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1.
Ann Neurol ; 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38721781

RESUMO

OBJECTIVE: Bradykinesia and rigidity are considered closely related motor signs in Parkinson disease (PD), but recent neurophysiological findings suggest distinct pathophysiological mechanisms. This study aims to examine and compare longitudinal changes in bradykinesia and rigidity in PD patients treated with bilateral subthalamic nucleus deep brain stimulation (STN-DBS). METHODS: In this retrospective cohort study, the clinical progression of appendicular and axial bradykinesia and rigidity was assessed up to 15 years after STN-DBS in the best treatment conditions (ON medication and ON stimulation). The severity of bradykinesia and rigidity was examined using ad hoc composite scores from specific subitems of the Unified Parkinson's Disease Rating Scale motor part (UPDRS-III). Short- and long-term predictors of bradykinesia and rigidity were analyzed through linear regression analysis, considering various preoperative demographic and clinical data, including disease duration and severity, phenotype, motor and cognitive scores (eg, frontal score), and medication. RESULTS: A total of 301 patients were examined before and 1 year after surgery. Among them, 101 and 56 individuals were also evaluated at 10-year and 15-year follow-ups, respectively. Bradykinesia significantly worsened after surgery, especially in appendicular segments (p < 0.001). Conversely, rigidity showed sustained benefit, with unchanged clinical scores compared to preoperative assessment (p > 0.05). Preoperative motor disability (eg, composite scores from the UPDRS-III) predicted short- and long-term outcomes for both bradykinesia and rigidity (p < 0.01). Executive dysfunction was specifically linked to bradykinesia but not to rigidity (p < 0.05). INTERPRETATION: Bradykinesia and rigidity show long-term divergent progression in PD following STN-DBS and are associated with independent clinical factors, supporting the hypothesis of partially distinct pathophysiology. ANN NEUROL 2024.

2.
J Neurointerv Surg ; 16(3): 261-265, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-36927657

RESUMO

BACKGROUND: We report the first case series of spontaneous intracranial hypotension (SIH) patients who underwent CT-guided percutaneous cyanoacrylate injection targeting the cerebrospinal fluid (CSF) leak. METHODS: A retrospective analysis was performed for all consecutive cases of SIH patients with CSF leak confirmed on CT myelography, treated by CT-guided percutaneous cyanoacrylate injection at our institution from 2016 to 2022. On pretreatment brain and spine MRIs, we analyzed signs of SIH according to the Bern score, and dichotomized cases into positive/negative for spinal longitudinal extradural CSF collection (SLEC-P or SLEC-N). The leaks detected on CT myelography were classified into three types according to Schievink et al. We collected the Headache Impact Test 6 (HIT-6) scores throughout a 6-month follow-up, with a brain CT scan at each visit. RESULTS: 11 patients were included (mean age 48.4 years, six men). Five SLEC-P type 1, three SLEC-P type 2, and three SLEC-N type 3 leaks were identified. All patients had significant signs of SIH on pretreatment brain MRI (mean Bern score 7.8±1.1). Six patients underwent a foraminal puncture, and five patients had a cervical epidural approach. Two patients experienced mild and transient locoregional pain after cervical epidural injection. Mean HIT-6 score at baseline was 66.8±3.2 and at the 6-month follow-up was 38±3.6 (P<0.001). All patients achieved improvement in their symptoms, with 82% of them (9/11) having complete resolution of headaches and SIH findings on CT scans at 6 months. No clinical worsening or recurrence was observed. CONCLUSIONS: CT-guided percutaneous cyanoacrylate injection may be a potential therapeutic option for the different types of CSF leak causing SIH.


Assuntos
Hipotensão Intracraniana , Masculino , Humanos , Pessoa de Meia-Idade , Hipotensão Intracraniana/diagnóstico por imagem , Hipotensão Intracraniana/terapia , Cianoacrilatos , Estudos Retrospectivos , Punção Espinal/efeitos adversos , Vazamento de Líquido Cefalorraquidiano/diagnóstico por imagem , Vazamento de Líquido Cefalorraquidiano/terapia , Vazamento de Líquido Cefalorraquidiano/complicações , Imageamento por Ressonância Magnética , Mielografia/efeitos adversos , Tomografia Computadorizada por Raios X
3.
Childs Nerv Syst ; 39(11): 3065-3070, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37668670

RESUMO

We describe the first case of regression of a white epidermoid cyst in a child. White epidermoid cysts are rare benign lesions, particularly in pediatric cases. Typically, these cysts need surgical resection. However, we report the case of a 3-year-old child with recurrent aseptic meningitis, in whom CT scan and MRI revealed a white epidermoid cyst in the pre-bulbar cistern. Surprisingly, over a 5-year follow-up period, the cyst showed dramatic regression without any symptoms. This case sheds light on the potential for spontaneous regression of white epidermoid cysts in children, challenging the need for risky surgical interventions. This report opens up new perspectives on the pathophysiology and management options for this type of lesion in children.


