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OBJECTIVE: To evaluate the safety and clinical outcome of biological therapies in patients with large vessel vasculitis (LVV) or polymyalgia rheumatica (PMR) refractory to standard of care therapy in a real-life setting in Germany. METHODS: GRAID 2 (German Registry in Autoimmune Diseases 2) is a retrospective, noninterventional, multicenter registry collecting data from all patients with inflammatory rheumatic diseases refractory to conventional therapy treated with an initial off-label biological between August 2006 and December 2013. The retrospective documentation comprised case history, diagnosis, course of disease including safety and overall efficacy. RESULTS: Data from 14 patients were collected, 11 with LVV (78.6%) and 3 with isolated PMR (21.4%). Ten patients were treated with tocilizumab (71.4%), while 3 patients received infliximab infusions (21.4%) and 1 patient was treated with rituximab (7.1%). All clinical as well as laboratory efficacy parameters improved substantially. After the first application, tolerability of biologicals was assessed as "very good"/"good" by the physicians in 92.3% of the patients. Altogether, 8 adverse events (AEs) occurred in 4 patients including 3 infections (1 urogenital infection, 2 diverticulitis) representing a rate of 23.6 infections per 100 patient-years. One of these infections (diverticulitis under infliximab treatment) was rated as serious AE, requiring ICU treatment representing a rate of serious AEs of 7.9 per 100 patient-years. No deaths occurred during the observation period. CONCLUSION: With known limitations of a retrospective database, the results of this survey confirm data of smaller case series and proof-of-concept studies and suggest a substantial response to biological therapies in patients with otherwise refractory LVV or PMR with no new safety signals.
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Uso Fuera de lo Indicado , Polimialgia Reumática , Terapia Biológica , Alemania , Humanos , Polimialgia Reumática/tratamiento farmacológico , Sistema de Registros , Estudios RetrospectivosRESUMEN
Needlefishes (Beloniformes) were observed employing a range of stalking and attacking behaviours to attack schools of bait fishes ranging from the use of tactics common to predatory fishes to a novel behaviour: the use of leaping, aerial attacks. These aerial attacks are suggested to serve two purposes: to extend the attack range of the needlefishes and to reduce their prey's potential for evasion. Furthermore, a third purpose is hypothesized that the needlefishes are taking advantage of Snell's Window, an optical effect which may mask their approach to their prey.
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Beloniformes/fisiología , Fenómenos Ópticos , Conducta Predatoria , Animales , NataciónRESUMEN
A novel lithium-oxygen battery exploiting PYR14TFSI-LiTFSI as ionic liquid-based electrolyte medium is reported. The Li/PYR14TFSI-LiTFSI/O2 battery was fully characterized by electrochemical impedance spectroscopy, capacity-limited cycling, field emission scanning electron microscopy, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. The results of this extensive study demonstrate that this new Li/O2 cell is characterized by a stable electrode-electrolyte interface and a highly reversible charge-discharge cycling behavior. Most remarkably, the charge process (oxygen oxidation reaction) is characterized by a very low overvoltage, enhancing the energy efficiency to 82%, thus, addressing one of the most critical issues preventing the practical application of lithium-oxygen batteries.
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Cancer is a disease caused by DNA mutations. Cancer therapies targeting defined functional mutations have shown clinical benefit. However, as 95% of the mutations in a tumour are unique to that single patient and only a small number of mutations are shared between patients, the addressed medical need is modest. A rapidly determined patient-specific tumour mutation pattern combined with a flexible mutation-targeting drug platform could generate a mutation-targeting individualised therapy, which would benefit each single patient. Next-generation sequencing enables the rapid identification of somatic mutations in individual tumours (the mutanome). Immunoinformatics enables predictions of mutation immunogenicity. Mutation-targeting RNA-based vaccines can be rapidly and affordably synthesised as custom GMP drug products. Integration of these cutting-edge technologies into a clinically applicable process holds the promise of a disruptive innovation benefiting cancer patients. Here, we describe our translation of the individualised RNA-based cancer vaccine concept into clinic trials.
