64 results on '"Tavakol S"'
Search Results
2. Topographic divergence of atypical cortical asymmetry and atrophy patterns in temporal lobe epilepsy
- Author
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Park, B.-y., Larivière, S., Rodríguez-Cruces, R., Royer, J., Tavakol, S., Wang, Y., Caciagli, L., Caligiuri, M.E., Gambardella, A., Concha, L., Keller, S.S., Cendes, F., Alvim, M.K.M., Yasuda, C., Bonilha, L., Gleichgerrcht, E., Focke, N.K., Kreilkamp, B.A.K., Domin, M., Podewils, F. von, Langner, S., Rummel, C., Rebsamen, M., Wiest, R., Martin, P., Kotikalapudi, R., Bender, B., O’Brien, T.J., Law, M., Sinclair, B., Vivash, L., Kwan, P., Desmond, P.M., Malpas, C.B., Lui, E., Alhusaini, S., Doherty, C.P., Cavalleri, G.L., Delanty, N., Kälviäinen, R., Jackson, G.D., Kowalczyk, M., Mascalchi, M., Semmelroch, M., Thomas, R.H., Soltanian-Zadeh, H., Davoodi-Bojd, E., Zhang, J., Lenge, M., Guerrini, R., Bartolini, E., Hamandi, K., Foley, S., Weber, B., Depondt, C., Absil, J., Carr, S.J.A., Abela, E., Richardson, M.P., Devinsky, O., Severino, M., Striano, P., Parodi, C., Tortora, D., Hatton, S.N., Vos, S.B., Duncan, J.S., Galovic, M., Whelan, C.D., Bargalló, N., Pariente, J., Conde-Blanco, E., Vaudano, A.E., Tondelli, M., Meletti, S., Kong, X.Z., Francks, C., Fisher, S.E., Caldairou, B., Ryten, M., Labate, A., Sisodiya, S.M., Thompson, P.M., McDonald, C.R., Bernasconi, A., Bernasconi, N., Bernhardt, B.C., Park, B.-y., Larivière, S., Rodríguez-Cruces, R., Royer, J., Tavakol, S., Wang, Y., Caciagli, L., Caligiuri, M.E., Gambardella, A., Concha, L., Keller, S.S., Cendes, F., Alvim, M.K.M., Yasuda, C., Bonilha, L., Gleichgerrcht, E., Focke, N.K., Kreilkamp, B.A.K., Domin, M., Podewils, F. von, Langner, S., Rummel, C., Rebsamen, M., Wiest, R., Martin, P., Kotikalapudi, R., Bender, B., O’Brien, T.J., Law, M., Sinclair, B., Vivash, L., Kwan, P., Desmond, P.M., Malpas, C.B., Lui, E., Alhusaini, S., Doherty, C.P., Cavalleri, G.L., Delanty, N., Kälviäinen, R., Jackson, G.D., Kowalczyk, M., Mascalchi, M., Semmelroch, M., Thomas, R.H., Soltanian-Zadeh, H., Davoodi-Bojd, E., Zhang, J., Lenge, M., Guerrini, R., Bartolini, E., Hamandi, K., Foley, S., Weber, B., Depondt, C., Absil, J., Carr, S.J.A., Abela, E., Richardson, M.P., Devinsky, O., Severino, M., Striano, P., Parodi, C., Tortora, D., Hatton, S.N., Vos, S.B., Duncan, J.S., Galovic, M., Whelan, C.D., Bargalló, N., Pariente, J., Conde-Blanco, E., Vaudano, A.E., Tondelli, M., Meletti, S., Kong, X.Z., Francks, C., Fisher, S.E., Caldairou, B., Ryten, M., Labate, A., Sisodiya, S.M., Thompson, P.M., McDonald, C.R., Bernasconi, A., Bernasconi, N., and Bernhardt, B.C.
- Abstract
Contains fulltext : 252489.pdf (Publisher’s version ) (Open Access)
- Published
- 2022
3. Topographic divergence of atypical cortical asymmetry and atrophy patterns in temporal lobe epilepsy
- Author
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Park, B-Y, Lariviere, S, Rodriguez-Cruces, R, Royer, J, Tavakol, S, Wang, Y, Caciagli, L, Caligiuri, ME, Gambardella, A, Concha, L, Keller, SS, Cendes, F, Alvim, MKM, Yasuda, C, Bonilha, L, Gleichgerrcht, E, Focke, NK, Kreilkamp, BAK, Domin, M, von Podewils, F, Langner, S, Rummel, C, Rebsamen, M, Wiest, R, Martin, P, Kotikalapudi, R, Bender, B, O'Brien, TJ, Law, M, Sinclair, B, Vivash, L, Kwan, P, Desmond, PM, Malpas, CB, Lui, E, Alhusaini, S, Doherty, CP, Cavalleri, GL, Delanty, N, Kalviainen, R, Jackson, GD, Kowalczyk, M, Mascalchi, M, Semmelroch, M, Thomas, RH, Soltanian-Zadeh, H, Davoodi-Bojd, E, Zhang, J, Lenge, M, Guerrini, R, Bartolini, E, Hamandi, K, Foley, S, Weber, B, Depondt, C, Absil, J, Carr, SJA, Abela, E, Richardson, MP, Devinsky, O, Severino, M, Striano, P, Parodi, C, Tortora, D, Hatton, SN, Vos, SB, Duncan, JS, Galovic, M, Whelan, CD, Bargallo, N, Pariente, J, Conde-Blanco, E, Vaudano, AE, Tondelli, M, Meletti, S, Kong, X-Z, Francks, C, Fisher, SE, Caldairou, B, Ryten, M, Labate, A, Sisodiya, SM, Thompson, PM, McDonald, CR, Bernasconi, A, Bernasconi, N, Bernhardt, BC, Park, B-Y, Lariviere, S, Rodriguez-Cruces, R, Royer, J, Tavakol, S, Wang, Y, Caciagli, L, Caligiuri, ME, Gambardella, A, Concha, L, Keller, SS, Cendes, F, Alvim, MKM, Yasuda, C, Bonilha, L, Gleichgerrcht, E, Focke, NK, Kreilkamp, BAK, Domin, M, von Podewils, F, Langner, S, Rummel, C, Rebsamen, M, Wiest, R, Martin, P, Kotikalapudi, R, Bender, B, O'Brien, TJ, Law, M, Sinclair, B, Vivash, L, Kwan, P, Desmond, PM, Malpas, CB, Lui, E, Alhusaini, S, Doherty, CP, Cavalleri, GL, Delanty, N, Kalviainen, R, Jackson, GD, Kowalczyk, M, Mascalchi, M, Semmelroch, M, Thomas, RH, Soltanian-Zadeh, H, Davoodi-Bojd, E, Zhang, J, Lenge, M, Guerrini, R, Bartolini, E, Hamandi, K, Foley, S, Weber, B, Depondt, C, Absil, J, Carr, SJA, Abela, E, Richardson, MP, Devinsky, O, Severino, M, Striano, P, Parodi, C, Tortora, D, Hatton, SN, Vos, SB, Duncan, JS, Galovic, M, Whelan, CD, Bargallo, N, Pariente, J, Conde-Blanco, E, Vaudano, AE, Tondelli, M, Meletti, S, Kong, X-Z, Francks, C, Fisher, SE, Caldairou, B, Ryten, M, Labate, A, Sisodiya, SM, Thompson, PM, McDonald, CR, Bernasconi, A, Bernasconi, N, and Bernhardt, BC
- Abstract
Temporal lobe epilepsy, a common drug-resistant epilepsy in adults, is primarily a limbic network disorder associated with predominant unilateral hippocampal pathology. Structural MRI has provided an in vivo window into whole-brain grey matter structural alterations in temporal lobe epilepsy relative to controls, by either mapping (i) atypical inter-hemispheric asymmetry; or (ii) regional atrophy. However, similarities and differences of both atypical asymmetry and regional atrophy measures have not been systematically investigated. Here, we addressed this gap using the multisite ENIGMA-Epilepsy dataset comprising MRI brain morphological measures in 732 temporal lobe epilepsy patients and 1418 healthy controls. We compared spatial distributions of grey matter asymmetry and atrophy in temporal lobe epilepsy, contextualized their topographies relative to spatial gradients in cortical microstructure and functional connectivity calculated using 207 healthy controls obtained from Human Connectome Project and an independent dataset containing 23 temporal lobe epilepsy patients and 53 healthy controls and examined clinical associations using machine learning. We identified a marked divergence in the spatial distribution of atypical inter-hemispheric asymmetry and regional atrophy mapping. The former revealed a temporo-limbic disease signature while the latter showed diffuse and bilateral patterns. Our findings were robust across individual sites and patients. Cortical atrophy was significantly correlated with disease duration and age at seizure onset, while degrees of asymmetry did not show a significant relationship to these clinical variables. Our findings highlight that the mapping of atypical inter-hemispheric asymmetry and regional atrophy tap into two complementary aspects of temporal lobe epilepsy-related pathology, with the former revealing primary substrates in ipsilateral limbic circuits and the latter capturing bilateral disease effects. These findings refine ou
- Published
- 2022
4. Necrotic, apoptotic and autophagic cell fates triggered by nanoparticles
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Mohammadinejad, R., Moosavi, M.A., Tavakol, S., Vardar, D.Ö., Hosseini, A., Rahmati, M., Klionsky, D.J., and [Belirlenecek]
- Subjects
autophagy ,stress ,cell death ,nanotoxicity ,lysosome ,Apoptosis ,nanoparticles ,necrosis - Abstract
Nanomaterials have gained a rapid increase in use in a variety of applications that pertain to many aspects of human life. The majority of these innovations are centered on medical applications and a range of industrial and environmental uses ranging from electronics to environmental remediation. Despite the advantages of NPs, the knowledge of their toxicological behavior and their interactions with the cellular machinery that determines cell fate is extremely limited. This review is an attempt to summarize and increase our understanding of the mechanistic basis of nanomaterial interactions with the cellular machinery that governs cell fate and activity. We review the mechanisms of NP-induced necrosis, apoptosis and autophagy and potential implications of these pathways in nanomaterial-induced outcomes. Abbreviations: Ag, silver; CdTe, cadmium telluride; CNTs, carbon nanotubes; EC, endothelial cell; GFP, green fluorescent protein; GO, graphene oxide; GSH, glutathione; HUVECs, human umbilical vein endothelial cells; NP, nanoparticle; PEI, polyethylenimine; PVP, polyvinylpyrrolidone; QD, quantum dot; ROS, reactive oxygen species; SiO2, silicon dioxide; SPIONs, superparamagnetic iron oxide nanoparticles; SWCNT, single-walled carbon nanotubes; TiO2, titanium dioxide; USPION, ultra-small super paramagnetic iron oxide; ZnO, zinc oxide. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group. National Institutes of Health, NIH; National Institute of General Medical Sciences, NIGMS: GM053396; Honeywell Hometown Solutions, HHS; Kerman University of Medical Sciences, KMU; National Institute for Genetic Engineering and Biotechnology, NIGEB; National Institute for Medical Research Development, NIMAD: 940943 Reza Mohammadinejad is thankful for the financial support of Kerman University of Medical Sciences. Amin Moosavi acknowledges National Institute for Medical Research Development (NIMAD) grant 940943 and financial supports of National Institute of Genetic Engineering and Biotechnology and Iranian National Science Foundation. Daniel J. Klionsky is supported by NIH grant GM053396. This work was supported by the HHS | NIH | National Institute of General Medical Sciences (NIGMS) [GM053396]. 2-s2.0-85057096523 PubMed: 30160607
- Published
- 2019
5. Neuroimaging and connectomics of drug-resistant epilepsy at multiple scales: From focal lesions to macroscale networks
- Author
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Tavakol, S, Royer, J, Lowe, AJ, Bonilha, L, Tracy, JI, Jackson, GD, Duncan, JS, Bernasconi, A, Bernasconi, N, Bernhardt, BC, Tavakol, S, Royer, J, Lowe, AJ, Bonilha, L, Tracy, JI, Jackson, GD, Duncan, JS, Bernasconi, A, Bernasconi, N, and Bernhardt, BC
- Abstract
Epilepsy is among the most common chronic neurologic disorders, with 30%-40% of patients having seizures despite antiepileptic drug treatment. The advent of brain imaging and network analyses has greatly improved the understanding of this condition. In particular, developments in magnetic resonance imaging (MRI) have provided measures for the noninvasive characterization and detection of lesions causing epilepsy. MRI techniques can probe structural and functional connectivity, and network analyses have shaped our understanding of whole-brain anomalies associated with focal epilepsies. This review considers the progress made by neuroimaging and connectomics in the study of drug-resistant epilepsies due to focal substrates, particularly temporal lobe epilepsy related to mesiotemporal sclerosis and extratemporal lobe epilepsies associated with malformations of cortical development. In these disorders, there is evidence of widespread disturbances of structural and functional connectivity that may contribute to the clinical and cognitive prognosis of individual patients. It is hoped that studying the interplay between macroscale network anomalies and lesional profiles will improve our understanding of focal epilepsies and assist treatment choices.