Assuntos
Cisto Epidérmico , Meningite Asséptica , Humanos , Criança , Pré-Escolar , Cisto Epidérmico/diagnóstico por imagem , Cisto Epidérmico/cirurgia , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X
4.
J Struct Biol ; 215(3): 108006, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37507029

RESUMO

Eukaryotic initiation factor 2 (eIF2) plays a key role in protein synthesis and in its regulation. The assembly of this heterotrimeric factor is facilitated by Cdc123, a member of the ATP grasp family that binds the γ subunit of eIF2. Notably, some mutations related to MEHMO syndrome, an X-linked intellectual disability, affect Cdc123-mediated eIF2 assembly. The mechanism of action of Cdc123 is unclear and structural information for the human protein is awaited. Here, the crystallographic structure of human Cdc123 (Hs-Cdc123) bound to domain 3 of human eIF2γ (Hs-eIF2γD3) was determined. The structure shows that the domain 3 of eIF2γ is bound to domain 1 of Cdc123. In addition, the long C-terminal region of Hs-Cdc123 provides a link between the ATP and Hs-eIF2γD3 binding sites. A thermal shift assay shows that ATP is tightly bound to Cdc123 whereas the affinity of ADP is much smaller. Yeast cell viability experiments, western blot analysis and two-hybrid assays show that ATP is important for the function of Hs-Cdc123 in eIF2 assembly. These data and recent findings allow us to propose a refined model to explain the mechanism of action of Cdc123 in eIF2 assembly.


Assuntos
Deficiência Intelectual Ligada ao Cromossomo X , Proteínas de Saccharomyces cerevisiae , Humanos , Trifosfato de Adenosina/metabolismo , Sítios de Ligação , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Fator de Iniciação 2 em Eucariotos/genética , Fator de Iniciação 2 em Eucariotos/química , Fator de Iniciação 2 em Eucariotos/metabolismo , Deficiência Intelectual Ligada ao Cromossomo X/genética , Ligação Proteica , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química
5.
J Neurooncol ; 163(1): 195-205, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37171700

RESUMO

BACKGROUND: The HIT-SKK protocol is used for low/standard-risk medulloblastomas in young children with the aim to eliminate cranial irradiation and its neuropsychological (NP) sequelae. This therapy includes IV and intraventricular (ITV) methotrexate (MTX) potentially responsible for leukoencephalopathy (LE) and neurocognitive disorders. This study describes the risk factors and course of LE, and investigates its correlation with neurocognitive impact. METHODS: A retrospective, multicenter study was conducted in 35 children under 5 years old, with a median follow-up of 72 months (range 14 to 130). The main analysis was performed in 30 patients who received cumulative doses of MTX as per-protocol (group 1). Five patients who received higher cumulative doses of MTX were analyzed separately. All follow-up MRIs and NP assessments were centrally reviewed by experts. RESULTS: Twenty patients in group 1 developed LE, grade 2 and 3 abnormalities did not correlate with higher cumulative doses of ITV-MTX (p = 0.698). Considering the most recent NP evaluation, the Full-Scale IQ (FSIQ) and Wechsler indices were in the average to lower average range. The FSIQ was deficient in 6/17 evaluable patients. Cumulative dose of ITV-MTX was almost associated with decreased processing speed competence (p = 0.055) which was the most frequently impaired neurocognitive domain. Neuropsychological assessment scores were not statistically lower in patients with persistent grade 2 LE at the end of follow-up. CONCLUSION: This study described that the use of cumulative dose of MTX (IV and ITV) according to the HIT-SKK protocol resulted in LE that tented to decrease over time, without significant correlation with a decline in neuro-intellectual skills.