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Vacunas contra el Cáncer/genética , Medicina de Precisión , ARN Neoplásico/genética , Investigación Biomédica Traslacional , Evaluación Preclínica de Medicamentos , Humanos , MutaciónRESUMEN
BACKGROUND: Intravenous thrombolysis with alteplase for ischemic stroke is fixed at a maximal dose of 90 mg for safety reasons. Little is known about the clinical outcomes of stroke patients weighing >100 kg, who may benefit less from thrombolysis due to this dose limitation. METHODS: Prospective data on 1,479 consecutive stroke patients treated with intravenous alteplase in six Swiss stroke units were analyzed. Presenting characteristics and the frequency of favorable outcomes, defined as a modified Rankin scale (mRS) score of 0 or 1, a good outcome (mRS score 0-2), mortality and symptomatic intracranial hemorrhage (SICH) were compared between patients weighing >100 kg and those weighing ≤100 kg. RESULTS: Compared to their counterparts (n = 1,384, mean body weight 73 kg), patients weighing >100 kg (n = 95, mean body weight 108 kg) were younger (61 vs. 67 years, p < 0.001), were more frequently males (83 vs. 60%, p < 0.001) and more frequently suffered from diabetes mellitus (30 vs. 13%, p < 0.001). As compared with patients weighing ≤100 kg, patients weighing >100 kg had similar rates of favorable outcomes (45 vs. 48%, p = 0.656), good outcomes (58 vs. 64%, p = 0.270) and mortality (17 vs. 12%, p = 0.196), and SICH risk (1 vs. 5%, p = 0.182). After multivariable adjustment, body weight >100 kg was strongly associated with mortality (p = 0.007) and poor outcome (p = 0.007). CONCLUSION: Our data do not suggest a reduced likehood of favorable outcomes in patients weighing >100 kg treated with the current dose regimen. The association of body weight >100 kg with mortality and poor outcome, however, demands further large-scale studies to replicate our findings and to explore the underlying mechanisms.
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Peso Corporal , Fibrinolíticos/administración & dosificación , Obesidad/complicaciones , Accidente Cerebrovascular/tratamiento farmacológico , Terapia Trombolítica , Activador de Tejido Plasminógeno/administración & dosificación , Anciano , Distribución de Chi-Cuadrado , Femenino , Fibrinolíticos/efectos adversos , Humanos , Infusiones Intravenosas , Modelos Logísticos , Masculino , Persona de Mediana Edad , Obesidad/diagnóstico , Obesidad/mortalidad , Oportunidad Relativa , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/mortalidad , Suiza , Terapia Trombolítica/efectos adversos , Terapia Trombolítica/mortalidad , Activador de Tejido Plasminógeno/efectos adversos , Resultado del TratamientoRESUMEN
This study describes two bioanalytical methods for the quantitation of the two methadone enantiomers in dried matrix spots using high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) and high performance supercritical chromatography tandem mass spectrometry (HPSFC-MS/MS). Dried matrix spots were obtained by spotting 10 µL of each sample fluid on a Whatman paper. Methadone and its main metabolite, EDDP, were extracted with 100 µL methanol and subsequently injected into the LC-MS/MS and SFC-MS/MS systems. Enantiomeric separation was achieved with AGP-column for the LC conditions and with Chiralpak IH-3 in SFC. The two methods were fully validated and 93 post-mortem samples were analysed with both analytical methods. Results from validation parameters and results obtained for all post-mortem samples were compared with a significant spearman correlation of rs = 0.9978 for R-methadone and rs = 0.9981 for S-methadone. The LC method provided better results in terms of uncertainty, retention factor and resolution, whereas SFC provides better sensitivity, with lower LOD. Median R-/S-methadone ratio in peripheral blood was found equal to 1.60 (N = 32), varying from 0.79 to 4.23. The reported values were in good agreement with previously published results. Based on the results obtained here, SFC-MS/MS can be considered a reliable alternative to the widely used LC-MS/MS for the quantitation of methadone enantiomers in bioanalysis and should be evaluated for other bioanalytical methods. Both methods can be easily and quickly used in toxicological routine analysis for the methadone quantitation in human fluids matrices, even if considering that the polysaccharide coated column IH-3 used in SFC does not allow the enantiomeric EDDP separation.
