Polineuropatías agudas en un hospital del sur de España: diez años de experiencia / Acute polyneuropathies in a hospital in the south of Spain: ten years’ experience

Introducción. El síndrome de Guillain-Barré es la causa más frecuente de parálisis flácida aguda en niños. Objetivo. Describir características de los pacientes diagnosticados de polineuropatías agudas y su evolución a largo plazo. Pacientes y métodos. Análisis descriptivo retrospectivo de los menores de 14 años ingresados en nuestro hospital entre enero de 2004 y diciembre de 2014. Se recogieron variables clínicas, demográficas, neurofisiológicas y otras pruebas de imagen. Resultados. Veintiséis pacientes, con una mediana de edad de 3,83 años, fueron diagnosticados de polineuropatías agudas, cuatro de ellos de origen marroquí. Veinte (76%) tenían antecedentes de infección previa. El tiempo medio desde el inicio de los síntomas hasta su ingreso fue de 9,2 días y, desde éste hasta el inicio de gammaglobulinas, de 1,6 días. La sintomatología que precedió al diagnóstico fue de carácter muy heterogéneo. Todos presentaron debilidad muscular; el 90%, arreflexia; y el 30%, afectación de los pares craneales. El 100% recibió gammaglobulinas intravenosas, y el 38,4%, corticoides sistémicos. Presentaron cronificación de la patología dos pacientes. No hubo mortalidad en la serie. Conclusiones. Los pacientes incluidos en nuestro estudio presentaron en fases tempranas síntomas muy inespecíficos que llevaron a diagnósticos alternativos iniciales; para evitar este retraso diagnóstico, resulta fundamental realizar una exhaustiva exploración física que incluya los reflejos osteotendinosos y mantener un alto índice de sospecha de la enfermedad aun con normalidad en las pruebas complementarias si éstas son precoces. Detectamos un mayor número de polineuropatía axonal, posiblemente explicado por el elevado número de pacientes atendidos de origen marroquí (AU)

Introduction. Guillain-Barré syndrome is the most frequent cause of acute flaccid paralysis in children. Aim. To describe the characteristics of patients diagnosed with acute polyneuropathies and their long-term progress. Patients and methods. We conducted a retrospective descriptive analysis of children under 14 years of age admitted toour hospital between January 2004 and December 2014. Clinical, demographic and neurophysiological variables were collected together with other imaging tests. Results. Twenty-six patients, with a mean age of 3.83 years, were diagnosed with acute polyneuropathies, four of them of Moroccan origin. Twenty of them (76%) had a history of previous infection. The mean time elapsed since the onset of the symptoms until admission to hospital was 9.2 days, and from admission until beginning with gamma globulins it was 1.6 days. The clinical signs and symptoms prior to diagnosis were of a very heterogeneous nature. They all presented muscular weakness; 90% displayed areflexia; and 30% showed involvement of the cranial nerves. All of them (100%) received intravenous gamma globulins, and 38.4% were given systemic corticosteroids. Two patients presented chronification of the pathology. There was no mortality in the series. Conclusions. The patients included in our study presented very unspecific symptoms in the early phases, which initially led to alternative diagnoses. To avoid this delay in the diagnosis, it is essential to perform an exhaustive physical examination that includes the myotatic reflexes and to maintain a high level of suspicion of the disease even with normal results in the complementary tests if they are performed at an early stage. We detected a greater number of cases of axonal polyneuropathy, which can possibly be explained by the high number of patients of Moroccan origin who were treated (AU)

[Acute polyneuropathies in a hospital in the south of Spain: ten years' experience]. / Polineuropatias agudas en un hospital del sur de España: diez años de experiencia.

INTRODUCTION: Guillain-Barre syndrome is the most frequent cause of acute flaccid paralysis in children. AIM: To describe the characteristics of patients diagnosed with acute polyneuropathies and their long-term progress. PATIENTS AND METHODS: We conducted a retrospective descriptive analysis of children under 14 years of age admitted to our hospital between January 2004 and December 2014. Clinical, demographic and neurophysiological variables were collected together with other imaging tests. RESULTS: Twenty-six patients, with a mean age of 3.83 years, were diagnosed with acute polyneuropathies, four of them of Moroccan origin. Twenty of them (76%) had a history of previous infection. The mean time elapsed since the onset of the symptoms until admission to hospital was 9.2 days, and from admission until beginning with gamma globulins it was 1.6 days. The clinical signs and symptoms prior to diagnosis were of a very heterogeneous nature. They all presented muscular weakness; 90% displayed areflexia; and 30% showed involvement of the cranial nerves. All of them (100%) received intravenous gamma globulins, and 38.4% were given systemic corticosteroids. Two patients presented chronification of the pathology. There was no mortality in the series. CONCLUSIONS: The patients included in our study presented very unspecific symptoms in the early phases, which initially led to alternative diagnoses. To avoid this delay in the diagnosis, it is essential to perform an exhaustive physical examination that includes the myotatic reflexes and to maintain a high level of suspicion of the disease even with normal results in the complementary tests if they are performed at an early stage. We detected a greater number of cases of axonal polyneuropathy, which can possibly be explained by the high number of patients of Moroccan origin who were treated.

