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Ferreira J, Longatto-Filho A, Dionísio A, Correia-Neves M, Cunha P, Mansilha A. Peri-Carotid Adipose Tissue and Atherosclerosis at Carotid Bifurcation. J Cardiovasc Dev Dis 2024; 11:58. [PMID: 38392272 PMCID: PMC10889387 DOI: 10.3390/jcdd11020058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/29/2024] [Accepted: 01/31/2024] [Indexed: 02/24/2024] Open
Abstract
Vulnerable carotid plaques are responsible for 20% of the ischemic strokes. The identification of these asymptomatic carotid plaques that will become symptomatic is essential but remains unclear. Our main goal was to investigate whether the amount of the peri-carotid adipose tissue, estimated by the extra-media thickness (EMT), is associated with the atherosclerotic characteristics at the carotid bifurcation in patients with PAD. An observational, prospective, single-center, longitudinal study was conducted. Overall, 177 patients were subjected to carotid Doppler ultrasound at the study admission. The following data were collected: EMT, intima-media thickness (IMT), the presence of carotid plaques, the area of the highest plaque, the presence of "acute culprit" carotid stenosis, and the grade of internal carotid stenosis. "Acute culprit" carotid stenosis was defined as a significant atherosclerotic plaque that leads to a neurologic event within 15 days. From each carotid bifurcation, a right and a left EMT were determined. We analyzed both the mean EMTs (calculated as the mean between the right and the left EMT) and the EMT ipsilateral to the carotid bifurcation. The presence of carotid plaques was associated with a higher mean EMT [Median = 1.14; IQR = 0.66 versus Median = 0.97; IQR = 0.40; p = 0.001]. A positive correlation was found between the mean EMT and IMT (right: ρ = 0.20; p = 0.010; left: ρ = 0.21; p = 0.007) and between the mean EMT and the area of the largest carotid plaque (right: ρ = 0.17; p = 0.036; left: ρ = 0.22; p = 0.004). Left carotid stenosis ≥ 70% was associated with higher ipsilateral EMT [Median = 1.56; IQR = 0.70 versus Median = 0.94; IQR = 0.42; p = 0.009]. Patients with "acute culprit" carotid stenosis had a higher ipsilateral EMT [left ipsilateral EMT: Median = 1.46; IQR = 0.63; "non-acute": Median = 0.94; IQR = 0.43; p = 0.009; right ipsilateral EMT: Median = 2.25; IQR = 0.62; "non-acute": Median = 1.00; IQR = 0.51; p = 0.015]. This difference was not found in the contra-lateral EMT. Six months after the neurologic event, EMT ipsilateral to an "acute culprit" carotid stenosis decreased (p = 0.036). The amount of peri-carotid adipose tissue, estimated with EMT, was associated with atherosclerosis at the carotid arteries. The mean EMT was associated with the features of chronic atherosclerosis lesions: the presence of carotid plaques, IMT, and the area of the highest plaque. Ipsilateral EMT was linked with "acute culprit" atherosclerotic plaque.
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Affiliation(s)
- Joana Ferreira
- Vascular Surgery Department, Physiology and Surgery, University Hospital Centre of São João, 4200-319 Porto, Portugal
- Academic Centre of Hospital Senhora da Oliveira, 4835-044 Guimarães, Portugal
- Life and Health Science Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, 4710-057 Braga, Portugal
| | - Adhemar Longatto-Filho
- Life and Health Science Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, 4710-057 Braga, Portugal
- Department of Pathology (LIM-14), Faculty of Medicine of the University of São Paulo, São Paulo 01246 903, Brazil
- Molecular Oncology Research Centre, Barretos Cancer Hospital, São Paulo 14784-400, Brazil
| | - Ana Dionísio
- Porto Vascular Conference Scientific Advising, 4050-430 Porto, Portugal
| | - Margarida Correia-Neves
- Life and Health Science Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, 4710-057 Braga, Portugal
| | - Pedro Cunha
- Life and Health Science Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, 4710-057 Braga, Portugal
- Medicine Department of Hospital Senhora da Oliveira, 4835-044 Guimarães, Portugal
- Centre for the Research and Treatment of Arterial Hypertension and Cardiovascular Risk, Internal Medicine, 4835-044 Guimarães, Portugal
| | - Armando Mansilha
- Vascular Surgery Department, Physiology and Surgery, University Hospital Centre of São João, 4200-319 Porto, Portugal
- Faculty of Medicine of the University of Porto, 4200-319 Porto, Portugal
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Dionísio A, Espírito A, Pereira AC, Mouga S, d'Almeida OC, Oliveira G, Castelo-Branco M. Neurochemical differences in core regions of the autistic brain: a multivoxel 1H-MRS study in children. Sci Rep 2024; 14:2374. [PMID: 38287121 PMCID: PMC10824733 DOI: 10.1038/s41598-024-52279-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 01/16/2024] [Indexed: 01/31/2024] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental condition which compromises various cognitive and behavioural domains. The understanding of the pathophysiology and molecular neurobiology of ASD is still an open critical research question. Here, we aimed to address ASD neurochemistry in the same time point at key regions that have been associated with its pathophysiology: the insula, hippocampus, putamen and thalamus. We conducted a multivoxel proton magnetic resonance spectroscopy (1H-MRS) study to non-invasively estimate the concentrations of total choline (GPC + PCh, tCho), total N-acetyl-aspartate (NAA + NAAG, tNAA) and Glx (Glu + Gln), presenting the results as ratios to total creatine while investigating replication for ratios to total choline as a secondary analysis. Twenty-two male children aged between 10 and 18 years diagnosed with ASD (none with intellectual disability, in spite of the expected lower IQ) and 22 age- and gender-matched typically developing (TD) controls were included. Aspartate ratios were significantly lower in the insula (tNAA/tCr: p = 0.010; tNAA/tCho: p = 0.012) and putamen (tNAA/tCr: p = 0.015) of ASD individuals in comparison with TD controls. The Glx ratios were significantly higher in the hippocampus of the ASD group (Glx/tCr: p = 0.027; Glx/tCho: p = 0.011). Differences in tNAA and Glx indices suggest that these metabolites might be neurochemical markers of region-specific atypical metabolism in ASD children, with a potential contribution for future advances in clinical monitoring and treatment.