Assuntos
Neoplasias Cerebelares , Leucoencefalopatias , Meduloblastoma , Criança , Humanos , Pré-Escolar , Meduloblastoma/diagnóstico por imagem , Meduloblastoma/tratamento farmacológico , Estudos Retrospectivos , Seguimentos , Metotrexato/efeitos adversos , Neoplasias Cerebelares/tratamento farmacológico , Estudos Multicêntricos como Assunto
6.
J Neurointerv Surg ; 15(10): 1046-1049, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36163345

RESUMO

BACKGROUND: Ruptured basilar artery perforator aneurysms (BAPAs), defined as microaneurysms which develop in basilar perforator arteries without direct involvement of the basilar trunk, represent a rare cause of subarachnoid hemorrhage (SAH). The diagnosis of BAPAs is difficult because of their small size, with high rates of negative angiography. The development of high-resolution MRI could increase the diagnostic performance. In this study we describe the usefulness of susceptibility weighted imaging (SWI) for the diagnosis of ruptured BAPAs. METHODS: In a case series, we retrospectively collected data of patients admitted to our institution from 2018 to 2021 for SAH with negative CT angiography who underwent MRI (including SWI) and DSA during hospitalization. RESULTS: Eight patients with a definitive diagnosis of ruptured BAPA and five patients with a definitive diagnosis of angiogram-negative SAH were included. In all of the patients with BAPAs MRI showed a focal, thick, semi-circumferential SWI hypointensity covering the vessel wall at the level of the BAPA subsequently revealed on DSA; this phenomen is known as 'SWI capping'. No SWI capping was observed in the five patients with a definitive diagnosis of angiogram-negative SAH. CONCLUSION: SWI capping appears to be a reliable indirect sign for the diagnosis and localization of ruptured BAPAs, a rare form of microaneurysm easily misdiagnosed on DSA in initial angiogram-negative SAH.


Assuntos
Aneurisma Roto , Aneurisma Intracraniano , Acidente Vascular Cerebral , Hemorragia Subaracnóidea , Humanos , Hemorragia Subaracnóidea/diagnóstico por imagem , Hemorragia Subaracnóidea/etiologia , Estudos Retrospectivos , Artéria Basilar , Aneurisma Roto/diagnóstico por imagem , Aneurisma Roto/cirurgia , Aneurisma Roto/complicações , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/complicações , Imageamento por Ressonância Magnética , Acidente Vascular Cerebral/complicações , Angiografia Cerebral/métodos
7.
NPJ Parkinsons Dis ; 8(1): 121, 2022 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-36153351

RESUMO

In this retrospective study, we longitudinally analyzed axial impairment and falls in people with Parkinson's disease (PD) and subthalamic nucleus deep brain stimulation (STN-DBS). Axial scores and falling frequency were examined at baseline, and 1, 10, and 15 years after surgery. Preoperative demographic and clinical data, including PD duration and severity, phenotype, motor and cognitive scales, medications, and vascular changes on neuroimaging were examined as possible risk factors through Kaplan-Meier and Cox regression analyses. Of 302 individuals examined before and at 1 year after surgery, 102 and 57 were available also at 10 and 15 years of follow-up, respectively. Axial scores were similar at baseline and at 1 year but worsened at 10 and 15 years. The prevalence rate of frequent fallers progressively increased from baseline to 15 years. Preoperative axial scores, frontal dysfunction and age at PD onset were risk factors for axial impairment progression after surgery. Axial scores, akinetic/rigid phenotype, age at disease onset and disease duration at surgery predicted frequent falls. Overall, axial signs progressively worsened over the long-term period following STN-DBS, likely related to the progression of PD, especially in a subgroup of subjects with specific risk factors.

8.
Front Hum Neurosci ; 16: 931858, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35799771

RESUMO

Background: In Parkinson's disease (PD), the side of motor symptoms onset may influence disease progression, with a faster motor symptom progression in patients with left side lateralization. Moreover, worse neuropsychological outcomes after subthalamic nucleus deep brain stimulation (STN-DBS) have been described in patients with predominantly left-sided motor symptoms. The objective of this study was to evaluate if the body side of motor symptoms onset may predict motor outcome of bilateral STN-DBS. Methods: This retrospective study included all consecutive PD patients treated with bilateral STN-DBS at Grenoble University Hospital from 1993 to 2015. Demographic, clinical and neuroimaging data were collected before (baseline condition) and 1 year after surgery (follow-up condition). The predictive factors of motor outcome at one-year follow-up, measured by the percentage change in the MDS-UPDRS-III score, were evaluated through univariate and multivariate linear regression analysis. Results: A total of 233 patients were included with one-year follow-up after surgery [143 males (61.40%); 121 (51.90 %) right body onset; 112 (48.10%) left body onset; mean age at surgery, 55.31 ± 8.44 years; mean disease duration, 11.61 ± 3.87]. Multivariate linear regression analysis showed that the left side of motor symptoms onset did not predict motor outcome (ß = 0.093, 95% CI = -1.967 to 11.497, p = 0.164). Conclusions: In this retrospective study, the body side of motor symptoms onset did not significantly influence the one-year motor outcome in a large cohort of PD patients treated with bilateral STN-DBS.