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Cromatografía Liquida/métodos , Cromatografía con Fluido Supercrítico/métodos , Pruebas con Sangre Seca/métodos , Metadona , Espectrometría de Masas en Tándem/métodos , Toxicología Forense/métodos , Humanos , Límite de Detección , Modelos Lineales , Metadona/sangre , Metadona/química , Reproducibilidad de los Resultados , EstereoisomerismoRESUMEN
The paper describes the first three deaths reported in Europe involved in isotonitazene consumption, a potent benzimidazole derivate opioid consumed in the recreational drug scene. Isotonitazene powder and purity determination was performed on the sample collected in the first death scene by NMR, HRMS, GC-FTIR, ATR-FTIR and GC-MS. Isotonitazene purity was determined by GC-MS analysis and proton NMR, and was defined to be above 95 % and 98 %, respectively. Quantification of isotonitazene in biological samples was performed using a targeted analysis based on SPE extraction and ultra-high performance liquid chromatography tandem mass spectrometry. The isotonitazene median concentration in femoral whole blood was 1.20ng/mL. Isotonitazene concentration in hair was similar or even lower compared to that seen in fentanyl abusers. Isotonitazene distribution in tissues converges in the brain, lungs and heart, respectively. Surprisingly, isotonitazene concentration in liver is the lowest measured for all tissues and fluids analyzed. Based on circumstantial evidence, autopsy findings and the results of the toxicological analysis, the medical examiner concluded that the cause of all three deaths was an acute intoxication with isotonitazene. Since isotonitazene toxic concentration levels are very low, the consumption of this new psychoactive drug is a real hazard for human health.
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Bencimidazoles/envenenamiento , Sobredosis de Droga , Psicotrópicos/envenenamiento , Bencimidazoles/análisis , Cromatografía Liquida , Cromatografía de Gases y Espectrometría de Masas , Humanos , Espectroscopía de Resonancia Magnética , Masculino , Psicotrópicos/análisis , Espectroscopía Infrarroja por Transformada de Fourier , Trastornos Relacionados con Sustancias , Suiza , Espectrometría de Masas en Tándem , Distribución TisularRESUMEN
The measured voltage derivative of the nonlinear resistance of tiny point contacts can be separated into a phonon-emission effect (alpha(2)F) and an analytic functional form (background effect). The alpha(2)F's show structure coincident with bulk phonon densities of states. Values of the integral of 2 alpha(2)F/omega are closely related to literature values. The background effect is related to the impurity concentration of the materials.
