Neuropathology of the 21st century for the Latin American epilepsy community.

Many people with epilepsy remain drug-resistant, despite continuous efforts and advances in research and treatment. It is mandatory to understand the epilepsy's underlying etiology, whether it is structural, genetic, infectious, metabolic, immune or (currently) unknown, as it contains major information about the clinical phenotype, cognitive comorbidities, (new) drug targets and also help to predict postsurgical outcome. A multimodal approach, including digital slides and multichannel immunofluorescence labelling can increase the diagnostic yield of subtle pathologies, while DNA methylation arrays could helps in the diagnosis of difficult-to-classify lesions. Such techniques are not always available, however, in low-income countries. Even without access to expensive molecular techniques, automated analysis scripts and machine learning algorithms can be developed by Latin American researchers to improve our diagnostic yield from routine Hematoxylin & Eosin stained tissue sections. The pathology community of Latin America contributed substantially to our current knowledge of etiologies related to human epilepsies and experimental epilepsy models. To further boost the impact of Latin American research, local centers should adhere to modern, multimodal neuropathology techniques, integrate different levels of knowledge, and strengthen their scientific collaborations. Dedicated teaching courses in Epileptology, such as the Latin American Summer Schools of Epilepsy (LASSE) or International Summer School for Neuropathology and Epilepsy Surgery (INES) addressing young researcher and neurologists, are most successful to promote this endeavor. In this review, we will describe the state of neuropathology at the 21st century and also highlight Latin American researchers' contributions to the current knowledge in neuropathology of epilepsy.

Academic achievement and perception of two teaching methods in histology: light microscopy and digital systems / Rendimiento académico y percepción de dos métodos de enseñanza en histología: microscopía óptica y sistema digital

With the advent of digital systems, the role of the microscope as an irreplaceable instrument in the practical teaching of histology has been called into question. In this study academic performance and student perception for three learning methods was compared: digital systems, microscopy, and microscopy plus digital systems, in the muscle tissue unit of the morphology course for first-year dentistry at the Universidad de los Andes, Santiago, Chile. Ninety-five students were divided into 3 groups: Group 1: individual optical microscopy, Group 2: digital systems (one projector per room), and Group 3: microscopy plus digital systems. All participants observed the same striate muscle, cardiac striated muscle, and smooth muscle mounts. Their diagnostic capacity was evaluated. A perception test was conducted after everyone had learned with both systems. For data analysis the Kruskal-Wallis test and logistic regression were used. In the cognitive evaluation, the median grades were 4.5 for group 2 and 5.45 for group 3 (Kruskal-Wallis p-value= 0.0023). In the perception survey, 69% of students reported feeling motivated by the use of the microscope and 51% reported that they felt motivated by the use of digital system (p-value= 0.0016). It was concluded that the combined use of optical microscopy and digital systems achieves better performance as compared to the digital system alone. The use of the microscope improves student perception as compared to those using only the digital system.

Con el advenimiento de los sistemas digitales, se ha puesto en tela de juicio el rol del microscopio como instrumento insustituible para la enseñanza práctica de la histología. El objetivo fue comparar el rendimiento académico y la percepción de los alumnos utilizando tres métodos de aprendizaje: sistema digital, microscopía y microscopía más sistema digital, en la unidad de tejido muscular del curso de morfología de primer año de Odontología de la Universidad de los Andes. Noventa y cinco alumnos fueron divididos en 3 grupos: 1: microscopía óptica individual, 2: sistema digital (proyección única en sala) y 3: microscopía más sistema digital. Todos observaron los mismos preparados de músculo estriado esquelético, estriado cardiaco y liso. Al finalizar, rindieron una evaluación cognitiva y luego los grupos fueron invertidos. Una vez que todos aprendieron con ambos sistemas realizaron una encuesta de percepción. Para el análisis de datos se utilizaron los test de Kruskall-wallis y Regresión Logística. En la evaluación cognitiva, el grupo 3 resultó ser significativamente superior a las del grupo 2 (Kruskall-wallis P= 0,0023). En la encuesta de percepción el 69% de los alumnos expresaron sentirse motivados por el uso del microscopio y un 51% respondieron que se sintieron motivados con el uso de sistema digital (p= 0,0016). En conclusión, el uso combinado de microscopía más sistema digital obtuvo mejores resultados que el sistema digital solo, y el uso de microscopio obtuvo una mejor percepción comparada entre quienes usaron únicamente el sistema digital.

Biogeographic specializations of two large hypotrich ciliates: Australocirrus shii and A. australis and proposed synonymy of Australocirrus and Cyrtohymenides.