9.
Eur J Neurol ; 29(9): 2645-2653, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35666167

RESUMO

BACKGROUND AND PURPOSE: Studies on long-term nonmotor outcomes of subthalamic nucleus stimulation in Parkinson disease (PD) are scarce. This study reports on very long-term non-motor and motor outcomes in one of the largest cohorts of people with advanced PD, treated for >10 years with subthalamic nucleus stimulation. The main outcome was to document the evolution of independence in activities of daily living. The secondary outcomes were to measure the change in quality of life, as well as non-motor and motor outcomes. METHODS: Patients were studied preoperatively, at 1 year, and beyond 10 years after subthalamic stimulation with an established protocol including motor, non-motor, and neuropsychological assessments. RESULTS: Eighty-five people with PD were included. Independence scores in the off-medication condition (measured with the Schwab & England Activities of Daily Living Scale) as well as quality of life (measured with the Parkinson's Disease Questionnaire [PDQ]-37) remained improved at longest follow-up compared to preoperatively (respectively, p < 0.001, p = 0.015). Cognitive scores, measured with the Mattis Dementia Rating Scale, significantly worsened compared to before and 1 year after surgery (p < 0.001), without significant change in depression, measured with the Beck Depression Inventory. Motor fluctuations, dyskinesias, and off dystonia remained improved at longest follow-up (p < 0.001), with a significant reduction in dopaminergic treatment (45%, p < 0.001). CONCLUSIONS: This study highlights the long-term improvement of subthalamic stimulation on independence and quality of life, despite the progression of disease and the occurrence of levodopa-resistant symptoms.


Assuntos
Estimulação Encefálica Profunda , Doença de Parkinson , Atividades Cotidianas , Estimulação Encefálica Profunda/métodos , Seguimentos , Humanos , Doença de Parkinson/complicações , Qualidade de Vida , Resultado do Tratamento
10.
Neurology ; 2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34078713

RESUMO

OBJECTIVE: To evaluate the effects of deep brain stimulation of the subthalamic nucleus (STN-DBS) in Parkinson disease (PD) patients on motor complications beyond 15 years after surgery. METHODS: Data about motor complications, quality of life (QoL), activities of daily living, the UPDRS motor scores, dopaminergic treatment, stimulation parameters, and side effects of STN-DBS were retrospectively retrieved and compared between before surgery, at 1 year and beyond 15 years after bilateral STN-DBS. RESULTS: Fifty-one patients with 17.06 ± 2.18 years STN-DBS follow-up were recruited. Compared to baseline, the time spent with dyskinesia and the time spent in the off state were reduced by 75% (p<0.001) and by 58.7% (p<0.001), respectively. Moreover, dopaminergic drugs were reduced by 50.6% (p<0.001). The PDQL total score, and the emotional function and social function domains improved of 13.8% (p=0.005), 13.6% (p=0.01) and 29.9% (p<0.001), respectively. Few and mostly manageable device-related adverse events were observed during the follow-up. CONCLUSIONS: STN-DBS is still effective beyond 15 years from the intervention, notably with significant improvement in motor complications and stable reduction of dopaminergic drugs. Furthermore, despite the natural continuous progression of PD with worsening of levodopa-resistant motor and non-motor symptoms over the years, STN-DBS patients could maintain an improvement in QoL. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that, for patients with PD, STN-DBS remains effective at treating motor complications 15 years after surgery.

11.
Ann Neurol ; 89(3): 587-597, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33349939

RESUMO

OBJECTIVE: This study was undertaken to identify preoperative predictive factors of long-term motor outcome in a large cohort of consecutive Parkinson disease (PD) patients with bilateral subthalamic nucleus deep brain stimulation (STN-DBS). METHODS: All consecutive PD patients who underwent bilateral STN-DBS at the Grenoble University Hospital (France) from 1993 to 2015 were evaluated before surgery, at 1 year (short-term), and in the long term after surgery. All available demographic variables, neuroimaging data, and clinical characteristics were collected. Preoperative predictors of long-term motor outcome were investigated by performing survival and univariate/multivariate Cox regression analyses. Loss of motor benefit from stimulation in the long term was defined as a reduction of less than 25% in the Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part III scores compared to the baseline off-medication scores. As a secondary objective, potential predictors of short-term motor outcome after STN-DBS were assessed by performing univariate and multivariate linear regression analyses. RESULTS: In the long-term analyses (mean follow-up = 8.4 ± 6.26 years, median = 10 years, range = 1-17 years), 138 patients were included. Preoperative higher frontal score and off-medication MDS-UPDRS part III scores predicted a better long-term motor response to stimulation, whereas the presence of vascular changes on neuroimaging predicted a worse motor outcome. In 357 patients with available 1-year follow-up, preoperative levodopa response, tremor dominant phenotype, baseline frontal score, and off-medication MDS-UPDRS part III scores predicted the short-term motor outcome. INTERPRETATION: Frontal lobe dysfunction, disease severity in the off-medication condition, and the presence of vascular changes on neuroimaging represent the main preoperative clinical predictors of long-term motor STN-DBS effects. ANN NEUROL 2021;89:587-597.