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BACKGROUND: In ambulatory stroke survivors, outdoor walking is important for participation, so adapting to heightened levels (e.g. curbs) is essential. This needs precise step regulation and foot positioning and has to be achieved despite impaired balance and motor regulation. RESEARCH QUESTION: How do stroke patients approach and cross elevated surfaces? METHODS: Gait of 12 hemiparetic stroke patients (62.8 ± 10.3 years; Functional Ambulatory Category 3-5) and 13 controls (60.0 ± 12.4 years) was compared using a sensor carpet and 3D motion capturing to collect tempo-spatial parameters and foot trajectories in two conditions: flat walking vs. approaching to and stepping onto an elevated surface (height 15 cm) in a self-selected manner (6 trials each). Tempo-spatial adaptations were normalized to flat walking while trajectory analysis focused on foot clearance and placement. Complementary assessments included the Dynamic-Gait-Index, the Berg-Balance-Test and the Falls Efficacy Scale. RESULTS: Patients showed significantly worse Dynamic-Gait-Indices, less balance and more fear of falling. During the approach phase, patients slowed down, partly accompanied by shorter steps which controls did not. During crossing, no preference for a specific leading leg was detected. Clearance of the leading leg on average was not reduced but patients landed closer to the edge. Still clearance of the paretic leg was less than that of the non-paretic leg and the minimal clearance across all trials suggested an increased tripping risk, most evident for the trailing leg. In particular slower approaching caused difficulties to ensure sufficient leg clearance and to place the foot safely. Independent from that, better balance correlated with safer clearance. SIGNIFICANCE: When managing elevated levels, leading with the paretic leg causes more difficulties to safely clear the legs which is considerably dependent upon speed. Therapists should consider that slow walking may not increase safety while faster gait and aspects of postural control potentially facilitate crossing a curb.
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Adaptación Fisiológica , Trastornos Neurológicos de la Marcha/fisiopatología , Paresia/fisiopatología , Accidente Cerebrovascular/fisiopatología , Accidentes por Caídas , Anciano , Fenómenos Biomecánicos , Estudios de Casos y Controles , Femenino , Pie , Análisis de la Marcha , Trastornos Neurológicos de la Marcha/etiología , Humanos , Masculino , Persona de Mediana Edad , Paresia/etiología , Equilibrio Postural/fisiología , Análisis Espacio-Temporal , Accidente Cerebrovascular/complicacionesRESUMEN
During the process of chromatin diminution in Ascaris suum (formerly named Ascaris lumbricoides var. suum), developmentally regulated chromosomal fragmentation and new telomere addition occur within specific chromosomal breakage regions (CBRs). The DNA sequences flanking one of these CBRs (CBR-1) were analyzed, and two protein-encoding genes were found on either side. The noneliminated gene, agp-1, whose AUG start codon is located within approximately 2 kb of the boundary of CBR-1, encodes a putative GTP-binding protein which is structurally related to eukaryotic and prokaryotic elongation factors. Northern (RNA) blot analyses revealed that transcripts of this gene are present at all developmental stages, suggesting that the massive chromosomal rearrangements associated with the process of chromatin diminution have no influence on agp-1 expression. This demonstrates that addition of new telomeres in CBR-1 does not result in a telomeric position effect, a phenomenon previously described in Saccharomyces cerevisiae.
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Ascaris suum/genética , Genes de Helminto , Telómero/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Caenorhabditis elegans/genética , Cartilla de ADN/genética , ADN Complementario/genética , ADN de Helmintos/genética , Femenino , Datos de Secuencia Molecular , Saccharomyces cerevisiae/genética , Especificidad de la EspecieRESUMEN
Dogs with osteosarcoma provide an important model for the same disease in humans. In this report, the comparative nature of human and canine osteosarcoma including incidence and risk factors, clinical presentation and diagnosis, genetic abnormalities, biologic behaviour and prognostic factors, as well as treatment options are reviewed.