- Published
- 2019
6. Gastrointestinal Helminths of Magpies (Pica pica), Rooks (Corvus frugilegus) and Carrion Crows (Corvus corone) in Mazandaran Province, North of Iran.
- Author
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Halajian, A., Eslami, A., Mobedi, I., Amin, O., Mariaux, J., Mansoori, J., and Tavakol, S.
- Subjects
HELMINTHS ,MAGPIES ,BLACK-billed magpie ,CORVUS frugilegus ,CARRION crow - Abstract
Background: Corvidae is a cosmopolitan family of oscine birds including crows, rooks, magpies, jays, chough, and ravens. These birds are migratory species, especially in the shortage of foods, so they can act like vectors for a wide range of microorganisms. They live generally in temperate climates and in a very close contact with human residential areas as well as poultry farms. There is no available information in the literature concerning the parasitic infections of these three species of corvidae in Mazandaran Province, northern Iran, so this study was conducted to clarify this. Methods: As there are three species of corvid birds in Mazandaran Province, 106 birds including 79 magpies, 11 rooks, and 16 carrion crows were examined between winter 2007 and spring 2008 at post mortem for gastrointestinal helminths. The helminths were drawn and identified morphologically in the Laboratory of Parasitology, Islamic Azad University, Science and Research Branch, Tehran and also partly in the School of Public Health, Tehran University of Medical Sciences, based on the reference books and identification keys like Soulsby, Khalil et al. and Anderson et al. Results: Four species of nematodes, 2 species of cestodes, 1 species of trematodes and 1 species of acanthocephalans were identified in these three corvid species. Conclusion: Five species of the helminths are identified for the first time in Iran, and the acanthocephalan species is new host record for rooks. It is clear that these corvid birds have diverse range of helminths and can act as carriers for infecting the domestic fowls. [ABSTRACT FROM AUTHOR]
- Published
- 2011
7. The relationship between family-to-work conflict of employee and co-workers' turnover intention
- Author
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Tavakol Sharafi and Zohreh dehdashti shahrokh
- Subjects
Work–family conflict ,Employee engagement ,Turnover intention ,Business records management ,HF5735-5746 - Abstract
Previous studies have convincingly shown that employees' family lives can affect their work outcomes. We investigate whether family-to-work conflict (FWC) experienced by the employee also affects the turnover intention of a co-worker. We predict that the employee's FWC has an effect on the co-worker's turnover intention through the crossover of positive and negative work attitudes. Using a sample of 154 co-worker dyads, we found that the employee FWC was positively related to co-worker turnover intention through the crossover of (reduced) work engagement. Results show that family matters at work, affecting employee. In addition, employee's job engagement was positively related to his (her) co-worker job engagement and it was negatively related co-worker turnover intention and employee's FWC was not positively related to co-worker turnover intention trough the crossover of (reduced) feelings of engagement.
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- 2012
8. The relationship between dimensions of intellectual capital and knowledge creation: Case Study of the headquarters of national gas corporation of Iran
- Author
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Mehdi Sharafi, Yousof Mohammadi moghadam, and Tavakol Sharafi
- Subjects
Intellectual capital ,Structural capital ,Relational capital ,Human capital ,Knowledge creation ,Business records management ,HF5735-5746 - Abstract
Intellectual capital is the main property of any organization in knowledge-based economics. Knowledge is the fundamental principle of intellectual capital. Hence, it is the core of organizational capabilities. The aim of this study is to survey the relationship between dimensions of intellectual capital and knowledge creation in the headquarters of National Gas Corporation of Iran in the year 2010. The research method is descriptive – survey and follows practical objective. The research population consists of the formal staffs of the Corporation (managers, senior staff and other staff). We selected 261 people from the population randomly. We also used a reliable and valid questionnaire to gather data. We also used informative factor analysis to examine goodness of the model and we used SEM by Lisrel to confirm or reject the hypothesis in this study. The results show that all dimensions of intellectual capital have a significant impact on dimensions of knowledge creation, except for the effects of structural capital on knowledge combination as well as relational capital on knowledge internalization.
- Published
- 2012
9. Gastrointestinal helminths of magpies (pica pica), rooks (corvus frugilegus) and carrion crows (corvus corone) in mazandaran province, North of Iran
- Author
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Ali Halajian, Eslami A, Mobedi I, Amin O, Mariaux J, Mansoori J, and Tavakol S
- Subjects
Magpie ,Crow ,Helminths ,lcsh:RC109-216 ,Original Article ,Rook ,Iran ,lcsh:Infectious and parasitic diseases - Abstract
Background: Corvidae is a cosmopolitan family of oscine birds including crows, rooks, magpies, jays, chough, and ravens. These birds are migratory species, especially in the shortage of foods, so they can act like vectors for a wide range of microorganisms. They live generally in temperate climates and in a very close contact with human residential areas as well as poultry farms. There is no available information in the literature concerning the parasitic infections of these three species of corvidae in Mazandaran Province, northern Iran, so this study was conducted to clarify this. Methods: As there are three species of corvid birds in Mazandaran Province, 106 birds including 79 magpies, 11 rooks, and 16 carrion crows were examined between winter 2007 and spring 2008 at post mortem for gastrointestinal helminths. The helminths were drawn and identified morphologically in the Laboratory of Parasitology, Islamic Azad University, Science and Research Branch, Tehran and also partly in the School of Public Health, Tehran University of Medical Sciences, based on the reference books and identification keys like Soulsby, Khalil et al. and Anderson et al. Results: Four species of nematodes, 2 species of cestodes, 1 species of trematodes and 1 species of acanthocephalans were identified in these three corvid species. Conclusion: Five species of the helminths are identified for the first time in Iran, and the acanthocephalan species is new host record for rooks. It is clear that these corvid birds have diverse range of helminths and can act as carriers for infecting the domestic fowls.
10. Psychometric properties and confirmatory factor analysis of the Jefferson Scale of Physician Empathy
- Author
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Tavakol Sina, Dennick Reg, and Tavakol Mohsen
- Subjects
Empathy ,JSPE ,confirmatory factor analysis ,structure validation ,Special aspects of education ,LC8-6691 ,Medicine - Abstract
Abstract Background Empathy towards patients is considered to be associated with improved health outcomes. Many scales have been developed to measure empathy in health care professionals and students. The Jefferson Scale of Physician Empathy (JSPE) has been widely used. This study was designed to examine the psychometric properties and the theoretical structure of the JSPE. Methods A total of 853 medical students responded to the JSPE questionnaire. A hypothetical model was evaluated by structural equation modelling to determine the adequacy of goodness-of-fit to sample data. Results The model showed excellent goodness-of-fit. Further analysis showed that the hypothesised three-factor model of the JSPE structure fits well across the gender differences of medical students. Conclusions The results supported scale multi-dimensionality. The 20 item JSPE provides a valid and reliable scale to measure empathy among not only undergraduate and graduate medical education programmes, but also practising doctors. The limitations of the study are discussed and some recommendations are made for future practice.
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- 2011
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11. A descriptive study of medical educators' views of problem-based learning
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Dennick Reg, Tavakol Mohsen, and Tavakol Sina
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Special aspects of education ,LC8-6691 ,Medicine - Abstract
Abstract Background There is a growing amount of literature on the benefits and drawbacks of Problem-Based Learning (PBL) compared to conventional curricula. However, it seems that PBL research studies do not provide information rigorously and formally that can contribute to making evidence-based medical education decisions. The authors performed an investigation aimed at medical education scholars around the question, "What are the views of medical educators concerning the PBL approach?" Methods After framing the question, the method of data collection relied on asking medical educators to report their views on PBL. Two methods were used for collecting data: the questionnaire survey and an online discussion forum. Results The descriptive analysis of the study showed that many participants value the PBL approach in the practice and training of doctors. However, some participants hold contrasting views upon the importance of the PBL approach in basic medical education. For example, more than a third of participants (38.5%) had a neutral stance on PBL as a student-oriented educational approach. The same proportion of participants also had a neutral view of the efficiency of traditional learning compared to a PBL tutorial. The open-ended question explored the importance of faculty development in PBL. A few participants had negative perceptions of the epistemological assumptions of PBL. Two themes emerged from the analysis of the forum repliers: the importance of the faculty role and self-managed education. Conclusion Whilst many participants valued the importance of the PBL approach in the practice and training of doctors and agreed with most of the conventional descriptions of PBL, some participants held contrasting views on the importance of the PBL approach in undergraduate medical education. However there was a strong view concerning the importance of facilitator training. More research is needed to understand the process of PBL better.
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- 2009
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12. Correction: Firoozi et al. A Cell-Free SDKP-Conjugated Self-Assembling Peptide Hydrogel Sufficient for Improvement of Myocardial Infarction. Biomolecules 2020, 10 , 205.
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Firoozi S, Pahlavan S, Ghanian MH, Rabbani S, Tavakol S, Barekat M, Yakhkeshi S, Mahmoudi E, Soleymani M, and Baharvand H
- Abstract
The authors wish to make the following corrections to this paper [...].
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- 2024
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13. The impact of social determinants of health on early outcomes after adult Chiari surgery.
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Tavakol S, Zieles K, Peters M, Omini M, Chen S, and Jea A
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- Humans, Treatment Outcome, Retrospective Studies, Social Determinants of Health, Decompression, Surgical, Arnold-Chiari Malformation surgery
- Abstract
We sought to identify social determinants of health (SDoH) for adult patients undergoing Chiari decompression surgery and to analyze their association with postoperative outcomes, including length of stay (LOS), return to the system within 30 days, and the Chicago Chiari Outcomes Score (CCOS). This is a retrospective study of adult patients who underwent Chiari decompression surgery between June 2021 and January 2023. Data was gathered through electronic medical record review and telephone surveys. Descriptive statistics were used to evaluate demographics of all patients meeting inclusion criteria. Fisher's exact tests and logistic regression were used for data analysis. A total of 37 patients underwent Chiari decompression (23 CCOS/SDoH survey respondents): 48% bony decompression only, 30% bony decompression plus intradural exploration, and 22% occipitocervical fusion. Seven patients (30%) had a LOS > 2 days, 1 patient (4%) required inpatient rehabilitation postoperatively, 4 patients (17%) returned to the system within 30 days, 10 patients (43%) had an extremely favorable CCOS (15-16), and 11 patients (48%) reported interaction with a Chiari support group. Mean follow-up was 9.5 months. Patients with occipitocervical fusion were more likely to have a LOS > 2 days (p = 0.03), patients who exercised ≥ 3 days per week were more likely to have a favorable CCOS (p = 0.04), and patients who participated in a Chiari support group were less likely to have a favorable CCOS (p = 0.03). Chiari decompression plus occipitocervical fusion may be associated with increased LOS. While more frequent exercise may be associated with better post-surgical outcomes, participation in a Chiari support group may be correlated with worse outcomes., (© 2023. The Author(s), under exclusive licence to American Aging Association.)
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- 2024
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14. The human brain connectome weighted by the myelin content and total intra-axonal cross-sectional area of white matter tracts.