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Affiliation(s)
- Ana Dionísio
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal
- Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal
| | - Ana Espírito
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal
- Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal
| | - Andreia C Pereira
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal
- Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal
| | - Susana Mouga
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal
- Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal
- Centro de Desenvolvimento da Criança, Unidade de Neurodesenvolvimento e Autismo, Hospital Pediátrico, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | - Otília C d'Almeida
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal
- Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal
| | - Guiomar Oliveira
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal
- Centro de Desenvolvimento da Criança, Unidade de Neurodesenvolvimento e Autismo, Hospital Pediátrico, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
- Faculty of Medicine, University Clinic of Pediatrics, University of Coimbra, Coimbra, Portugal
| | - Miguel Castelo-Branco
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal.
- Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal.
- Faculty of Medicine, University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal.
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Dionísio A, Carvalho S, Castelhano J. Editorial: TMS application in both health and disease. Front Hum Neurosci 2023; 16:1110274. [PMID: 36684836 PMCID: PMC9846602 DOI: 10.3389/fnhum.2022.1110274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 12/14/2022] [Indexed: 01/06/2023] Open
Affiliation(s)
- Ana Dionísio
- Coimbra Institute for Biomedical Imaging and Translational Research, University of Coimbra, Pólo das Ciências da Saúde, Coimbra, Portugal,Institute for Nuclear Sciences Applied to Health, Pólo das Ciências da Saúde, University of Coimbra, Coimbra, Portugal
| | - Sandra Carvalho
- Translational Neuropsychology Laboratory, Department of Education and Psychology, William James Center for Research, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
| | - Joao Castelhano
- Coimbra Institute for Biomedical Imaging and Translational Research, University of Coimbra, Pólo das Ciências da Saúde, Coimbra, Portugal,Institute for Nuclear Sciences Applied to Health, Pólo das Ciências da Saúde, University of Coimbra, Coimbra, Portugal,*Correspondence: Joao Castelhano ✉
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Parracha JL, Borsoi G, Veiga R, Flores-Colen I, Nunes L, Viegas CA, Moreira LM, Dionísio A, Gomes MG, Faria P. Durability assessment of external thermal insulation composite systems in urban and maritime environments. Sci Total Environ 2022; 849:157828. [PMID: 35934022 DOI: 10.1016/j.scitotenv.2022.157828] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 07/07/2022] [Accepted: 07/31/2022] [Indexed: 06/15/2023]
Abstract
External Thermal Insulation Composite Systems (ETICS) are multilayer solutions which provide an enhanced thermal performance to the building envelope. However, significant anomalies can be detected on ETICS facades, in some cases shortly after the application of these systems. This study intends to evaluate and compare the durability of six commercially available ETICS after two years of outdoor exposure at both urban and maritime conditions in Portugal. The systems were characterized by means of non-destructive testing (i.e., visual and microscopic assessment, water transport properties, thermal conductivity, surface roughness), thus allowing to evaluate the performance loss throughout natural aging. The bio-susceptibility and aesthetic properties (color and gloss) were also investigated. Results showed that the performance and durability of the complete system is significantly affected by the rendering system formulation. The lime-based specimens obtained the highest rate of mold development after one year of aging in a maritime environment, becoming considerably darker and with lower surface gloss. Fungal analysis of this darkish stained area indicated the presence of mold species of the genera Alternaria, Didymella, Cladosporium and Epicoccum, and yeasts of the genera Vishniacozyma and Cystobasidium. An increase of both capillary water absorption and water vapor permeability was also registered for the aged lime-based specimens. Acrylic-based systems obtained lower capillary water absorption after aging and greater dirt deposition on their surfaces, especially in urban conditions. These systems had also higher color variation and surface gloss decrease and slightly higher mold growth, when compared with those aged in a maritime environment. Finally, no mold growth was detected on the silicate-based specimens after two years of aging. However, these specimens obtained higher capillary water absorption and lower vapor permeability after aging, possibly leading to moisture accumulation within the system. Results contribute towards the development of ETICS with enhanced performance and durability.