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Neoplasias Óseas/patología , Neoplasias Óseas/veterinaria , Enfermedades de los Perros/patología , Osteosarcoma/patología , Osteosarcoma/veterinaria , Animales , Neoplasias Óseas/genética , Neoplasias Óseas/terapia , Modelos Animales de Enfermedad , Enfermedades de los Perros/genética , Enfermedades de los Perros/terapia , Perros , Humanos , Osteosarcoma/genética , Osteosarcoma/terapiaRESUMEN
Deletions of chromosome 6q have been reported in several hematological malignancies, but data are not conclusive regarding their biological and prognostic impact. Therefore, we focused on pediatric patients diagnosed with T-cell lymphoblastic lymphoma (T-LBL) treated uniformly according to the NHL-BFM95 protocol. We used loss-of-heterozygosity (LOH) analysis of 25 microsatellite markers located on chromosome 6q14-q24. Fragment-length analysis was performed on ABI-PRISM3100 Genetic-Analyzer. Eligibility criterion was > or =3 informative markers. Between April 1995 and March 2003, 185 T-LBL patients were treated according to the NHL-BFM95 protocol. Five-year event-free (EFS) and disease-free survival (DFS) were 79+/-3 and 87+/-3% (median follow-up 4.7 [1.2-10.1] years). Sixty-one patients were evaluable for LOH analysis, including 18 out of 23 patients with relapse. EFS and DFS were 67+/-6 and 69+/-6% for these 61 patients. Testing of 853 markers in the 61 patients identified the presence of LOH in 19 patients (31%): 13 of the 18 relapse patients and five of the 41 in complete remission (odds ratio 18.7, 95% confidence interval 4.7-75.3). One LOH-positive patient died from treatment-related toxicity. We conclude that LOH on chromosome 6q14-q24 may have conferred a high risk of relapse on our group of children with T-LBL treated according to the NHL-BFM95 protocol.
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Cromosomas Humanos Par 6 , Leucemia-Linfoma de Células T del Adulto/genética , Pérdida de Heterocigocidad , Adolescente , Niño , Supervivencia sin Enfermedad , Femenino , Humanos , Leucemia-Linfoma de Células T del Adulto/mortalidad , MasculinoRESUMEN
Lysergic acid diethylamide (LSD) induces profound changes in various mental domains, including perception, self-awareness and emotions. We used functional magnetic resonance imaging (fMRI) to investigate the acute effects of LSD on the neural substrate of emotional processing in humans. Using a double-blind, randomised, cross-over study design, placebo or 100 µg LSD were orally administered to 20 healthy subjects before the fMRI scan, taking into account the subjective and pharmacological peak effects of LSD. The plasma levels of LSD were determined immediately before and after the scan. The study (including the a priori-defined study end point) was registered at ClinicalTrials.gov before study start (NCT02308969). The administration of LSD reduced reactivity of the left amygdala and the right medial prefrontal cortex relative to placebo during the presentation of fearful faces (P<0.05, family-wise error). Notably, there was a significant negative correlation between LSD-induced amygdala response to fearful stimuli and the LSD-induced subjective drug effects (P<0.05). These data suggest that acute administration of LSD modulates the engagement of brain regions that mediate emotional processing.
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Amígdala del Cerebelo/efectos de los fármacos , Miedo/psicología , Alucinógenos/efectos adversos , Dietilamida del Ácido Lisérgico/efectos adversos , Adulto , Amígdala del Cerebelo/diagnóstico por imagen , Concienciación/efectos de los fármacos , Encéfalo/diagnóstico por imagen , Encéfalo/efectos de los fármacos , Estudios Cruzados , Método Doble Ciego , Emociones/efectos de los fármacos , Miedo/fisiología , Femenino , Alucinógenos/sangre , Voluntarios Sanos , Humanos , Dietilamida del Ácido Lisérgico/administración & dosificación , Dietilamida del Ácido Lisérgico/sangre , Dietilamida del Ácido Lisérgico/farmacología , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Percepción/efectos de los fármacos , Corteza Prefrontal/diagnóstico por imagen , Corteza Prefrontal/efectos de los fármacosRESUMEN
BACKGROUND: The ribosome--essential for protein synthesis in all organisms--has been an evasive target for structural studies. The best available structures for the 70S Escherichia coli ribosome or its 30S and 50S subunits are based on electron microscopical tilt experiments and are limited in resolution to 28-55 A. The angular reconstitution approach, which exploits the random orientations of particles within a vitreous ice matrix, can be used in conjunction with cryo-electron microscopy to yield a higher-resolution structure. RESULTS: Our 23 A resolution map of the 70S ribosome elucidates many structural details, such as an extensive system of channels within the 50S subunit and an intersubunit gap ideally shaped to accommodate two transfer RNA molecules. The resolution achieved is sufficient to allow the preliminary fitting of double-helical regions of an earlier three-dimensional ribosomal RNA model. CONCLUSIONS: Although we are still a long way from attaining an atomic-resolution structure of the ribosome, cryo-electron microscopy, in combination with angular reconstitution, is likely to yield three-dimensional maps with gradually increasing resolution. As exemplified by our current 23 A reconstruction, these maps will lead to progressive refinement of models of the ribosomal RNA.