- Author
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Nelson MC, Royer J, Lu WD, Leppert IR, Campbell JSW, Schiavi S, Jin H, Tavakol S, Vos de Wael R, Rodriguez-Cruces R, Pike GB, Bernhardt BC, Daducci A, Misic B, and Tardif CL
- Abstract
A central goal in neuroscience is the development of a comprehensive mapping between structural and functional brain features, which facilitates mechanistic interpretation of brain function. However, the interpretability of structure-function brain models remains limited by a lack of biological detail. Here, we characterize human structural brain networks weighted by multiple white matter microstructural features including total intra-axonal cross-sectional area and myelin content. We report edge-weight-dependent spatial distributions, variance, small-worldness, rich club, hubs, as well as relationships with function, edge length, and myelin. Contrasting networks weighted by the total intra-axonal cross-sectional area and myelin content of white matter tracts, we find opposite relationships with functional connectivity, an edge-length-independent inverse relationship with each other, and the lack of a canonical rich club in myelin-weighted networks. When controlling for edge length, networks weighted by either fractional anisotropy, radial diffusivity, or neurite density show no relationship with whole-brain functional connectivity. We conclude that the co-utilization of structural networks weighted by total intra-axonal cross-sectional area and myelin content could improve our understanding of the mechanisms mediating the structure-function brain relationship., Competing Interests: Competing Interests: The authors have declared that no competing interests exist., (© 2023 Massachusetts Institute of Technology.)
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- 2023
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15. Cortical microstructural gradients capture memory network reorganization in temporal lobe epilepsy.
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Royer J, Larivière S, Rodriguez-Cruces R, Cabalo DG, Tavakol S, Auer H, Ngo A, Park BY, Paquola C, Smallwood J, Jefferies E, Caciagli L, Bernasconi A, Bernasconi N, Frauscher B, and Bernhardt BC
- Subjects
- Humans, Quality of Life, Brain pathology, Magnetic Resonance Imaging, Brain Mapping, Epilepsy, Temporal Lobe pathology
- Abstract
Temporal lobe epilepsy (TLE), one of the most common pharmaco-resistant epilepsies, is associated with pathology of paralimbic brain regions, particularly in the mesiotemporal lobe. Cognitive dysfunction in TLE is frequent, and particularly affects episodic memory. Crucially, these difficulties challenge the quality of life of patients, sometimes more than seizures, underscoring the need to assess neural processes of cognitive dysfunction in TLE to improve patient management. Our work harnessed a novel conceptual and analytical approach to assess spatial gradients of microstructural differentiation between cortical areas based on high-resolution MRI analysis. Gradients track region-to-region variations in intracortical lamination and myeloarchitecture, serving as a system-level measure of structural and functional reorganization. Comparing cortex-wide microstructural gradients between 21 patients and 35 healthy controls, we observed a reorganization of this gradient in TLE driven by reduced microstructural differentiation between paralimbic cortices and the remaining cortex with marked abnormalities in ipsilateral temporopolar and dorsolateral prefrontal regions. Findings were replicated in an independent cohort. Using an independent post-mortem dataset, we observed that in vivo findings reflected topographical variations in cortical cytoarchitecture. We indeed found that macroscale changes in microstructural differentiation in TLE reflected increased similarity of paralimbic and primary sensory/motor regions. Disease-related transcriptomics could furthermore show specificity of our findings to TLE over other common epilepsy syndromes. Finally, microstructural dedifferentiation was associated with cognitive network reorganization seen during an episodic memory functional MRI paradigm and correlated with interindividual differences in task accuracy. Collectively, our findings showing a pattern of reduced microarchitectural differentiation between paralimbic regions and the remaining cortex provide a structurally-grounded explanation for large-scale functional network reorganization and cognitive dysfunction characteristic of TLE., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Guarantors of Brain.)
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- 2023
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16. Cancer cells same as zombies reprogram normal cells via the secreted microenvironment.
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Rabiee S, Hoveizi E, Barati M, Salehzadeh A, Joghataei MT, and Tavakol S
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- Humans, Culture Media, Conditioned pharmacology, Culture Media, Conditioned metabolism, Fibroblasts metabolism, DNA metabolism, Tumor Microenvironment, Cell Line, Tumor, Signal Transduction, Neoplasms pathology
- Abstract
The cancer microenvironment plays a crucial role in promoting metastasis and malignancy even in normal cells. In the present study, the effect of acidic and conditioned media of cancer cells (MDA-MB-231), separately and in combination, was studied for the first time on the cell death mechanisms and DNA methylation of normal fibroblasts (NIH/3T3). Cell survival of conditioned media was rescued by the addition of acidic media to conditioned media, as shown by the results. Cell metabolic activity is deviated in a direction other than the Krebs cycle by acidic media The mitochondrial metabolic activity of all groups was enhanced over time, except for acidic media. Unlike the highest amount of ROS in conditioned media, its level decreased to the level of acidic media in the combination group. Furthermore, cells were deviated towards autophagy, rather than apoptosis, by the addition of acidic media to the conditioned media, unlike the conditioned media. Global DNA methylation analysis revealed significantly higher DNA hypomethylation in acidic media than in normal and combination media. Not only were cells treated with conditioned media rescued by acidic media, but also DNA hypomethylation and apoptosis in the combination group were decreased through epigenetic modifications. The acidic and conditioned media produced by cancer cells can remotely activate malignant signaling pathways, much like zombies, which can cause metabolic and epigenetic changes in normal cells., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Rabiee et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
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- 2023
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17. Atypical intrinsic neural timescales in temporal lobe epilepsy.
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Xie K, Royer J, Lariviere S, Rodriguez-Cruces R, de Wael RV, Park BY, Auer H, Tavakol S, DeKraker J, Abdallah C, Caciagli L, Bassett DS, Bernasconi A, Bernasconi N, Frauscher B, Concha L, and Bernhardt BC
- Subjects
- Adult, Humans, Magnetic Resonance Imaging methods, Hippocampus diagnostic imaging, Temporal Lobe, Seizures, Epilepsy, Temporal Lobe diagnosis
- Abstract
Objective: Temporal lobe epilepsy (TLE) is the most common pharmacoresistant epilepsy in adults. Here we profiled local neural function in TLE in vivo, building on prior evidence that has identified widespread structural alterations. Using resting-state functional magnetic resonance imaging (rs-fMRI), we mapped the whole-brain intrinsic neural timescales (INT), which reflect temporal hierarchies of neural processing. Parallel analysis of structural and diffusion MRI data examined associations with TLE-related structural compromise. Finally, we evaluated the clinical utility of INT., Methods: We studied 46 patients with TLE and 44 healthy controls from two independent sites, and mapped INT changes in patients relative to controls across hippocampal, subcortical, and neocortical regions. We examined region-specific associations to structural alterations and explored the effects of age and epilepsy duration. Supervised machine learning assessed the utility of INT for identifying patients with TLE vs controls and left- vs right-sided seizure onset., Results: Relative to controls, TLE showed marked INT reductions across multiple regions bilaterally, indexing faster changing resting activity, with strongest effects in the ipsilateral medial and lateral temporal regions, and bilateral sensorimotor cortices as well as thalamus and hippocampus. Findings were similar, albeit with reduced effect sizes, when correcting for structural alterations. INT reductions in TLE increased with advancing disease duration, yet findings differed from the aging effects seen in controls. INT-derived classifiers discriminated patients vs controls (balanced accuracy, 5-fold: 76% ± 2.65%; cross-site, 72%-83%) and lateralized the focus in TLE (balanced accuracy, 5-fold: 96% ± 2.10%; cross-site, 95%-97%), with high accuracy and cross-site generalizability. Findings were consistent across both acquisition sites and robust when controlling for motion and several methodological confounds., Significance: Our findings demonstrate atypical macroscale function in TLE in a topography that extends beyond mesiotemporal epicenters. INT measurements can assist in TLE diagnosis, seizure focus lateralization, and monitoring of disease progression, which emphasizes promising clinical utility., (© 2023 The Authors. Epilepsia published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)
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- 2023
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18. Meningioma resection and venous thromboembolism incidence, management, and outcomes.
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Rizzo SM, Tavakol S, Bi WL, Li S, Secemsky EA, Campia U, Piazza G, Goldhaber SZ, and Schmaier AA
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Background: Meningioma resection is associated with the risk of venous thromboembolism (VTE)., Objectives: To determine the incidence and risk factors for VTE following meningioma resection and VTE outcomes based on the type and timing of anticoagulation., Methods: From 2011 to 2019, 901 consecutive patients underwent meningioma resection. We retrospectively evaluated the postoperative incidence of VTE and bleeding. For VTE, we determined the treatment strategy and rate of VTE complications and bleeding., Results: Pharmacologic prophylaxis was administered to 665 (73.8%) patients. The cumulative incidence for total postoperative VTE was 8.7% (95% CI: 6.9%-10.6%), and for symptomatic VTE was 6.0% (95% CI: 4.6%-7.7%). A multivariable model identified the following independent predictors of symptomatic VTE: history of VTE, obesity, and lack of pharmacologic prophylaxis. Following postoperative VTE, 58 (74.3%) patients received therapeutic anticoagulation either initially (33.3%) or after a median delay of 23.5 days (41.0%). Symptomatic recurrent VTE occurred in 13 (16.6%) patients. Following VTE, the use of subtherapeutic anticoagulation was associated with a lower rate of total VTE extension than no anticoagulation (17.5% vs 42.9%, OR 0.28, 95% CI: 0.09-0.93). In total, 14 patients (1.6%) experienced clinically relevant bleeding: 4 received therapeutic anticoagulants, 8 received prophylactic anticoagulation, and 2 received no anticoagulation. Among patients with VTE, 4 (5.1%) experienced bleeding., Conclusion: Recognition of risk factors for VTE following meningioma resection may help improve approaches to thromboprophylaxis. The management of postoperative VTE is highly variable, but most VTE patients are ultimately treated with therapeutic anticoagulants., (© 2023 The Author(s).)
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- 2023
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19. Long-range functional connections mirror and link microarchitectural and cognitive hierarchies in the human brain.
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Wang Y, Royer J, Park BY, Vos de Wael R, Larivière S, Tavakol S, Rodriguez-Cruces R, Paquola C, Hong SJ, Margulies DS, Smallwood J, Valk SL, Evans AC, and Bernhardt BC
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- Humans, Magnetic Resonance Imaging methods, Brain Mapping methods, Cognition, Emotions, Neural Pathways, Neocortex, Connectome methods
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Background: Higher-order cognition is hypothesized to be implemented via distributed cortical networks that are linked via long-range connections. However, it is unknown how computational advantages of long-range connections reflect cortical microstructure and microcircuitry., Methods: We investigated this question by (i) profiling long-range cortical connectivity using resting-state functional magnetic resonance imaging (MRI) and cortico-cortical geodesic distance mapping, (ii) assessing how long-range connections reflect local brain microarchitecture, and (iii) examining the microarchitectural similarity of regions connected through long-range connections., Results: Analysis of 2 independent datasets indicated that sensory/motor areas had more clustered short-range connections, while transmodal association systems hosted distributed, long-range connections. Meta-analytical decoding suggested that this topographical difference mirrored shifts in cognitive function, from perception/action towards emotional/social processing. Analysis of myelin-sensitive in vivo MRI as well as postmortem histology and transcriptomics datasets established that gradients in functional connectivity distance are paralleled by those present in cortical microarchitecture. Notably, long-range connections were found to link spatially remote regions of association cortex with an unexpectedly similar microarchitecture., Conclusions: By mapping covarying topographies of long-range functional connections and cortical microcircuits, the current work provides insights into structure-function relations in human neocortex., (© The Author(s) 2022. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
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- 2023
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20. Dutasteride nanoemulsion preparation to inhibit 5-alpha-hair follicle reductase enzymes in the hair follicle; an ex vivo study.
