Characteristics of Devic's disease (neuromyelitis optica) in Mexico.

OBJECTIVE: To report clinical and epidemiological data of Devic's disease in Mexico. DESIGN: Retrospective study of hospital case records. SETTING: The medical records were those of the National Institute for Neurology and Neurosurgery (INNN), a tertiary care referral center in Mexico City. PATIENTS: There were 424 medical histories available for review among 561 discharges with diagnoses of multiple sclerosis (MS), neuromyelitis optica (NMO), or equivalents. 390 met the diagnostic criteria of MS and 34 the NMO criteria. MAIN OUTCOME MEASURES: We recorded clinical signs, visual acuities, and the Expanded Disability Status Scale (EDSS) at the initial diagnostic admission and during follow-up. All patients had examination of cerebrospinal fluid (CSF) at diagnosis; head and spine magnetic resonance imaging (MRI) were performed at diagnosis and at follow-up. RESULTS: All 34 patients were Mexican Mestizos, who comprise 79 % of the residents of Mexico City. There were 23 monophasic and 11 relapsing cases. Intervals between initial and defining events for the 8 ON and 12 myelitis onsets were 17 and 24 months (means) and 15 and 17 months (medians), respectively. Mean follow- up from onset was 70.2 months and 42.9 months from diagnostic examination. No patient showed improvement in EDSS scores. Visual loss was severe. CONCLUSION: A provisional prevalence rate of about 1 per 100,000 population for NMO in Mexican Mestizos might be offered. The disease seems more severe in our population than in other recent series.

Genetic testing improves the diagnosis of adult type hypolactasia in the Mediterranean population of Sardinia.

OBJECTIVE: Recently, the C/T-13910 polymorphism on chromosome 2q21 in North-European populations has been found completely associated with lactase activity and its genetic typing proposed as first-stage screening test for adult hypolactasia. However, the C/T-13910 variant in some sub-Saharan African groups is not a predictor of lactase persistence. In this work, we wanted to verify if in the Mediterranean island of Sardinia, located in Southern Europe, the C/T-13910 polymorphism may be useful or not for the diagnosis of adult type hypolactasia. DESIGN: Validation study of a genetic testing for adult type hypolactasia in Sardinians. SETTING: Brotzu Hospital and Microcitemico Hospital, Cagliari, Italy. SUBJECTS: The sample consisted in 84 Sardinian individuals (63 women and 21 men; range 20-73 years) selected from a group of 832 patients. METHODS: Genetic testing was compared to an improved test obtained by a combination of different breath hydrogen tests and clinical assessment. RESULTS: We found that all 49 individuals with lactose malabsorption, demonstrated by a combination of different breath hydrogen tests and clinical assessment, carried the C/C-13910 genotype associated with lactase non-persistence, 23 individuals with lactose normal absorption carried the C/T-13910 genotype associated with lactase persistence and only one person with the above phenotype showed a discordant C/C-13910 genotype. The genetic testing showed very high sensitivity, specificity, positive and negative predictive values of 100, 95.8, 98 and 100%, respectively. CONCLUSIONS: Sardinians, unlike some ethnic groups in sub-Saharan Africa, show the same genetic association of hypolactasia with the C/T-13910 variant as other North-European populations. The genetic testing for the C/T-13910 variant may contribute to improving the diagnosis of adult type hypolactasia.

[Diagnostic tests in myasthenia gravis. Creation of a standard for diagnosis using a method of consensus]. / Pruebas diagnósticas en miastenia gravis. Conformación de un estándar diagnóstico mediante un método de consenso.

INTRODUCTION: Nowadays the best test for the diagnosis of myasthenia gravis (MG) is the single fiber electromyography (SFEMG). Due to the cost of the test it has not become routine in most part of the hospitals to confirm the diagnosis of MG. OBJECTIVE: To identify an acceptable gold standard for hospitals which do not have access to SFEMG, but have access to some other classical test through the use of a consensus methodology. SUBJECTS AND METHODS: The study was realized in three stages. The first two stages were done through a prolective survey and the third stage through a Delfos methodology. During the first stage 59 general neurologist were interviewed, applying an instrument in which they were asked which were the best test and the best group of tests to diagnose MG without using the SFEMG. During a second stage, a second collection instrument was applied to 15 experts in motoneuron diseases to identify the best isolated test and the best test scheme with and without using the SFEMG in four frequent clinical situations in clinical practice (typical clinical case of generalized MG, patient with ocular myasthenia, patient with generalized MG of medium and low probability). Finally four flowcharts were created of the four analyzed clinical situations and were approved through a Delfos methodology with 8 neurologist motoneuron disease. RESULTS: We identified an acceptable gold standard for hospitals which do not have access to SFEMG through the use of a consensus methodology. We have also completed four diagnostic flowcharts about the most frequent clinical situations that we have faced in the ordinary practice. CONCLUSIONS: We have found a series of important results for the diagnosis of MG available to general physicians, internists and neurologist that do not have all the test for the diagnosis of MG.