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Escherichia coli/ultraestructura , Modelos Estructurales , ARN Ribosómico/ultraestructura , Ribosomas/ultraestructura , Congelación , Microscopía Electrónica , ARN Ribosómico/química , Difracción de Rayos XRESUMEN
BACKGROUND: In recent years, the three-dimensional structure of the ribosome has been visualised in different functional states by single-particle cryo-electron microscopy (cryo-EM) at 13-25 A resolution. Even more recently, X-ray crystallography has achieved resolution levels better than 10 A for the ribosomal structures of thermophilic and halophilic organisms. We present here the 7.5 A solution structure of the 50S large subunit of the Escherichia coli ribosome, as determined by cryo-EM and angular reconstitution. RESULTS: The reconstruction reveals a host of new details including the long alpha helix connecting the N- and C-terminal domains of the L9 protein, which is found wrapped like a collar around the base of the L1 stalk. A second L7/L12 dimer is now visible below the classical L7/L12 'stalk', thus revealing the position of the entire L8 complex. Extensive conformational changes occur in the 50S subunit upon 30S binding; for example, the L9 protein moves by some 50 A. Various rRNA stem-loops are found to be involved in subunit binding: helix h38, located in the A-site finger; h69, on the rim of the peptidyl transferase centre cleft; and h34, in the principal interface protrusion. CONCLUSIONS: Single-particle cryo-EM is rapidly evolving towards the resolution levels required for the direct atomic interpretation of the structure of the ribosome. Structural details such as the minor and major grooves in rRNA double helices and alpha helices of the ribosomal proteins can already be visualised directly in cryo-EM reconstructions of ribosomes frozen in different functional states.
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Escherichia coli/ultraestructura , Proteínas Ribosómicas/química , Proteínas Ribosómicas/ultraestructura , Ribosomas/ultraestructura , Proteínas Bacterianas/química , Proteínas Bacterianas/ultraestructura , Microscopía por Crioelectrón/métodos , Procesamiento de Imagen Asistido por Computador , Modelos Moleculares , Factor Tu de Elongación Peptídica/química , Factor Tu de Elongación Peptídica/ultraestructura , Conformación Proteica , Estructura Secundaria de ProteínaRESUMEN
Background: Arthrosonography has proven to be more sensitive and reliable for the detection of synovitis than clinical examination, but a comprehensive examination of small joints is time-consuming. The automated breast volume scanner (ABVS) has been developed to allow automatic and reproducible series of consecutive B-mode pictures of the female breast. Objectives: To analyze the comparability of ABVS and conventional manual ultrasonography (mUS) for the detection of synovitis in hands and feet of patients with rheumatoid arthritis (RA). Methods: 45 patients with early and established active rheumatoid arthritis were recruited for this trial. All subjects were assessed clinically and by manual (Esaote MyLab70) and automated ultrasound (ACUSON S2000™ ABVS). The wrists, the metacarpophalangeal and proximal interphalangeal joints of the hands and the metatarsophalangeal joints of the feet were examined. Results: A total of 2 340 joint aspects were examined with both methods. ABVS detected 291 grade 1, 124 grade 2, 100 grade 3 cases of synovitis (515 in total) compared to 267, 180 and 145 cases of synovitis (592 in total) with mUS. 242 erosions and 52 cases of tenosynovitis were found by ABVS compared to 244 erosions and 99 cases of tenosynovitis found by mUS. Kappa coefficients for the agreement between both methods ranged from 0.51 in PIP joints to 0.71 in MCP joints. The correlations with clinical parameters as well as interrater agreements were comparable for both ultrasound methods. Conclusion: Based on the results, ABVS seems to be a promising technology for the comprehensive and time-saving assessment of synovitis in RA.
