Helga Cristina Almeida da Silva

Downregulation of VAPB expression in motor neurons derived from induced pluripotent stem cells of ALS8 patients

Amyotrophic lateral sclerosis (ALS) is an incurable neuromuscular disease that leads to a profound loss of life quality and premature death. Around 10% of the cases are inherited and ALS8 is an autosomal dominant form of familial ALS caused by mutations in the vamp-associated protein B/C (VAPB) gene. The VAPB protein is involved in many cellular processes and it likely contributes to the pathogenesis of other forms of ALS besides ALS8. A number of successful drug tests in ALS animal models could not be translated to humans underscoring the need for novel approaches. The induced pluripotent stem cells (iPSC) technology brings new hope, since it can be used to model and investigate diseases in vitro. Here we present an additional tool to study ALS based on ALS8-iPSC. Fibroblasts from ALS8 patients and their non-carrier siblings were successfully reprogrammed to a pluripotent state and differentiated into motor neurons. We show for the first time that VAPB protein levels are reduced in ALS8-derived motor neurons but, in contrast to over-expression systems, cytoplasmic aggregates could not be identified. Our results suggest that optimal levels of VAPB may play a central role in the pathogenesis of ALS8, in agreement with the observed reduction of VAPB in sporadic ALS.

Ringo: Discordance between the molecular and clinical manifestation in a Golden Retriever Muscular Dystrophy dog

Of the various genetic homologues to Duchenne Muscular Dystrophy (DMD), the Golden Retriever Muscular Dystrophy (GRMD) dog, which presents a variable but usually severe and progressive muscle weakness, has the closest relevance to DMD in both clinical severity and histopathological change. Among 77 GRMD dogs born in our colony in Brazil, we have identified a very mildly affected dog, Ringo, born July 2003. Among his descendants, at least one male, Suflair, is also showing a mild course. In an attempt to better characterize these two dogs, we studied the pattern of muscle proteins expression in Ringo and Suflair, as compared to severely affected and normal control dogs. Dystrophin was absent in both and utrophin was overexpressed in a pattern similar to the observed in severely affected dogs. Understanding the mechanism that is protecting Ringo and Suflair from the deleterious effect of the dystrophin gene mutation is of utmost interest. In addition it points out that the clinical impact of therapeutic trials should be interpreted with caution.

Central core disease due to recessive mutations in RYR1 gene : Is it more common than described?

Central core disease (CCD) is an autosomal‐dominant congenital myopathy, with muscle weakness and malignant hyperthermia (MH) susceptibility. We identified two of nine Brazilian CCD families carrying two mutations in the RYR1 gene. The heterozygous parents were clinically asymptomatic, and patients were mildly affected, differing from the few autosomal‐recessive cases described previously. Recessive inheritance in CCD may therefore be more common than previously appreciated, which has important implications for genetic counseling and MH prevention in affected families. Muscle Nerve, 2007

Post-polio syndrome: epidemiologic and prognostic aspects in Brazil

Objectives –  To describe the clinical and epidemiological aspects of post‐polio syndrome (PPS) and identify predictors of its severity.

Amyotrophic lateral sclerosis: considerations on diagnostic criteria

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder, compromising the motor neuron, characterized by progressive muscle weakness, with reserved prognosis. The diagnosis is based on inclusion and exclusion clinical criteria, since there is no specific confirmation test. The objective of this research is to critically examine the main diagnosis instrument - El Escorial revisited, from the World Federation of Neurology (1998). Of the 540 patients with initial ALS diagnosis, either probable or definite, seen at UNIFESP-EPM, 190 underwent thorough investigation, following regular clinical and therapeutic treatment for over two years. Thirty patients (15.78%) had their diagnosis completely changed. The false-positive diagnoses were related to: early age, clinical presentation of symmetry, weakness greater than atrophy, symptomatic exacerbation. In addition, three patients with myasthenia gravis developed framework for ALS, suggesting the post-synaptic disability as a sign of early disease.

