GERSON CHADI
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Neurologia, Faculdade de Medicina - Docente
LIM/45 - Laboratório de Fisiopatologia Neurocirúrgica, Hospital das Clínicas, Faculdade de Medicina - Líder
LIM/45 - Laboratório de Fisiopatologia Neurocirúrgica, Hospital das Clínicas, Faculdade de Medicina - Líder
38 resultados
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- Spinal cord injury as a trigger to develop periodic leg movements during sleep: an evolutionary perspective(2012) TELLES, Susana Cristina Lerosa; ALVES, Rosana S. Cardoso; CHADI, GersonThe primary trigger to periodic limb movement (PLM) during sleep is still unknown. Its association with the restless legs syndrome (RLS) is established in humans and was reported in spinal cord injury (SCI) patients classified by the American Spinal Injury Association (ASIA) as A. Its pathogenesis has not been completely unraveled, though recent advances might enhance our knowledge about those malfunctions. PLM association with central pattern generator (CPG) is one of the possible pathologic mechanisms involved. This article reviewed the advances in PLM and RLS genetics, the evolution of CPG functioning, and the neurotransmitters involved in CPG, PLM and RLS. We have proposed that SCI might be a trigger to develop PLM.
- Early gene expression changes in spinal cord from SOD1(G93A) Amyotrophic Lateral Sclerosis animal model(2013) OLIVEIRA, Gabriela P. de; ALVES, Chrystian J.; CHADI, GersonAmyotrophic Lateral Sclerosis (ALS) is an adult-onset and fast progression neurodegenerative disease that leads to the loss of motor neurons. Mechanisms of selective motor neuron loss in ALS are unknown. The early events occurring in the spinal cord that may contribute to motor neuron death are not described, neither astrocytes participation in the pre-symptomatic phases of the disease. In order to identify ALS early events, we performed a microarray analysis employing a whole mouse genome platform to evaluate the gene expression pattern of lumbar spinal cords of transgenic SOD1(G93A) mice and their littermate controls at pre-symptomatic ages of 40 and 80 days. Differentially expressed genes were identified by means of the Bioconductor packages Agi4x44Preprocess and limma. FunNet web based tool was used for analysis of over-represented pathways. Furthermore, immunolabeled astrocytes from 40 and 80 days old mice were submitted to laser microdissection and RNA was extracted for evaluation of a selected gene by qPCR. Statistical analysis has pointed to 492 differentially expressed genes (155 up and 337 down regulated) in 40 days and 1105 (433 up and 672 down) in 80 days old ALS mice. KEGG analysis demonstrated the over-represented pathways tight junction, antigen processing and presentation, oxidative phosphorylation, endocytosis, chemokine signaling pathway, ubiquitin mediated proteolysis and glutamatergic synapse at both pre-symptomatic ages. Ube2i gene expression was evaluated in astrocytes from both transgenic ages, being up regulated in 40 and 80 days astrocytes enriched samples. Our data points to important early molecular events occurring in pre-symptomatic phases of ALS in mouse model. Early SUMOylation process linked to astrocytes might account to non-autonomous cell toxicity in ALS. Further studies on the signaling pathways presented here may provide new insights to better understand the events triggering motor neuron death in this devastating disorder.