Using standard methods, we studied the morphology and distribution of an Australian population of Australocirrus shii (Shi et al., 1997) nov. comb. and a Jamaican population of A. australis (Foissner, 1995) nov. comb. We identified three features, not or rarely used earlier, that distinguish Australocirrus shii from A. australis: the distance between the anterior pretransverse cirrus and the anteriormost transverse cirrus (5-8% vs. 1.5-1.7% of body length), the arrangement of the transverse cirri (3+2 vs. an oblique row), and the resting cyst macronuclear nodules (separate vs. fused). Australocirrus shii has been reported from Asia and Australia while A. australis is possibly restricted to the Neotropic. Because of problems in getting voucher materials of A. shii, we emphasise that permanent slides should be deposited in international repositories. Based on previous studies and new data, especially a refined interpretation of the shape of the paroral membrane, we suggest synonymy of Cyrtohymenides and Australocirrus. Thus, Cyrtohymena (Cyrtohymenides) shii, C. (Cyrtohymenides) aspoecki, and C. (Cyrtohymenides) australis are transferred to Australocirrus which is, inter alia, defined by a moderately to distinctly curved, but not recurved, paroral membrane, multiple fragmentation of dorsal kinety 3 and three or more dorsomarginal kineties.

In-house PCR with DNA extracted directly from positive slides to confirm or exclude the diagnosis of tuberculosis: focus on biosafety.

The possibility to obtain DNA from smears is a valuable alternative to remedy the lack of samples when they are totally used for bacilloscopy; this technique solves the biosafety problem related to a possible accident with the transportation of flasks containing potentially transmissible clinical samples. Hence, the purpose of this study was to utilize the insertion sequence IS6110 for amplification of DNA from a smear-positive sample for tuberculosis (TB) diagnosis. Among the 52 positive bacilloscopies, sensitivity, specificity, positive predictive value and negative predictive value were 52.3%, 100%, 100% and 89.7%, respectively whereas accuracy was 90.7%. The IS6110-based PCR for TB diagnosis developed in DNA extracted from a positive smear is a fast, simple, specific, and safe method.

PCR interna con ADN extraído directamente de portaobjetos positivos para confirmar o excluir el diagnóstico de tuberculosis: enfoque en la bioseguridad / In-house PCR with DNA extracted directly from positive slides to confirm or exclude the diagnosis of tuberculosis: focus on biosafety

The possibility to obtain DNA from smears is a valuable alternative to remedy the lack of samples when they are totally used for bacilloscopy; this technique solves the biosafety problem related to a possible accident with the transportation of flasks containing potentially transmissible clinical samples. Hence, the purpose of this study was to utilize the insertion sequence IS6110 for amplification of DNA from a smear-positive sample for tuberculosis (TB) diagnosis. Among the 52 positive bacilloscopies, sensitivity, specificity, positive predictive value and negative predictive value were 52.3%, 100%, 100% and 89.7%, respectively whereas accuracy was 90.7%. The IS6110-based PCR for TB diagnosis developed in DNA extracted from a positive smear is a fast, simple, specific, and safe method

La posibilidad de obtener ADN a partir de frotis es una valiosa alternativa para remediar la falta de muestras cuando estas son totalmente utilizadas para la baciloscopia; esta opción soluciona, además, el problema de bioseguridad asociado a la posibilidad de accidente al transportar frascos que contienen muestras clínicas potencialmente infectivas. Por lo tanto, el propósito de este estudio fue utilizar para el diagnóstico de la tuberculosis la secuencia de inserción IS6110 para amplificación del ADN a partir de frotis que resultaron positivos por baciloscopia. Del análisis de 52 baciloscopias positivas surge que la sensibilidad, la especificidad, el valor predictivo positivo y el valor predictivo negativo de esta técnica fueron, respectivamente, del 52,3%, del 100%, del 100% y del 89,7%; y la precisión fue del 90,7%. La PCR IS6110 para el diagnóstico de tuberculosis, desarrollada con ADN extraído de frotis positivos, es un método rápido, simple, específico y seguro

Diagnosing Pathological Prognostic Factors in Retinoblastoma: Correlation between Traditional Microscopy and Digital Slides.

