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Parmigiani S, Cline CC, Sarkar M, Forman L, Truong J, Ross JM, Gogulski J, Keller CJ. Real-time optimization to enhance noninvasive cortical excitability assessment in the human dorsolateral prefrontal cortex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.29.596317. [PMID: 38853941 PMCID: PMC11160722 DOI: 10.1101/2024.05.29.596317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Objective We currently lack a robust noninvasive method to measure prefrontal excitability in humans. Concurrent TMS and EEG in the prefrontal cortex is usually confounded by artifacts. Here we asked if real-time optimization could reduce artifacts and enhance a TMS-EEG measure of left prefrontal excitability. Methods This closed-loop optimization procedure adjusts left dlPFC TMS coil location, angle, and intensity in real-time based on the EEG response to TMS. Our outcome measure was the left prefrontal early (20-60 ms) and local TMS-evoked potential (EL-TEP). Results In 18 healthy participants, this optimization of coil angle and brain target significantly reduced artifacts by 63% and, when combined with an increase in intensity, increased EL-TEP magnitude by 75% compared to a non-optimized approach. Conclusions Real-time optimization of TMS parameters during dlPFC stimulation can enhance the EL-TEP. Significance Enhancing our ability to measure prefrontal excitability is important for monitoring pathological states and treatment response.
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Gogulski J, Cline CC, Ross JM, Truong J, Sarkar M, Parmigiani S, Keller CJ. Mapping cortical excitability in the human dorsolateral prefrontal cortex. Clin Neurophysiol 2024; 164:138-148. [PMID: 38865780 DOI: 10.1016/j.clinph.2024.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 04/10/2024] [Accepted: 05/22/2024] [Indexed: 06/14/2024]
Abstract
BACKGROUND Transcranial magnetic stimulation (TMS) to the dorsolateral prefrontal cortex (dlPFC) is an effective treatment for depression, but the neural effects after TMS remains unclear. TMS paired with electroencephalography (TMS-EEG) can causally probe these neural effects. Nonetheless, variability in single pulse TMS-evoked potentials (TEPs) across dlPFC subregions, and potential artifact induced by muscle activation, necessitate detailed mapping for accurate treatment monitoring. OBJECTIVE To characterize early TEPs anatomically and temporally (20-50 ms) close to the TMS pulse (EL-TEPs), as well as associated muscle artifacts (<20 ms), across the dlPFC. We hypothesized that TMS location and angle influence EL-TEPs, and specifically that conditions with larger muscle artifact may exhibit lower observed EL-TEPs due to over-rejection during preprocessing. Additionally, we sought to determine an optimal group-level TMS target and angle, while investigating the potential benefits of a personalized approach. METHODS In 16 healthy participants, we applied single-pulse TMS to six targets within the dlPFC at two coil angles and measured EEG responses. RESULTS Stimulation location significantly influenced observed EL-TEPs, with posterior and medial targets yielding larger EL-TEPs. Regions with high EL-TEP amplitude had less muscle artifact, and vice versa. The best group-level target yielded 102% larger EL-TEP responses compared to other dlPFC targets. Optimal dlPFC target differed across subjects, suggesting that a personalized targeting approach might boost the EL-TEP by an additional 36%. SIGNIFICANCE EL-TEPs can be probed without significant muscle-related confounds in posterior-medial regions of the dlPFC. The identification of an optimal group-level target and the potential for further refinement through personalized targeting hold significant implications for optimizing depression treatment protocols.
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Ross JM, Cline CC, Sarkar M, Truong J, Keller CJ. Neural effects of TMS trains on the human prefrontal cortex. Sci Rep 2023; 13:22700. [PMID: 38123591 PMCID: PMC10733322 DOI: 10.1038/s41598-023-49250-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 12/06/2023] [Indexed: 12/23/2023] Open
Abstract
How does a train of TMS pulses modify neural activity in humans? Despite adoption of repetitive TMS (rTMS) for the treatment of neuropsychiatric disorders, we still do not understand how rTMS changes the human brain. This limited understanding stems in part from a lack of methods for noninvasively measuring the neural effects of a single TMS train-a fundamental building block of treatment-as well as the cumulative effects of consecutive TMS trains. Gaining this understanding would provide foundational knowledge to guide the next generation of treatments. Here, to overcome this limitation, we developed methods to noninvasively measure causal and acute changes in cortical excitability and evaluated this neural response to single and sequential TMS trains. In 16 healthy adults, standard 10 Hz trains were applied to the dorsolateral prefrontal cortex in a randomized, sham-controlled, event-related design and changes were assessed based on the TMS-evoked potential (TEP), a measure of cortical excitability. We hypothesized that single TMS trains would induce changes in the local TEP amplitude and that those changes would accumulate across sequential trains, but primary analyses did not indicate evidence in support of either of these hypotheses. Exploratory analyses demonstrated non-local neural changes in sensor and source space and local neural changes in phase and source space. Together these results suggest that single and sequential TMS trains may not be sufficient to modulate local cortical excitability indexed by typical TEP amplitude metrics but may cause neural changes that can be detected outside the stimulation area or using phase or source space metrics. This work should be contextualized as methods development for the monitoring of transient noninvasive neural changes during rTMS and contributes to a growing understanding of the neural effects of rTMS.