- Dysregulated expression of death, stress and mitochondrion related genes in the sciatic nerve of presymptomatic SOD1(G93A) mouse model of Amyotrophic Lateral Sclerosis(2015) ALVES, Chrystian J.; MAXIMINO, Jessica R.; CHADI, GersonSchwann cells are the main source of paracrine support to motor neurons. Oxidative stress and mitochondrial dysfunction have been correlated to motor neuron death in Amyotrophic Lateral Sclerosis (ALS). Despite the involvement of Schwann cells in early neuromuscular disruption in ALS, detailed molecular events of a dying-back triggering are unknown. Sciatic nerves of presymptomatic (60-day-old) SOD1(G93A) mice were submitted to a high-density oligonucleotide microarray analysis. DAVID demonstrated the deregulated genes related to death, stress and mitochondrion, which allowed the identification of Cell cycle, ErbB signaling, Tryptophan metabolism and Rig-l-like receptor signaling as the most representative KEGG pathways. The protein-protein interaction networks based upon deregulated genes have identified the top hubs (TRAF2, H2AFX, E2F1, FOXO3, MSH2, NGFR, TGFBR1) and bottlenecks (TRAF2, E2F1, CDKN1B, TWIST1, FOXO3). Schwann cells were enriched from the sciatic nerve of presymptomatic mice using flow cytometry cell sorting. qPCR showed the up regulated (Ngfr, Cdnkn1b, E2f1, Traf2 and Erbb3, H2afic, Cdkn1a, Hspa1, Prdx, Mapk10) and down-regulated (Foxo3, Mtor) genes in the enriched Schwann cells. In conclusion, molecular analyses in the presymptomatic sciatic nerve demonstrated the involvement of death, oxidative stress, and mitochondrial pathways in the Schwann cell non-autonomous mechanisms in the early stages of ALS.
- Evaluation of Neuronal Apoptosis Precursors in an Experimental Model of Acute Normovolemic Hemodilution(2014) FRAZILIO, Fabricio O.; OTSUKI, Denise Aya; NOEL-MORGAN, Jessica; MAXIMINO, Jessica Ruivo; OLIVEIRA, Gabriela Pintar; CHADI, Gerson; AULER JR., Jose Otavio Costa; FANTONI, Denise TabacchiBackground: The effects of acute anemia on neuronal cells and the safe limits of hematocrit are not well established. The objective of this study was to evaluate neuronal pro-and anti-apoptotic Bax and Bcl-x proteins, caspase-3 and -9 activity, and DNA fragmentation after acute normovolemic hemodilution (ANH). Methods: Twenty-four pigs were anesthetized and randomized into 4 groups: Sham, ANH to 15% hematocrit (ANH15%), ANH to 10% hematocrit (ANH10%) and hypoxia (Hx). ANH was achieved by simultaneous blood withdrawal and hydroxyethyl starch infusion. Hx consisted of ventilation with a 6% inspired oxygen fraction for 60 minutes. Bax and Bcl-x proteins as well as DNA fragmentation were evaluated in cortical nuclear and mitochondrial fractions. Caspase-3 and -9 activity was evaluated in the cortical mitochondrial and hippocampal cytosolic fractions. The data were compared using analysis of variance followed by Tukey's test (P<0.05). Results: No changes were observed in Bax protein expression after hemodilution in the ANH15% and ANH10% groups compared to the Sham group. Bax expression in the Hx group was increased in the nuclear and mitochondrial fractions compared to all other groups. No significant difference was observed in Bcl-x expression. Caspase-3 and -9 activity in the cytosolic and mitochondrial fractions was different in the Hx group compared to all other groups. No statistical significance in DNA fragmentation was found among the Sham, ANH15% or ANH10% groups. Conclusion: ANH to 10 and 15% hematocrit did not induce alterations in apoptosis precursors, suggesting that cerebral oxygenation was preserved during these anemic states.