Assuntos
Estimulação Encefálica Profunda , Doença de Parkinson/terapia , Núcleo Subtalâmico , Adulto , Idoso , Transtornos Cerebrovasculares/diagnóstico por imagem , Transtornos Cerebrovasculares/epidemiologia , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/psicologia , Função Executiva , Feminino , Seguimentos , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Testes Neuropsicológicos , Doença de Parkinson/epidemiologia , Doença de Parkinson/fisiopatologia , Doença de Parkinson/psicologia , Prognóstico , Modelos de Riscos Proporcionais , Índice de Gravidade de Doença , Resultado do Tratamento
12.
RNA ; 26(11): 1589-1602, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32680846

RESUMO

Cyclodipeptide synthases (CDPSs) catalyze the synthesis of various cyclodipeptides by using two aminoacyl-tRNA (aa-tRNA) substrates in a sequential mechanism. Here, we studied binding of phenylalanyl-tRNAPhe to the CDPS from Candidatus Glomeribacter gigasporarum (Cglo-CDPS) by gel filtration and electrophoretic mobility shift assay. We determined the crystal structure of the Cglo-CDPS:Phe-tRNAPhe complex to 5 Å resolution and further studied it in solution using small-angle X-ray scattering (SAXS). The data show that the major groove of the acceptor stem of the aa-tRNA interacts with the enzyme through the basic ß2 and ß7 strands of CDPSs belonging to the XYP subfamily. A bending of the CCA extremity enables the amino acid moiety to be positioned in the P1 pocket while the terminal A76 adenosine occupies the P2 pocket. Such a positioning indicates that the present structure illustrates the binding of the first aa-tRNA. In cells, CDPSs and the elongation factor EF-Tu share aminoacylated tRNAs as substrates. The present study shows that CDPSs and EF-Tu interact with opposite sides of tRNA. This may explain how CDPSs hijack aa-tRNAs from canonical ribosomal protein synthesis.


Assuntos
Peptídeo Sintases/química , Peptídeo Sintases/metabolismo , Aminoacil-RNA de Transferência/química , Aminoacil-RNA de Transferência/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Burkholderiaceae/efeitos dos fármacos , Burkholderiaceae/genética , Cromatografia em Gel , Cristalografia por Raios X , Ensaio de Desvio de Mobilidade Eletroforética , Modelos Moleculares , Fator Tu de Elongação de Peptídeos/química , Fator Tu de Elongação de Peptídeos/metabolismo , Estrutura Secundária de Proteína , Espalhamento a Baixo Ângulo , Difração de Raios X
13.
PLoS Comput Biol ; 16(1): e1007600, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31917825

RESUMO

Designed enzymes are of fundamental and technological interest. Experimental directed evolution still has significant limitations, and computational approaches are a complementary route. A designed enzyme should satisfy multiple criteria: stability, substrate binding, transition state binding. Such multi-objective design is computationally challenging. Two recent studies used adaptive importance sampling Monte Carlo to redesign proteins for ligand binding. By first flattening the energy landscape of the apo protein, they obtained positive design for the bound state and negative design for the unbound. We have now extended the method to design an enzyme for specific transition state binding, i.e., for its catalytic power. We considered methionyl-tRNA synthetase (MetRS), which attaches methionine (Met) to its cognate tRNA, establishing codon identity. Previously, MetRS and other synthetases have been redesigned by experimental directed evolution to accept noncanonical amino acids as substrates, leading to genetic code expansion. Here, we have redesigned MetRS computationally to bind several ligands: the Met analog azidonorleucine, methionyl-adenylate (MetAMP), and the activated ligands that form the transition state for MetAMP production. Enzyme mutants known to have azidonorleucine activity were recovered by the design calculations, and 17 mutants predicted to bind MetAMP were characterized experimentally and all found to be active. Mutants predicted to have low activation free energies for MetAMP production were found to be active and the predicted reaction rates agreed well with the experimental values. We suggest the present method should become the paradigm for computational enzyme design.