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Ross JM, Cline CC, Sarkar M, Truong J, Keller CJ. Neural effects of TMS trains on the human prefrontal cortex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.30.526374. [PMID: 36778457 PMCID: PMC9915614 DOI: 10.1101/2023.01.30.526374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
How does a train of TMS pulses modify neural activity in humans? Despite adoption of repetitive TMS (rTMS) for the treatment of neuropsychiatric disorders, we still do not understand how rTMS changes the human brain. This limited understanding stems in part from a lack of methods for noninvasively measuring the neural effects of a single TMS train - a fundamental building block of treatment - as well as the cumulative effects of consecutive TMS trains. Gaining this understanding would provide foundational knowledge to guide the next generation of treatments. Here, to overcome this limitation, we developed methods to noninvasively measure causal and acute changes in cortical excitability and evaluated this neural response to single and sequential TMS trains. In 16 healthy adults, standard 10 Hz trains were applied to the dorsolateral prefrontal cortex (dlPFC) in a randomized, sham-controlled, event-related design and changes were assessed based on the TMS-evoked potential (TEP), a measure of cortical excitability. We hypothesized that single TMS trains would induce changes in the local TEP amplitude and that those changes would accumulate across sequential trains, but primary analyses did not indicate evidence in support of either of these hypotheses. Exploratory analyses demonstrated non-local neural changes in sensor and source space and local neural changes in phase and source space. Together these results suggest that single and sequential TMS trains may not be sufficient to modulate local cortical excitability indexed by typical TEP amplitude metrics but may cause neural changes that can be detected outside the stimulation area or using phase or source space metrics. This work should be contextualized as methods development for the monitoring of transient noninvasive neural changes during rTMS and contributes to a growing understanding of the neural effects of rTMS.
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Gogulski J, Cline CC, Ross JM, Truong J, Sarkar M, Parmigiani S, Keller CJ. Mapping cortical excitability in the human dorsolateral prefrontal cortex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.20.524867. [PMID: 36711689 PMCID: PMC9882363 DOI: 10.1101/2023.01.20.524867] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Objective To characterize early TEPs anatomically and temporally (20-50 ms) close to the TMS pulse (EL-TEPs), as well as associated muscle artifacts (<20 ms), across the dlPFC. We hypothesized that TMS location and angle influence EL-TEPs, and that EL-TEP amplitude is inversely related to muscle artifact. Additionally, we sought to determine an optimal group-level TMS target and angle, while investigating the potential benefits of a personalized approach. Methods In 16 healthy participants, we applied single-pulse TMS to six targets within the dlPFC at two coil angles and measured EEG responses. Results Stimulation location significantly influenced EL-TEPs, with posterior and medial targets yielding larger EL-TEPs. Regions with high EL-TEP amplitude had less muscle artifact, and vice versa. The best group-level target yielded 102% larger EL-TEP responses compared to other dlPFC targets. Optimal dlPFC target differed across subjects, suggesting that a personalized targeting approach might boost the EL-TEP by an additional 36%. Significance Early local TMS-evoked potentials (EL-TEPs) can be probed without significant muscle-related confounds in posterior-medial regions of the dlPFC. The identification of an optimal group-level target and the potential for further refinement through personalized targeting hold significant implications for optimizing depression treatment protocols. Highlights Early local TMS-evoked potentials (EL-TEPs) varied significantly across the dlPFC as a function of TMS target.TMS targets with less muscle artifact had significantly larger EL-TEPs.Selection of a postero-medial target increased EL-TEPs by 102% compared to anterior targets.