- Neuraminidase-1 mediates skeletal muscle regeneration(2015) NEVES, Juliana de Carvalho; RIZZATO, Vanessa Rodrigues; FAPPI, Alan; GARCIA, Mariana Miranda; CHADI, Gerson; VLEKKERT, Diantha van de; D'AZZO, Alessandra; ZANOTELI, EdmarNeuraminidase-1 (NEU1) is the sialidase responsible for the catabolism of sialoglycoconjugates in lysosomes. Congenital NEU1 deficiency causes sialidosis, a severe lysosomal storage disease associated with a broad spectrum of clinical manifestations, which also include skeletal deformities, skeletal muscle hypotonia and weakness. Neu1(-/-) mice, a model of sialidosis, develop an atypical form of muscle degeneration caused by progressive expansion of the connective tissue that infiltrates the muscle bed, leading to fiber degeneration and atrophy. Here we investigated the role of Neu1 in the myogenic process that ensues during muscle regeneration after cardiotoxin-induced injury of limb muscles. A comparative analysis of cardiotoxin-treated muscles from Neu1(-/-) mice and Neu1(+/+) mice showed increased inflammatory and proliferative responses in the absence of Neu1 during the early stages of muscle regeneration. This was accompanied by significant and sequential upregulation of Pax7, MyoD, and myogenin mRNAs. The levels of both MyoD and myogenin proteins decreased during the late stages of regeneration, which most likely reflected an increased rate of degradation of the myogenic factors in the Neu1(-/-) muscle. We also observed a delay in muscle cell differentiation, which was characterized by prolonged expression of embryonic myosin heavy chain, as well as reduced myofiber cross-sectional area. At the end of the regenerative process, collagen type III deposition was increased compared to wild-type muscles and internal controls, indicating the initiation of fibrosis. Overall, these results point to a role of Neu1 throughout muscle regeneration.
- Clinical aspects of patients with sarcoglycanopathies under steroids therapy(2014) ALBUQUERQUE, Marco A. V.; ABATH-NETO, Osorio; MAXIMINO, Jessica R.; CHADI, Gerson; ZANOTELI, Edmar; REED, Umbertina C.Patients with sarcoglycanopathies, which comprise four subtypes of autosomal recessive limb-girdle muscular dystrophies, usually present with progressive weakness leading to early loss of ambulation and premature death, and no effective treatment is currently available. Objective: To present clinical aspects and outcomes of six children with sarcoglycanopathies treated with steroids for at least one year. Method: Patient files were retrospectively analyzed for steroid use. Results: Stabilization of muscle strength was noted in one patient, a slight improvement in two, and a slight worsening in three. In addition, variable responses of forced vital capacity and cardiac function were observed. Conclusions: No overt clinical improvement was observed in patients with sarcoglycanopathies under steroid therapy. Prospective controlled studies including a larger number of patients are necessary to determine the effects of steroids for sarcoglycanopathies.
- Effects of Lidocaine, Bupivacaine, and Ropivacaine on Calcitonin Gene-Related Peptide and Substance P Levels in the Incised Rat Skin(2016) LAPIN, Guilherme A. F.; HOCHMAN, Bernardo; MAXIMINO, Jessica R.; CHADI, Gerson; FERREIRA, Lydia M.OBJECTIVE: To evaluate the effect of 2% lidocaine, 0.5% bupivacaine, and 0.75% ropivacaine on the release of substance P (SP) and calcitonin gene-related peptide (CGRP) in skin wounds. DESIGN: A primary, experimental, analytical, prospective, self-controlled, blinded study. SETTING: The study is set in a university research center. INTERVENTIONS: Twenty-eight Wistar rats were randomly divided into 4 groups: lidocaine, bupivacaine, ropivacaine, and the control. After general anesthesia, a local anesthetic or 0.9% saline (control) was injected subdermally along a 2-cm line on the dorsal midline of each rat; 30 minutes later, an incision (nociceptive stimulus) was made along this line. The animals were euthanized, and skin samples were collected from the center of the incision line and sent for CGRP and SP quantification. MAIN OUTCOME MEASURES: Quantification of CGRP and SP by Western blotting. RESULTS: Substance P levels were similar in the lidocaine and ropivacaine groups but were significantly lower than those of the control group (P = .002); no significant difference in SP levels was found between the bupivacaine and control groups. Procalcitonin gene-related peptide levels were significantly lower in the experimental groups than those in control subjects (P = .009), with no significant differences among the experimental groups. No significant differences in CGRP levels were found among all groups. Lidocaine and ropivacaine inhibited SP release. All 3 local anesthetics inhibited the release of procalcitonin gene-related peptide, but not the release of CGRP in rat skin. CONCLUSIONS: Lidocaine and ropivacaine may inhibit neurogenic inflammation by biochemical pathways activated by SP, whereas bupivacaine seems to have no influence on this process.