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Affiliation(s)
- J L Parracha
- LNEC, National Laboratory for Civil Engineering, Av. do Brasil, 101, 1700-066 Lisbon, Portugal; CERIS, DECivil, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal.
| | - G Borsoi
- LNEC, National Laboratory for Civil Engineering, Av. do Brasil, 101, 1700-066 Lisbon, Portugal; CERIS, DECivil, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - R Veiga
- LNEC, National Laboratory for Civil Engineering, Av. do Brasil, 101, 1700-066 Lisbon, Portugal
| | - I Flores-Colen
- CERIS, DECivil, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - L Nunes
- LNEC, National Laboratory for Civil Engineering, Av. do Brasil, 101, 1700-066 Lisbon, Portugal; cE3c, Centre for Ecology, Evolution and Environmental Changes, Azorean Biodiversity Group, University of Azores, 9700-042 Angra do Heroísmo, Azores, Portugal
| | - C A Viegas
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal; Department of Bioengineering, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - L M Moreira
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal; Department of Bioengineering, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - A Dionísio
- CERENA, DECivil, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - M Glória Gomes
- CERIS, DECivil, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - P Faria
- CERIS, DECivil, NOVA School of Science and Technology, NOVA University of Lisbon, 2829-516 Caparica, Portugal
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Abuhaiba SI, Duarte IC, Castelhano J, Dionísio A, Sales F, Edden R, Castelo-Branco M. The impact of cathodal tDCS on the GABAergic system in the epileptogenic zone: A multimodal imaging study. Front Neurol 2022; 13:935029. [PMID: 35989912 PMCID: PMC9388822 DOI: 10.3389/fneur.2022.935029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 07/08/2022] [Indexed: 11/16/2022] Open
Abstract
Objectives We aimed to investigate the antiepileptic effects of cathodal transcranial direct current stimulation (c-tDCS) and mechanisms of action based on its effects on the neurotransmitters responsible for the abnormal synchrony patterns seen in pharmacoresistant epilepsy. This is the first study to test the impact of neurostimulation on epileptiform interictal discharges (IEDs) and to measure brain metabolites in the epileptogenic zone (EZ) and control regions simultaneously in patients with pharmacoresistant epilepsy. Methods This is a hypothesis-driven pilot prospective single-blinded repeated measure design study in patients diagnosed with pharmacoresistant epilepsy of temporal lobe onset. We included seven patients who underwent two sessions of c-tDCS (sham followed by real). The real tDCS session was 20 min in duration and had a current intensity of 1.5 mA delivered via two surface electrodes that had dimensions of 3 × 4 cm. The cathode electrode was placed at FT7 in the center whereas the anode at Oz in the center. After each session, we performed electroencephalographic recording to count epileptiform IEDs over 30 min. We also performed magnetic resonance spectroscopy (MRS) to measure brain metabolite concentrations in the two areas of interest (EZ and occipital region), namely, gamma-aminobutyric acid (GABA), glutamate (Glx), and glutathione. We focused on a homogenous sample where the EZ and antiepileptic medications are shared among patients. Results Real tDCS decreased the number of epileptiform IEDs per min (from 9.46 ± 2.68 after sham tDCS to 5.37 ± 3.38 after real tDCS), p = 0.018, as compared to sham tDCS. GABA was decreased in the EZ after real c-tDCS stimulation as compared to sham tDCS (from 0.129 ± 0.019 to 0.096 ± 0.018, p = 0.02). The reduction in EZ GABA correlated with the reduction in the frequency of epileptiform IED per min (rho: 0.9, p = 0.003). Conclusion These results provide a window into the antiepileptic mechanisms of action of tDCS, based on local and remote changes in GABA and neural oscillatory patterning responsible for the generation of interictal epileptiform discharges.