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Memar Bashi Aval M, Hoveizi E, Mombeiny R, Kazemi M, Saeedi S, and Tavakol S
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- Animals, Rats, Dutasteride therapeutic use, 5-alpha Reductase Inhibitors pharmacology, 5-alpha Reductase Inhibitors therapeutic use, Alopecia drug therapy, Hair Follicle, Cholestenone 5 alpha-Reductase
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Alopecia is a treatable disorder that usually occurs due to high levels of 5-alpha dihydrotestosterone in hair follicles. To enhance the storage capacity of hair follicles and alleviate the inherent characteristics of dutasteride, 5-alpha reductase inhibitor, a prolonged-release nanocarrier was synthesised, and its influence on rat abdomen's skin was investigated. Results showed the lower ratio of S/Co (higher ethanol concentration) increased the hydrodynamic nanocarriers' particle size due to thermodynamic disturbance and Ostwald ripening. In contrast, an increase in surfactant through a decrease in interfacial tension resulted in smaller nanocarriers of 32.4 nm. Moreover, an increase in viscosity had an inverse correlation with the nanoemulsions' particle size. Nanocarriers containing ethanol showed less entrapment efficacy, perhaps due to the rapid dissolution of dutasteride into ethanol during nanoemulsification, while, based on Stokes' equation, the addition of ethanol resulted in smaller particle size and stability of the system. Skin permeation analysis using Franz diffusion cells showed nanocarriers could pass through the skin and release dutasteride for 6 days. In conclusion, the optimum concentration of ingredients is decisive in guaranteeing the ideal particle size, stability, and skin permeation of nanocarriers. The Present dutasteride nanocarrier would promise a prolonged and sustained-release drug delivery system for Alopecia therapy., (© 2022 The Authors. IET Nanobiotechnology published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology.)
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- 2023
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21. The Twofold Role of Osteogenic Small Molecules in Parkinson's Disease Therapeutics: Crosstalk of Osteogenesis and Neurogenesis.
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Tavakol S
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- Aged, Humans, Osteogenesis, Substantia Nigra, Neurogenesis, Signal Transduction physiology, Dopaminergic Neurons, Ubiquitin-Protein Ligases metabolism, Parkinson Disease drug therapy, Parkinson Disease metabolism
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Deemed one of the most problematic neurodegenerative diseases in the elderly population, Parkinson's disease remains incurable to date. Ongoing diagnostic studies, however, have revealed that a large number of small molecule drugs that trigger the BMP2-Smad signaling pathway with an osteogenic nature may be effective in Parkinson's disease treatment. Although BMP2 and Smad1, 3, and 5 biomolecules promote neurite outgrowth and neuroprotection in dopaminergic cells as well, small molecules are quicker at crossing the BBB and reaching the damaged dopaminergic neurons located in the substantia nigra due to a molecular weight less than 500 Da. It is worth noting that osteogenic small molecules that inhibit Smurf1 phosphorylation do not offer therapeutic opportunities for Parkinson's disease; whereas, osteogenic small molecules that trigger Smad1, 3, and 5 phosphorylation may have strong therapeutic implications in Parkinson's disease by increasing the survival rate of dopaminergic cells and neuritogenesis. Notably, from a different perspective, it might be said that osteogenic small molecules can possibly put forth therapeutic options for Parkinson's disease by improving neuritogenesis and cell survival., Competing Interests: The author indicates no potential conflicts of interest., (Copyright © 2022 Shima Tavakol.)
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- 2022
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22. An Open MRI Dataset For Multiscale Neuroscience.
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Royer J, Rodríguez-Cruces R, Tavakol S, Larivière S, Herholz P, Li Q, Vos de Wael R, Paquola C, Benkarim O, Park BY, Lowe AJ, Margulies D, Smallwood J, Bernasconi A, Bernasconi N, Frauscher B, and Bernhardt BC
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- Adult, Canada, Diffusion Magnetic Resonance Imaging, Female, Humans, Male, Connectome, Neuroimaging methods
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Multimodal neuroimaging grants a powerful window into the structure and function of the human brain at multiple scales. Recent methodological and conceptual advances have enabled investigations of the interplay between large-scale spatial trends (also referred to as gradients) in brain microstructure and connectivity, offering an integrative framework to study multiscale brain organization. Here, we share a multimodal MRI dataset for Microstructure-Informed Connectomics (MICA-MICs) acquired in 50 healthy adults (23 women; 29.54 ± 5.62 years) who underwent high-resolution T1-weighted MRI, myelin-sensitive quantitative T1 relaxometry, diffusion-weighted MRI, and resting-state functional MRI at 3 Tesla. In addition to raw anonymized MRI data, this release includes brain-wide connectomes derived from (i) resting-state functional imaging, (ii) diffusion tractography, (iii) microstructure covariance analysis, and (iv) geodesic cortical distance, gathered across multiple parcellation scales. Alongside, we share large-scale gradients estimated from each modality and parcellation scale. Our dataset will facilitate future research examining the coupling between brain microstructure, connectivity, and function. MICA-MICs is available on the Canadian Open Neuroscience Platform data portal ( https://portal.conp.ca ) and the Open Science Framework ( https://osf.io/j532r/ )., (© 2022. The Author(s).)
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- 2022
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23. Fingolimod Nanoemulsions at Different Particle Sizes Define the Fate of Spinal Cord Injury Recovery.
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Poormoghadam D, Shiadeh BR, Azedi F, Tavakol H, Rezayat SM, and Tavakol S
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- Animals, Delayed-Action Preparations pharmacology, Endothelial Cells, Particle Size, Rats, Spinal Cord metabolism, Fingolimod Hydrochloride pharmacology, Spinal Cord Injuries metabolism
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Spinal cord injury (SCI) is a debilitating condition for which no definitive treatment has yet been identified. Notably, it influences other tissues through inflammatory reactions and metabolic disturbances. Therefore, fingolimod (FTY-720), as an FDA-approved inflammatory modulator, would be promising. In the present study, nanocarriers with two distinct monodisperse particle sizes of 60 (nF60) and 190 (nF190) nm were prepared via low-(stirring) and high-energy (probe ultrasound) emulsion oil in water (O/W) methods. Larger nanocarriers showed higher EE% and sustained-release profile than smaller nanocarriers. Neural stem cell (NSC) viability and lactate dehydrogenase (LDH) release were studied in the presence of nanocarriers and free FTY-720. The results indicated that nanocarriers and free FTY-720 enhanced NSC viability compared with the control group. However, nF190 induced significantly less cell membrane damage than nF60. Nanocarriers and free FTY-720 enhanced motor neuron recovery in SCI rats, while body weight and return to bladder reflux by nF190 were significantly higher than those in the nF60 group. Return to bladder reflux might be due to the role of FTY-720 in the regulation of detrusor muscle tone and preservation of the integrity of vessels by acting on endothelial cells. Moreover, nF190 gained higher soleus muscle weight than the free drugs; probably decreasing proinflammatory cytokines in the soleus diminishes muscular atrophy in SCI rats. In summary, it might be said that larger nanocarriers with sustained-release profile and less cell membrane damage seem to be more efficient than smaller ones to manage SCI and enhance bladder reflux. These data will help pharmaceutical companies select the correct particle size for nanodrugs and develop more efficient drug formulations to treat SCI., Competing Interests: The authors declare no competing interests., (Copyright © 2022 Delaram Poormoghadam et al.)
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- 2022
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24. Epidural electrical stimulation of the cervical spinal cord opposes opioid-induced respiratory depression.
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Huang R, Worrell J, Garner E, Wang S, Homsey T, Xu B, Galer EL, Zhou Y, Tavakol S, Daneshvar M, Le T, Vinters HV, Salamon N, McArthur DL, Nuwer MR, Wu I, Leiter JC, and Lu DC
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- Analgesics, Opioid adverse effects, Apnea, Electric Stimulation methods, Humans, Remifentanil, Spinal Cord physiology, Cervical Cord, Respiratory Insufficiency chemically induced, Respiratory Insufficiency therapy, Spinal Cord Injuries
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Opioid overdose suppresses brainstem respiratory circuits, causes apnoea and may result in death. Epidural electrical stimulation (EES) at the cervical spinal cord facilitated motor activity in rodents and humans, and we hypothesized that EES of the cervical spinal cord could antagonize opioid-induced respiratory depression in humans. Eighteen patients requiring surgical access to the dorsal surface of the spinal cord between C2 and C7 received EES or sham stimulation for up to 90 s at 5 or 30 Hz during complete (OFF-State) or partial suppression (ON-State) of respiration induced by remifentanil. During the ON-State, 30 Hz EES at C4 and 5 Hz EES at C3/4 increased tidal volume and decreased the end-tidal carbon dioxide level compared to pre-stimulation control levels. EES of 5 Hz at C5 and C7 increased respiratory frequency compared to pre-stimulation control levels. In the OFF-State, 30 Hz cervical EES at C3/4 terminated apnoea and induced rhythmic breathing. In cadaveric tissue obtained from a brain bank, more neurons expressed both the neurokinin 1 receptor (NK1R) and somatostatin (SST) in the cervical spinal levels responsive to EES (C3/4, C6 and C7) compared to a region non-responsive to EES (C2). Thus, the capacity of cervical EES to oppose opioid depression of respiration may be mediated by NK1R+/SST+ neurons in the dorsal cervical spinal cord. This study provides proof of principle that cervical EES may provide a novel therapeutic approach to augment respiratory activity when the neural function of the central respiratory circuits is compromised by opioids or other pathological conditions. KEY POINTS: Epidural electrical stimulation (EES) using an implanted spinal cord stimulator (SCS) is an FDA-approved method to manage chronic pain. We tested the hypothesis that cervical EES facilitates respiration during administration of opioids in 18 human subjects who were treated with low-dose remifentanil that suppressed respiration (ON-State) or high-dose remifentanil that completely inhibited breathing (OFF-State) during the course of cervical surgery. Dorsal cervical EES of the spinal cord augmented the respiratory tidal volume or increased the respiratory frequency, and the response to EES varied as a function of the stimulation frequency (5 or 30 Hz) and the cervical level stimulated (C2-C7). Short, continuous cervical EES restored a cyclic breathing pattern (eupnoea) in the OFF-State, suggesting that cervical EES reversed the opioid-induced respiratory depression. These findings add to our understanding of respiratory pattern modulation and suggest a novel mechanism to oppose the respiratory depression caused by opioids., (© 2022 The Authors. The Journal of Physiology © 2022 The Physiological Society.)
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- 2022
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25. Topographic divergence of atypical cortical asymmetry and atrophy patterns in temporal lobe epilepsy.
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Park BY, Larivière S, Rodríguez-Cruces R, Royer J, Tavakol S, Wang Y, Caciagli L, Caligiuri ME, Gambardella A, Concha L, Keller SS, Cendes F, Alvim MKM, Yasuda C, Bonilha L, Gleichgerrcht E, Focke NK, Kreilkamp BAK, Domin M, von Podewils F, Langner S, Rummel C, Rebsamen M, Wiest R, Martin P, Kotikalapudi R, Bender B, O'Brien TJ, Law M, Sinclair B, Vivash L, Kwan P, Desmond PM, Malpas CB, Lui E, Alhusaini S, Doherty CP, Cavalleri GL, Delanty N, Kälviäinen R, Jackson GD, Kowalczyk M, Mascalchi M, Semmelroch M, Thomas RH, Soltanian-Zadeh H, Davoodi-Bojd E, Zhang J, Lenge M, Guerrini R, Bartolini E, Hamandi K, Foley S, Weber B, Depondt C, Absil J, Carr SJA, Abela E, Richardson MP, Devinsky O, Severino M, Striano P, Parodi C, Tortora D, Hatton SN, Vos SB, Duncan JS, Galovic M, Whelan CD, Bargalló N, Pariente J, Conde-Blanco E, Vaudano AE, Tondelli M, Meletti S, Kong XZ, Francks C, Fisher SE, Caldairou B, Ryten M, Labate A, Sisodiya SM, Thompson PM, McDonald CR, Bernasconi A, Bernasconi N, and Bernhardt BC
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- Adult, Atrophy pathology, Hippocampus pathology, Humans, Magnetic Resonance Imaging, Connectome, Epilepsy, Temporal Lobe pathology
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Temporal lobe epilepsy, a common drug-resistant epilepsy in adults, is primarily a limbic network disorder associated with predominant unilateral hippocampal pathology. Structural MRI has provided an in vivo window into whole-brain grey matter structural alterations in temporal lobe epilepsy relative to controls, by either mapping (i) atypical inter-hemispheric asymmetry; or (ii) regional atrophy. However, similarities and differences of both atypical asymmetry and regional atrophy measures have not been systematically investigated. Here, we addressed this gap using the multisite ENIGMA-Epilepsy dataset comprising MRI brain morphological measures in 732 temporal lobe epilepsy patients and 1418 healthy controls. We compared spatial distributions of grey matter asymmetry and atrophy in temporal lobe epilepsy, contextualized their topographies relative to spatial gradients in cortical microstructure and functional connectivity calculated using 207 healthy controls obtained from Human Connectome Project and an independent dataset containing 23 temporal lobe epilepsy patients and 53 healthy controls and examined clinical associations using machine learning. We identified a marked divergence in the spatial distribution of atypical inter-hemispheric asymmetry and regional atrophy mapping. The former revealed a temporo-limbic disease signature while the latter showed diffuse and bilateral patterns. Our findings were robust across individual sites and patients. Cortical atrophy was significantly correlated with disease duration and age at seizure onset, while degrees of asymmetry did not show a significant relationship to these clinical variables. Our findings highlight that the mapping of atypical inter-hemispheric asymmetry and regional atrophy tap into two complementary aspects of temporal lobe epilepsy-related pathology, with the former revealing primary substrates in ipsilateral limbic circuits and the latter capturing bilateral disease effects. These findings refine our notion of the neuropathology of temporal lobe epilepsy and may inform future discovery and validation of complementary MRI biomarkers in temporal lobe epilepsy., (© The Author(s) (2021). Published by Oxford University Press on behalf of the Guarantors of Brain.)