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MDMA ("ecstasy") is widely used as a recreational drug, although there has been some debate about its neurotoxic effects in humans. However, most studies have investigated subjects with heavy use patterns, and the effects of transient MDMA use are unclear. In this review, we therefore focus on subjects with moderate use patterns, in order to assess the evidence for harmful effects. We searched for studies applying neuroimaging techniques in man. Studies were included if they provided at least one group with an average of <50 lifetime episodes of ecstasy use or an average lifetime consumption of <100 ecstasy tablets. All studies published before July 2015 were included. Of the 250 studies identified in the database search, 19 were included. There is no convincing evidence that moderate MDMA use is associated with structural or functional brain alterations in neuroimaging measures. The lack of significant results was associated with high methodological heterogeneity in terms of dosages and co-consumption of other drugs, low quality of studies and small sample sizes.
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Trastornos Relacionados con Anfetaminas/tratamiento farmacológico , Encéfalo/efectos de los fármacos , Alucinógenos/farmacología , Drogas Ilícitas/farmacología , N-Metil-3,4-metilenodioxianfetamina/farmacología , Neuroimagen , Animales , HumanosRESUMEN
Postural instability is a frequent symptom of patients with idiopathic normal pressure hydrocephalus (iNPH), and might be due to the misperception of body verticality. The objective of this study was to assess the usefulness of the subjective body vertical (SBV) as a potential tool for diagnosing iNPH. Twenty patients with iNPH underwent tests of SBV in the pitch and roll planes before and after cerebrospinal fluid (CSF) drainage. Ten patients with other central gait disorders served as controls and also underwent tests for SBV. Before CSF drainage, patients with iNPH showed an impaired verticality perception in the pitch plane with a significant backward deviation of the SBV as compared to the control group (iNPH: mean ± SD -3.7 ± 3.6°; control group: -0.8 ± 2.2°; t value = -2.30, p t-test = 0.03). After CSF drainage, the SBV of the iNPH patients normalized for the pitch plane (-0.9 ± 1.9°). There was a correlation between the backward deviation of the SBV and the ventricular enlargement of the frontal horns (Evan's index; r = -0.52; p Pearson = 0.02). An even stronger correlation was found with the enlargement of the third ventricle (Thalamus index; r = -0.64; p Pearson = 0.002). The new and clinically relevant finding of this study is that verticality perception of patients with iNPH is primarily impaired the pitch plane, and it improves after CSF drainage. This disturbance in pitch might be due to a bilateral central vestibular dysfunction of the thalamus. Determination of the SBV in pitch promises to increase diagnostic accuracy in the cases of suspected iNPH.