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Affiliation(s)
- Sulaiman I. Abuhaiba
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, Coimbra, Portugal
- Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
- Epilepsy Unit, Faculty of Medicine, Clinical and Academic Center (CCAC), Coimbra, Portugal
| | - Isabel C. Duarte
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, Coimbra, Portugal
- Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
- Faculty of Medicine, Clinical and Academic Center (CCAC), University of Coimbra, Coimbra, Portugal
| | - João Castelhano
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, Coimbra, Portugal
- Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
- Faculty of Medicine, Clinical and Academic Center (CCAC), University of Coimbra, Coimbra, Portugal
| | - Ana Dionísio
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, Coimbra, Portugal
- Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
- Faculty of Medicine, Clinical and Academic Center (CCAC), University of Coimbra, Coimbra, Portugal
| | - Francisco Sales
- Epilepsy Unit, Faculty of Medicine, Clinical and Academic Center (CCAC), Coimbra, Portugal
| | - Richard Edden
- Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
- FM Kirby Center for Functional MRI, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Miguel Castelo-Branco
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, Coimbra, Portugal
- Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
- Faculty of Medicine, Clinical and Academic Center (CCAC), University of Coimbra, Coimbra, Portugal
- *Correspondence: Miguel Castelo-Branco
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Bernardino I, Dionísio A, Violante IR, Monteiro R, Castelo-Branco M. Motor Cortex Excitation/Inhibition Imbalance in Young Adults With Autism Spectrum Disorder: A MRS-TMS Approach. Front Psychiatry 2022; 13:860448. [PMID: 35492696 PMCID: PMC9046777 DOI: 10.3389/fpsyt.2022.860448] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 03/21/2022] [Indexed: 12/28/2022] Open
Abstract
Excitatory/inhibitory imbalance has been suggested as a neurobiological substrate of the cognitive symptomatology in Autism Spectrum Disorder (ASD). Studies using magnetic resonance spectroscopy (MRS) attempted to characterize GABA and Glutamate brain levels in ASD. However mixed findings have been reported. Here, we characterize both neurochemical and physiological aspects of GABA system in ASD by implementing a more comprehensive approach combining MRS and transcranial magnetic stimulation (TMS). A group of 16 young ASD adults and a group of 17 controls participated in this study. We employed one MRS session to assess motor cortex GABA+ and Glutamate+Glutamine (Glx) levels using MEGAPRESS and PRESS sequences, respectively. Additionally, a TMS experiment was implemented including paired-pulse (SICI, ICF and LICI), input-output curve and cortical silent period to probe cortical excitability. Our results showed a significantly increased Glx, with unchanged GABA+ levels in the ASD group compared with controls. Single TMS measures did not differ between groups, although exploratory within-group analysis showed impaired inhibition in SICI5ms, in ASD. Importantly, we observed a correlation between GABA levels and measures of the input-output TMS recruitment curve (slope and MEP amplitude) in the control group but not in ASD, as further demonstrated by direct between group comparisons. In this exploratory study, we found evidence of increased Glx levels which may contribute to ASD excitatory/inhibitory imbalance while highlighting the relevance of conducting further larger-scale studies to investigate the GABA system from complementary perspectives, using both MRS and TMS techniques.