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- 2022
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26. A molecularly integrated grade for meningioma.
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Driver J, Hoffman SE, Tavakol S, Woodward E, Maury EA, Bhave V, Greenwald NF, Nassiri F, Aldape K, Zadeh G, Choudhury A, Vasudevan HN, Magill ST, Raleigh DR, Abedalthagafi M, Aizer AA, Alexander BM, Ligon KL, Reardon DA, Wen PY, Al-Mefty O, Ligon AH, Dubuc AM, Beroukhim R, Claus EB, Dunn IF, Santagata S, and Bi WL
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- Adult, Cohort Studies, Humans, Neoplasm Grading, Neoplasm Recurrence, Local genetics, Prognosis, Retrospective Studies, World Health Organization, Meningeal Neoplasms pathology, Meningioma pathology
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Background: Meningiomas are the most common primary intracranial tumor in adults. Clinical care is currently guided by the World Health Organization (WHO) grade assigned to meningiomas, a 3-tiered grading system based on histopathology features, as well as extent of surgical resection. Clinical behavior, however, often fails to conform to the WHO grade. Additional prognostic information is needed to optimize patient management., Methods: We evaluated whether chromosomal copy-number data improved prediction of time-to-recurrence for patients with meningioma who were treated with surgery, relative to the WHO schema. The models were developed using Cox proportional hazards, random survival forest, and gradient boosting in a discovery cohort of 527 meningioma patients and validated in 2 independent cohorts of 172 meningioma patients characterized by orthogonal genomic platforms., Results: We developed a 3-tiered grading scheme (Integrated Grades 1-3), which incorporated mitotic count and loss of chromosome 1p, 3p, 4, 6, 10, 14q, 18, 19, or CDKN2A. 32% of meningiomas reclassified to either a lower-risk or higher-risk Integrated Grade compared to their assigned WHO grade. The Integrated Grade more accurately identified meningioma patients at risk for recurrence, relative to the WHO grade, as determined by time-dependent area under the curve, average precision, and the Brier score., Conclusion: We propose a molecularly integrated grading scheme for meningiomas that significantly improves upon the current WHO grading system in prediction of progression-free survival. This framework can be broadly adopted by clinicians with relative ease using widely available genomic technologies and presents an advance in the care of meningioma patients., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Neuro-Oncology.)
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- 2022
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27. Differentiation of Human Wharton's Jelly Mesenchymal Stem Cells into SOX17 Expressing Cells Using a Wnt/ß-catenin Pathway Agonist on Polylactic Acid/Chitosan Nanocomposite Scaffold.
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Hoveizi E and Tavakol SH
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Objective: The β-catenin signaling pathway promises the potential for differentiation of stem cells into definitive endoderm (DE) cells as precursors of beta cells. Therefore, it can be considered as an inducer for cell replacement therapies in diabetes. The main goal of this research is to successfully culture and induce differentiation of human Wharton's jelly mesenchymal stem cells (hWJMSCs) into Sox17-expressing cells using a Wnt/β-catenin pathway agonist (SKL2001) plus nanoparticles on a polylactic acid/chitosan (PLA/Cs) nanocomposite scaffold., Materials and Methods: In this experimental study, the nanocomposite was prepared through an electrospinning method and hWJMSCs were isolated through an explant technique. The morphology and the cell viability were evaluated by scanning electron microscopy (SEM) and 3-(4, 5- Dimethylthiazol-2)-2, 5-diphenyltetrazolium bromide (MTT) assay. Here, we present two differentiation protocols: the first one is induction with SKL2001; and the second one is with a combination of SKL2001 and zinc oxide nanoparticles (nZnO). Real-time quantitative reverse transcription (QRT-PCR) and immunocytochemistry analysis are carried out to examine the expression of specific markers in the differentiated cells., Results: The nanocomposite had appropriate biocompatibility for cell adhesion and growth. While the hWJMSCs cultured on the PLA/Cs scaffolds differentiated into DE cells in the presence of SKL2001, introducing nZnO to their environment increased the differentiation process. Analyses of DE-specific markers including SOX17, FOXA2 , and gooscoid (GSC) genes in mRNA level, indicated significantly high levels of expression in the SKL2001/nZnO group, followed by SKL2001 group compared to the control., Conclusion: Our results show the beneficial effects of the Wnt/β-catenin pathway agonist in three-dimensional (3D) cultures in cell replacement therapy for diabetes., Competing Interests: There is no conflict of interest in this study., (Copyright© by Royan Institute. All rights reserved.)
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- 2022
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28. Cyst Type Differentiates Rathke Cleft Cysts From Cystic Pituitary Adenomas.
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Tavakol S, Catalino MP, Cote DJ, Boles X, Laws ER Jr, and Bi WL
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Purpose: A classification system for cystic sellar lesions does not exist. We propose a novel classification scheme for these lesions based on the heterogeneity of the cyst wall/contents and the presence of a solid component on imaging., Methods: We retrospectively reviewed 205 patients' medical records (2008-2020) who underwent primary surgery for a cystic sellar lesion. Cysts were classified a priori into 1 of 4 cyst types based on the heterogeneity of the cyst wall/contents and the presence of a solid component imaging. There was high interrater reliability. Univariable and multivariable models were used to estimate the ability of cyst type to predict the two most common diagnoses: Rathke cleft cyst (RCC) and cystic pituitary adenoma., Results: The frequencies of RCC and cystic pituitary adenoma in our cohort were 45.4% and 36.4%, respectively. Non-neoplastic lesions (e.g., arachnoid cysts and RCC) were more likely to be Type 1 or 2, whereas cystic neoplasms (e.g., pituitary adenomas and craniopharyngiomas) were more likely to be Type 3 or 4 (p<0.0001). Higher cyst types, compared to Type 1, had higher odds of being cystic pituitary adenomas compared to RCCs (OR: 23.7, p=0.033, and 342.6, p <0.0001, for Types 2 and 4, respectively). Lesions with a fluid-fluid level on preoperative MRI also had higher odds of being pituitary adenomas (OR: 12.7; p=0.023). Cystic pituitary adenomas were more common in patients with obesity (OR: 5.0, p=0.003) or symptomatic hyperprolactinemia (OR: 11.5; p<0.001, respectively). The multivariable model had a positive predictive value of 82.2% and negative predictive value of 86.4%., Conclusion: When applied to the diagnosis of RCC versus cystic pituitary adenoma, higher cystic lesion types (Type 2 & 4), presence of fluid-fluid level, symptomatic hyperprolactinemia, and obesity were predictors of cystic pituitary adenoma. Further validation is needed, but this classification scheme may prove to be a useful tool for the management of patients with common sellar pathology., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Tavakol, Catalino, Cote, Boles, Laws and Bi.)
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- 2021
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29. Anti-inflammatory ethosomal nanoformulation in combination with iontophoresis in chronic wound healing: An ex vivo study.
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Mombeiny R, Tavakol S, Kazemi M, Mehdizadeh M, Hasanzadeh A, Karimi Babaahmadi M, Abedi A, and Keyhanvar P
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- Administration, Cutaneous, Animals, Anti-Inflammatory Agents pharmacology, Liposomes metabolism, Rats, Skin metabolism, Wound Healing, Iontophoresis, Skin Absorption
- Abstract
Prescription of anti-inflammatory drugs may be considered as a promising strategy in chronic wound healing where the inflammatory disturbance has delayed the healing process. It seems that hydrocortisone 17-butyrate (HB17) would be promising in the form of a nano-formulation to enhance drug delivery efficacy. In the present study, transdermal delivery of nano-HB17 in combination with iontophoresis was investigated ex vivo. Ethosomal-HB17 was synthesised using lecithin, ethanol and cholesterol with a different ratio by hot method. The negative ethosomal-HB17 particle size was around 244 ± 4.3 nm with high stability of up to 30 days. Additionally, evaluated entrapment efficiency of HB17 in ethosomes by high performance liquid chromatography was 40.6 ± 2.21%. Moreover, the permeation speed and amount of H17B in complete-thickness rat skin in the presence and absence of iontophoresis showed that the penetration of free H17B and ethosomal-H17B formulations were zero and 7.98 μg/cm
2 in 120 min, respectively. Whereas in the case of applying iontophoresis, permeation amount obtained was zero and 19.69 μg/cm2 in 30 min in free H17B and ethosomal-H17B formulations, respectively. It has been concluded that transdermal delivery of ethosomal-H17B is an effective strategy to enhance drug delivery and it will be improved when it is combined with iontophoresis., (© 2021 The Authors. IET Nanobiotechnology published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology.)- Published
- 2021
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30. Structural Connectivity Gradients of the Temporal Lobe Serve as Multiscale Axes of Brain Organization and Cortical Evolution.
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Vos de Wael R, Royer J, Tavakol S, Wang Y, Paquola C, Benkarim O, Eichert N, Larivière S, Xu T, Misic B, Smallwood J, Valk SL, and Bernhardt BC
- Subjects
- Brain diagnostic imaging, Humans, Magnetic Resonance Imaging methods, Temporal Lobe diagnostic imaging, Connectome methods, Epilepsy, Temporal Lobe
- Abstract
The temporal lobe is implicated in higher cognitive processes and is one of the regions that underwent substantial reorganization during primate evolution. Its functions are instantiated, in part, by the complex layout of its structural connections. Here, we identified low-dimensional representations of structural connectivity variations in human temporal cortex and explored their microstructural underpinnings and associations to macroscale function. We identified three eigenmodes which described gradients in structural connectivity. These gradients reflected inter-regional variations in cortical microstructure derived from quantitative magnetic resonance imaging and postmortem histology. Gradient-informed models accurately predicted macroscale measures of temporal lobe function. Furthermore, the identified gradients aligned closely with established measures of functional reconfiguration and areal expansion between macaques and humans, highlighting their potential role in shaping temporal lobe function throughout primate evolution. Findings were replicated in several datasets. Our results provide robust evidence for three axes of structural connectivity in human temporal cortex with consistent microstructural underpinnings and contributions to large-scale brain network function., (© The Author(s) 2021. Published by Oxford University Press.)
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- 2021
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31. Atypical neural topographies underpin dysfunctional pattern separation in temporal lobe epilepsy.