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Hidrocéfalo Normotenso/diagnóstico , Examen Neurológico/métodos , Percepción , Equilibrio Postural , Propiocepción , Accidentes por Caídas , Anciano , Fenómenos Biomecánicos , Derivaciones del Líquido Cefalorraquídeo , Drenaje , Femenino , Trastornos Neurológicos de la Marcha/diagnóstico , Humanos , Hidrocéfalo Normotenso/diagnóstico por imagen , Hidrocéfalo Normotenso/terapia , Masculino , Pruebas Neuropsicológicas , Índice de Severidad de la Enfermedad , Tercer Ventrículo/diagnóstico por imagenRESUMEN
Recently published models of the Escherichia coli 70 S ribosome at 20 A resolution, obtained by cryo-electron microscopy (cryo-EM) combined with computerized image processing techniques, exhibit two features that are directly relevant to the in situ three-dimensional folding of the rRNA molecules. First, at this level of resolution many fine structural details are visible, a number of them having dimensions comparable to those of nucleic acid helices. Second, in reconstructions of ribosomes in the pre- and post-translocational states, density can be seen that corresponds directly to the A and P site tRNAs, and to the P and E site tRNAs, respectively, thus enabling the decoding region on the 30 S subunit to be located rather precisely. Accordingly, we have refined our previous model for the 16 S rRNA, based on biochemical evidence, by fitting it to the cryo-EM contour of ribosomes carrying A and P site tRNAs. For this purpose, the most immediately relevant evidence consists of new site-directed cross-linking data in the decoding region, which define sets of contacts between the 16 S rRNA and mRNA, or between 16 S rRNA and tRNA at the A, P and E sites; these contact sites can be correlated directly with the tRNA positions in the EM structure. The model is extended to other parts of the 16 S molecule by fitting individual elements of the well-established secondary structure of the 16 S rRNA into the appropriate fine structural elements of the EM contour, at the same time taking into account other data used in the previous model, such as intra-RNA cross-links within the 16 S rRNA itself. The large body of available RNA-protein cross-linking and foot-printing data is also considered in the model, in order to correlate the rRNA folding with the known distribution of the 30 S ribosomal proteins as determined by neutron scattering and immuno-electron microscopy. The great majority of the biochemical data points involve single-stranded regions of the rRNA, and therefore, in contrast to most previous models, the single-stranded regions are included in our structure, with the help of a specially developed modelling programme, ERNA-3D. This allows the various biochemical data sets to be displayed directly, in this and in the accompanying papers, on diagrams of appropriate parts of the rRNA structure within the cryo-EM contour.
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ARN Ribosómico 16S/ultraestructura , Ribosomas/ultraestructura , Secuencia de Bases , Simulación por Computador , Reactivos de Enlaces Cruzados , Escherichia coli , Enlace de Hidrógeno , Microscopía Electrónica , Modelos Biológicos , Modelos Moleculares , Datos de Secuencia Molecular , Conformación de Ácido Nucleico , Programas InformáticosRESUMEN
The map of the mass centres of the 21 proteins from the Escherichia coli 30 S ribosomal subunit, as determined by neutron scattering, was fitted to a cryoelectron microscopic (cryo-EM) model at a resolution of 20 A of 70 S ribosomes in the pre-translocational state, carrying tRNA molecules at the A and P sites. The fit to the 30 S moiety of the 70 S particles was accomplished with the help of the well-known distribution of the ribosomal proteins in the head, body and side lobe regions of the 30 S subunit, as determined by immuno electron microscopy (IEM). Most of the protein mass centres were found to lie close to the surface (or even outside) of the cryo-EM contour of the 30 S subunit, supporting the idea that the ribosomal proteins are arranged peripherally around the rRNA. The ribosomal protein distribution was then compared with the corresponding model for the 16 S rRNA, fitted to the same EM contour (described in an accompanying paper), in order to analyse the mutual compatibility of the arrangement of proteins and rRNA in terms of the available RNA-protein interaction data. The information taken into account included the hydroxyl radical and base foot-printing data from Noller's laboratory, and our own in situ cross-linking results. Proteins S1 and S14 were not considered, due to the lack of RNA-protein data. Among the 19 proteins analysed, 12 (namely S2, S4, S5, S7, S8, S9, S10, S11, S12, S15, S17 and S21) showed a fit to the rRNA model that varied from being excellent to at least acceptable. Of the remaining 7, S3 and S13 showed a rather poor fit, as did S18 (which is considered in combination with S6 in the foot-printing experiments). S16 was difficult to evaluate, as the foot-print data for this protein cover a large area of the rRNA. S19 and S20 showed a bad fit in terms of the neutron map, but their foot-print and cross-link sites were clustered into compact groups in the rRNA model in those regions of the 30 S subunit where these proteins have respectively been located by IEM studies.