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Fiuza T, Sarkar M, Riedl JC, Beaughon M, Torres Bautista BE, Bhattacharya K, Cousin F, Barruet E, Demouchy G, Depeyrot J, Dubois E, Gélébart F, Geertsen V, Mériguet G, Michot L, Nakamae S, Perzynski R, Peyre V. Ion specific tuning of nanoparticle dispersion in an ionic liquid: a structural, thermoelectric and thermo-diffusive investigation. Phys Chem Chem Phys 2023; 25:28911-28924. [PMID: 37855156 DOI: 10.1039/d3cp02399k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
Dispersions of charged maghemite nanoparticles (NPs) in EAN (ethylammonium nitrate) a reference Ionic Liquid (IL) are studied here using a number of static and dynamical experimental techniques; small angle scattering (SAS) of X-rays and of neutrons, dynamical light scattering and forced Rayleigh scattering. Particular insight is provided regarding the importance of tuning the ionic species present at the NP/IL interface. In this work we compare the effect of Li+, Na+ or Rb+ ions. Here, the nature of these species has a clear influence on the short-range spatial organisation of the ions at the interface and thus on the colloidal stability of the dispersions, governing both the NP/NP and NP/IL interactions, which are both evaluated here. The overall NP/NP interaction is either attractive or repulsive. It is characterised by determining, thanks to the SAS techniques, the second virial coefficient A2, which is found to be independent of temperature. The NP/IL interaction is featured by the dynamical effective charge ξeff0 of the NPs and by their entropy of transfer ŜNP (or equivalently their heat of transport ) determined here thanks to thermoelectric and thermodiffusive measurements. For repulsive systems, an activated process rules the temperature dependence of these two latter quantities.
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Kumari S, Nath S, Narasimha VL, Sarkar M, Kumar R. Psychosis Unmasking a Diagnosis of Systemic Lupus Erythematosus: a Case Report. East Asian Arch Psychiatry 2023; 33:100-103. [PMID: 37771217 DOI: 10.12809/eaap2316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Abstract
Systemic lupus erythematosus (SLE) is an autoimmune disorder that affects multiple organs. Neuropsychiatric SLE (NPSLE) can manifest with a multitude of neurological and psychiatric symptoms. Psychosis is a rare NPSLE manifestation that can occur at any phase of the illness; 21% of SLE-related psychosis cases occur at the onset of SLE, but the evidence base for this is lacking. We report a case of acute-onset psychosis in a woman that led to a diagnosis of SLE, which was substantiated by physical evaluation and laboratory assessments. Assessment of acute-onset psychosis requires consideration of all differential diagnoses, especially in the presence of atypical features. This case also underscores the importance of physical examination and laboratory investigations in psychosis.
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Gogulski J, Ross JM, Talbot A, Cline CC, Donati FL, Munot S, Kim N, Gibbs C, Bastin N, Yang J, Minasi C, Sarkar M, Truong J, Keller CJ. Personalized Repetitive Transcranial Magnetic Stimulation for Depression. BIOLOGICAL PSYCHIATRY. COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2023; 8:351-360. [PMID: 36792455 DOI: 10.1016/j.bpsc.2022.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 10/20/2022] [Accepted: 10/23/2022] [Indexed: 11/06/2022]
Abstract
Personalized treatments are gaining momentum across all fields of medicine. Precision medicine can be applied to neuromodulatory techniques, in which focused brain stimulation treatments such as repetitive transcranial magnetic stimulation (rTMS) modulate brain circuits and alleviate clinical symptoms. rTMS is well tolerated and clinically effective for treatment-resistant depression and other neuropsychiatric disorders. Despite its wide stimulation parameter space (location, angle, pattern, frequency, and intensity can be adjusted), rTMS is currently applied in a one-size-fits-all manner, potentially contributing to its suboptimal clinical response (∼50%). In this review, we examine components of rTMS that can be optimized to account for interindividual variability in neural function and anatomy. We discuss current treatment options for treatment-resistant depression, the neural mechanisms thought to underlie treatment, targeting strategies, stimulation parameter selection, and adaptive closed-loop treatment. We conclude that a better understanding of the wide and modifiable parameter space of rTMS will greatly improve the clinical outcome.