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Affiliation(s)
- Inês Bernardino
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Coimbra Institute for Biomedical Imaging and Translational Research, University of Coimbra, Coimbra, Portugal.,Institute of Nuclear Sciences Applied to Health, University of Coimbra, Coimbra, Portugal
| | - Ana Dionísio
- Coimbra Institute for Biomedical Imaging and Translational Research, University of Coimbra, Coimbra, Portugal.,Institute of Nuclear Sciences Applied to Health, University of Coimbra, Coimbra, Portugal
| | - Inês R Violante
- School of Psychology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Raquel Monteiro
- Coimbra Institute for Biomedical Imaging and Translational Research, University of Coimbra, Coimbra, Portugal.,Institute of Nuclear Sciences Applied to Health, University of Coimbra, Coimbra, Portugal
| | - Miguel Castelo-Branco
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Coimbra Institute for Biomedical Imaging and Translational Research, University of Coimbra, Coimbra, Portugal.,Institute of Nuclear Sciences Applied to Health, University of Coimbra, Coimbra, Portugal
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Dionísio A, Gouveia R, Castelhano J, Duarte IC, Santo GC, Sargento-Freitas J, Duecker F, Castelo-Branco M. The Role of Continuous Theta Burst TMS in the Neurorehabilitation of Subacute Stroke Patients: A Placebo-Controlled Study. Front Neurol 2021; 12:749798. [PMID: 34803887 PMCID: PMC8599133 DOI: 10.3389/fneur.2021.749798] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 09/30/2021] [Indexed: 11/13/2022] Open
Abstract
Objectives: Transcranial magnetic stimulation, in particular continuous theta burst (cTBS), has been proposed for stroke rehabilitation, based on the concept that inhibition of the healthy hemisphere helps promote the recovery of the lesioned one. We aimed to study its effects on cortical excitability, oscillatory patterns, and motor function, the main aim being to identify potentially beneficial neurophysiological effects. Materials and Methods: We applied randomized real or placebo stimulation over the unaffected primary motor cortex of 10 subacute (7 ± 3 days) post-stroke patients. Neurophysiological measurements were performed using electroencephalography and electromyography. Motor function was assessed with the Wolf Motor Function Test. We performed a repeated measure study with the recordings taken pre-, post-cTBS, and at 3 months' follow-up. Results: We investigated changes in motor rhythms during arm elevation and thumb opposition tasks and found significant changes in beta power of the affected thumb's opposition, specifically after real cTBS. Our results are consistent with an excitatory response (increase in event-related desynchronization) in the sensorimotor cortical areas of the affected hemisphere, after stimulation. Neither peak-to-peak amplitude of motor-evoked potentials nor motor performance were significantly altered. Conclusions: Consistently with the theoretical prediction, this contralateral inhibitory stimulation paradigm changes neurophysiology, leading to a significant excitatory impact on the cortical oscillatory patterns of the contralateral hemisphere. These proof-of-concept results provide evidence for the potential role of continuous TBS in the neurorehabilitation of post-stroke patients. We suggest that these changes in ERS/ERD patterns should be further explored in future phase IIb/phase III clinical trials, in larger samples of poststroke patients.
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Affiliation(s)
- Ana Dionísio
- Institute of Nuclear Sciences Applied to Health ICNAS, Coimbra Institute for Biomedical Imaging and Translational Research CIBIT, University of Coimbra, Coimbra, Portugal.,Faculty of Sciences and Technology FCTUC, Department of Physics, University of Coimbra, Coimbra, Portugal.,Faculty of Medicine FMUC, University of Coimbra, Coimbra, Portugal
| | - Rita Gouveia
- Institute of Nuclear Sciences Applied to Health ICNAS, Coimbra Institute for Biomedical Imaging and Translational Research CIBIT, University of Coimbra, Coimbra, Portugal
| | - João Castelhano
- Institute of Nuclear Sciences Applied to Health ICNAS, Coimbra Institute for Biomedical Imaging and Translational Research CIBIT, University of Coimbra, Coimbra, Portugal.,Faculty of Medicine FMUC, University of Coimbra, Coimbra, Portugal
| | - Isabel Catarina Duarte
- Institute of Nuclear Sciences Applied to Health ICNAS, Coimbra Institute for Biomedical Imaging and Translational Research CIBIT, University of Coimbra, Coimbra, Portugal.,Faculty of Medicine FMUC, University of Coimbra, Coimbra, Portugal
| | - Gustavo C Santo
- Stroke Unit, Neurology Department, Coimbra Hospital and University Centre, Coimbra, Portugal
| | - João Sargento-Freitas
- Stroke Unit, Neurology Department, Coimbra Hospital and University Centre, Coimbra, Portugal
| | - Felix Duecker
- Institute of Nuclear Sciences Applied to Health ICNAS, Coimbra Institute for Biomedical Imaging and Translational Research CIBIT, University of Coimbra, Coimbra, Portugal.,Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands.,Maastricht Brain Imaging Center, Maastricht University, Maastricht, Netherlands
| | - Miguel Castelo-Branco
- Institute of Nuclear Sciences Applied to Health ICNAS, Coimbra Institute for Biomedical Imaging and Translational Research CIBIT, University of Coimbra, Coimbra, Portugal.,Faculty of Medicine FMUC, University of Coimbra, Coimbra, Portugal.,Maastricht Brain Imaging Center, Maastricht University, Maastricht, Netherlands.,Brain Imaging Network, University of Coimbra, Coimbra, Portugal
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Dionísio A, Gouveia R, Duarte IC, Castelhano J, Duecker F, Castelo-Branco M. Continuous theta burst stimulation increases contralateral mu and beta rhythms with arm elevation: implications for neurorehabilitation. J Neural Transm (Vienna) 2019; 127:17-25. [PMID: 31844983 DOI: 10.1007/s00702-019-02117-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Accepted: 12/07/2019] [Indexed: 11/24/2022]
Abstract
The study of the physiological effects underlying brain response to transcranial magnetic stimulation is important to understand its impact on neurorehabilitation. We aim to analyze the impact of a transcranial magnetic stimulation protocol, the continuous theta burst (cTBS), on human neurophysiology, particularly on contralateral motor rhythms. cTBS was applied in 20 subjects over the primary motor cortex. We recorded brain electrical activity pre- and post-cTBS with electroencephalography both at rest and while performing motor tasks, to evaluate changes in brain oscillatory patterns such as mu and beta rhythms. Moreover, we measured motor-evoked potentials before and after cTBS to assess its impact on brain's excitability. On the hemisphere contralateral to the protocol, we did observe a significant increase in mu (p = 0.027) and beta (p = 0.006) rhythms from pre- to post-cTBS, at the beginning of arm elevation. The topology of action planning and motor execution suggests that cTBS produced an inhibitory effect that propagated to the contralateral hemisphere, thereby precluding the expected/desired excitation for therapy purposes. This novel approach provides support for the notion that this protocol induces inhibitory changes in contralateral motor rhythms, by decreasing desynchronization, contradicting the ipsilateral inhibition vs. contralateral disinhibition hypothesis. Our results have implications for personalized cTBS usage as a rehabilitation intervention, suggesting that an unexpected propagation of inhibition can occur.
