Hippocampal subfields at ultra high field MRI: An overview of segmentation and measurement methods

The hippocampus is one of the most interesting and studied brain regions because of its involvement in memory functions and its vulnerability in pathological conditions, such as neurodegenerative processes. In the recent years, the increasing availability of Magnetic Resonance Imaging (MRI) scanners that operate at ultra-high field (UHF), that is, with static magnetic field strength ≥7T, has opened new research perspectives. Compared to conventional high-field scanners, these systems can provide new contrasts, increased signal-to-noise ratio and higher spatial resolution, thus they may improve the visualization of very small structures of the brain, such as the hippocampal subfields. Studying the morphometry of the hippocampus is crucial in neuroimaging research because changes in volume and thickness of hippocampal subregions may be relevant in the early assessment of pathological cognitive decline and Alzheimer's Disease (AD). The present review provides an overview of the manual, semi-automated and fully automated methods that allow the assessment of hippocampal subfield morphometry at UHF MRI, focusing on the different hippocampal segmentation produced. © 2017 Wiley Periodicals, Inc

Disease due to Mycobacterium simiae and “Mycobacterium sherrisii” in Argentina

Se presenta información reunida retrospectivamente sobre casos de micobacteriosis originados por mycobacterium simiae(n = 4) y “m. sherrisii”(n = 6). Los casos ocurrieron entre pacientes con sida (n = 6), historia de silicosis (n = 2) o tuberculosis previa (n = 1). Un caso se perdió luego de diagnosticado y nueve fueron tratados con esquemas terapéuticos basados en claritromicina, etambutol y quinolonas. La respuesta fue muy pobre: cinco pacientes fallecieron (cuatro eran hiV positivos), tres permanecieron crónicos y sólo uno curó. estas micobacterias originaron 2.1% de los casos de micobacteriosis registrados en un período de ocho años. La distinción de estas micobacterias raras de otras más frecuentes por métodos moleculares rápidos, parece ser clínicamente útil para advertir sobre la dificultad que puede presentar el tratamiento. Sin embargo, la diferenciación genotípica entre m. simiae y“m. sherrisii” parecería no ser clínicamente relevante, dado que no quedaron expuestas características que distingan a los pacientes afectados por los dos microorganismos tan estrechamente relacionados.A revision of mycobacterial disease due to msimiae(n = 4) and “m. sherrisii”(n = 6) identified during an eight-year period is presented. Cases occurred among patients with aiDs(n = 6), previous history of silicosis (n = 2) or tuberculosis (n = 2). one case was lost to follow-up and the remaining nine responded poorly to chemotherapy based on clarithromycin, ethambutol and fluoroquinolones. Five patients died of whom four were hiV-positive, three remained chronic and one was cured. these microorganisms originated 2.1% of mycobacterioses cases detected in an eight-year period. Timely identification of this group of uncommon mycobacteria by molecular methods seems to be clinically relevant in order to warn of difficulties inherent to the treatment. however, the distinction between both closely related microorganisms might not be crucial for case management as no distinctive characteristics were evident among patients affected by m. simiaeor “m. sherrisii”.Fil. Barrera, Lucía. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Palmero, Domingo. Hospital francisco J. Muñiz; Argentina.Fil: Paul, Roxana. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: López, Beatriz. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Grupo de investigación de mycobacterium simiae; Argentina

Disease due to Mycobacterium simiae and “Mycobacterium sherrisii” in Argentina

Se presenta información reunida retrospectivamente sobre casos de micobacteriosis originados por mycobacterium simiae(n = 4) y “m. sherrisii”(n = 6). Los casos ocurrieron entre pacientes con sida (n = 6), historia de silicosis (n = 2) o tuberculosis previa (n = 1). Un caso se perdió luego de diagnosticado y nueve fueron tratados con esquemas terapéuticos basados en claritromicina, etambutol y quinolonas. La respuesta fue muy pobre: cinco pacientes fallecieron (cuatro eran hiV positivos), tres permanecieron crónicos y sólo uno curó. estas micobacterias originaron 2.1% de los casos de micobacteriosis registrados en un período de ocho años. La distinción de estas micobacterias raras de otras más frecuentes por métodos moleculares rápidos, parece ser clínicamente útil para advertir sobre la dificultad que puede presentar el tratamiento. Sin embargo, la diferenciación genotípica entre m. simiae y“m. sherrisii” parecería no ser clínicamente relevante, dado que no quedaron expuestas características que distingan a los pacientes afectados por los dos microorganismos tan estrechamente relacionados.A revision of mycobacterial disease due to msimiae(n = 4) and “m. sherrisii”(n = 6) identified during an eight-year period is presented. Cases occurred among patients with aiDs(n = 6), previous history of silicosis (n = 2) or tuberculosis (n = 2). one case was lost to follow-up and the remaining nine responded poorly to chemotherapy based on clarithromycin, ethambutol and fluoroquinolones. Five patients died of whom four were hiV-positive, three remained chronic and one was cured. these microorganisms originated 2.1% of mycobacterioses cases detected in an eight-year period. Timely identification of this group of uncommon mycobacteria by molecular methods seems to be clinically relevant in order to warn of difficulties inherent to the treatment. however, the distinction between both closely related microorganisms might not be crucial for case management as no distinctive characteristics were evident among patients affected by m. simiaeor “m. sherrisii”.Fil. Barrera, Lucía. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Palmero, Domingo. Hospital francisco J. Muñiz; Argentina.Fil: Paul, Roxana. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: López, Beatriz. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Grupo de investigación de mycobacterium simiae; Argentina