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Hussain M, Ahmed K, Begum SS, Kalita MK, Borah P, Bhuyan D, Tamuly S, Medhi D, Paul V, Chakravartya P, Sarkar M. 70 Effect of seasons and additives in Arunachali yak bull semen at different stages of processing and freezing along with fresh semen characteristics. Reprod Fertil Dev 2022. [DOI: 10.1071/rdv35n2ab70] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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Singh R, Jiang Y, Tsoi L, Sarkar M, Plazyo O, Billi A, Maverakis E, Kahlenberg J, Gudjonsson J, Ward N. 717 TCF-4 negatively regulates IL-17C In human keratinocytes and in a mouse model of psoriasis. J Invest Dermatol 2022. [DOI: 10.1016/j.jid.2022.05.729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Simpson C, Sarkar M, Egolf S, Zou J, Capell B, Gudjonsson J. 451 Modeling darier disease using gene-edited human keratinocytes and organotypic epidermis to identify therapeutic targets. J Invest Dermatol 2022. [DOI: 10.1016/j.jid.2022.05.460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Yu Z, Gehad A, Teague J, Crouch J, Yu K, O'Malley J, Kupper T, Benezeder T, Gudjonsson J, Kahlenberg J, Sarkar M, Vieyra-Garcia P, Wolf P, Clark R. 605 Phototherapy-induced IFNκ drives type I IFN induced anticancer responses in CTCL. J Invest Dermatol 2022. [DOI: 10.1016/j.jid.2022.05.615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Tejaswi V, Bosco J, Verma V, Anjali, Pathak M, Samad H, Tiwari A, Chouhan V, Maurya V, Sarkar M, Singh G. Seasonal alterations in blood biochemical parameters among zebu and crossbred cattle. BIOL RHYTHM RES 2022. [DOI: 10.1080/09291016.2022.2098619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Ross JM, Sarkar M, Keller CJ. Experimental suppression of transcranial magnetic stimulation-electroencephalography sensory potentials. Hum Brain Mapp 2022; 43:5141-5153. [PMID: 35770956 PMCID: PMC9812254 DOI: 10.1002/hbm.25990] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 05/13/2022] [Accepted: 06/10/2022] [Indexed: 01/15/2023] Open
Abstract
The sensory experience of transcranial magnetic stimulation (TMS) evokes cortical responses measured in electroencephalography (EEG) that confound interpretation of TMS-evoked potentials (TEPs). Methods for sensory masking have been proposed to minimize sensory contributions to the TEP, but the most effective combination for suprathreshold TMS to dorsolateral prefrontal cortex (dlPFC) is unknown. We applied sensory suppression techniques and quantified electrophysiology and perception from suprathreshold dlPFC TMS to identify the best combination to minimize the sensory TEP. In 21 healthy adults, we applied single pulse TMS at 120% resting motor threshold (rMT) to the left dlPFC and compared EEG vertex N100-P200 and perception. Conditions included three protocols: No masking (no auditory masking, no foam, and jittered interstimulus interval [ISI]), Standard masking (auditory noise, foam, and jittered ISI), and our ATTENUATE protocol (auditory noise, foam, over-the-ear protection, and unjittered ISI). ATTENUATE reduced vertex N100-P200 by 56%, "click" loudness perception by 50%, and scalp sensation by 36%. We show that sensory prediction, induced with predictable ISI, has a suppressive effect on vertex N100-P200, and that combining standard suppression protocols with sensory prediction provides the best N100-P200 suppression. ATTENUATE was more effective than Standard masking, which only reduced vertex N100-P200 by 22%, loudness by 27%, and scalp sensation by 24%. We introduce a sensory suppression protocol superior to Standard masking and demonstrate that using an unjittered ISI can contribute to minimizing sensory confounds. ATTENUATE provides superior sensory suppression to increase TEP signal-to-noise and contributes to a growing understanding of TMS-EEG sensory neuroscience.