Pretreatment with pentoxifylline attenuates lung injury induced by intestinal ischemia/reperfusion in rats

PURPOSE To investigate the protective effect of pentoxifylline against the lung injury observed after intestinal ischemia (I) followed by a period of reperfusion (R). METHODS Twenty-eight male Wistar rats were equally divided into 4 experimental groups and operated under ketamine-xylazine anesthesia. (1) Sham: falsely-operated animals; (2) SS+IR: intestinal ischemia was accomplished by clipping the superior mesenteric artery during 60 minutes, with an administration of a standard volume of saline solution (SS) 5 min before the end of the ischemia period; the clip was then releases or a 120-min period of reperfusion; (3) I+PTX+R: ischemia as above, PTX was administered (25 mg/kg) and the gut reperfused as above; (4) PTX+I+PTX+R: Five minutes before arterial occlusion PTX was administered; the superior mesenteric artery was then clipped for 60 minutes. After 55-min ischemia, an additional dosis of PTX was administered; the clip was removed for reperfusion as above. At the 60th min of reperfusion a third dosis of PTX was administered. RESULTS PTX markedly attenuated lung injury as manifested by significant decreases (all P<0.001 as compared with the SS+IR group) of pulmonary wet/dry tissue weight ratio, total protein content, myeloperoxidase activity and tumor necrosis factor-alpha. Moreover, it was apparent that in the group PTX+I+PTX+R the improvements have been even more significant. CONCLUSION PTX exerted a protective effect on the lung from the injuries caused by intestinal ischemia/reperfusion.

Malignant hyperthermia in Brazil: analysis of hotline activity in 2009

BACKGROUND AND OBJECTIVES Malignant hyperthermia (MH) is a pharmacogenetic disease that causes abnormal hypermetabolic reaction to halogenated anesthetics and/or depolarizing muscle relaxants. In Brazil, there is a hotline telephone service for MH since 1991, available 24 hours a day in São Paulo. This article analyzes the activity of the Brazilian hotline service for MH in 2009. METHODS Prospective analysis of all phone calls made to the Brazilian hotline service for MH from January to December 2009. RESULTS Twenty-two phone calls were received: 21 from the South/Southeast region of Brazil and one from the North region. Fifteen calls were requests for general information about MH. Seven were about suspected MH acute episodes, two of which were not considered as MH. In five episodes compatible with MH, all patients received halogenated volatile anesthetics (2, isoflurane; 3, sevoflurane) and one also used succinylcholine; there were four men and one woman, with a mean age of 18 years (2-27). The problems described in the five MH episodes were tachycardia (5), increased expired carbon dioxide (4), hyperthermia (3), acidemia (1), rhabdomyolysis (1), and myoglobinuria (1). One patient received dantrolene. All five patients with MH episodes were follow-up in the intensive care unit and recovered without sequelae. Susceptibility to MH was later confirmed in two patients by in vitro muscle contracture test. CONCLUSIONS The number of calls per year in the Brazilian hotline service for MH is still low. The characteristics of MH episode were similar to those reported in other countries. The knowledge of MH in Brazil needs to be increased.

Frequency and clinical manifestations of post-poliomyelitis syndrome in a brazilian tertiary care center

OBJECTIVE To determine the frequency and clinical manifestations of patients with post-poliomyelitis syndrome (PPS) in a Brazilian division of neuromuscular disorders. METHODS A total of 167 patients with prior history of paralytic poliomyelitis was investigated for PPS, based on international diagnostic criteria. Other variables analyzed were: gender, race, age at poliomyelitis infection, age at PPS onset, and PPS symptoms. RESULTS One hundred and twenty-nine patients presented PPS, corresponding to 77.2% of the studied population. 62.8% were women and 37.2% were men. Mean age of patients with PPS at onset of PPS symptoms was 39.9±9.69 years. Their main clinical manifestations were: new weakness in the previously affected limbs (69%) and in the apparently not affected limbs (31%); joint pain (79.8%); fatigue (77.5%); muscle pain (76%); and cold intolerance (69.8%). CONCLUSIONS Most patients of our sample presented PPS. In Brazil, PPS frequency and clinical features are quite similar to those of other countries.

