clamped homogeneous electric field (CHEF) and miniCHEF chambers. However, miniCHEF resolved the patterns in shorter times, because it uses thinner samples. The relationship between sample thickness and CHEF run time is also presented.

Monoclonal antibody affinities of structurally related modified nucleosides.

A scale of relative affinities of a series of 2'-deoxycytidine and cytidine (CD) derivatives was established based on the data of cross-reactivities of these compounds as well as the displacements obtained from a competitive ELISA. No correlation could be established between the nucleosides modifying structures and the affinities. This can be explained by the possibilities of the modifying structures of intra- and intermolecular nonimmunospecific interactions owing to their degree of functionalization.

Pvu II RFLPs of LDL receptor gene in normolipidemic subjects from Havana City.

Allele and genotype frequencies for Pvu II restriction fragment length polymorphism of LDL receptor gene were determined in 36 normolipidemic unrelated subjects from Havana City. The frequencies were similar to those reported for other populations.

Evaluation of chemiluminescent detection of bromodeoxyuridine-labeled DNA.

Colorimetric immunoenzymatic procedures using monoclonal antibodies to detect 5-bromo-2-deoxy-uridine-DNA in hybridization experiments are not sensitive enough. We have developed a chemiluminescent immunodot assay to improve the sensitivity of the immunoenzymatic procedure, and attained a suitable detection level for single-stranded DNA. This new chemiluminescent immunodot assay has also been used to detect our recently synthesized cytidine analogue by means of its corresponding monoclonal antibody.

Molecular weight and kinetic parameters of DNA undergoing pulsed field gel electrophoresis.

Functions relating DNA size to reorientation time (Tr) should improve the theoretical basis to design pulsed field gel electrophoresis experiments. We initially developed a quantitative approach to calculate Tr based on kinetic data: DNA migration per pulse (d), and pulse time duration. Using this procedure with some modifications and a computer controlled pulsed field electrophoresis switching unit, we obtained the Trs of several DNA molecules of known molecular weight and analyzed the functional dependence between these parameters. The function obtained was used to interpolate the Tr values of yeast (Saccharomyces cerevisiae) chromosomes. We also interpolated the sizes of yeast chromosomes I and VI, and compared them with those obtained by another independent method, using lambda-mers and polynomial functions relating lambda-mers migration and DNA sizes. The equation obtained should be useful to separate chromosomes by PFGE and to study the genomes of microorganisms, parasites and mammals. (Arch Med Res 1994; 25:193).

A simple procedure to obtain plasmids suitable for transfecting mammalian cell lines.

A simple procedure to obtain plasmid preparations, suitable for transfecting mammalian cell lines using a calcium phosphate co-precipitation technique, is described. The protocol is based on the purification of plasmid DNA by double gel-filtration chromatography on Sephacryl S-1000 and additional slight modifications to the original transfection procedure. The purity of plasmid preparation was verified by analytical methods. The resulting preparation efficiently transfected NIH-3T3 cells.