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Cheng VW, de Pennington N, Zakaria R, Larkin JR, Serres S, Sarkar M, Kirkman MA, Bristow C, Croal P, Plaha P, Campo L, Chappell MA, Lord S, Jenkinson MD, Middleton MR, Sibson NR. VCAM-1-targeted MRI Improves Detection of the Tumor-brain Interface. Clin Cancer Res 2022; 28:2385-2396. [PMID: 35312755 PMCID: PMC9662863 DOI: 10.1158/1078-0432.ccr-21-4011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 01/25/2022] [Accepted: 03/17/2022] [Indexed: 01/07/2023]
Abstract
PURPOSE Despite optimal local therapy, tumor cell invasion into normal brain parenchyma frequently results in recurrence in patients with solid tumors. The aim of this study was to determine whether microvascular inflammation can be targeted to better delineate the tumor-brain interface through vascular cell adhesion molecule-1 (VCAM-1)-targeted MRI. EXPERIMENTAL DESIGN Intracerebral xenograft rat models of MDA231Br-GFP (breast cancer) brain metastasis and U87MG (glioblastoma) were used to histologically examine the tumor-brain interface and to test the efficacy of VCAM-1-targeted MRI in detecting this region. Human biopsy samples of the brain metastasis and glioblastoma margins were examined for endothelial VCAM-1 expression. RESULTS The interface between tumor and surrounding normal brain tissue exhibited elevated endothelial VCAM-1 expression and increased microvessel density. Tumor proliferation and stemness markers were also significantly upregulated at the tumor rim in the brain metastasis model. T2*-weighted MRI, following intravenous administration of VCAM-MPIO, highlighted the tumor-brain interface of both tumor models more extensively than gadolinium-DTPA-enhanced T1-weighted MRI. Sites of VCAM-MPIO binding, evident as hypointense signals on MR images, correlated spatially with endothelial VCAM-1 upregulation and bound VCAM-MPIO beads detected histologically. These findings were further validated in an orthotopic medulloblastoma model. Finally, the tumor-brain interface in human brain metastasis and glioblastoma samples was similarly characterized by microvascular inflammation, extending beyond the region detectable using conventional MRI. CONCLUSIONS This work illustrates the potential of VCAM-1-targeted MRI for improved delineation of the tumor-brain interface in both primary and secondary brain tumors.
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Ross JM, Sarkar M, Keller CJ. Experimental suppression of TMS-EEG sensory potentials requires an optimal combination of techniques due to the multisensory experience of TMS. Brain Stimul 2021. [DOI: 10.1016/j.brs.2021.10.239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Sarkar M, Ross J, Keller C. Minimizing discomfort from TMS through experimental optimization of sensory suppression protocols. Brain Stimul 2021. [DOI: 10.1016/j.brs.2021.10.240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Sarkar M, Nath A, Kumer A, Mallik C, Akter F, Moniruzzaman M, Ali M. Synthesis, molecular docking screening, ADMET and dynamics studies of synthesized 4-(4-methoxyphenyl)-8-methyl-3,4,5,6,7,8-hexahydroquinazolin-2(1H)-one and quinazolinone derivatives. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2021.130953] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Riedl JC, Sarkar M, Fiuza T, Cousin F, Depeyrot J, Dubois E, Mériguet G, Perzynski R, Peyre V. Design of concentrated colloidal dispersions of iron oxide nanoparticles in ionic liquids: Structure and thermal stability from 25 to 200 °C. J Colloid Interface Sci 2021; 607:584-594. [PMID: 34509733 DOI: 10.1016/j.jcis.2021.08.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 08/02/2021] [Accepted: 08/03/2021] [Indexed: 11/19/2022]
Abstract
HYPOTHESIS Some of the most promising fields of application of ionic liquid-based colloids imply elevated temperatures. Their careful design and analysis is therefore essential. We assume that tuning the structure of the nanoparticle-ionic liquid interface through its composition can ensure colloidal stability for a wide temperature range, from room temperature up to 200 °C. EXPERIMENTS The system under study consists of iron oxide nanoparticles (NPs) dispersed in ethylmethylimidazolium bistriflimide (EMIM TFSI). The key parameters of the solid-liquid interface, tuned at room temperature, are the surface charge density and the nature of the counterions. The thermal stability of these nanoparticle dispersions is then analysed on the short and long term up to 200 °C. A multiscale analysis is performed combining dynamic light scattering (DLS), small angle X-ray/neutron scattering (SAXS/SANS) and thermogravimetric analysis (TGA). FINDINGS Following the proposed approach with a careful choice of the species at the solid-liquid interface, ionic liquid-based colloidal dispersions of iron oxide NPs in EMIM TFSI stable over years at room temperature can be obtained, also stable at least over days up to 200 °C and NPs concentrations up to 12 vol% (≈30 wt%) thanks to few near-surface ionic layers.