Idiopathic hyperCKemia and malignant hyperthermia susceptibility

PurposeHyperCKemia is a persistent rise in serum creatine kinase (CK) levels of at least 1.5 times the normal value, as evidenced by a minimum of two measurements at 30-day intervals. One of the neuromuscular diseases associated with hyperCKemia is malignant hyperthermia (MH). This study investigated the susceptibility to MH in patients with hyperCKemia via in vitro contracture testing (IVCT) and a search of mutations in the RYR1 gene.MethodsPatients in an MH centre were followed from 1997-2012, and their epidemiologic, clinical, and laboratory data were analyzed, including IVCT, muscle histochemical analysis, and next-generation sequencing molecular analysis.ResultsThere were nine patients (eight male) in our study with a mean (SD) age of 33 (12) yr. Four patients were Caucasian and five were African Brazilian. Most complained about myalgia or cramps, but all had a normal neurological examination. They persistently presented with hyperCKemia from three months to ten years, with a mean (SD) CK value of 788 (507) IU·L−1 ranging from 210-1,667 IU·L−1. These values corresponded to a 1.5- to nine-fold increase in the normal value (mean increase, 3.7-fold). Six patients were MH susceptible (MHS) after a positive IVCT. Histopathological muscular analysis disclosed unspecified changes in four of the MHS patients. Mitochondrial proliferation was observed in the other two MHS patients and in three MH negative patients. No pathogenic mutations were identified in the RYR1 gene in the five patients evaluated.ConclusionWhen investigating patients with idiopathic hyperCKemia, susceptibility to MH should be taken into account, and guidance should be offered to prevent anesthetic complications in the family.RésuméObjectifL’hyperCKémie est définie comme étant l’élévation persistante des taux sériques de créatine kinase (CK) d’au moins 1,5 fois les valeurs normales, tel qu’attesté par un minimum de deux mesures prises à 30 jours d’intervalle. L’une des maladies neuromusculaires associées à l’hyperCKémie est l’hyperthermie maligne (HM). Cette étude a évalué la susceptibilité à l’HM de patients atteints d’hyperCKémie via un test de contracture in vitro (ou IVCT, pour in vitro contracture testing) et une recherche des mutations du gène RYR1.MéthodeDes patients d’un centre d’HM ont été suivis entre 1997 et 2012 et leurs données épidémiologiques, cliniques et de laboratoire ont été analysées, notamment par IVCT, par analyse histochimique musculaire et par analyse moléculaire séquentielle de nouvelle génération.RésultatsNeuf patients (huit hommes) ont été inclus dans notre étude, d’un âge moyen (ÉT) de 33 (12) ans. Quatre patients étaient d’origine caucasienne et cinq d’origine afro-brésilienne. La plupart se plaignaient de myalgie ou de crampes, mais l’examen neurologique était normal chez tous les patients. Ils ont présenté de façon persistante une hyperCKémie allant de trois mois à dix ans, avec une valeur moyenne de CK (ÉT) de 788 (507) IU·L−1, allant de 210 à 1667 IU·L−1. Ces valeurs correspondent à une augmentation de 1,5 à 9 fois les valeurs normales (augmentation moyenne, 3,7 fois). Six patients étaient susceptibles à l’HM (SHM) après un IVCT positif. L’analyse musculaire histopathologique a révélé des changements non spécifiés chez quatre des patients SHM. Une prolifération mitochondriale a été observée chez les deux autres patients SHM et chez trois patients négatifs à l’HM. Aucune mutation pathogénique n’a été identifiée sur le gène RYR1 chez les cinq patients évalués.ConclusionLorsqu’on étudie des patients atteints d’hyperCKémie idiopathique, la susceptibilité à l’HM devrait être prise en compte, et il convient de conseiller ces patients afin de prévenir les complications anesthésiques dans la famille.

Assessment of induction, recovery, agitation upon awakening, and consumption with the use of two brands of sevoflurane for ambulatory anesthesia

BACKGROUND AND OBJECTIVES Due to its pharmacological characteristics, sevoflurane is the ideal anesthetic for short-duration procedures. There are two brands of sevoflurane in the Brazilian market, Sevocris® and Sevorane®, with different formulations and packaging. The objective of this study was to assess whether there are differences between the two anesthetics regarding induction, maintenance, recovery, and consumption. METHODS One hundred and thirty children were included, divided into two groups according to the brand used: Group 1 was assigned to sevoflurane Cristália® and Group 2 to sevoflurane Abbott®. The following parameters were assessed: heart rate, systolic and diastolic blood pressure, fraction of inspired and expired sevoflurane, BIS values, tympanic temperature, induction and recovery time, agitation upon awakening measured by the PAED scale, and anesthetic consumption by weighing the vaporizers. Anesthesia was induced with 1 MAC and increased every three breaths at 0.5 MAC, up to 3 MAC. RESULTS There was no difference between groups regarding the duration of the procedure, the anesthesia, and the parameters evaluated at induction. In Group 1, the number of children who required additional bolus of sevoflurane for anesthesia maintenance was higher than in Group 2 (p<0.05). The fraction of inspired and expired sevoflurane at the end of the procedure was lower in Group 1 (p<0.001). Upon awakening, BIS value was lower in Group 1 (p=0.045). Other parameters evaluated in recovery showed no difference between groups. The use of anesthesia was similar between groups.