TITLE: Polineuropatias agudas en un hospital del sur de España: diez años de experiencia.Introduccion. El sindrome de Guillain-Barre es la causa mas frecuente de paralisis flacida aguda en niños. Objetivo. Describir caracteristicas de los pacientes diagnosticados de polineuropatias agudas y su evolucion a largo plazo. Pacientes y metodos. Analisis descriptivo retrospectivo de los menores de 14 años ingresados en nuestro hospital entre enero de 2004 y diciembre de 2014. Se recogieron variables clinicas, demograficas, neurofisiologicas y otras pruebas de imagen. Resultados. Veintiseis pacientes, con una mediana de edad de 3,83 años, fueron diagnosticados de polineuropatias agudas, cuatro de ellos de origen marroqui. Veinte (76%) tenian antecedentes de infeccion previa. El tiempo medio desde el inicio de los sintomas hasta su ingreso fue de 9,2 dias y, desde este hasta el inicio de gammaglobulinas, de 1,6 dias. La sintomatologia que precedio al diagnostico fue de caracter muy heterogeneo. Todos presentaron debilidad muscular; el 90%, arreflexia; y el 30%, afectacion de los pares craneales. El 100% recibio gammaglobulinas intravenosas, y el 38,4%, corticoides sistemicos. Presentaron cronificacion de la patologia dos pacientes. No hubo mortalidad en la serie. Conclusiones. Los pacientes incluidos en nuestro estudio presentaron en fases tempranas sintomas muy inespecificos que llevaron a diagnosticos alternativos iniciales; para evitar este retraso diagnostico, resulta fundamental realizar una exhaustiva exploracion fisica que incluya los reflejos osteotendinosos y mantener un alto indice de sospecha de la enfermedad aun con normalidad en las pruebas complementarias si estas son precoces. Detectamos un mayor numero de polineuropatia axonal, posiblemente explicado por el elevado numero de pacientes atendidos de origen marroqui.

Looking for natural variation in chiasma frequency in Arabidopsis thaliana.

Information concerning natural variation either in chiasma frequency or in the genetic basis of any such variation is a valuable tool to characterize phenotypic traits and their genetic control. Here meiotic recombination frequencies are analysed in nine geographically and ecologically diverse accessions of Arabidopsis thaliana, and a comparative study was carried out incorporating previous data from another eight accessions. Chiasma frequencies, estimated by counting rod and ring bivalents at metaphase I, varied up to 22% among accessions. However, no differences were found among plants of the same accession. There was a relationship, which does not necessarily imply direct proportionality, between the size of the chromosomes and their mean chiasma frequency. Chiasma frequency and distribution between arms and among chromosomes were not consistent over accessions. These findings indicate the existence of genetic factors controlling meiotic recombination both throughout the whole genome and at the whole chromosome level. The reliability of chiasma scoring as an indicator of reciprocal recombination events is also discussed.

ASY1 coordinates early events in the plant meiotic recombination pathway.

Meiosis is a fundamental and evolutionarily conserved process that is central to the life cycles of all sexually reproducing eukaryotes. An understanding of this process is critical to furthering research on reproduction, fertility, genetics and breeding. Plants have been used extensively in cytogenetic studies of meiosis during the last century. Until recently, our knowledge of the molecular and functional aspects of meiosis has emerged from the study of non-plant model organisms, especially budding yeast. However, the emergence of Arabidopsis thaliana as the model organism for plant molecular biology and genetics has enabled significant progress in the characterisation of key genes and proteins controlling plant meiosis. The development of molecular and cytological techniques in Arabidopsis, besides allowing investigation of the more conserved aspects of meiosis, are also providing insights into features of this complex process which may vary between organisms. This review highlights an example of this recent progress by focussing on ASY1, a meiosis-specific Arabidopsis protein which shares some similarity with the N-terminus region of the yeast axial core-associated protein, HOP1, a component of a multiprotein complex which acts as a meiosis-specific barrier to sister-chromatid repair in budding yeast. In the absence of ASY1, synapsis is interrupted and chiasma formation is dramatically reduced. ASY1 protein is initially detected during early meiotic G2 as numerous foci distributed over the chromatin. As G2 progresses the signal appears to be increasingly continuous and is closely associated with the axial elements. State-of-the-art cytogenetic techniques have revealed that initiation of recombination is synchronised with the formation of the chromosome axis. Furthermore, in the context of the developing chromosome axes, ASY1 plays a crucial role in co-ordinating the activity of a key member of the homologous recombination machinery, AtDMC1.

Understanding the cytological diploidization mechanism of polyploid wild wheats.

The allohexaploid Aegilops species (2n = 6x = 42), Ae. neglecta 6x (UUXtXtNN), Ae. juvenalis (DcDcXcXcUU), and Ae. vavilovii (DcDcXcXcSsSs) regularly form bivalents at metaphase I. However, in Ae. crassa 6x (DcDcXcXcDD) 0.27 quadrivalents per cell were observed probably as a consequence of the partial homology displayed by the D and Dc genomes. Likewise, the synthetic amphiploid Ae. ventricosa-Secale cereale (DDNNRR) is fertile and displays a diploid-like behavior at metaphase I, despite its recent origin. The pattern of synapsis at late zygotene and pachytene in the natural and artificial allohexaploids was analyzed by whole-mount surface-spreading of synaptonemal complexes under an electron microscope. It revealed that chromosomes were mostly associated as bivalents in all cases, the mean of multivalents per nucleus ranging from 0.17 (Ae. neglecta 6x) to 1.03 (Ae. crassa 6x) in the natural species and 1.05 in the Ae. ventricosa-S. cereale amphiploid. It can be concluded that the mechanism controlling bivalent formation in these species and also in the synthetic amphiploid acts mainly at zygotene by restricting synapsis to homologous chromosomes, but also acts at pachytene by preventing chiasma formation in the homoeologous associations. These observations are discussed in relation to the origin and evolution of the mechanism of diploidization in the allopolyploid species of the Poaceae family.