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Paul V, Krishnan G, Deori S, Bam J, Chakravarty P, Sarkar M. Body status and blood metabolites profiles during resumption of postpartum ovarian activity in yak (Poephagus grunniens). Reprod Domest Anim 2021; 56:1377-1386. [PMID: 34378257 DOI: 10.1111/rda.14002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 08/09/2021] [Indexed: 11/28/2022]
Abstract
We examined the changes in body weight (BW), back-fat thickness (BFT) and blood metabolites in relation to postpartum (PP) ovarian activity status in twenty female yaks raised under semi-intensive system. BFT and ovarian activities, like follicle development, ovulation (OV) and corpus luteum (CL) development, were monitored from 4 to 15 weeks (wk) PP using ultrasonography. Resumption of ovarian activity was confirmed with ovulation of dominant follicle (DF) and subsequent CL development, and >1 ng/ml progesterone concentration in blood plasma sample after 1week of ovulation. Yaks were further classified as cyclic (with CL), acyclic (without CL), and cystic (with >25 mm follicular cyst; FC). Within 20 weeks PP, 60% yaks resumed cyclic ovarian activity, while 25% failed to initiate cycling activity, and 15% developed follicular cysts. In all categories of yak, BW gradually decreased (p < .05) till nadir; however, nadir reached earlier (p < .05) in acyclic yaks. BFT differed (p < .05) among the yak groups, but it tended to be higher in cyclic yaks as compared to acyclic and cystic. No difference (p > .05) in non-esterified fatty acids (NEFA) values was found among the different categories of yaks, whereas, beta-hydroxy butyrate (BHB) levels were higher in cystic animals as compared to acyclic and cyclic. Blood glucose levels decreased in all yaks during initial 2 weeks after calving. Our findings suggest that yaks with low BW, BFT and glucose levels, and higher BHB values were at risk of delayed resumption of ovarian activity and concomitant development of follicular cysts.
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Fiuza T, Sarkar M, Riedl JC, Cēbers A, Cousin F, Demouchy G, Depeyrot J, Dubois E, Gélébart F, Mériguet G, Perzynski R, Peyre V. Thermodiffusion anisotropy under a magnetic field in ionic liquid-based ferrofluids. SOFT MATTER 2021; 17:4566-4577. [PMID: 33949423 DOI: 10.1039/d0sm02190c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Ferrofluids based on maghemite nanoparticles (NPs), typically 10 nm in diameter, are dispersed in an ionic liquid (1-ethyl 3-methylimidazolium bistriflimide - EMIM-TFSI). The average interparticle interaction is found to be repulsive by small angle scattering of X-rays and of neutrons, with a second virial coefficient A2 = 7.3. A moderately concentrated sample at Φ = 5.95 vol% is probed by forced Rayleigh scattering under an applied magnetic field (up to H = 100 kA m-1) from room temperature up to T = 460 K. Irrespective of the values of H and T, the NPs in this study are always found to migrate towards the cold region. The in-field anisotropy of the mass diffusion coefficient Dm and that of the (always positive) Soret coefficient ST are well described by the presented model in the whole range of H and T. The main origin of anisotropy is the spatial inhomogeneities of concentration in the ferrofluid along the direction of the applied field. Since this effect originates from the magnetic dipolar interparticle interaction, the anisotropy of thermodiffusion progressively vanishes when temperature and thermal motion increase.