Assuntos
Enzimas , Método de Monte Carlo , Ligação Proteica/genética , Engenharia de Proteínas/métodos , Especificidade por Substrato/genética , Monofosfato de Adenosina/análogos & derivados , Monofosfato de Adenosina/química , Monofosfato de Adenosina/metabolismo , Azidas/química , Azidas/metabolismo , Sítios de Ligação/genética , Catálise , Enzimas/química , Enzimas/genética , Enzimas/metabolismo , Metionina/análogos & derivados , Metionina/química , Metionina/metabolismo , Metionina tRNA Ligase/química , Metionina tRNA Ligase/genética , Metionina tRNA Ligase/metabolismo , Mutação/genética , Norleucina/análogos & derivados , Norleucina/química , Norleucina/metabolismo
14.
J Struct Biol ; 209(2): 107435, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31862305

RESUMO

Polypeptides containing ß-amino acids are attractive tools for the design of novel proteins having unique properties of medical or industrial interest. Incorporation of ß-amino acids in vivo requires the development of efficient aminoacyl-tRNA synthetases specific of these non-canonical amino acids. Here, we have performed a detailed structural and biochemical study of the recognition and use of ß3-Met by Escherichia coli methionyl-tRNA synthetase (MetRS). We show that MetRS binds ß3-Met with a 24-fold lower affinity but catalyzes the esterification of the non-canonical amino acid onto tRNA with a rate lowered by three orders of magnitude. Accurate measurements of the catalytic parameters required careful consideration of the presence of contaminating α-Met in ß3-Met commercial samples. The 1.45 Å crystal structure of the MetRS: ß3-Met complex shows that ß3-Met binds the enzyme essentially like α-Met, but the carboxylate moiety is mobile and not adequately positioned to react with ATP for aminoacyl adenylate formation. This study provides structural and biochemical bases for engineering MetRS with improved ß3-Met aminoacylation capabilities.


Assuntos
Aminoácidos/genética , Escherichia coli/genética , Metionina tRNA Ligase/genética , Metionina/metabolismo , Aminoácidos/química , Sítios de Ligação/genética , Escherichia coli/química , Metionina/química , Metionina tRNA Ligase/química , Conformação Proteica , Especificidade por Substrato
15.
J Struct Biol ; 209(1): 107399, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31586599

RESUMO

G-quadruplexes (G4) are secondary structures of nucleic acids that can form in cells and have diverse biological functions. Several biologically important proteins interact with G-quadruplexes, of which RHAU (or DHX36) - a helicase from the DEAH-box superfamily, was shown to bind and unwind G-quadruplexes efficiently. We report a X-ray co-crystal structure at 1.5 Šresolution of an N-terminal fragment of RHAU bound to an exposed tetrad of a parallel-stranded G-quadruplex. The RHAU peptide folds into an L-shaped α-helix, and binds to a G-quadruplex through π-stacking and electrostatic interactions. X-ray crystal structure of our complex identified key amino acid residues important for G-quadruplex-peptide binding interaction at the 3'-end G•G•G•G tetrad. Together with previous solution and crystal structures of RHAU bound to the 5'-end G•G•G•G and G•G•A•T tetrads, our crystal structure highlights the occurrence of a robust G-quadruplex recognition motif within RHAU that can adapt to different accessible tetrads.


Assuntos
RNA Helicases DEAD-box/ultraestrutura , Proteínas de Ligação a DNA/ultraestrutura , Quadruplex G , Conformação de Ácido Nucleico , Motivos de Aminoácidos/genética , Cristalografia por Raios X , RNA Helicases DEAD-box/química , RNA Helicases DEAD-box/genética , Humanos , Peptídeos/química , Peptídeos/genética , Ligação Proteica/genética , Conformação Proteica em alfa-Hélice/genética
16.
Neurology ; 93(1): e97-e105, 2019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31101738

RESUMO

OBJECTIVE: To determine the postoperative attempted and completed suicide rates after subthalamic nucleus deep brain stimulation (STN-DBS) in a single-center cohort and to determine factors associated with attempted and completed suicide. METHODS: We retrospectively included all patients with Parkinson disease (PD) who underwent bilateral STN-DBS surgery at the Grenoble University Hospital between 1993 and 2016. For each patient who committed or attempted suicide, 2 patients with PD with STN-DBS without any suicidal behaviors were matched for age (±1 year), sex, and year of surgery (±2 years). Clinical data were collected from medical records. Detailed preoperative and postoperative neuropsychological evaluations, including frontal and Beck Depression Inventory (BDI) scores, were gathered. RESULTS: A total of 534 patients with PD were included. Completed and attempted suicide percentages were 0.75% (4 of 534) and 4.11% (22 of 534), respectively. The observed suicide rate in the first postoperative year (187.20 of 100,000 per year, 1 of 534) was higher than the expected National Observatory on Suicide Risks rate adjusted for age and sex (standardized mortality ratio 8.1). This rate remained similar over the second and third postoperative years. In a comparison of the 26 patients completing/attempting suicide and the 52 controls, the first group showed more frequent history of suicidal ideation/suicide attempts and psychotic symptoms, higher percentage of family psychiatric history, higher psychiatric medication use, and higher preoperative frontal and BDI scores on neuropsychological evaluations. CONCLUSIONS: Suicide behaviors can occur after STN-DBS, especially during the first 3 years. A careful multidisciplinary assessment and long-term follow-up are recommended to recognize and treat this potentially preventable risk for mortality.