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Affiliation(s)
- Ana Dionísio
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal.,Department of Physics, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal.,Institute for Biomedical Imaging and Life Sciences (CNC.IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Rita Gouveia
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal
| | - Isabel Catarina Duarte
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal.,Institute for Biomedical Imaging and Life Sciences (CNC.IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - João Castelhano
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal.,Institute for Biomedical Imaging and Life Sciences (CNC.IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Felix Duecker
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal.,Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.,Maastricht Brain Imaging Center, Maastricht University, Maastricht, The Netherlands
| | - Miguel Castelo-Branco
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal. .,Institute for Biomedical Imaging and Life Sciences (CNC.IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal. .,Brain Imaging Network, University of Coimbra, Coimbra, Portugal.
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Dionísio A, Duarte I, Patrício M, Castelo-Branco M. Transcranial Magnetic Stimulation as an Intervention Tool to Recover from Language, Swallowing and Attentional Deficits after Stroke: A Systematic Review. Cerebrovasc Dis 2018; 46:178-185. [DOI: 10.1159/000494213] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 10/02/2018] [Indexed: 11/19/2022] Open
Abstract
Background: Following a stroke event, patients often are severely affected by disabilities that hinder their quality-of-life. There are currently several rehabilitative options and strategies, and it is crucial to find the most effective interventions. The applicability of transcranial magnetic stimulation (TMS) to the recovery of nonmotor functions such as communication skills, swallowing ability and spatial attention after stroke remains important clinical questions. Summary: We searched PubMed and ISI Web of Science for articles that used repetitive TMS protocols to rehabilitate post-stroke deficits. We analysed qualitatively 38 articles that met the eligibility criteria; of these, 21 dealt with aphasia, 8 with dysphagia, 8 with neglect and 1 with visual extinction. The efficacy of TMS as an intervention for post-stroke rehabilitation of these nonmotor deficits was studied as well as the current limitations were assessed. Key Messages: Most part of the included studies reported statistically significant functional improvements, supporting the use of TMS for the rehabilitation of aphasia, dysphagia and neglect. Future research, with larger sample sizes, is mandatory to confirm its efficacy, determine the optimal stimulation parameters and investigate inter-subject variability.
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Dionísio A, Duarte IC, Patrício M, Castelo-Branco M. The Use of Repetitive Transcranial Magnetic Stimulation for Stroke Rehabilitation: A Systematic Review. J Stroke Cerebrovasc Dis 2017; 27:1-31. [PMID: 29111342 DOI: 10.1016/j.jstrokecerebrovasdis.2017.09.008] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 07/12/2017] [Accepted: 09/07/2017] [Indexed: 12/11/2022] Open
Abstract
OBJECTIVES Stroke is a leading cause of disability. Alternative and more effective techniques for stroke rehabilitation have been sought to overcome limitations of conventional therapies. Repetitive transcranial magnetic stimulation (rTMS) arises as a promising tool in this context. This systematic review aims to provide a state of the art on the application of rTMS in stroke patients and to assess its effectiveness in clinical rehabilitation of motor function. METHODS Studies included in this review were identified by searching PubMed and ISI Web of Science. The search terms were (rTMS OR "repetitive transcranial magnetic stimulation") AND (stroke OR "cerebrovascular accident" OR CVA) AND (rehab OR rehabilitation OR recover*). The retrieved records were assessed for eligibility and the most relevant features extracted to a summary table. RESULTS Seventy out of 691 records were deemed eligible, according to the selection criteria. The majority of the articles report rTMS showing potential in improving motor function, although some negative reports, all from randomized controlled trials, contradict this claim. Future studies are needed because there is a possibility that a bias for non-publication of negative results may be present. CONCLUSIONS rTMS has been shown to be a promising tool for stroke rehabilitation, in spite of the lack of standard operational procedures and harmonization. Efforts should be devoted to provide a greater understanding of the underlying mechanisms and protocol standardization.