[Monitoring dermatomal somatosensory evoked potentials at the ERB point, the cervical spinal cord and the cerebral cortex in the diagnosis of cervical radiculopathy]. / Registro de potenciales evocados somatosensoriales dermatómicos en punto de Erb, médula cervical y corteza cerebral en el diagnóstico de la radiculopatía cervical.

INTRODUCTION: Recording at various levels of the somatosensory pathway is often used in somatosensory evoked potentials to mixed nerve stimulation (SEP), but not in dermatomal somatosensory evoked potentials (DSEP) in which only the cortical potential is usually recorded. The aim of our study was to compare the recordings of upper limb DSEP at Erb point, cervical cord, and subcortical and cortical levels with SEP recordings in healthy subjects and patients with cervical radiculopathy. PATIENTS AND METHODS: 17 patients with clinical history, MRI and electromyography consistent with cervical radiculopathy and 17 healthy subjects were included. Median and ulnar nerves were stimulated at the wrist; and C6, C7 and C8 dermatomes at the 1st, 3rd and 5th fingers respectively. All the potentials obtained with SEP and DSEP were compared between controls and patients by t test for independent samples. We also used Pearson s correlation for height/latencies, weight/amplitude and age/peripheral nerve conduction velocity (PNCV). RESULTS: DSEP potentials were of similar morphology of those observed in SEP but had longer latencies and smaller amplitudes. We found a positive correlation between height and latencies, and a negative association of weight with amplitude of peripheral potential, and age/PNCV. No difference between controls and the neurological intact segments of patients was found. 13 patient had DSEP altered while only 5 of them had altered SEP recorded. The most common finding was prolongation of the conduction time of the segment N9 N13 on DSEP recordings. CONCLUSION: We found that it is possible to record and to identify all the potentials in DSEP as observed in the SEP. On cervical radiculopathy, DSEP with the present technique increase the sensitivity and give some additional and useful information regarding the extension and localization of the pathology. Besides, DSEP recording is a non invasive technique, non traumatic and well tolerated for our patients.

Regulation of a carotenoid biosynthesis gene promoter during plant development.

Carotenoids are terpenoid pigments which are accumulated in the chloroplasts of leaves and in the chromoplasts of many flowers and fruits. Phytoene desaturase (Pds), the second dedicated enzyme in carotenoid biosynthesis, is encoded in tomato by a single copy gene. A 2 kb fragment from the tomato Pds gene, comprising 1.5 kb from the promoter and 0.5 kb from the 5' non-translated region, is able to drive developmentally regulated expression of the GUS reporter gene in transgenic tomato and tobacco plants. In tomato, high levels of Pds/GUS expression are found in organs and at stages of development where chromoplasts are formed: petals, anthers and ripening fruits. Tobacco petals and fruits, which do not contain chromoplasts, show instead low levels of Pds/GUS expression. Transgenic tobacco seedlings were subjected to treatment with a range of inhibitors of carotenoid and chlorophyll biosynthesis. The results indicate that, in green tissues, carotenoid and chlorophyll levels are tightly co-regulated and that a chemically induced arrest in pigment biosynthesis results in activation of the Pds promoter. The promoter is also induced in etiolated seedlings, which contain much lower carotenoid levels than light-grown seedlings. These data suggest that in green tissues Pds gene transcription may respond to end-product regulation.