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Li Q, Tavakol S, Royer J, Larivière S, Vos De Wael R, Park BY, Paquola C, Zeng D, Caldairou B, Bassett DS, Bernasconi A, Bernasconi N, Frauscher B, Smallwood J, Caciagli L, Li S, and Bernhardt BC
- Subjects
- Adult, Connectome, Female, Functional Laterality physiology, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Neuropsychological Tests, Young Adult, Brain diagnostic imaging, Cognition physiology, Epilepsy, Temporal Lobe diagnostic imaging, Memory, Episodic
- Abstract
Episodic memory is the ability to remember events from our past accurately. The process of pattern separation is hypothesized to underpin this ability and is defined as the capacity to orthogonalize memory traces, to maximize the features that make them unique. Contemporary cognitive neuroscience suggests that pattern separation entails complex interactions between the hippocampus and neocortex, where specific hippocampal subregions shape neural reinstatement in the neocortex. To test this hypothesis, the current work studied both healthy controls and patients with temporal lobe epilepsy who presented with hippocampal structural anomalies. We measured neural activity in all participants using functional MRI while they retrieved memorized items or lure items, which shared features with the target. Behaviourally, patients with temporal lobe epilepsy were less able to exclude lures than controls and showed a reduction in pattern separation. To assess the hypothesized relationship between neural patterns in the hippocampus and neocortex, we identified the topographic gradients of intrinsic connectivity along neocortical and hippocampal subfield surfaces and determined the topographic profile of the neural activity accompanying pattern separation. In healthy controls, pattern separation followed a graded topography of neural activity, both along the hippocampal long axis (and peaked in anterior segments that are more heavily engaged in transmodal processing) and along the neocortical hierarchy running from unimodal to transmodal regions (peaking in transmodal default mode regions). In patients with temporal lobe epilepsy, however, this concordance between task-based functional activations and topographic gradients was markedly reduced. Furthermore, person-specific measures of concordance between task-related activity and connectivity gradients in patients and controls were related to inter-individual differences in behavioural measures of pattern separation and episodic memory, highlighting the functional relevance of the observed topographic motifs. Our work is consistent with an emerging understanding that successful discrimination between memories with similar features entails a shift in the locus of neural activity away from sensory systems, a pattern that is mirrored along the hippocampal long axis and with respect to neocortical hierarchies. More broadly, our study establishes topographic profiling using intrinsic connectivity gradients, capturing the functional underpinnings of episodic memory processes in a manner that is sensitive to their reorganization in pathology., (© The Author(s) (2021). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For permissions, please email: journals.permissions@oup.com.)
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- 2021
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32. A Structure-Function Substrate of Memory for Spatial Configurations in Medial and Lateral Temporal Cortices.
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Tavakol S, Li Q, Royer J, Vos de Wael R, Larivière S, Lowe A, Paquola C, Jefferies E, Hartley T, Bernasconi A, Bernasconi N, Smallwood J, Bohbot V, Caciagli L, and Bernhardt B
- Subjects
- Adult, Female, Humans, Magnetic Resonance Imaging methods, Male, Semantics, Memory physiology, Photic Stimulation methods, Psychomotor Performance physiology, Space Perception physiology, Temporal Lobe diagnostic imaging, Temporal Lobe physiology
- Abstract
Prior research has shown a role of the medial temporal lobe, particularly the hippocampal-parahippocampal complex, in spatial cognition. Here, we developed a new paradigm, the conformational shift spatial task (CSST), which examines the ability to encode and retrieve spatial relations between unrelated items. This task is short, uses symbolic cues, incorporates two difficulty levels, and can be administered inside the scanner. A cohort of 48 healthy young adults underwent the CSST, together with a set of behavioral measures and multimodal magnetic resonance imaging (MRI). Inter-individual differences in CSST performance correlated with scores on an established spatial memory paradigm, but neither with episodic memory nor mnemonic discrimination, supporting specificity. Analyzing high-resolution structural MRI data, individuals with better spatial memory showed thicker medial and lateral temporal cortices. Functional relevance of these findings was supported by task-based functional MRI analysis in the same participants and ad hoc meta-analysis. Exploratory resting-state functional MRI analyses centered on clusters of morphological effects revealed additional modulation of intrinsic network integration, particularly between lateral and medial temporal structures. Our work presents a novel spatial memory paradigm and supports an integrated structure-function substrate in the human temporal lobe. Task paradigms are programmed in python and made open access., (© The Author(s) 2021. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.)
- Published
- 2021
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33. The role of nanotechnology in current COVID-19 outbreak.
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Tavakol S, Zahmatkeshan M, Mohammadinejad R, Mehrzadi S, Joghataei MT, Alavijeh MS, and Seifalian A
- Abstract
COVID-19 has recently become one of the most challenging pandemics of the last century with deadly outcomes and a high rate of reproduction number. It emphasizes the critical need for the designing of efficient vaccines to prevent virus infection, early and fast diagnosis by the high sensitivity and selectivity diagnostic kits, and effective antiviral and protective therapeutics to decline and eliminate the viral load and side effects derived from tissue damages. Therefore, non-toxic antiviral nanoparticles (NPs) have been under development for clinical application to prevent and treat COVID-19. NPs showed great promise to provide nano vaccines against viral infections. Here, we discuss the potentials of NPs that may be applied as a drug itself or as a platform for the aim of drug and vaccine repurposing and development. Meanwhile, the advanced strategies based on NPs to detect viruses will be described with the goal of encouraging scientists to design effective and cost-benefit nanoplatforms for prevention, diagnosis, and treatment., (© 2021 Published by Elsevier Ltd.)
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- 2021
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34. Signal diffusion along connectome gradients and inter-hub routing differentially contribute to dynamic human brain function.
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Park BY, Vos de Wael R, Paquola C, Larivière S, Benkarim O, Royer J, Tavakol S, Cruces RR, Li Q, Valk SL, Margulies DS, Mišić B, Bzdok D, Smallwood J, and Bernhardt BC
- Subjects
- Adult, Brain physiology, Cognition, Female, Humans, Male, Markov Chains, Neural Pathways diagnostic imaging, Neural Pathways physiology, Young Adult, Brain diagnostic imaging, Connectome, Diffusion Magnetic Resonance Imaging, Functional Neuroimaging, Magnetic Resonance Imaging
- Abstract
Human cognition is dynamic, alternating over time between externally-focused states and more abstract, often self-generated, patterns of thought. Although cognitive neuroscience has documented how networks anchor particular modes of brain function, mechanisms that describe transitions between distinct functional states remain poorly understood. Here, we examined how time-varying changes in brain function emerge within the constraints imposed by macroscale structural network organization. Studying a large cohort of healthy adults (n = 326), we capitalized on manifold learning techniques that identify low dimensional representations of structural connectome organization and we decomposed neurophysiological activity into distinct functional states and their transition patterns using Hidden Markov Models. Structural connectome organization predicted dynamic transitions anchored in sensorimotor systems and those between sensorimotor and transmodal states. Connectome topology analyses revealed that transitions involving sensorimotor states traversed short and intermediary distances and adhered strongly to communication mechanisms of network diffusion. Conversely, transitions between transmodal states involved spatially distributed hubs and increasingly engaged long-range routing. These findings establish that the structure of the cortex is optimized to allow neural states the freedom to vary between distinct modes of processing, and so provides a key insight into the neural mechanisms that give rise to the flexibility of human cognition., Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interest., (Copyright © 2020. Published by Elsevier Inc.)
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- 2021
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35. New Horizons in Hydrogels for Methotrexate Delivery.
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Dehshahri A, Kumar A, Madamsetty VS, Uzieliene I, Tavakol S, Azedi F, Fekri HS, Zarrabi A, Mohammadinejad R, and Thakur VK
- Abstract
Since its first clinical application, methotrexate (MTX) has been widely used for the treatment of human diseases. Despite great advantages, some properties such as poor absorption, short plasma half-life and unpredictable bioavailability have led researchers to seek novel delivery systems to improve its characteristics for parenteral and oral administration. Recently, great attention has been directed to hydrogels for the preparation of MTX formulations. This review describes the potential of hydrogels for the formulation of MTX to treat cancer, rheumatoid arthritis, psoriasis and central nervous system diseases. We will delineate the state-of-the-art and promising potential of hydrogels for systemic MTX delivery as well as transdermal delivery of the drug-using hydrogel-based formulations.
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- 2020
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36. Convergence of cortical types and functional motifs in the human mesiotemporal lobe.
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Paquola C, Benkarim O, DeKraker J, Larivière S, Frässle S, Royer J, Tavakol S, Valk S, Bernasconi A, Bernasconi N, Khan A, Evans AC, Razi A, Smallwood J, and Bernhardt BC
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- Adult, Aged, Brain Mapping, Female, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Neural Pathways physiology, Cognition physiology, Hippocampus physiology, Models, Biological, Parahippocampal Gyrus physiology, Temporal Lobe physiology
- Abstract
The mesiotemporal lobe (MTL) is implicated in many cognitive processes, is compromised in numerous brain disorders, and exhibits a gradual cytoarchitectural transition from six-layered parahippocampal isocortex to three-layered hippocampal allocortex. Leveraging an ultra-high-resolution histological reconstruction of a human brain, our study showed that the dominant axis of MTL cytoarchitectural differentiation follows the iso-to-allocortical transition and depth-specific variations in neuronal density. Projecting the histology-derived MTL model to in-vivo functional MRI, we furthermore determined how its cytoarchitecture underpins its intrinsic effective connectivity and association to large-scale networks. Here, the cytoarchitectural gradient was found to underpin intrinsic effective connectivity of the MTL, but patterns differed along the anterior-posterior axis. Moreover, while the iso-to-allocortical gradient parametrically represented the multiple-demand relative to task-negative networks, anterior-posterior gradients represented transmodal versus unimodal networks. Our findings establish that the combination of micro- and macrostructural features allow the MTL to represent dominant motifs of whole-brain functional organisation., Competing Interests: CP, OB, JD, SL, SF, JR, ST, SV, AB, NB, AK, AE, AR, JS, BB No competing interests declared, (© 2020, Paquola et al.)
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- 2020
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37. Progress in Delivery of siRNA-Based Therapeutics Employing Nano-Vehicles for Treatment of Prostate Cancer.
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Ashrafizadeh M, Hushmandi K, Rahmani Moghadam E, Zarrin V, Hosseinzadeh Kashani S, Bokaie S, Najafi M, Tavakol S, Mohammadinejad R, Nabavi N, Hsieh CL, Zarepour A, Zare EN, Zarrabi A, and Makvandi P
- Abstract
Prostate cancer (PCa) accounts for a high number of deaths in males with no available curative treatments. Patients with PCa are commonly diagnosed in advanced stages due to the lack of symptoms in the early stages. Recently, the research focus was directed toward gene editing in cancer therapy. Small interfering RNA (siRNA) intervention is considered as a powerful tool for gene silencing (knockdown), enabling the suppression of oncogene factors in cancer. This strategy is applied to the treatment of various cancers including PCa. The siRNA can inhibit proliferation and invasion of PCa cells and is able to promote the anti-tumor activity of chemotherapeutic agents. However, the off-target effects of siRNA therapy remarkably reduce its efficacy in PCa therapy. To date, various carriers were designed to improve the delivery of siRNA and, among them, nanoparticles are of importance. Nanoparticles enable the targeted delivery of siRNAs and enhance their potential in the downregulation of target genes of interest. Additionally, nanoparticles can provide a platform for the co-delivery of siRNAs and anti-tumor drugs, resulting in decreased growth and migration of PCa cells. The efficacy, specificity, and delivery of siRNAs are comprehensively discussed in this review to direct further studies toward using siRNAs and their nanoscale-delivery systems in PCa therapy and perhaps other cancer types.
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- 2020
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38. Myeloarchitecture gradients in the human insula: Histological underpinnings and association to intrinsic functional connectivity.