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Affiliation(s)
- Ana Dionísio
- Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal; Department of Physics, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal; Institute for Biomedical Imaging and Life Sciences (CNC.IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Isabel Catarina Duarte
- Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal; Institute for Biomedical Imaging and Life Sciences (CNC.IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Miguel Patrício
- Institute for Biomedical Imaging and Life Sciences (CNC.IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal; Laboratory of Biostatistics and Medical Informatics, Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Miguel Castelo-Branco
- Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal; Institute for Biomedical Imaging and Life Sciences (CNC.IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal; Laboratory of Biostatistics and Medical Informatics, Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal; Brain Imaging Network, University of Coimbra, Coimbra, Portugal.
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Miller AZ, Hernández-Mariné M, Jurado V, Dionísio A, Barquinha P, Fortunato E, Afonso MJ, Chaminé HI, Saiz-Jimenez C. Enigmatic reticulated filaments in subsurface granite. Environ Microbiol Rep 2012; 4:596-603. [PMID: 23760930 DOI: 10.1111/j.1758-2229.2012.00375.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Revised: 05/15/2012] [Accepted: 07/23/2012] [Indexed: 06/02/2023]
Abstract
In the last few years, geomicrobiologists have focused their researches on the nature and origin of enigmatic reticulated filaments reported in modern and fossil samples from limestone caves and basalt lava tubes. Researchers have posed questions on these filaments concerning their nature, origin, chemistry, morphology, mode of formation and growth. A tentative microbial origin has been elusive since these filaments are found as hollow tubular sheaths and could not be affiliated to any known microorganism. We describe the presence of similar structures in a 16th century granite tunnel in Porto, Northwest Portugal. The reticulated filaments we identify exhibit fine geometry surface ornamentation formed by cross-linked Mn-rich nanofibres, surrounded by a large amount of extracellular polymeric substances. Within these Mn-rich filaments we report for the first time the occurrence of microbial cells.
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Affiliation(s)
- A Z Miller
- Centro de Petrologia e Geoquímica, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001, Lisboa, Portugal
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Miller AZ, Sanmartín P, Pereira-Pardo L, Dionísio A, Saiz-Jimenez C, Macedo MF, Prieto B. Bioreceptivity of building stones: a review. Sci Total Environ 2012; 426:1-12. [PMID: 22534363 DOI: 10.1016/j.scitotenv.2012.03.026] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 03/09/2012] [Accepted: 03/10/2012] [Indexed: 05/31/2023]
Abstract
In 1995, Guillitte defined bioreceptivity, a new term in ecology, as the ability of a material to be colonized by living organisms. Information about the bioreceptivity of stone is of great importance since it will help us to understand the material properties which influence the development of biological colonization in the built environment, and will also provide useful information as regards selecting stones for the conservation of heritage monuments and construction of new buildings. Studies of the bioreceptivity of stone materials are reviewed here with the aim of providing a clear set of conclusions on the topic. Definitions of bioreceptivity are given, stone bioreceptivity experiments are described, and finally the stone properties related to bioreceptivity are discussed. We suggest that a standardized laboratory protocol for evaluating stone bioreceptivity and definition of a stone bioreceptivity index are required to enable creation of a database on the primary bioreceptivity of stone materials.
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Affiliation(s)
- A Z Miller
- Centro de Petrologia e Geoquímica, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001, Lisboa, Portugal.
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Miller AZ, Rogerio-Candelera MA, Laiz L, Wierzchos J, Ascaso C, Sequeira Braga MA, Hernández-Mariné M, Maurício A, Dionísio A, Macedo MF, Saiz-Jimenez C. Laboratory-induced endolithic growth in calcarenites: biodeteriorating potential assessment. Microb Ecol 2010; 60:55-68. [PMID: 20440490 DOI: 10.1007/s00248-010-9666-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Accepted: 02/10/2010] [Indexed: 05/29/2023]
Abstract
This study is aimed to assess the formation of photosynthetic biofilms on and within different natural stone materials, and to analyse their biogeophysical and biogeochemical deterioration potential. This was performed by means of artificial colonisation under laboratory conditions during 3 months. Monitoring of microbial development was performed by image analysis and biofilm biomass estimation by chlorophyll extraction technique. Microscopy investigations were carried out to study relationships between microorganisms and the mineral substrata. The model applied in this work corroborated a successful survival strategy inside endolithic microhabitat, using natural phototrophic biofilm cultivation, composed by cyanobacteria and algae, which increased intrinsic porosity by active mineral dissolution. We observed the presence of mineral-like iron derivatives (e.g. maghemite) around the cells and intracellularly and the precipitation of hausmannite, suggesting manganese transformations related to the biomineralisation.