- Motor Recovery and Cortical Plasticity After Functional Electrical Stimulation in a Rat Model of Focal Stroke(2014) CECATTO, Rebeca Boltes; MAXIMINO, Jessica Ruivo; CHADI, GersonObjective: The aim of this study was to investigate the functional responses and plastic cortical changes in a sample of animals with sequelae of cerebral ischemia that were subjected to a model of functional electrical stimulation (FES). Design: Rats received an ischemic cortical lesion (Rose Bengal method) and were randomized and submitted to an FES stimulation (1-2 mA, 30 Hz, 20-40 mins for 14 days) or sham stimulation. The Foot Fault Test was performed before inducing the cortical lesion and also before and after FES. Brain immunochemistry labeling with microtubule-associated protein-2 and neurofilament-200 markers was performed after FES. Results: The authors found a decreased percentage of errors in the Foot Fault Test (P < 0.001) in the stimulated group compared with the sham group after FES. FES has not altered the lesion size. Spontaneous motor parameters returned to basal values in both groups. The qualitative analysis showed an increased amount of radial microtubule-associated protein-2 immunoreactive fibers in the preserved cortex adjacent to stroke site in the stimulated animals. Regarding the measurements of neurofilament-200 immunostaining, there were no differences between the hemispheres or groups in area or intensity. Conclusions: Acute and short period of FES led to motor recovery of ankle joint neurodisability. The extent to which compensatory plasticity occurs after stroke or after FES and the extent to which it contributes to functional recovery are yet unclear. The changes induced by the stimulation may improve the ability of the nervous system to undergo spontaneous recovery, which is of substantial interest for neurorehabilitation strategies.
- A SEVERE PHENOTYPE OF KENNEDY DISEASE ASSOCIATED WITH A VERY LARGE CAG REPEAT EXPANSION(2018) MADEIRA, Joao L. O.; SOUZA, Alexandre B. C.; CUNHA, Flavia S.; BATISTA, Rafael L.; GOMES, Nathalia L.; RODRIGUES, Andresa S.; JORGE, Frederico Mennucci de Haidar; CHADI, Gerson; CALLEGARO, Dagoberto; MENDONCA, Berenice B.; COSTA, Elaine M. F.; DOMENICE, Sorahia
- Periodic limb movements during sleep and restless legs syndrome in patients with ASIA A spinal cord injury(2011) TELLES, Susana C. L.; ALVES, Rosana C.; CHADI, GersonObjective: To establish the occurrence of Periodic Leg Movements (PLM) and Restless Legs Syndrome (RLS) in Spinal Cord Injury (SCI) subjects. Methods: In this study, twenty four patients were submitted to a full night polysomnography and were assessed with Epworth Sleepiness Scale and an adapted form of International Restless Legs Syndrome Scale Rating Scale (IRLS Rating Scale). Control Group (CG) was composed of 16 subjects, 50% of each sex, age: 24.38 +/- 4 years old. Spinal Cord Injury Group (SCIG) was composed of 8 subjects (29 +/- 5 years old) with a complete SCI (ASIA A) of about three and a half years of duration, 100% males. Results: 100% of SCIG had RLS compared to 17% in CG ( p < 0.0001). SCIG had 18.11 +/- 20.07 of PLM index while CG had 5.96 +/- 11.93 (p = 0.01). Arousals related to PLM were recorded in CG and SCIG. There was a positive moderate correlation between RLS and age (r = 0.5; p = 0.01), RLS and PLM (r = 0.49; p = 0.01), adapted IRLS Rating Scale and PLM index (r = 0.64; p = 0.03) and also a negative moderate correlation between Epworth Sleepiness Scale and PLM index (r = -0.4; p = 0.04) in both groups. Conclusion: RLS and PLM are common findings in SCI patients with a complete injury.