OBJECTIVE: It was the aim of this study to determine the diagnostic accuracy of high-risk prognostic factors and morphological characteristics of retinoblastomas using digital whole slide images (WSI) generated by a scanner. METHODS: Forty-seven H&E sections of glass slides with high-risk morphological features of retinoblastoma were analyzed. Slides were scanned as WSI and reviewed. The results were compared with those obtained after reviewing the slides using a regular microscope as the gold standard. McNemar's test (MT), the percentage of agreement (POA), and sensitivity (S) and specificity (Sp) were evaluated between WSI and conventional microscopy. RESULTS: There were no differences with respect to multicentricity, growth type, rosette formation, choroidal invasion, anterior chamber invasion, extraocular extension, scleral extension, optic nerve invasion, necrosis, or Azzopardi effect between WSI analysis and light microscopy (MT, p = 1.0; POA = 100%; S = 100%, and Sp = 100%). Discordance was found in 1 case where calcification could not be found using WSI (MT, p = 1.00; POA = 97.9%; S = 100%, and Sp = 97.8%). CONCLUSION: To the best of our knowledge, this is the first report using digital pathology (WSI) to evaluate prognostic factors in eyes containing retinoblastomas. Using WSI, the pathologist was able to detect high-risk morphological features in retinoblastoma. To date, WSI is an important tool, in particular for ophthalmic pathologists examining enucleation and exenteration specimens.

Comparison of four DNA extraction methods for the detection of Mycobacterium leprae from Ziehl-Neelsen-stained microscopic slides.

OBJECTIVE/BACKGROUND: The diagnosis of leprosy has been a challenge due to the low sensibility of the conventional methods and the impossibility of culturing the causative organism. In this study, four methods for Mycobacterium leprae nucleic-acid extraction from Ziehl-Neelsen-stained slides (ZNS slides) were compared: Phenol/chloroform, Chelex 100 resin, and two commercial kits (Wizard Genomic DNA Purification Kit and QIAamp DNA Mini Kit). METHODS: DNA was extracted from four groups of slides: a high-codification-slide group (bacteriological index [BI]⩾4), a low-codification-slide group (BI=1), a negative-slide group (BI=0), and a negative-control-slide group (BI=0). Quality DNA was evidenced by the amplification of specific repetitive element present in M. leprae genomic DNA (RLEP) using a nested polymerase chain reaction. RESULTS: This is the first report comparing four different extraction methods for obtaining M. leprae DNA from ZNS slides in Cuban patients, and applied in molecular diagnosis. Good-quality DNA and positive amplification were detected in the high-codification-slide group with the four methods, while from the low-codification-slide group only the QIAGEN and phenol-chloroform methods obtained amplification of M. leprae. In the negative-slide group, only the QIAGEN method was able to obtain DNA with sufficient quality for positive amplification of the RLEP region. No amplification was observed in the negative-control-slide group by any method. Patients with ZNS negative slides can still transmit the infection, and molecular methods can help identify and treat them, interrupting the chain of transmission and preventing the onset of disabilities. CONCLUSION: The ZNS slides can be sent easily to reference laboratories for later molecular analysis that can be useful not only to improve the diagnosis, but also for the application of other molecular techniques.

Genotyping of Mycobacterium leprae present on Ziehl-Neelsen-stained microscopic slides and in skin biopsy samples from leprosy patients in different geographic regions of Brazil

We analysed 16 variable number tandem repeats (VNTR) and three single-nucleotide polymorphisms (SNP) in Mycobacterium leprae present on 115 Ziehl-Neelsen (Z-N)-stained slides and in 51 skin biopsy samples derived from leprosy patients from Ceará (n = 23), Pernambuco (n = 41), Rio de Janeiro (n = 22) and Rondônia (RO) (n = 78). All skin biopsies yielded SNP-based genotypes, while 48 of the samples (94.1%) yielded complete VNTR genotypes. We evaluated two procedures for extracting M. leprae DNA from Z-N-stained slides: the first including Chelex and the other combining proteinase and sodium dodecyl sulfate. Of the 76 samples processed using the first procedure, 30.2% were positive for 16 or 15 VNTRs, whereas of the 39 samples processed using the second procedure, 28.2% yielded genotypes defined by at least 10 VNTRs. Combined VNTR and SNP analysis revealed large variability in genotypes, but a high prevalence of SNP genotype 4 in the Northeast Region of Brazil. Our observation of two samples from RO with an identical genotype and seven groups with similar genotypes, including four derived from residents of the same state or region, suggest a tendency to form groups according to the origin of the isolates. This study demonstrates the existence of geographically related M. leprae genotypes and that Z-N-stained slides are an alternative source for M. leprae genotyping.