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Affiliation(s)
- A Z Miller
- Departamento de Conservação e Restauro, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Monte de Caparica, Caparica, Portugal.
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Laiz L, Miller AZ, Jurado V, Akatova E, Sanchez-Moral S, Gonzalez JM, Dionísio A, Macedo MF, Saiz-Jimenez C. Isolation of five Rubrobacter strains from biodeteriorated monuments. Naturwissenschaften 2008; 96:71-9. [PMID: 18953520 DOI: 10.1007/s00114-008-0452-2] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 09/07/2008] [Accepted: 09/14/2008] [Indexed: 10/21/2022]
Abstract
In the last few years, the microbial colonisation of mural paintings in ancient monuments has been attracting the attention of microbiologists and conservators. The genus Rubrobacter is commonly found in biodeteriorated monuments, where it has been reported to cause rosy discolouration. However, to date, only three species of this genus have been isolated, all from thermophilic environments. In this paper, we studied three monuments: the Servilia and Postumio tombs in the Roman Necropolis of Carmona (Spain), and Vilar de Frades church (Portugal), in search of Rubrobacter strains. In all cases, biodeterioration and the formation of efflorescences were observed, and five Rubrobacter strains were isolated. These isolates showed different physiology and migration in denaturing gradient gel electrophoresis, suggesting they might represent new species within this genus. The isolates reproduced some biodeterioration processes in the laboratory and revealed their biomediation in crystal formation.
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Affiliation(s)
- L Laiz
- Instituto de Recursos Naturales y Agrobiologia, CSIC, Apartado 1052, 41080, Seville, Spain
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Abstract
AbstractLisbon Cathedral, built in Late Romanesque style, is one of the most ancient Portuguese monuments. Its cloister was severely damaged by a fire that occurred in 1755 right after an earthquake. The aim of this investigation is to study stone thermal damage through the application of in situ and laboratory techniques. With this study it is possible to identify and characterize (chemically and mineralogically) the main thermal decay forms. Special attention is given to colour modification and granular disintegration. Through the application of an indirect ultrasound method it is verified that only a small number of stone blocks are relatively sound (11%). In terms of chromatic alteration, two factors are considered to explain heat-induced colour modification: the transformation of goethite into hematite and an increase in hematite single crystalline domains. It is also established that the most probable high-temperature range to which the cloister stones were subjected during the fire was 300–350 °C.
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Affiliation(s)
- A. Dionísio
- Laboratory of Mineralogy and Petrology, Mining and Georesources Department, Centro de Petrologia e Geoquímica, Instituto Superior TécnicoAv. Rovisco Pais, 1049-001 Lisbon, Portugal (e-mail: )
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Vilarinho L, Santorelli FM, Coelho I, Rodrigues L, Maia M, Barata I, Cabral P, Dionísio A, Costa A, Guimarães A, DiMauro S. The mitochondrial DNA A3243G mutation in Portugal: clinical and molecular studies in 5 families. J Neurol Sci 1999; 163:168-74. [PMID: 10371079 DOI: 10.1016/s0022-510x(99)00030-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Out of 90 Portuguese patients with mitochondrial cytopathy, six harbored the A3243G mutation in the mtDNA tRNA(Leu(UUR)) gene ('MELAS mutation'). They had heterogeneous clinical features, including myopathy with stroke-like episodes, progressive external ophthalmoparesis, diabetes mellitus, and subacute encephalopathy. Histochemical and biochemical analyses of muscle biopsies showed abundant ragged-red fibers reacting positively with the cytochrome oxidase stain, and decreased respiratory chain enzyme activities. On average, the proportion of mutated mtDNA was 67% (20-88%) in tissues from patients and 21% (0-49%) in blood from 20 maternal relatives. The proportion of mutated mitochondrial genomes in muscle did not correlate with clinical presentation or duration of disease. This study, the first in Portuguese patients, confirms the frequent occurrence of the A3243G mutation in patients with mitochondrial diseases, and emphasises the usefulness of genetic testing in reaching a correct diagnosis.
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Affiliation(s)
- L Vilarinho
- Department of Clinical Biology, Pr. Pedro Nunes, Instituto de Genética Médica, Porto, Portugal.
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