Evaluación neuropsicológica de un adulto colombiano diagnosticado con Síndrome de Morquio B / Neuropsychological assessment of a Colombian adult diagnosed with Morquio B Syndrome

Resumen El síndrome de Morquio B es una enfermedad rara y de baja prevalencia, por lo cual poco se ha estudiado sobre el funcionamiento neuropsicológico y estado cognitivo de quienes lo padecen. Este estudio de caso presenta los resultados del funcionamiento en atención, memoria, lenguaje, gnosias, praxias y funciones ejecutivas de un adulto colombiano diagnosticado con este síndrome. Se encontró que el paciente puede adquirir nuevo conocimiento; muestra memoria visoespacial y de trabajo verbal conservadas; repite, lee y escribe información sencilla que es conocida para él; sigue órdenes simples a partir de comandos verbales; muestra habilidades viso perceptuales y grafomotoras; tiene un desarrollo normal de pensamiento abstracto y asociativo, y es capaz de planear y solucionar problemas. Sin embargo, presenta dificultades en atención visual sostenida, atención audio-verbal, velocidad de procesamiento, lenguaje comprensivo, repetición y escritura al dictado de frases completas, flexibilidad cognitiva, y fluidez verbal semántica y fonológica. Se discute como factores más relevantes del funcionamiento cognitivo del paciente la relación entre el síndrome de Morquio B y la gangliosidosis GM1, y la falta de entrenamiento en el manejo de información de alta complejidad, dada su condición de desescolarización.

Abstract Since Morquio B syndrome is a low-prevalence rare disease, scarce evidence about neuropsychological functioning and cognitive status in diagnosed people is known. This case study shows the results of functioning in attention, memory, language, gnosias, praxias, and executive functions in a Colombian man diagnosed with this syndrome. It was found that the patient is capable of acquiring new information and exhibits preserved visuospatial and verbal working memory; he is also able to repeat, read and write simple information as long as it is familiar to him, and is capable of following simple verbal instructions with no difficulty; moreover, he displays preserved visuospatial and graphomotor abilities, has a normal development of abstract and associative thinking, and is able to plan and solve problems. Nonetheless, he exhibits difficulties in audio-verbal and sustained visual attention, as well as in processing speed, comprehensive language, repetition and writing of complete phrases, cognitive flexibility, and semantic and phonological verbal fluency. It is discussed the association between Morquio B syndrome and gangliosidosis GM1 as well as the lack of training in the management of highly complex information due to unschooling of this patient as the two most relevant factors of his cognitive functioning.

Transcriptomic Changes of Piscirickettsia salmonis During Intracellular Growth in a Salmon Macrophage-Like Cell Line.

Piscirickettsia salmonis is the causative agent of Piscirickettsiosis, a systemic infection of salmonid fish species. P. salmonis infects and survives in its host cell, a process that correlates with the expression of virulence factors including components of the type IVB secretion system. To gain further insights into the cellular and molecular mechanism behind the adaptive response of P. salmonis during host infection, we established an in vitro model of infection using the SHK-1 cell line from Atlantic salmon head kidney. The results indicated that in comparison to uninfected SHK-1 cells, infection significantly decreased cell viability after 10 days along with a significant increment of P. salmonis genome equivalents. At that time, the intracellular bacteria were localized within a spacious cytoplasmic vacuole. By using a whole-genome microarray of P. salmonis LF-89, the transcriptome of this bacterium was examined during intracellular growth in the SHK-1 cell line and exponential growth in broth. Transcriptome analysis revealed a global shutdown of translation during P. salmonis intracellular growth and suggested an induction of the stringent response. Accordingly, key genes of the stringent response pathway were up-regulated during intracellular growth as well as at stationary phase bacteria, suggesting a role of the stringent response on bacterial virulence. Our results also reinforce the participation of the Dot/Icm type IVB secretion system during P. salmonis infection and reveals many unexplored genes with potential roles in the adaptation to intracellular growth. Finally, we proposed that intracellular P. salmonis alternates between a replicative phase and a stationary phase in which the stringent response is activated.