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Royer J, Paquola C, Larivière S, Vos de Wael R, Tavakol S, Lowe AJ, Benkarim O, Evans AC, Bzdok D, Smallwood J, Frauscher B, and Bernhardt BC
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- Adult, Aged, Diagnosis, Female, Humans, Male, Young Adult, Cerebral Cortex anatomy & histology, Cerebral Cortex diagnostic imaging, Cerebral Cortex physiology, Connectome methods, Limbic System anatomy & histology, Limbic System diagnostic imaging, Limbic System physiology, Magnetic Resonance Imaging methods, Myelin Sheath
- Abstract
Insular cortex is a core hub involved in multiple cognitive and socio-affective processes. Yet, the anatomical mechanisms that explain how it is involved in such a diverse array of functions remain incompletely understood. Here, we tested the hypothesis that changes in myeloarchitecture across the insular cortex explain how it can be involved in many different facets of cognitive function. Detailed intracortical profiling, performed across hundreds of insular locations on the basis of myelin-sensitive magnetic resonance imaging (MRI), was compressed into a lower-dimensional space uncovering principal axes of myeloarchitectonic variation. Leveraging two datasets with different high-resolution MRI contrasts, we obtained robust support for two principal dimensions of insular myeloarchitectonic differentiation in vivo, one running from ventral anterior to posterior banks and one radiating from dorsal anterior towards both ventral anterior and posterior subregions. Analyses of post mortem 3D histological data showed that the antero-posterior axis was mirrored in cytoarchitectural markers, even when controlling for sulco-gyral folding. Resting-state functional connectomics in the same individuals and ad hoc meta-analyses showed that myelin gradients in the insula relate to diverse affiliation to macroscale intrinsic functional systems, showing differential shifts in functional network embedding across each myelin-derived gradient. Collectively, our findings offer a novel approach to capture structure-function interactions of a key node of the limbic system, and suggest a multidimensional structural basis underlying the diverse functional roles of the insula., (Copyright © 2020. Published by Elsevier Inc.)
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- 2020
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39. BrainSpace: a toolbox for the analysis of macroscale gradients in neuroimaging and connectomics datasets.
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Vos de Wael R, Benkarim O, Paquola C, Lariviere S, Royer J, Tavakol S, Xu T, Hong SJ, Langs G, Valk S, Misic B, Milham M, Margulies D, Smallwood J, and Bernhardt BC
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- Diffusion Tensor Imaging, Humans, Neocortex physiology, Nerve Net physiology, Predictive Value of Tests, Reproducibility of Results, Workflow, Artificial Intelligence, Brain Mapping, Image Interpretation, Computer-Assisted, Magnetic Resonance Imaging, Neocortex diagnostic imaging, Nerve Net diagnostic imaging
- Abstract
Understanding how cognitive functions emerge from brain structure depends on quantifying how discrete regions are integrated within the broader cortical landscape. Recent work established that macroscale brain organization and function can be described in a compact manner with multivariate machine learning approaches that identify manifolds often described as cortical gradients. By quantifying topographic principles of macroscale organization, cortical gradients lend an analytical framework to study structural and functional brain organization across species, throughout development and aging, and its perturbations in disease. Here, we present BrainSpace, a Python/Matlab toolbox for (i) the identification of gradients, (ii) their alignment, and (iii) their visualization. Our toolbox furthermore allows for controlled association studies between gradients with other brain-level features, adjusted with respect to null models that account for spatial autocorrelation. Validation experiments demonstrate the usage and consistency of our tools for the analysis of functional and microstructural gradients across different spatial scales.
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- 2020
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40. Curcumin Delivery Mediated by Bio-Based Nanoparticles: A Review.
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Moballegh Nasery M, Abadi B, Poormoghadam D, Zarrabi A, Keyhanvar P, Khanbabaei H, Ashrafizadeh M, Mohammadinejad R, Tavakol S, and Sethi G
- Subjects
- Animals, Drug Carriers chemistry, Drug Delivery Systems methods, Humans, Polyphenols chemistry, Curcumin administration & dosage, Curcumin chemistry, Nanoparticles chemistry
- Abstract
Todays, nano-pharmaceutics is emerging as an important field of science to develop and improve efficacy of different drugs. Although nutraceuticals are currently being utilized in the prevention and treatment of various chronic diseases such as cancers, a number of them have displayed issues associated with their solubility, bioavailability, and bio-degradability. In the present review, we focus on curcumin, an important and widely used polyphenol, with diverse pharmacological activities such as anti-inflammatory, anti-carcinogenic, anti-viral, etc. Notwithstanding, it also exhibits poor solubility and bioavailability that may compromise its clinical application to a great extent. Therefore, the manipulation and encapsulation of curcumin into a nanocarrier formulation can overcome these major drawbacks and potentially may lead to a far superior therapeutic efficacy. Among different types of nanocarriers, biological and biopolymer carriers have attracted a significant attention due to their pleiotropic features. Thus, in the present review, the potential protective and therapeutic applications of curcumin, as well as different types of bio-nanocarriers, which can be used to deliver curcumin effectively to the different target sites will be discussed., Competing Interests: The author report no potential conflict of interest.
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- 2020
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41. Acidic pH derived from cancer cells as a double-edged knife modulates wound healing through DNA repair genes and autophagy.
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Rabiee Motmaen S, Tavakol S, Joghataei MT, and Barati M
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- Animals, Cells, Cultured drug effects, DNA Repair genetics, Humans, Hydrogen-Ion Concentration, Kruppel-Like Factor 4, Mice, Models, Animal, Apoptosis drug effects, Autophagy drug effects, Cell Proliferation drug effects, DNA Repair drug effects, Fibroblasts, Neoplasms physiopathology, Wound Healing drug effects
- Abstract
Wound healing is a sequester program that involves diverse cell signalling cascades. Notwithstanding, complete signal transduction pathways underpinning acidic milieu derived from cancer cells is not clear, yet. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, fluorescein diacetate/propidium iodide staining, and cell cycle flow cytometry revealed that acidic media decreased cell viability and cell number along with enhanced dead cells and S-phase arrest in normal fibroblasts. Notably, the trends of intracellular reactive oxygen species production and lactate dehydrogenase release significantly increased with time. It seems the downregulation of Klf4 is in part due to acidosis-induced DNA damage. It promoted cells towards S-phase arrest and diminished cell proliferation. Klf4 downregulation had a direct correlation with the P53 level while acidic microenvironment promotes cells towards cell death mechanisms including apoptosis and autophagy. Noteworthily, the unchanged levels of Rb and Mlh1 indicated in those genes had no dominant role in the repairing of DNA damage in fibroblasts treated with the acidic microenvironment. Therefore, cells owing to not entering to mitosis and accumulation of DNA damage were undergone cell death to preserve cell homeostasis. Since acidic media decreased the level of tumour suppressor and DNA repair genes and altered the normal survival pathways in fibroblasts, caution should be exercised to not lead to cancer rather than wound healing., (© 2019 Medicalhelplines.com Inc and John Wiley & Sons Ltd.)
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- 2020
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42. Calcified Prolactinoma of the Pituitary Gland: Illustrative Case Reports Highlighting Medical versus Surgical Intervention.
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Tavakol S, Hasan A, Wedemeyer MA, Bakhsheshian J, Liu CJ, Shiroishi MS, Mathew A, Carmichael JD, and Zada G
- Abstract
The presence of calcification is uncommon in pituitary adenomas, and often lends support to other diagnoses including craniopharyngioma. The majority of calcified pituitary adenomas are prolactin-secreting tumors. We report two patients with calcified macroprolactinomas, one that was treated medically with a biochemical response and partial tumor response, and one that was treated successfully via an endoscopic endonasal transsphenoidal approach. Suspected calcified prolactinomas can be initially managed medically as per standard treatment for typical prolactinomas; however, the presence of diffuse calcification may hinder tumor shrinkage. Tumors that are refractory to medical treatment can be safely managed with surgery., Competing Interests: Declaration of Interest The authors have no conflicts of interest to declare., (© Thieme Medical Publishers.)
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- 2020
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43. A Cell-Free SDKP-Conjugated Self-Assembling Peptide Hydrogel Sufficient for Improvement of Myocardial Infarction.
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Firoozi S, Pahlavan S, Ghanian MH, Rabbani S, Tavakol S, Barekat M, Yakhkeshi S, Mahmoudi E, Soleymani M, and Baharvand H
- Subjects
- Animals, Biocompatible Materials pharmacology, Bone Marrow Cells cytology, Cell-Free System, Chick Embryo, Inflammation, Male, Mesenchymal Stem Cell Transplantation, Mesenchymal Stem Cells cytology, Mice, Myocytes, Cardiac cytology, Neovascularization, Physiologic, Rats, Rats, Sprague-Dawley, Stroke Volume drug effects, Vascular Endothelial Growth Factor A metabolism, Ventricular Function, Left drug effects, Hydrogels chemistry, Myocardial Infarction drug therapy, Peptides chemistry
- Abstract
Biomaterials in conjunction with stem cell therapy have recently attracted attention as a new therapeutic approach for myocardial infarction (MI), with the aim to solve the delivery challenges that exist with transplanted cells. Self-assembling peptide (SAP) hydrogels comprise a promising class of synthetic biomaterials with cardiac-compatible properties such as mild gelation, injectability, rehealing ability, and potential for sequence modification. Herein, we developed an SAP hydrogel composed of a self-assembling gel-forming core sequence (RADA) modified with SDKP motif with pro-angiogenic and anti-fibrotic activity to be used as a cardioprotective scaffold. The RADA-SDKP hydrogel was intramyocardially injected into the infarct border zone of a rat model of MI induced by left anterior descending artery (LAD) ligation as a cell-free or a cell-delivering scaffold for bone marrow mesenchymal stem cells (BM-MSCs). The left ventricular ejection fraction (LVEF) was markedly improved after transplantation of either free hydrogel or cell-laden hydrogel. This cardiac functional repair coincided very well with substantially lower fibrotic tissue formation, expanded microvasculature, and lower inflammatory response in the infarct area. Interestingly, BM-MSCs alone or in combination with hydrogel could not surpass the cardiac repair effects of the SDKP-modified SAP hydrogel. Taken together, we suggest that the RADA-SDKP hydrogel can be a promising cell-free construct that has the capability for functional restoration in the instances of acute myocardial infarction (AMI) that might minimize the safety concerns of cardiac cell therapy and facilitate clinical extrapolation., Competing Interests: The authors declare no conflict of interest.
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- 2020
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44. Multiscale Structure-Function Gradients in the Neonatal Connectome.
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Larivière S, Vos de Wael R, Hong SJ, Paquola C, Tavakol S, Lowe AJ, Schrader DV, and Bernhardt BC
- Subjects
- Female, Humans, Image Processing, Computer-Assisted, Infant, Magnetic Resonance Imaging, Male, Neural Pathways anatomy & histology, Neural Pathways physiology, White Matter anatomy & histology, White Matter physiology, Brain anatomy & histology, Brain physiology, Connectome
- Abstract
The adult functional connectome is well characterized by a macroscale spatial gradient of connectivity traversing from unimodal toward higher-order transmodal cortices that recapitulates known principles of hierarchical organization and myelination patterns. Despite an emerging literature assessing connectome properties in neonates, the presence of connectome gradients and particularly their correspondence to microstructure remains largely unknown. We derived connectome gradients using unsupervised techniques applied to functional connectivity data from 40 term-born neonates. A series of cortex-wide analysis examined associations to magnetic resonance imaging-derived morphological parameters (cortical thickness, sulcal depth, curvature), measures of tissue microstructure (intracortical T1w/T2w intensity, superficial white matter diffusion parameters), and subcortico-cortical functional connectivity. Our findings indicate that the primary neonatal connectome gradient runs between sensorimotor and visual anchors and captures specific associations to cortical and superficial white matter microstructure as well as thalamo-cortical connectivity. A second gradient indicated an anterior-to-posterior asymmetry in macroscale connectivity alongside an immature differentiation between unimodal and transmodal areas, indicating a connectome-level circuitry en route to an adult-like organization. Our findings reveal an important coordination of structural and functional interactions in the neonatal connectome across spatial scales. Observed associations were replicable across individual neonates, suggesting consistency and generalizability., (© The Author(s) 2019. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2020
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45. Targeting age-related differences in brain and cognition with multimodal imaging and connectome topography profiling.