Pruebas diagnósticas en miastenia gravis. Conformación de un estándar diagnóstico mediante un método de consenso / Diagnostic test in myasthenia gravis. Creation of a standard for diagnosis using a method of consensus

Introducción. En la actualidad la mejor prueba para el diagnóstico de miastenia gravis (MG) es la electromiografía de fibra única (EFU). Debido al coste de la prueba, pocos hospitales en el mundo la pueden tener para uso rutinario para confirmar el diagnóstico de MG. Objetivo. Identificar un estándar de oro aceptable para hospitales que no cuenten de manera habitual con EFU mediante la utilización de una metodología de consenso realizado en tres etapas. Sujetos y métodos. Las dos primeras etapas del estudio se realizaron mediante encuestas prolectivas y la tercera etapa mediante una metodología Delfos. En la primera etapa se aplicó un instrumento a 55 neurólogos generales donde se preguntaba cuál era la mejor combinación de pruebas y la mejor prueba aislada con las que habitualmente realizaban el diagnóstico de MG. En la segunda etapa se aplicó un segundo instrumento de recolección a 15 expertos de unidad motora (EUM), quienes analizaron cuatro situaciones clínicas frecuentes en la práctica (cuadro clínico clásico de MG generalizada, paciente con cuadro de miastenia ocular, cuadro de MG generalizada de mediana probabilidad y cuadro clínico de baja probabilidad), identificando la mejor prueba aislada y el mejor conjunto de pruebas para el diagnóstico de miastenia gravis con y sin el uso de EFU. Finalmente, se crearon cuatro flujogramas de las cuatro situaciones clínicas analizadas que fueron consensuados mediante una metodología Delfos con ocho neurólogos EUM. Resultados. Hemos identificado un estándar de oro aceptable para hospitales que no cuenten de manera general con EFU mediante una metodología de consenso. También hemos consensuado cuatro flujogramas diagnósticos de las situaciones clínicas más frecuentes a las que nos enfrentamos en la práctica clínica habitual. Conclusión. Hemos encontrado una serie de resultados con una utilidad importante para el diagnóstico de MG aplicables a médicos generales, médicos internistas y neurólogos que no cuenten con todas las pruebas disponibles para el diagnóstico de esta enfermedad (AU)

Registro de potenciales evocados somatosensoriales dermatómicos en punto de Erb, médula cervical y corteza cerebral en el diagnóstico de la radiculopatía cervical / Monitoring dermatomal somatosensory evoked potentials at the Erb point, the cervical spinal cord and the cerebral cortex in the diagnosis of cervical radiculopathy

Introducción. El registro de potenciales evocados somatosensoriales en puntos intermedios de la vía somatosensorial, como el punto de Erb y la médula cervical, se utiliza sólo con estimulación de nervio mixto (PESS), y no en potenciales evocados somatosensoriales con estímulo dermatómico (PESSD). El objetivo del estudio fue comparar el registro del PESSD de miembros superiores en punto de Erb, médula cervical y regiones subcorticales y corticales, con el registro del PESS convencional en sujetos sanos y pacientes con radiculopatía cervical (RC). Pacientes y métodos. Participaron 17 sujetos sanos y 17 pacientes con historia clínica consistente con RC, confirmada por electromiografía y RM. Se estimularon los nervios mediano y cubital en la muñeca, y los dermatomas C6, C7 y C8 en el 1.º, 3.º y 5.º dedos. Se compararon los componentes de los PESS con los PESSD, en controles y pacientes, por medio de la prueba t de Student para muestras independientes y se realizaron correlaciones de Pearson entre talla/latencias, peso/amplitud y edad/velocidad de conducción periférica (VCNP) para determinar los factores que correlacionaban en el estudio. Resultados. Los PESSD presentaron similar morfología, pero latencias más largas y menor amplitud, que los PESS. Se encontró una correlación directa entre talla y latencias e inversa entre peso y amplitud del potencial periférico así como entre edad y la VCNP. No hubo diferencias entre el grupo control y el lado no afectado del grupo de pacientes. En 13 pacientes se detectó alteración en los PESSD, mientras sólo se detectó en cinco en los PESS. La alteración más común fue la prolongación en la conducción del segmento N9-N13. Conclusiones. Con el presente estudio se confirma que es posible registrar e identificar adecuadamente todos los componentes de los PESSD a lo largo de la vía somato sensorial, para utilizarlos en la clínica al igual que en los PESS convencionales. En la RC, los PESSD con captaciones intermedias de la vía aumentan la sensibilidad diagnóstica y brindan información adicional referente a la extensión y localización de la lesión; ofrecen, además, la ventaja de ser un estudio no invasivo, no traumático y mejor tolerado por los pacientes (AU)