Assuntos
Estimulação Encefálica Profunda/efeitos adversos , Doença de Parkinson/psicologia , Doença de Parkinson/terapia , Suicídio , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/mortalidade , Complicações Pós-Operatórias/mortalidade , Estudos Retrospectivos , Núcleo Subtalâmico
17.
J Neurointerv Surg ; 11(1): 14-19, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30297541

RESUMO

BACKGROUND: The effectiveness of mechanical thrombectomy (MT) in acute ischemic stroke due to large vessel occlusion is time-dependent. While only stroke centers with endovascular capabilities perform MT, many patients who had a stroke initially present to the closest primary stroke centers capable of administering earlier intravenous thrombolysis, and then require to be transferred to a comprehensive stroke center for MT. PURPOSE: To compare the outcomes of this care pathway (drip and ship (DS)) with that whereby patients are directly transferred to a comprehensive stroke center (mothership (MS)). METHODS: We performed a systematic review and meta-analysis of published studies using several electronic databases to determine whether successful reperfusion (modified Thrombolysis In Cerebral Infarction ≥2b), functional independence at 90 days (modified Rankin Scale score ≤2), symptomatic intracranial hemorrhage, and 90-day mortality differed between those who underwent MT with the DS or the MS treatment pathway. Outcomes were meta-analyzed and the results expressed as adjusted relative risk (aRR) for the primary analysis and unadjusted relative risk (uRR) for secondary analysis. RESULTS: Eight studies including 2068 patients were selected, including one study reporting results fully adjusted for baseline characteristics. Patients undergoing MS had better functional independence than those undergoing DS (uRR=0.87, 95% CI 0.81 to 0.93; aRR=0.87, 95% CI 0.77 to 0.98). No difference was found between the treatment pathways in successful reperfusion (uRR=1.05, 95% CI 0.95 to 1.15; aRR=1.00, 95% CI 0.92 to 1.10), symptomatic intracranial hemorrhage (uRR=1.37, 95% CI 0.91 to 2.06; aRR, 1.53, 95% CI 0.79 to 2.98), and 90-day mortality (uRR=1.00, 95% CI 0.84 to 1.19; aRR=1.21, 95% CI 0.89 to 1.64). CONCLUSIONS: Patients who had an acute ischemic stroke admitted directly to a comprehensive stroke center (MS patients) with endovascular capacities may have better 90-day outcomes than those receiving DS treatment. However, major limitations of current evidence (ie, retrospective studies and selection bias) suggest a need for adequately powered studies. Multicenter randomized controlled trials are expected to answer this question.


Assuntos
Isquemia Encefálica/terapia , Fibrinolíticos/administração & dosagem , Acidente Vascular Cerebral/terapia , Trombectomia/métodos , Administração Intravenosa , Idoso , Isquemia Encefálica/diagnóstico , Infarto Cerebral/diagnóstico , Infarto Cerebral/terapia , Feminino , Humanos , Hemorragias Intracranianas/diagnóstico , Hemorragias Intracranianas/terapia , Pessoa de Meia-Idade , Reperfusão/métodos , Reperfusão/tendências , Estudos Retrospectivos , Acidente Vascular Cerebral/diagnóstico , Trombectomia/tendências , Resultado do Tratamento
18.
EMBO J ; 37(13)2018 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-29844016

RESUMO

The Arp2/3 complex generates branched actin networks that exert pushing forces onto different cellular membranes. WASH complexes activate Arp2/3 complexes at the surface of endosomes and thereby fission transport intermediates containing endocytosed receptors, such as α5ß1 integrins. How WASH complexes are assembled in the cell is unknown. Here, we identify the small coiled-coil protein HSBP1 as a factor that specifically promotes the assembly of a ternary complex composed of CCDC53, WASH, and FAM21 by dissociating the CCDC53 homotrimeric precursor. HSBP1 operates at the centrosome, which concentrates the building blocks. HSBP1 depletion in human cancer cell lines and in Dictyostelium amoebae phenocopies WASH depletion, suggesting a critical role of the ternary WASH complex for WASH functions. HSBP1 is required for the development of focal adhesions and of cell polarity. These defects impair the migration and invasion of tumor cells. Overexpression of HSBP1 in breast tumors is associated with increased levels of WASH complexes and with poor prognosis for patients.