- Author
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Lowe AJ, Paquola C, Vos de Wael R, Girn M, Lariviere S, Tavakol S, Caldairou B, Royer J, Schrader DV, Bernasconi A, Bernasconi N, Spreng RN, and Bernhardt BC
- Subjects
- Adult, Age Factors, Aged, Aged, 80 and over, Brain Mapping methods, Connectome methods, Female, Humans, Male, Middle Aged, Multimodal Imaging methods, Aging physiology, Brain diagnostic imaging, Brain physiology, Brain Mapping trends, Connectome trends, Multimodal Imaging trends
- Abstract
Aging is characterized by accumulation of structural and metabolic changes in the brain. Recent studies suggest transmodal brain networks are especially sensitive to aging, which, we hypothesize, may be due to their apical position in the cortical hierarchy. Studying an open-access healthy cohort (n = 102, age range = 30-89 years) with MRI and Aβ PET data, we estimated age-related cortical thinning, hippocampal atrophy and Aβ deposition. In addition to carrying out surface-based morphological and metabolic mapping experiments, we stratified effects along neocortical and hippocampal resting-state functional connectome gradients derived from independent datasets. The cortical gradient depicts an axis of functional differentiation from sensory-motor regions to transmodal regions, whereas the hippocampal gradient recapitulates its long-axis. While age-related thinning and increased Aβ deposition occurred across the entire cortical topography, increased Aβ deposition was especially pronounced toward higher-order transmodal regions. Age-related atrophy was greater toward the posterior end of the hippocampal long-axis. No significant effect of age on Aβ deposition in the hippocampus was observed. Imaging markers correlated with behavioral measures of fluid intelligence and episodic memory in a topography-specific manner, confirmed using both univariate as well as multivariate analyses. Our results strengthen existing evidence of structural and metabolic change in the aging brain and support the use of connectivity gradients as a compact framework to analyze and conceptualize brain-based biomarkers of aging., (© 2019 The Authors. Human Brain Mapping published by Wiley Periodicals, Inc.)
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- 2019
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46. A combination therapy of nanoethosomal piroxicam formulation along with iontophoresis as an anti-inflammatory transdermal delivery system for wound healing.
- Author
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Kazemi M, Mombeiny R, Tavakol S, Keyhanvar P, and Mousavizadeh K
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- Administration, Cutaneous, Combined Modality Therapy, Drug Delivery Systems, Humans, Nanoparticles, Particle Size, Sensitivity and Specificity, Drug Compounding methods, Iontophoresis methods, Piroxicam therapeutic use, Wound Healing drug effects, Wounds and Injuries drug therapy
- Abstract
Inflammation accounts as one of the major phases in wound healing, while prolonged and chronic inflammation may lead to adverse pathological conditions. Therefore, transdermal delivery of nonsteroidal anti-inflammatory (NSAIDs) such as encapsulated piroxicam into a nanocarrier seems to be promising. For the first time, a nanoethosomal piroxicam of <200 nm was prepared and combined with iontophoresis. Results showed that there was a critical point at the concentration of 5 mg lecithin with the smallest particle size. Besides, lecithin concentration had direct and inverse linear relationships with turbidity and pH of nanocarriers, respectively. Moreover, as there was no linear relationship between the lecithin concentration and particle size, the effect of lecithin concentration was dominant on turbidity compared with particle size. It seems that a pH higher than 5.5 disturbed the linear relationship of pH and entrapment efficacy percentage (EE%) while at the pH range of 4 to 5.5, the relationship was linear and EE% gradually decreased with increasing pH. These data showed that an optimised nanocarrier with special physicochemical properties is dominant to the just particle size. Besides, ex vivo permeation studies in rat skin showed that there was no significant difference between the permeation of free drug and ethosomal ones. However, iontophoresis significantly enhanced ethosomal piroxicam permeation compared with the free drug. Overall, these data emphasise the superiority of iontophoresis for the transdermal delivery of nanoethosomal medications while nanoethosomal delivery without iontophoresis did not show significant transdermal potential. To sum up, transdermal nanoethosomal piroxicam along with iontophoresis seems to be promising in wound healing., (© 2019 Medicalhelplines.com Inc and John Wiley & Sons Ltd.)
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- 2019
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47. Autophagy Modulators: Mechanistic Aspects and Drug Delivery Systems.
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Tavakol S, Ashrafizadeh M, Deng S, Azarian M, Abdoli A, Motavaf M, Poormoghadam D, Khanbabaei H, Afshar EG, Mandegary A, Pardakhty A, Yap CT, Mohammadinejad R, and Kumar AP
- Subjects
- Animals, Cell Proliferation drug effects, Humans, Neoplasms metabolism, Neoplasms pathology, Signal Transduction drug effects, Antineoplastic Agents pharmacology, Autophagy drug effects, Drug Delivery Systems, Neoplasms drug therapy
- Abstract
Autophagy modulation is considered to be a promising programmed cell death mechanism to prevent and cure a great number of disorders and diseases. The crucial step in designing an effective therapeutic approach is to understand the correct and accurate causes of diseases and to understand whether autophagy plays a cytoprotective or cytotoxic/cytostatic role in the progression and prevention of disease. This knowledge will help scientists find approaches to manipulate tumor and pathologic cells in order to enhance cellular sensitivity to therapeutics and treat them. Although some conventional therapeutics suffer from poor solubility, bioavailability and controlled release mechanisms, it appears that novel nanoplatforms overcome these obstacles and have led to the design of a theranostic-controlled drug release system with high solubility and active targeting and stimuli-responsive potentials. In this review, we discuss autophagy modulators-related signaling pathways and some of the drug delivery strategies that have been applied to the field of therapeutic application of autophagy modulators. Moreover, we describe how therapeutics will target various steps of the autophagic machinery. Furthermore, nano drug delivery platforms for autophagy targeting and co-delivery of autophagy modulators with chemotherapeutics/siRNA, are also discussed., Competing Interests: The authors declare no conflict of interest.
- Published
- 2019
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48. The impact of the particle size of curcumin nanocarriers and the ethanol on beta_1-integrin overexpression in fibroblasts: A regenerative pharmaceutical approach in skin repair and anti-aging formulations.
- Author
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Tavakol S, Zare S, Hoveizi E, Tavakol B, and Rezayat SM
- Subjects
- Animals, Cell Line, Cell Proliferation, Cell Survival drug effects, Curcumin chemistry, Female, Fibroblasts drug effects, Fibroblasts metabolism, Humans, Mice, NF-kappa B genetics, Nanoparticles, Particle Size, bcl-2-Associated X Protein genetics, Curcumin pharmacology, Ethanol chemistry, Fibroblasts cytology, Integrin beta1 genetics, Skin Aging drug effects, Up-Regulation
- Abstract
Background: Since women pay more attention to their skin's health, pharmaceutical companies invest heavily on skin care product development. Further, the success of drug nano-carriers in passing through the skin justifies the need to conduct studies at the nano-scale. β1-integrin down regulation has been proposed as a sign of skin aging., Methods: Six drug nano-carriers (50 and 75 nm) were prepared at three ethanol concentrations (0, 3,and 5%) and different temperatures. Then, the impact of Nanocarriers on fibroblasts were investigated., Results: DLS showed that increasing ethanol concentration decreased the surface tension that caused a decrease in the particle size in non-temperature formulations while increasing the temperature to 60 °C to lower Gibbs free energy increased the particle size. Ethanol addition decreased β1-integrin over-expression, whereas larger nano-carriers induced an over-expression of β1-integrin, Bcl2/Bax ratio, and an increase in live cell number. β1-integrin over-expression did not correlate with the rate of fibroblast proliferation and NFκB expression. An increase in fibroblast mortality in relation to smaller nano-carriers was not only due to the increase in Bax ratio, but was related to NFκB over-expression., Conclusion: The development of a regenerative pharmaceutical approach in skin repair was based on the effect of particle size and ethanol concentration of the drug nano-carriers on the expression of β1-integrin in fibroblasts. A curcumin nanoformulation sized 77 nm and containing of 3% ethanol was more effective in increasing β1-integrin gene over-expression, anti-apoptosis of fibroblast cells (Bcl2/Bax ratio), and in decreasing Bax and NFκB gene expression than that with a particle size of 50 nm. Such a formulation may be considered a valuable candidate in anti-aging and wound-healing formulations. Graphical abstract The effect of particle size on Bcl2/Bax ratio and NFκ-B gene expression through the cell surface receptor of ß1- integrin. Bigger nanocarriers induce over-expression of integrin ß1 gene and also lead to an increase in Bcl2/Bax ratio along with a decrease in NFκ-B, unlike the smaller nanocarriers.
- Published
- 2019
- Full Text
- View/download PDF
49. Neuroimaging and connectomics of drug-resistant epilepsy at multiple scales: From focal lesions to macroscale networks.
- Author
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Tavakol S, Royer J, Lowe AJ, Bonilha L, Tracy JI, Jackson GD, Duncan JS, Bernasconi A, Bernasconi N, and Bernhardt BC
- Subjects
- Humans, Magnetic Resonance Imaging methods, Neuroimaging methods, Connectome methods, Drug Resistant Epilepsy diagnostic imaging, Drug Resistant Epilepsy physiopathology
- Abstract
Epilepsy is among the most common chronic neurologic disorders, with 30%-40% of patients having seizures despite antiepileptic drug treatment. The advent of brain imaging and network analyses has greatly improved the understanding of this condition. In particular, developments in magnetic resonance imaging (MRI) have provided measures for the noninvasive characterization and detection of lesions causing epilepsy. MRI techniques can probe structural and functional connectivity, and network analyses have shaped our understanding of whole-brain anomalies associated with focal epilepsies. This review considers the progress made by neuroimaging and connectomics in the study of drug-resistant epilepsies due to focal substrates, particularly temporal lobe epilepsy related to mesiotemporal sclerosis and extratemporal lobe epilepsies associated with malformations of cortical development. In these disorders, there is evidence of widespread disturbances of structural and functional connectivity that may contribute to the clinical and cognitive prognosis of individual patients. It is hoped that studying the interplay between macroscale network anomalies and lesional profiles will improve our understanding of focal epilepsies and assist treatment choices., (Wiley Periodicals, Inc. © 2019 International League Against Epilepsy.)
- Published
- 2019
- Full Text
- View/download PDF
50. Necrotic, apoptotic and autophagic cell fates triggered by nanoparticles.
- Author
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Mohammadinejad R, Moosavi MA, Tavakol S, Vardar DÖ, Hosseini A, Rahmati M, Dini L, Hussain S, Mandegary A, and Klionsky DJ
- Subjects
- Apoptosis genetics, Autophagy genetics, Endoplasmic Reticulum Stress drug effects, Endoplasmic Reticulum Stress genetics, Lysosomes drug effects, Metal Nanoparticles chemistry, Mitochondria drug effects, Mitochondria metabolism, Necroptosis drug effects, Necroptosis genetics, Necrosis, Particle Size, Quantum Dots chemistry, Quantum Dots toxicity, Reactive Oxygen Species metabolism, Signal Transduction, Apoptosis drug effects, Autophagy drug effects, Metal Nanoparticles toxicity
- Abstract
Nanomaterials have gained a rapid increase in use in a variety of applications that pertain to many aspects of human life. The majority of these innovations are centered on medical applications and a range of industrial and environmental uses ranging from electronics to environmental remediation. Despite the advantages of NPs, the knowledge of their toxicological behavior and their interactions with the cellular machinery that determines cell fate is extremely limited. This review is an attempt to summarize and increase our understanding of the mechanistic basis of nanomaterial interactions with the cellular machinery that governs cell fate and activity. We review the mechanisms of NP-induced necrosis, apoptosis and autophagy and potential implications of these pathways in nanomaterial-induced outcomes. Abbreviations: Ag, silver; CdTe, cadmium telluride; CNTs, carbon nanotubes; EC, endothelial cell; GFP, green fluorescent protein; GO, graphene oxide; GSH, glutathione; HUVECs, human umbilical vein endothelial cells; NP, nanoparticle; PEI, polyethylenimine; PVP, polyvinylpyrrolidone; QD, quantum dot; ROS, reactive oxygen species; SiO
2 , silicon dioxide; SPIONs, superparamagnetic iron oxide nanoparticles; SWCNT, single-walled carbon nanotubes; TiO2 , titanium dioxide; USPION, ultra-small super paramagnetic iron oxide; ZnO, zinc oxide.- Published
- 2019
- Full Text
- View/download PDF
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