Memoria para eventos emocionais: o papel do momento da testagem e do tipo de teste / Memory for emotional events: The role of time of testing and type of test

O impacto da emoção no desempenho da memória é amplamente discutido na literatura científica. No presente trabalho, a relação entre memória e emoção foi investigada em três experimentos por meio do Procedimento de Apresentação de Slides. No primeiro experimento, a memória de 128 participantes foi testada por meio de um teste de recordação livre para a versão emocionalmente estimulante ou neutra do Procedimento. No segundo experimento, 75 participantes responderam ao teste de recordação livre para a versão estimulante imediatamente após assistila ou uma semana depois. No terceiro experimento, 75 estudantes universitários assistiram à versão estimulante e responderam a um teste de recordação livre ou de reconhecimento uma semana depois. Os resultados indicaram que a memória para situações estimulantes é melhor quando testada imediatamente após a exposição ao estímulo por meio de recordação livre.

The impact of emotion on memory performance is widely debated in the scientific literature. In the present paper, the relation between emotion and memory was addressed in three experiments using the Slideshow Procedure. In the first experiment, 128 participants' memory was tested for one of two versions of the Procedure (arousal or neutral) through free recall. In the second experiment, 75 participants were asked to recall the information of the arousal version immediately after or one week after watching it. In the third experiment, 75 participants watched the arousal version and answered either a free recall or a recognition test one week after. The results suggested that memory for arousal events is better when tested immediately after the stimuli using free recall.

Mind map teaching of gross anatomy is sex dependent / Mapa conceptual en la enseñanza de la anatomía macroscópica es dependiente del sexo

The aim of this study was to evaluate the effectiveness of using Mind Maps in teaching anatomy and compare it with traditional based slide. This cross-sectional research was carried out in 2009 on 79 second year medical undergraduate students at Ahvaz Jondishapour University of Medical sciences. Four class lectures on the topics of head and neck osteology were taught. The lectures were slide based designed that were chosen from the chapters in the anatomy textbooks and presented by means of a video projection power point system. The students divided randomly into two groups; one group educated by traditional slides while the other by mind map based designed ones. At the end of the term, a multiple-choice involved forty test was undertaken from two groups. The data was investigated using analysis of variance (ANOVA) and paired T test (p<0.05). The mean scores of females in mind map group were higher than that for traditional one (p<0.04), while there were no significant differences in the mean scores of the men of two groups. The mean scores of females were significantly higher than the males in mind map group (p<0.02) and although the mean scores of females in traditional group was higher it was not significant. This paper has shown the efficacy of using mind maps for teaching gross anatomy as a study aid, even when use has been limited to a single exposure. The study found sex-dependent of learning, suggesting that sex may determine the optimal neural network for designing teaching protocols. Indeed, for females, that have obtained better scores, the use of bilateral neural network seems to facilitate the learning process by mind map teaching of anatomy.

El objetivo de este estudio fue evaluar la efectividad del uso de mapas conceptuales en la enseñanza de la anatomía y compararla con la tradicional basada en diapositivas. Esta investigación de corte transversal se llevó a cabo en el año 2009 en 79 estudiantes de pregrado del Segundo Año de Medicina en la Universidad de Ciencias Médicas Ahvaz Jondishapour. Fueron analizadas cuatro clases conferenciales en los temas de cabeza y cuello óseo. Las conferencias diseñadas se basaron en el uso de diapositivas las que fueron seleccionadas desde los capítulos de libros de Anatomía y se presentaron por medio de proyección de videos utilizando el sistema power point. Los estudiantes fueron divididos aleatoriamente en dos grupos: un grupo educado por diapositivas tradicionales mientras que el otro se basó en el diseño de mapas mentales. Al final del ciclo de conferencias, una prueba de opción múltiple de cuarenta preguntas se aplicó en ambos grupos. Los datos fueron investigados mediante el análisis de varianza (ANOVA) y prueba de la t de Student (p<0,05). Las puntuaciones medias de las mujeres en el grupo de mapa mental fueron mayores que las del grupo diapositivas (p<0,04), mientras que no hubo diferencias significativas en las puntuaciones medias de los hombres de ambos grupos. Las puntuaciones medias de las mujeres fueron significativamente mayores que los hombres en el grupo de mapa mental (p <0,02) y aunque las puntuaciones medias de las mujeres en el grupo diapositivas fue más alto, no fue estadísticamente significativo. En este trabajo se ha demostrado la eficacia del uso de mapas mentales para la enseñanza de anatomía como una ayuda al estudio, incluso cuando el uso se ha limitado a una sola exposición. El estudio encontró que el aprendizaje depende del sexo, lo que sugiere que el sexo puede determinar una red neuronal para el diseño de protocolos óptimos de enseñanza. En efecto, para las mujeres, que tienen mejores calificaciones, el uso de redes neuronales bi...