Assuntos
Centrossomo/metabolismo , Proteínas de Choque Térmico/metabolismo , Proteínas dos Microfilamentos/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proteínas de Choque Térmico/química , Proteínas de Choque Térmico/genética , Humanos , Modelos Moleculares , Prognóstico
19.
J Neurol Neurosurg Psychiatry ; 89(8): 836-843, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29436490

RESUMO

BACKGROUND: Reports on behavioural outcomes after subthalamic nucleus deep brain stimulation in Parkinson's disease are controversial and limited to short-term data. Long-term observation in a large cohort allows a better counselling and management. METHODS: To determine whether a long-term treatment with subthalamic stimulation induces or reduces impulse control behaviours, neuropsychiatric fluctuations and apathy, 69 patients treated with subthalamic stimulation are prospectively and retrospectively assessed using Ardouin Scale of Behavior in Parkinson's Disease before and after 3-10 years of stimulation. RESULTS: At a mean follow-up of 6 years, all impulse control disorders and dopaminergic addiction were significantly decreased, apart from eating behaviour and hypersexuality. Neuropsychiatric fluctuations also significantly improved (ON euphoria: 38% of the patients before surgery and 1% after surgery, P<0.01; OFF dysphoria: 39% of the patients before surgery and 10% after surgery, P<0.01). However, apathy increased (25% of the patients after surgery and 3% before, P<0.01). With the retrospective analysis, several transient episodes of depression, apathy, anxiety and impulse control disorders occurred. CONCLUSIONS: Bilateral subthalamic nucleus stimulation was overall very effective in improving impulse control disorders and neuropsychiatric fluctuations in parkinsonian patients in the long term despite a counteracting frequent apathy. Transient episodes of impulse control disorders still occurred within the follow-up. These findings recommend a close follow-up in parkinsonian patients presenting with neuropsychiatric symptoms before deep brain stimulation surgery. CLINICAL TRIAL REGISTRATION: NCT01705418;Post-results.


Assuntos
Cognição/fisiologia , Estimulação Encefálica Profunda , Doença de Parkinson/terapia , Núcleo Subtalâmico/fisiopatologia , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Doença de Parkinson/fisiopatologia , Doença de Parkinson/psicologia , Estudos Retrospectivos , Resultado do Tratamento
20.
Oper Neurosurg (Hagerstown) ; 14(1): 1-8, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29117337

RESUMO

BACKGROUND: The exploration of the insula in pre-surgical evaluation of epilepsy is considered to be associated with a high vascular risk resulting in an incomplete exploration of the insular cortex. OBJECTIVE: To report a retrospective observational study of insular exploration using stereoelectroencephalography (sEEG) with transopercular and parasagittal oblique intracerebral electrodes from January 2008 to January 2016. The first purpose of this study was to evaluate the surgical risks of insular cortex sEEG exploration. The second purpose was to define the ability of placing intracerebral contacts in the whole insular cortex. METHODS: Ninety-nine patients underwent 108 magnetic resonance imaging (MRI)-guided stereotactic implantations of intracerebral electrodes in the context of preoperative assessment of drug-resistant epilepsy, including at least 1 electrode placed in the insular cortex. On postoperative computed tomography images co-registered with MRI, followed by MRI segmentation and application of a transformation matrix, intracerebral contact coordinates of the insular electrodes' contacts were anatomically localized in the Talairach space. Finally, dispersion and clustering analysis was performed. RESULTS: There was no morbidity, in particular hemorrhagic complications, or mortality related to insular electrodes. Statistical comparison of intracerebral contact positions demonstrated that whole insula exploration is possible on the left and right sides. In addition, the clustering analysis showed the homogeneous distribution of the electrodes within the insular cortex. CONCLUSION: In the presurgical evaluation of drug-resistant epilepsy, the insular cortex can be explored safely and comprehensively using transopercular sEEG electrodes. Parasagittal oblique trajectories may also be associated to achieve an optimal exploration.


Assuntos
Córtex Cerebral/cirurgia , Epilepsia Resistente a Medicamentos/terapia , Eletrodos Implantados , Eletroencefalografia/métodos , Neuronavegação/métodos , Adolescente , Adulto , Criança , Epilepsia Resistente a Medicamentos/cirurgia , Eletroencefalografia/instrumentação , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Cuidados Pré-Operatórios , Estudos Retrospectivos , Adulto Jovem
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