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Sarkar M, Bag P, Kumar B, A. Chawla P. Development and Validation by Reverse Phase High Performance Liquid Chromatography Method for the Estimation of Piperine and Coenzyme Q10 in Bulk and Pharmaceutical Dosage Form. Indian J Pharm Sci 2021. [DOI: 10.36468/pharmaceutical-sciences.875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Pandey Y, Pooja AR, Devi HL, Jalmeria NS, Punetha M, Kumar S, Paul A, Kumar K, Sonawane A, Samad HA, Singh G, Bag S, Sarkar M, Chouhan VS. Expression and functional role of IGFs during early pregnancy in placenta of water buffalo. Theriogenology 2020; 161:313-331. [PMID: 33373934 DOI: 10.1016/j.theriogenology.2020.12.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 12/09/2020] [Accepted: 12/10/2020] [Indexed: 01/16/2023]
Abstract
Adequate vascularisation is a key factor for successful fetal development. We hypothesized that Insulin-Like Growth Factor (IGF) family members regulate angiogenesis along with promoting fetal development and growth. In this experiment, we determined the expression and functional role of IGF family in placental compartments (caruncle; CAR, cotyledon; COT) during different stages of early pregnancy in the water buffalo (Bubalus bubalis). Samples were collected from early pregnancy 1 (EP1, 28-45 days), early pregnancy 2 (EP2, 45-90 days), and third stage of estrous cycle (11-16 days), which was taken as control. In addition, the role of IGF1 on mRNA expression of vWF, StAR, CYP11A1, 3βHSD, PCNA, and BAX were elucidated in cultured trophoblast cells (TCC) obtained from EP2. Quantitative real-time PCR (q-PCR), westernblot, and immunohistochemistry were done to investigate the gene expression, protein expression, and localization of examined factors, and RIA was also done to assess progesterone (P4) concentration. Expression of IGFs, its receptors and binding proteins were found to be significantly higher (p < 0.05) in both CAR and COT as compared to control during early pregnancy, except binding proteins IGFBP1, 3 and 4 which were significantly (p < 0.05) downregulated in COT with advancement of pregnancy. mRNA expression was consistent with the findings of immunoblotting and immunolocalization experiments. Trophoblasts cell culture (TCC) study showed a significant time and dose-dependent effect of IGF1 onsteroidogenic transcript, which was found to be maximum at 100 ng/ml that paralleled with P4 accretion in the media (p < 0.05). Further, IGF1 upregulated the transcripts of vWF, PCNA, and downregulated BAX at the same concentration (p < 0.05). Overall, our results demonstrated that the expression of IGFs is a site-specific phenomenon in placentome, which indicates autocrine/paracrine and endocrine function. Our in-vitro finding support that IGF1 plays a critical role in placental development by promoting angiogenesis, steroid synthesis, and cell proliferation during early pregnancy.
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Madabhavi I, Sarkar M, Sandeep S, Madabhavi N, Modi M, Naik U. Metronomic Chemotherapy After Palliative Radiotherapy In Rare Soft Tissue Sarcomas; An Insight Into Radiation Therapy And The Immune Response. Am J Clin Pathol 2020. [DOI: 10.1093/ajcp/aqaa161.150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Introduction/Objective
Soft tissue sarcomas (STSs) account for less than 1% of the overall human burden of malignant tumors. The intent of treatment in metastatic STSs is palliative and prognosis is dismal. This study aims to evaluate the role of low dose radiotherapy and low dose oral metronomic therapy in heavily pretreated metastatic infrequent STSs.
Methods
This research was conducted in a prospective observational manner in a tertiary care center. A total of 16 cases met the inclusion criteria for enrollment in the study group. The diagnosis of all subtypes of STS was confirmed by histopathology and immunohistochemistry or cytogenetic studies. All the enrolled patients with metastatic STSs who were treated with surgery and two lines of chemotherapy were initially treated with low dose radiotherapy of twenty Gy in five fractions or thirty Gy in ten fractions according to ECOG performance status of the patient.
Results
Out of 16 patients, seven patients (43.75%) were treated with 20Gy, 5# and 9 patients (56.25%) were treated with 30Gy, 10 # radiotherapy (RT). Out of 16 patients, four were of malignant fibrohistiocytic sarcoma, three were angiosarcoma, three were malignant phylloides tumor of the breast, and two were fibrosarcoma. One patient from each of the following subtypes inflammatory myofiroblastic tumor, leiomyosarcoma, synovial sarcoma, and dermato fibrosarcoma protuberance. Out of 16 patients, seven (43.75%) had a partial response (PR), nine (56.25%) had stable disease (SD) at 3 months and all the patients had stable disease (SD) at 6 months of evaluation. All the patients had enjoyed a better quality of life as compared to their life during injectable chemotherapy.
Conclusion
Targeted low dose radiation and metronomic chemotherapy lead to quantifiable antiangiogenic effects, immune effects in the local tumor microenvironment, and influences circulating immune mediators and anti- angiogenesis that could potentially help eradicate disease both within and outside the radiation treatment field.
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Sarkar M, Uppala R, Tsoi A, Shao S, Billi A, White BEP, Kidder A, Xing X, Kahlenberg J, Gudjonsson J. 276 Autocrine IFN-κ restricts CRISPR-Cas9 Keratinocyte transfection through STING-APOBEC3G activation. J Invest Dermatol 2020. [DOI: 10.1016/j.jid.2020.03.282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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